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Scientists have continued to advance efforts to identify and validate plants and natural products with antiviral properties, especially against the deadly Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV2).

Nigerian researchers have identified ginger, garlic, onion, bitter kola, alligator pepper, black seed, turmeric, bitter leaf, zinc and vitamin C to have the capacity to prevent and treat COVID-19.

The study titled “Frugal Chemoprophylaxis against COVID-19: Possible preventive benefits for the populace” was published in the International Journal of Advanced Research in Biological Sciences.

The researchers from Departments of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Oyo State; University of Lagos, Lagos State; and Federal University of Technology, Akure, Ondo State, led by Dr. Teibo John Oluwafemi, concluded: “…The pathophysiology of SARS-CoV-2 infection, is associated with aggressive inflammatory responses which uncontrolled inflammation inflicts multi-organ damage leading to organ failure, especially of the cardiac, hepatic and renal systems and most patients with this infection who progressed to renal failure eventually death.

“In this review, some medicinal foods were elucidated, which include ginger, garlic, onion, bitter kola, alligator pepper, black seed, turmeric, bitter leaf, zinc and vitamin C which possess potent pharmacological activities which include anti-inflammatory, anti-viral, anti-pyretic properties, inhibition of viral replication properties against the symptoms displayed by SARS-COV-2 infection. These frugal medicinal foods offer great chemoprophylaxis benefits and can play potent roles in the prevention and curtailing of the community spread of COVID-19 as it enhances boosted immunity and defense of the body system as a result of its cost effectiveness and availability.

“We hereby recommend that further research should be done to evaluate the protective roles of these medicinal foods on COVID-19 infection as well as promote the development of drugs and improved plant medicines as this outcome can prepare the global populace against subsequent global outbreak of viruses.”

Also, another research found that curcumin, a natural compound found in the spice turmeric, could help eliminate certain viruses.

A study published in the Journal of General Virology showed that curcumin could prevent Transmissible gastroenteritis virus (TGEV) – an alpha-group coronavirus that infects pigs – from infecting cells. At higher doses, the compound was also found to kill virus particles.

Infection with TGEV causes a disease called transmissible gastroenteritis in piglets, which is characterised by diarrhoea, severe dehydration and death. TGEV is highly infectious and is invariably fatal in piglets younger than two weeks, thus posing a major threat to the global swine industry. There are currently no approved treatments for alpha-coronaviruses and although there is a vaccine for TGEV, it is not effective in preventing the spread of the virus.

To determine the potential antiviral properties of curcumin, the research team treated experimental cells with various concentrations of the compound, before attempting to infect them with TGEV. They found that higher concentrations of curcumin reduced the number of virus particles in the cell culture.

The research suggests that curcumin affects TGEV in a number of ways: by directly killing the virus before it is able to infect the cell, by integrating with the viral envelope to ‘inactivate’ the virus, and by altering the metabolism of cells to prevent viral entry.

Lead author of the study and researcher at the Wuhan Institute of Bioengineering, Dr. Lilan Xie, said: “Curcumin has a significant inhibitory effect on TGEV adsorption step and a certain direct inactivation effect, suggesting that curcumin has great potential in the prevention of TGEV infection.”

Curcumin has been shown to inhibit the replication of some types of virus, including dengue virus, hepatitis B and Zika virus. The compound has also been found to have a number of significant biological effects, including antitumor, anti-inflammatory and antibacterial activities. Curcumin was chosen for this research due to having low side effects according to Xie. They said: “There are great difficulties in the prevention and control of viral diseases, especially when there are no effective vaccines. Traditional Chinese medicine and its active ingredients are ideal screening libraries for antiviral drugs because of their advantages, such as convenient acquisition and low side effects.”

The researchers now hope to continue their research in vivo, using an animal model to assess whether the inhibiting properties of curcumin would be seen in a more complex system. “Further studies will be required, to evaluate the inhibitory effect in vivo and explore the potential mechanisms of curcumin against TGEV, which will lay a foundation for the comprehensive understanding of the antiviral mechanisms and application of curcumin” said Xie.

Meanwhile, the researchers from Departments of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Oyo State; University of Lagos, Lagos State; and Federal University of Technology, Akure, Ondo State, reviewed some medicinal foods, leafs and spices that has chemoprophylaxis and potent pharmacological activities which include anti-inflammatory, anti-viral, anti-bacterial, antioxidant, anti-pyretic and inhibition of viral replication properties against the SARS-COV-2 symptoms and elucidated their bioactive compounds with their mechanism of action and suggested possible preventive roles they play in the abating the spread of the COVID-19 and reduce the cases globally in a bid of raising the immune system function and possible abate the development of symptoms and general health function.

The researchers said frugal chemoprophylaxis, using natural products and foods were considered due to some factors which include readily available, cost effective as well as economical provident due to the current state of the global economy and as such foods, herbs and spices that are already known globally are considered.

They presented the preventive potentials of some medicinal foods, natural products and their role in mitigating as well as abating the community spread of COVID-19 globally and enhancing immune system function.

Top on their list is alligator pepper/grains of paradise (Aframomum melegeuta). According to the study, alligator pepper is one seed with many healing power and of great benefits to mankind. The seeds of the plant are used to flavour foods and as components of traditional African medicine. Alligator pepper has been reported to have anti-ulcer, anti-microbial, anti-nociceptive, anti-plasmodial, hepato-protective and anticancer activities. Aframomum melegueta is mixed with other herbs for the treatment of common ailments such as body pains, diarrhoea, sore throat, catarrh, congestion and rheumatism in Nigeria. Diabetes, a major underlying disease of people afflicted with COVID-19 might also be combated by Aframomum melegueta.

A myriad of compounds found in Aframomum melegueta such as 6-paradol, 6-shagaol, 6-gingerol, oleanolic acid and acarbose exert an anti-diabetic effect by inhibiting enzymes such as α-amylase and α-glucosidase. These enzymes are responsible for digestion and break down of carbohydrates and polysaccharides from food into simple sugars to increase blood glucose levels. Among the compounds, 6-gingerol and oleanolic acid are more effective in inhibiting the enzymes.

Aframomum melegueta is suitable for consumption by diabetic patients; its consumption will help a diabetic patient stay healthy. The ethanolic seed extract and stem bark of Aframomum melegueta contains phytochemicals such as tannins, saponins, flavonoids, steroids, terpernoids, cardiac glycosides and alkaloids that possess antimicrobial and anti-inflammatory effects. These compounds, which are natural antioxidant, are believed to scavenge free radicals and offer protections against viruses, allergens, microbes, platelet aggregation, tumours, ulcers and hepatotoxins (chemical liver damage) in the body. To support this claim of anti-inflammatory properties of Aframomum melegueta Ilic et al. reported that ethanolic Aframomum melegueta extract inhibited cyclooxygenase-2 (COX-2). Compounds that inhibit COX-2 activity are capable of reducing inflammatory responses. The most active COX-2 inhibitory compound in the Aframomum melegueta extract was [6]-paradol, while [6]-shogaol was found to inhibit expression of a pro-inflammatory gene, interleukin-1 beta (IL-1β).

Turmeric (Curcuma longa) belongs to the family of ginger (Zingiberaceae) and natively grows in India and Southeast Asia. The plants rhizomes contain several secondary metabolites including curcuminoids, sesquiterpenes, and steroids with the curcuminoid curcumin being the principal component of the yellow pigment and the major bioactive substance. It has been used as traditional medicine from ancient time, especially in Asian countries. Plants as a rich source of phytochemicals with different biological activities including antiviral activities are in interest of scientists. It has been demonstrated that curcumin as a plant derivative has a wide range of antiviral activity against different viruses. Inosine monophosphate dehydrogenase (IMPDH) enzyme due to rate-limiting activity in the de novo synthesis of guanine nucleotides is suggested as a therapeutic target for antiviral and anticancer compounds.

Among the 15 different polyphenols, curcumin through inhibitory activity against IMPDH effect in either noncompetitive or competitive manner is suggested as a potent antiviral compound via this process.

Furthermore, protein molecules encoded by the SARS-CoV-2 genome are potential targets for chemotherapeutic inhibition of viral infection and its replication. These intriguing targets include the spike protein (S), which mediates the entry of the virus, the SARS-CoV-2 main protease (3CL protease), the NTPase/helicase, the RNA-dependent RNA polymerase, the membrane protein (M) required for virus budding; the envelope protein (E) which plays a role in coronavirus assembly and the nucleocapsid phosphoprotein (N) that relates to viral RNA inside the virion and possibly other viral protein-mediated processes. With such a drastic increase in molecular and biochemical information about various components of the SARS-CoV-2 and their cellular targets, it is important and timely to again evaluate anti-SARS-CoV-2 activities of various turmeric phyto-compounds. It is to be noted that in vitro studies have positively demonstrated effective antiviral properties of curcumin against enveloped viruses such as Dengue virus (DENV), influenza virus and emerging arboviruses like the Zika virus (ZIKV) or chikungunya virus (CHIKV), which are similar to the SARS-CoV-2 an enveloped virus.

Bitter leaf (Vernonia amygdalina) commonly called bitter leaf is the most widely cultivated species of the genus Vernonia that has about 1,000 species of shrubs. Bitter leaf is a seedless plant, green in colouration with a characteristic odour and bitter taste. It has different names such as ‘Omjunso’ in East Africa especially Tanzania, ‘Ewuro’ in Yoruba, Etidot (Ibibio), Ityuna (Tiv), Oriwo (Edo), Chusa-dokiShiwaka (Hausa), and ‘Omubirizi’ in southwestern Uganda.

Vernonia amygdalina is known as food and medicinal plants used in Asia and Africa (West Africa) due to its pharmacological effects which include antioxidant, anti-inflammatory, anti-diabetes, anticancer, anti-malaria etc. One major properties of considering Vernonia amygdalina in the management of COVID-19 is its antioxidants property. Antioxidants inhibit deleterious effects of free radicals that are capable of deteriorating lipid biomembranes in the human body.

Researchers in the field of medical sciences have observed free radical scavenging ability and antioxidant property in Vernonia amygdalina. Vernonia amygdalina has been documented to possess antioxidant properties, which correlates to its medicinal properties. Antioxidant activities of bioactive compounds isolated from Vernonia amygdalina leaves have been established from various studies.

Farombi and Owoeye (2011) observes phytochemicals compounds such as saponins and alkaloids, terpenes, steroids, coumarins, flavonoids, phenolic acids, lignans, xanthones, anthraquinones, edotides, sesquiterpenes extracted and isolated from Vernonia amygdalina to elicit various biological effects in humans including cancer chemoprevention. The chemoprophylaxis properties of Vernonia amygdalina was attributed to their abilities to scavenge free radicals, induce detoxification, inhibit stress response proteins and interfere with DNA binding activities of some transcription factors.

Nigella sativa, commonly known, as black seed is native to Southern Europe, North Africa and Southwest Asia and it is cultivated in many countries in the world like Middle Eastern Mediterranean region, South Europe, India, Pakistan, Syria, Turkey, and Saudi Arabia.

Nigella sativa is regarded as a valuable remedy for various ailments, the seeds, oil and extracts have played an important role over the years in ancient Islamic system of herbal medicine. Bukhari reported that Holy Prophet Muhammad (peace be upon him) told, “There exists, in the black grains, health care of all the diseases, except death”.

Many studies have been carried out to affirm the acclaimed medicinal properties emphasized on different pharmacological effects of N. sativa seeds such as antioxidant, anti-tussive, gastro protective, anti-anxiety, anti-inflammatory, anti-cancer, immunomodulatory and anti-tumor properties, hepatoprotective effect, protective effects on lipid peroxidation, antibacterial activity, antiviral activity against cytomegalovirus have been reported for this medicinal plant.

It should be noted that the seeds of N. sativa are the source of the active ingredients of this plant.

Thymoquinone (TQ), dithymquinone (DTQ), which is believed to be nigellone, thymohydroquinone (THQ), and thymol (THY), are considered the main phytochemicals of the seed.
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Nigella sativa seeds contain other ingredients, including nutritional components such as carbohydrates, fats, vitamins, mineral elements, and proteins, including eight of the nine essential amino acids. The potential immune-modulatory and immunotherapeutic potentials of Nigella sativa seed active ingredients, most especially TQ will show a promising therapy in managing COVID-19 virus.

Ginger, with the botanical name Zingiber officinale is a commonly used spice and belongs to the family Zingiberaceae. Its local names are Ata-ile, Jinja, and Cithar among the Yoruba, Igbo and Hausa folks of Nigeria. Commonly, ginger can be found in subtropical and tropical Asia, Africa, Far East Asia, China, and India. It can be used as a component in curry powder, sauces, ginger bread, and ginger-flavoured carbonated drinks and also in the preparation of dietaries for its aroma and flavour. Investigations reveal that ginger possesses several biological properties such as anti-inflammatory and anti-oxidative, antimicrobial, neuro-protective, cardiovascular protective, antidiabetic and anti-nausea, antiemetic activities and chemo-protective effects.

Its main bioactive components are 6-gingerol, 6-shogaol which are phenolics, thus accounting for its various bioactivities.

Till date, there are no antiviral therapeutics that specifically target human corona viruses, and thus completely eradicating the pandemic. Even though several potential vaccines have been developed, such as recombinant attenuated viruses, live virus vectors, or individual viral proteins expressed from DNA plasmids.

However, none have been yet approved for use. The limitation with the use of vaccines is a propensity of the viruses to recombine, thereby posing a problem of rendering the vaccine useless and potentially increasing the evolution and diversity of the virus into a more virulent form. It therefore implies that a preventive approach could be a better option.

Possible Mechanism of action of ginger against Corona virus: Virus–receptor interactions play a key regulatory role in viral host range, tissue tropism, and viral pathogenesis. Many α-coronaviruses utilise amino-peptidase N (APN) as their receptor, SARS-CoV and HCoV-NL63 use angiotensin-converting enzyme 2 (ACE2) as their receptor, MHV enters through CEACAM1, and the recently identified Middle East Respiratory Syndrome Coronavirus (MERS-CoV) binds to dipeptidyl-peptidase 4 (DPP4) to gain entry into human cells. Following receptor binding, the viruses then proceeds into the cytosol of the host.

A possible mechanism of preventing access of the viruses into the host’s cell could be the inhibition of microbial binding to cellular receptors. In the antimicrobial mechanism of ginger, inhibition of receptor binding has been identified as a major mechanism.

Hitherto, ACE-2 has been associated with an obscure function, not until in recent times with the widespread of COVID-19. It is now established as a protein being recognised by various corona viruses to gain entry into hosts cell, suggesting it to be a therapeutic target in the treatment of the disease.

The researchers noted: “We propose that both ACE receptor antagonism and agonism can be an effective mechanism of ginger in its chemo preventive strategy against corona viruses. This claims are supported by a recent report of Cava et al. who demonstrated through computational methods that anti-ACE 2 compounds could be effective in blocking the replication of SARS-CoV variant.

“Moreover, Huentelman et al. also used docking methods to predict the inhibitory ability of small molecules against ACE 2 enzymes, and possibly inhibiting SARS corona virus S protein mediated cell fusion, and high binding affinity was scored. In addition, different bioactive compounds in ginger have been shown to have different effects on ACE2. One mechanism is through ACE 2 inhibition.

“A study by Alu’datt et al. in the bid to evaluate the anti-hypertensive activity of ginger, demonstrated that its methanolic extract has excellent inhibitory activity on ACE 2 at an extraction temperature and time of 400C and six hours respectively. To further corroborate our hypothesis, 3-3’-digallate, a phenolic compound present in ginger was found to interact with ACE2 receptor in recent computational modelling studies. Taken together, we suggest that the intake of ginger might be beneficial for both prevention and treatment of the pandemic COVID-19. Ginger is able to inhibit ACE-2, thereby preventing the binding of the corona virus to the protein.”

Garlic (Allium sativum) is a widely consumed spice in the world, and it contains diverse phytochemicals such as organosulphur compounds, saponins, phenolic compounds, and polysaccharides. However, its major bioactive compounds are the organosulphur compounds including allicin, alliin, diallylsulphide, diallyldisulphide, diallyltrisulphide, ajoene, and S-allyl-cysteine. It has been reported that garlic and its constituents exhibit different bioactivities such as anti-carcinogenic, antioxidant, anti-diabetic, reno-protective, anti-atherosclerotic, antibacterial, antifungal, and antihypertensive activities.

The researchers noted: “From the foregoing, worthy of relevance to our subject matter among the bioactivities of garlic is its antiviral properties. We suggest that this could be due in part to its anti-inflammatory and antioxidative abilities. The antiviral potential of garlic extracts has been demonstrated against influenza virus and entero-virus, herpes simplex type 2, dengue virus, Infectious Bronchitis virus, Newcastle Disease virus etc.

“Major challenges in treating viral diseases are the development of resistance in the virus against the antiviral drugs, due to the high mutation rate of the viral RNA Polymerase and some of the antiviral drugs can also induce negative side effects in the body. Therefore, it is necessary to find alternative therapies in natural plants and their products, out of which garlic stands out significantly, because of its robust pharmacological bioactive components as stated above. Below is a possible mechanism of action of garlic for the prevention and treatment of the human corona virus.

“…Interestingly, allicin and quercetin, which are bioactive compounds of garlic were found to exhibit inhibitory action on the COVID-19, thereby demonstrating similar binding affinity when compared to other potent peptide inhibitors such as Nelfinavir and lopinavir in an in silico study of protein-protein docking.

“Furthermore, it was demonstrated by Weber et al. that treatment of different bioactive components of garlic against different viral strains led to the inhibition of viral adsorption or penetration. Taken together, we suggest that through this mechanism, garlic could prevent the attachment of the corona virus to the host’s cellular machinery.”

Findings from a new study suggest that inadequate consumption of fruits and vegetables may be a major factor in heart disease death.

Fruits and vegetables are rich in vitamins, fiber, potassium, magnesium, and antioxidants.

A diet that includes fruits and vegetables can lower blood pressure, reduce the risk of heart disease and cancer, and improve digestive health.

Previous research — part of the Harvard-based Nurses’ Health Study and Health Professionals Follow-up Study — confirmed that a diet containing lots of fruits and vegetables can even lower the risk of heart disease and stroke.

After analyzing these results and combining them with findings from other studies, researchers estimated that the risk of heart disease is 20 per cent lower among individuals who eat more than five servings of fruits and vegetables per day, compared with those who eat fewer than three servings per day.

The United States Department of Agriculture recommend that adults eat at least 1.5 to two cups per day of fruit and two– three cups per day of vegetables. According to another study by the Centers for Disease Control and Prevention (CDC), only around one in 10 adults meet these guidelines.

Now, a new study — the results of which the researchers presented at Nutrition 2019, the American Society for Nutrition annual meeting in Baltimore, MD — suggests that a low fruit intake can cause one in seven deaths from heart disease, and that a low vegetable intake can cause one in 12 deaths from heart disease.

Analyzing data from 2010, researchers found that low fruit consumption resulted in almost two million deaths from cardiovascular disease, while low vegetable intake resulted in one million deaths. The global impact was more significant in countries with a low average consumption of fruits and vegetables.

The data suggest that low fruit consumption results in more than one million deaths from stroke and more than 500,000 deaths from heart disease worldwide every year, while low vegetable intake results in about 200,000 deaths from stroke and more than 800,000 deaths from heart disease per year.

“Our findings indicate the need for population-based efforts to increase fruit and vegetable consumption throughout the world,” says study co-author Victoria Miller, a postdoctoral researcher at the Friedman School of Nutrition Science and Policy at Tufts University in Medford, MA. The researchers tracked the death toll by region, age, and sex using diet surveys and food availability data of 113 countries. They combined these with data on causes of death in each country and data on the cardiovascular risk linked to low fruit and vegetable intake.

The findings showed that fruit intake was lower in South Asia, East Asia, and Sub-Saharan Africa, while vegetable consumption was lower in Central Asia and Oceania. Countries in these regions have low average fruit and vegetable intakes and high rates of deaths from heart disease and stroke.

When the researchers analyzed the impact of inadequate fruit and vegetable consumption by age and sex, they found that the biggest impact was among young adults and males. Miller adds that females tend to eat more fruits and vegetables.

“These findings indicate a need to expand the focus to increasing availability and consumption of protective foods like , and legumes — a positive message with tremendous potential for improving global health.”

Exercising women who struggle to consume enough calories and have menstrual disorders can simply increase their food intake to recover their menstrual cycle, according to a study accepted for presentation at ENDO 2020, the Endocrine Society’s annual meeting, and publication in the Journal of the Endocrine Society.

The study found that exercising women with menstrual disorders can start menstruating again by consuming an additional 300-400 calories a day.

“These findings can impact all exercising women, because many women strive to exercise for competitive and health-related reasons but may not be getting enough calories to support their exercise,” said lead researcher Mary Jane De Souza, Ph.D., of Penn State University.

By consuming enough calories, exercising women with menstrual disorders can avoid complications associated with a condition known as the Female Athlete Triad, De Souza said. This is a medical condition that starts with inadequate food intake that fails to meet the body’s needs. It leads to menstrual disorders and poor bone health. It is associated with a high incidence of stress fractures.

The study included 62 young, exercising women with infrequent menstrual periods. Thirty-two women increased their calorie intake an average of 300-400 calories a day, and 30 maintained their exercise and eating habits for the 12-month study. Women who consumed the extra calories were twice as likely to have their menstrual period during the study compared with the women who maintained their regular exercise and eating routine.

“This strategy is easy to implement with the help of a nutritionist. It does not require a prescription and avoids complications from drug therapy,” De Souza said. “The findings will encourage healthcare providers to try to help exercising women with menstrual disorders who consume too few calories to eat more, and this may help them to be healthier athletes and avoid bone complications.”

A colourful and fresh spread of grilled eggplant/aubergine with salad, herb butter and mashed butter beans. A balanced and healthy meal for vegans, vegetarians or vegetable lovers!

Plant-based diets support healthy aging and could significantly reduce the risk of cardiometabolic diseases, including diabetes and heart disease, finds a new review.

Plant-based diets are becoming increasingly popular in the United States. A 2017 report estimated that 6% of U.S. consumers eat a vegan diet, up from just 1% in 2014.

There are many reasons why people choose to adopt a vegan diet, including avoiding harm to animals and mitigating the environmental impact of intensive farming.

A plant-based diet also provides health benefits. This diet is higher in fiber and lower in cholesterol and fat than an omnivorous diet, and it scores higher on the Healthy Eating Index.

A new review of the evidence on plant-based diets suggests that they may also protect against type 2 diabetes and heart disease and could reduce cardiometabolic-related deaths in the U.S.

The Physicians Committee for Responsible Medicine (PCRM) in Washington, DC, led the review, which features in the Journal of the American College of Nutrition.

An aging world

The review focuses on health in the context of aging, an important topic given that the world’s population is rapidly getting older.

“The global population of adults 60 years old or older is expected to double from 841 million to 2 billion by 2050, presenting clear challenges for our healthcare system,” explains first author Hana Kahleova, M.D., Ph.D., director of clinical research for the PCRM.

Dr. Kahleova and her team reviewed both clinical trials — which researchers perform under controlled conditions, usually to test the effect of a specific intervention on a particular outcome — and epidemiological studies, which follow people over time under normal conditions.

They found evidence that a plant-based diet reduces the risk of obesity, type 2 diabetes, and coronary heart disease.

Specifically, they found that plant-based diets could halve the risk of metabolic syndrome, which increases a person’s risk of developing cardiovascular disease and type 2 diabetes. Eating a plant-based diet could also halve the risk of type 2 diabetes itself, as well as reducing the risk of coronary heart disease events, such as a heart attack, by 40%.

‘Blue Zones’

People who eat plant-based diets may also live longer. The authors refer to so-called Blue Zones, where people live longer than the average. Examples include Loma Linda, CA, where people live up to 10 years longer than other people in California, and Okinawa, Japan, which has one of the highest life expectancy rates in the world.

As well as not smoking and engaging in moderate physical activity, people in Blue Zones tend to have a mostly plant-based diet. In Okinawa, for example, people consume a diet high in sweet potatoes, green leafy vegetables, and soy products.

As well as living longer, people who eat a plant-based diet may also remain cognitively healthy for longer.

The authors found one study which showed that the MIND diet — which is rich in fruits, vegetables, grains, nuts, and seeds but does not exclude animal products — reduced the risk of developing Alzheimer’s disease. The team found that the DASH diet, which is similar to the MIND diet, and the Mediterranean diet were also associated with a reduced risk of developing Alzheimer’s disease.

A cost effective approach

Although aging is inevitable, the authors say that adopting a healthful, plant-based diet could help delay the aging process and reduce the risk of age-associated diseases. It could also increase a person’s life expectancy.

“[S]imple diet changes can go a long way in helping populations lead longer, healthier lives.” Dr. Hana Kahleova, Ph.D.

This conclusion is in line with the findings of the Global Burden of Disease Study 2017, which showed that a low intake of fruits, vegetables, and whole grains and a high intake of red and processed meats are major risk factors for disease.

The authors say that as well as offering significant benefits for health, plant-based diets could reduce healthcare costs in the U.S., which are close to $3.5 trillion each year. They suggest that a healthful diet is a cost effective approach to preventing disease and recommend incorporating it into everyday life.

Serious senior woman in her 90s, with eyes closed. CreativeContentBrief 686998459: Senior Portrait

A study looks at the impact of having both hearing and vision impairment on the chances of developing dementia.

Researchers have linked hearing impairment and vision impairment individually to an increased chance of developing dementia. However, a new study finds that an individual’s chances of developing dementia are significantly higher when they have both conditions.

The risk of developing dementia increases by 86% for individuals who have both hearing and visual impairment.

“Evaluation of vision and hearing in older adults may predict who will develop dementia and Alzheimer’s. This has important implications for identifying potential participants in prevention trials for Alzheimer’s disease, as well as whether treatments for vision and hearing loss can modify risk for dementia.” – Study lead author Phillip H. Hwang, University of Washington

Re-purposing a previous study’s data

The research, “Dual sensory impairment in older adults and risk of dementia from the GEM Study,” appears in Alzheimer’s & Dementia: Diagnosis, Assessment & Disease Monitoring.

According to the study, some 33% of people aged 70 and older experience hearing loss, and vision loss affects about 18% of people in this age group. Since these conditions worsen with age, researchers think that a correlation exists between the advance of these conditions and the loss of a person’s functionality and mortality.

Previous research found a less obvious connection between hearing or visual loss and the onset of dementia.

The two leading theories indicate that either these specific impairments result from similar physical processes that cause dementia, or that hearing and visual loss lead to an increasing sense of social isolation, depression, and physical inactivity, each of which may lead to dementia.

The new study looks at the impact of having both conditions together. It refers to this combination as “dual sensory impairment.” According to the study:

“Although most prior studies have focused on impairments in hearing and vision individually, the impact of having combined hearing and visual impairment, or dual sensory impairment (DSI), on dementia risk is unclear.”

To investigate the impact of DSI on developing dementia, the researchers analyzed data collected by the Gingko Evaluation of Memory (GEM) study, a double‐blind randomized‐controlled trial investigating the value of Ginkgo biloba for preventing dementia in older people.

The GEM study involved adults aged 75 or older who, at the outset of the study, had normal cognitive function, or at most, mild dementia. The researchers studied the participants for 8 years.

In addition to collecting self-reported data regarding the individuals’ hearing and vision, follow-up examinations of participants assessed the development of dementia.

DSI and the risk of dementia

The final data set that Hwang and his colleagues studied consisted of 2,051 individuals. Of these, 1,480 people had neither hearing nor visual loss. 14.9% reported visual impairment, and 7.8% reported hearing loss. Just 5.1%, or 104 individuals, had DSI.

Compared to participants who did not have hearing or visual loss, those reporting DSI were more likely to be male, have other comorbidities, and describe themselves as smokers and drinkers.

The GEM study’s follow-up examinations revealed the following likelihoods of developing dementia:

  • 14.3% of those without any reported hearing or vision loss developed dementia.
  • 16.9% of those reporting a single impairment developed dementia.
  • 28.8% of those with DSI developed dementia.

People with both hearing and visual loss were nearly twice as likely to develop dementia as those without such impairments.

However, according to the results, the increased risk of dementia for an individual with DSI is only somewhat related to the severity of hearing and visual impairment.

While those classified as having a high level of DSI are at the greatest risk of developing dementia, those with lower DSI levels also have a significantly higher risk of dementia.

Risk for different forms of dementia

The researchers analyzed the link between DSI and three types of dementia: all-cause dementia, Alzheimer’s-related dementia, and vascular dementia.

The chances of acquiring Alzheimer’s’-related dementia are even higher. The study indicated that people with DSI are 112% more likely to develop Alzheimer’s than those without any impairment.

Hwang and his colleagues found no association between DSI and vascular dementia.

The implications of this research

The study’s conclusions suggest that doing more to mitigate hearing and visual loss in older people may be a way to hold off or thwart the onset of dementia.

The authors conclude, “Further research is needed to characterize the exact role of sensory impairments and whether treatments that improve sensory function, such as surgery or sensory aids, devices, and prostheses, can modify this risk.”

The study’s authors add that shifts toward an older general population make addressing the prevalence of dementia in the elderly more urgent.

They write: “Because the public health burden of dementia will increase over the next three decades, evaluation of vision and hearing function in older adults may help identify patients at elevated risk of developing dementia.”

Olusola Malomo, a leading Lagos nutritionist/Publicity Secretary of Nutrition Society of Nigeria, has called for regular intake of 100% fruit juice and regular exercise among others, as measures to boost the immune system and combat the Coronavirus Disease (COVID-19) pandemic. He gave the advice at his monthly healthy living dialogue.

While noting that COVID-19 is a respiratory infection which causes fever, tiredness, sore throat and in severe cases, shortness of breath and respiratory difficulty, he said that the World Health Organization (WHO) and other global public institutions have confirmed that the severity of the COVID-19 infection is linked with the overall state of the body’s immune system. He stated that this is the reason why people with pre-existing health challenges are most vulnerable to the contagion.

Quoting the Harvard Medical School in its Harvard Health Publishing, Malomo revealed that deficiency in Zinc, Iron, Copper, Folic Acid, Vitamins A, B6, C (which is contained in large quantity in fruit juice) and E have negative impacts on immune responses.

He said: “CNN reported that the United States retail sales of orange juice jumped about 38 percent in the four weeks ending on March 28, 2020, when compared to the same period last year. Also, the Florida Department of Citrus disclosed that there was a spike in demand for 100% orange juice within the same period.”

“During the five weeks the Federal Capital Territory, Lagos and Ogun were on lockdown, shops and supermarkets had run out of orange fruit juice stock in the first two or three weeks of the restriction.”

“In fact, less than a week into the lockdown, my favorite Chivita 100% Real Orange Fruit Juice which would have made the stay-at-home less boring for me, had rapidly been purchased off the shelves in Lagos. The scramble for unavailable raw fruits in the open markets started in earnest as the restriction on movement cut off a large chunk of the supplies.”

The expert, however, stated that fruit juice intake is just one of the many ways to boost one’s immune system. Others measures according to him include getting adequate sleep, thorough cooking of meat, maintaining good hygiene, moderate intake of alcohol and exercising regularly.

“Regular exercise is an essential component of healthy living. It improves cardiovascular function, helps control body weight, removes toxins in the body, increases blood circulation and lowers blood pressure. The result of these is a strengthened immune system that protects the body against infections and diseases. Regular exercise is most valuable when one shuns junk food and sticks to healthy eating habits and a balanced diet,” he noted. It is difficult to ascertain the level of good hygiene maintained by those who sell raw fruits, and considering that good hygiene is essential to combat COVID-19, Malomo said pure fruit juices, where available, can be substituted for raw fruits. He, however, cautioned against the consumption of brands whose production processes are not trusted.

Photo series of a virtual dinner date with video call during lockdown.

New research suggests that low-to-moderate alcohol consumption may reduce cognitive decline in older adults.

A new study has found that low-to-moderate alcohol consumption may slow cognitive decline in adults of middle age or older.

The research, which appears in the journal JAMA Open Network, lays the ground for future research to corroborate these findings and determine the underlying mechanism for the relationship.

Alcohol and health

Drinking alcohol is a central part of many cultures across the world. Beyond the immediate adverse effects of a hangover, drinking alcohol in excess has associations with various poor health outcomes.

According to the Centers for Disease Control and Prevention (CDC), excessive alcohol use includes heavy drinking (more than eight or 15 drinks a week for women and men, respectively), binge drinking (drinking four or five drinks in about 2 hours for women and men, respectively), or drinking while underage or pregnant.

The CDC define a drink as 14 grams of pure alcohol. This amount roughly equates to a 12-ounce (oz) can of 5% beer, a 5-oz glass of 12% wine, a 4-oz glass of 15% wine, or a single 1.5-oz shot of 40% distilled spirit or liquor.

The CDC note that excessive alcohol drinking is associated with various health problems. These include:

  • damage to the liver
  • inflammation of the pancreas
  • increased risk of cancer
  • hypertension
  • psychological disorders
  • unintentional injuries that a person sustained while drunk
  • harm to the fetus if a woman drinks while pregnant
  • sudden infant death syndrome
  • alcohol use disorder

Research has shown that the misuse of alcohol is a leading cause of illness and death and that any level of alcohol drinking, particularly in men who drink spirits, increases the risk of high blood pressure and stroke.

However, there is also evidence that low-to-moderate alcohol consumption — fewer than eight or 15 standard drinks in the United States per week for women and men, respectively — can have a beneficial effect on health, including various cardiovascular diseases.

The effects of low-to-moderate alcohol consumption on cognitive decline in later life have been mixed. Some research has found evidence that it may be protective, while other research suggests that it is probably not harmful. Conversely, some studies have found that it can exacerbate poor brain health.

The authors of the present study noted that previous studies exploring the relationship between alcohol consumption and cognitive decline are often limited in two ways.

First, they typically rely on single measures of cognitive decline, when it can present in a variety of ways. Second, they typically take into account net follow-up time to cognitive decline, despite the decline often being greater or lesser depending on age rather than general time passed.

As a consequence, the authors of the present research developed their study to take these factors into account, with the aim of better understanding the effects of low-to-moderate alcohol consumption on cognitive decline in older age.

About 20,000 participants

The authors drew on data from the Health and Retirement Study, which was a longitudinal study involving about 20,000 adults of middle age or older living in the U.S.

The sample that the researchers used was representative of the U.S. population, and they tracked the participants for an average time of 9.1 years.

The team regularly assessed the participants’ cognitive functioning during this time, focusing on three measures: total word recall, mental status, and vocabulary. They split the participants into those with persistently high scores across time and those with persistently low scores across time.

The participants also gave information on how many alcoholic drinks they consumed on average. During the data analysis, the researchers separated them into three groups: those who never drank, those who used to drink, and those who currently drink.

They then further classified drinkers as low-to-moderate drinkers (fewer than eight or 15 drinks per week for women and men, respectively), or heavy drinkers (more than moderate drinking).

Low-to moderate drinking may protect against cognitive decline

After analyzing the data, the researchers found that low-to-moderate drinking was associated with better cognitive outcomes across all three measures for middle-aged and older adults.

As other factors could be responsible for this association, the researchers took age, sex, race/ethnicity, educational level, marital status, and body mass index (BMI) into account in the analysis. The association between consistently high cognitive scores and low-to-moderate drinking persisted.

While this was true in general across the study, the researchers found that the association between low-to-moderate alcohol consumption and protection against cognitive decline was stronger for white participants than for Black participants. However, there were fewer Black participants, and this could account for the lack of strong association.

The researchers also noted that about 5% of women and 15% of men drank excessive amounts of alcohol, meaning that public health awareness campaigns that focus on this issue are still crucial. Drinking more than 14 drinks (self-defined) had worse cognitive outcomes for vocabulary, while more than 10 drinks impacted negatively on word recall.

Future research

While the study demonstrates an association between low-to-moderate alcohol drinking and protection against cognitive decline in later life, it is not yet clear why this is the case. According to study author Dr. Ruiyuan Zhang of the Department of Epidemiology and Biostatistics, University of Georgia College of Public Health, Athens, and his co-authors:

“The role of alcohol drinking in cognitive function may be a balance of its beneficial and harmful effects on the cardiovascular system. Among low-to-moderate drinkers, the beneficial effects may outweigh the harmful effects on the cardiovascular system.”

Future research to corroborate the study’s findings is important, given the previous conflicting research on the topic. In addition, if research conclusively demonstrates low-to-moderate alcohol consumption as protective against cognitive decline in older age, future research to help understand why this is the case is important so that clinicians can best advise their patients.

In the short-term, eating too much sugar may contribute to acne, weight gain, and tiredness. In the long-term, too much sugar increases the risk of chronic diseases, such as type 2 diabetes and heart disease.

According to the Centers for Disease Control and Prevention (CDC), people in the United States consume too much added sugar. Added sugars are sugars that manufacturers add to food to sweeten them.

In this article, we look at how much added sugar a person should consume, the symptoms and impact of eating too much sugar, and how someone can reduce their sugar intake.

How much sugar is too much? 

According to the Dietary Guidelines for Americans 2010-2015, on average, Americans consume 17 teaspoons (tsp) of added sugar each day. This adds up to 270 calories.

However, the guidelines advise that people limit added sugars to less than 10% of their daily calorie intake. For a daily intake of 2,000 calories, added sugar should account for fewer than 200 calories.

However, in 2015, the World Health Organization (WHO) advised that people eat half this amount, with no more than 5% of their daily calories coming from added sugar. For a diet of 2,000 calories per day, this would amount to 100 calories, or 6 tsp, at the most.

Symptoms of eating too much sugar

Some people experience the following symptoms after consuming sugar:

  • Low energy levels: 2019 study found that 1 hour after sugar consumption, participants felt tired and less alert than a control group.
  • Low mood: A 2017 prospective study found that higher sugar intake increased rates of depression and mood disorder in males.
  • Bloating: According to Johns Hopkins Medicine, certain types of sugar may cause bloating and gas in people who have digestive conditions, such as irritable bowel syndrome (IBS) or small intestinal bacterial overgrowth (SIBO).

Risks of eating too much sugar 

Consuming too much sugar can also contribute to long-term health problems.

Tooth decay

Sugar feeds bacteria that live in the mouth. When bacteria digest the sugar, they create acid as a waste product. This acid can erode tooth enamel, leading to holes or cavities in the teeth.

People who frequently eat sugary foods, particularly in between mealtimes as snacks or in sweetened drinks, are more likely to develop tooth decay, according to Action on Sugar, part of the Wolfson Institute in Preventive Medicine in the United Kingdom.

Acne

2018 study of university students in China showed that those who drank sweetened drinks seven times per week or more were more likely to develop moderate or severe acne.

Additionally, a 2019 study suggests that lowering sugar consumption may decrease insulin-like growth factors, androgens, and sebum, all of which may contribute to acne.

Weight gain and obesity

Sugar can affect the hormones in the body that control a person’s weight. The hormone leptin tells the brain a person has had enough to eat. However, according to a 2008 animal study, a diet high in sugar may cause leptin resistance.

This may mean, that over time, a high sugar diet prevents the brain from knowing when a person has eaten enough. However, researchers have yet to test this in humans.

Diabetes and insulin resistance

2013 article in PLOS ONE, indicated that high sugar levels in the diet might cause type 2 diabetes over time.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) add that other risk factors, such as obesity and insulin resistance, can also lead to type 2 diabetes.

Cardiovascular disease

A large prospective study in 2014 found that people who got 17–21% of their daily calories from added sugar had a 38% higher risk of dying from cardiovascular disease (CVD) than those who consumed 8% added sugars. For those who consumed 21% or more of their energy from added sugars, their risk for CVD doubled.

High blood pressure

In a 2011 study, researchers found a link between sugar-sweetened beverages and high blood pressure, or hypertension. A review in Pharmacological Research states that hypertension is a risk factor for CVD. This may mean that sugar exacerbates both conditions.

Cancer

Excess sugar consumption can cause inflammationoxidative stress, and obesity. These factors influence a person’s risk of developing cancer.

A review of studies in the Annual Review of Nutrition found a 23–200% increased cancer risk with sugary drink consumption. Another study found a 59% increased risk of some cancers in people who consumed sugary drinks and carried weight around their abdomen.

Aging skin

Excess sugar in the diet leads to the formation of advanced glycation end products (AGEs), which play a role in diabetes. However, they also affect collagen formation in the skin.

According to Skin Therapy Letter, there is some evidence to suggest that a high number of AGEs may lead to faster visible aging. However, scientists need to study this in humans more thoroughly to understand the impact of sugar in the aging process.

How to eat less sugar

A person can reduce the amount of added sugar they eat by:

  1. checking food labels for sweeteners
  2. reducing foods with added sugar
  3. avoiding processed foods in general

Checking food labels

Added sugar and sweeteners come in many forms. Ingredients to look out for on a food label include:

  • brown sugar
  • fructose
  • glucose
  • sucrose
  • maltose
  • honey
  • corn sweetener
  • corn syrup
  • high fructose corn syrup
  • raw sugar
  • molasses
  • malt syrup
  • evaporated cane juice
  • agave nectar
  • maple syrup
  • invert sugar
  • fruit juice concentrates
  • trehalose
  • turbinado sugar

Some of these ingredients are natural sources of sugar and are not harmful in small amounts. However, when manufacturers add them to food products, a person might easily consume too much sugar without realizing it.

Reducing foods that contain added sugar

Some food products contain large amounts of added sugars. Reducing or removing these foods is an efficient way to reduce the amount of sugar a person eats.

The Dietary Guidelines for Americans 2010–2015 state that soda and other soft drinks account for around half a person’s added sugar intake in the U.S. The average can of soda or fruit punch provides 10 tsp of sugar.

Another common source of sugar is breakfast cereal. According to EWG, many popular cereals contain over 60% sugar by weight, with some store brands containing over 80% sugar. This is especially true of cereals marketed towards children.

Swapping these foods for unsweetened alternatives will help a person lower their sugar intake, for example:

  • swapping soda for water, milk, or herbal teas
  • swapping sugary cereals for low sugar cereal, oatmeal, or eggs

Avoiding processed foods

Manufacturers often add sugars to foods to make them more appealing. Often, this means people do not realize how much sugar a food contains.

By avoiding processed foods, a person can get a better sense of what their food contains. Cooking whole foods at home also means someone can control what ingredients they put into their meals.

When to see a doctor

People should see their doctor if they experience the symptoms of high blood sugar. According to the NIDDK, symptoms include:

  • increased thirst and urination
  • increased hunger
  • fatigue
  • blurred vision
  • numbness or tingling in the hands or feet
  • unexplained weight loss
  • sores that do not heal

These symptoms may indicate a person has diabetes. A doctor can test for diabetes by taking a urine sample.

People should also speak to a doctor if they experience other symptoms after eating sugar, such as bloating.

Summary

Consuming too much added sugar has many adverse impacts on health, including tiredness and weight gain, and more severe conditions, such as heart disease. Added sugars are present in many processed foods and drinks.

People can reduce their sugar intake by knowing what to look for on food labels, avoiding or reducing common sources of sugar, such as soda and cereals, and prioritizing unprocessed whole foods.

If a person is concerned about weight gain, symptoms that may indicate diabetes, or other symptoms they experience after eating sugar, they should speak to a doctor.

The Director General of the Nigeria Natural Medicine Development Agency (NNMDA), Dr. Samuel Etatuvie in this interview with ONYEDIKA AGBEDO, explains steps his organization has taken towards finding a local cure for COVID-19 and also efforts being put in place to combat malaria fever among other issues.

Some herbal medicine advocates believe that the combination of garlic, ginger and some herbs can cure Coronavirus. How true is this belief?
Over the years, scientists have identified ginger, garlic and neem, among other herbs, as having antiviral and antioxidant properties. They can also assist in taking care of cough and feverish feelings associated with these infections.

Therefore, from a scientific point of view, definitely ginger, garlic and many other medicinal plants have the capacity to manage and take care of the associated symptoms of most viral infections, including, influenza and HIV/AIDS. One major thing is that most viral infections attack the immune system, of which these plants have the properties that could boost the immune system.

I think it is not really far from the truth to say that you can use extracts of ginger, garlic and many other medicinal plants to take care of the associated symptoms of viral infections, including COVID-19. If you look carefully, you will find out that COVID-19 symptoms are almost similar to other viral infections – cough, difficulty in breathing, difficulty in smelling and pains.

What level of research has NNMDA done to ensure that we have a local cure for COVID-19?
Like I said, you can manage the associated symptoms of COVID-19. The difficulty with viral infections is that even though you develop a product today to take out the ravaging disease, after a while, you will find out that such disease may mutate and you will begin to look for another product to take care of the mutation.

If you remember, COVID-19 is a novel disease and as scientists, we need to be patient to find out its characteristics. This is why I will not say we are looking for something to cure COVID-19.

As a research agency, we immediately thought of what we could do to support the government. At a point, it was difficult to get hand sanitiser in most countries. Therefore, what we immediately did in February this year was to develop hand sanitiser, using medicinal plants around.

We exhibited it at the last Science and Technology Expo held between March 16 and 20.

We are at the point of getting NAFDAC listing for it. There was an initial delay because of the six-week-stay-at-home order. Even accessing printing and packaging materials became difficult at a time.

Between now and the middle of June, we should have concluded all NAFDAC requirements, and sent it to the agency for listing. We would have given the country, for the first time, a 100 per cent herbal hand sanitiser, and also save her the hard earned foreign currency spent on importing hand sanitisers.

The hand sanitiser has 100 per cent local content and it is as effective as the imported ones. As at when we produced it, our thought was that if it becomes difficult to get raw materials for imported hand sanitiser, we would turn our medicinal plants, which have been shown to have anti-bacterial and anti-viral properties into local hand sanitiser. The advantages of such initiative are many, as the raw materials are locally sourced and are easily available.

One of our mandates is to promote traditional medicine and to sensitise members of the public on the rational use of traditional medicine. One of the steps we took in respect of COVID-19 is to create public awareness during the lockdown. In the social media campaign, we advised Nigerians that, in addiction to obeying all the guidelines outlined by the NCDC, they should practice aromatherapy.

Aromatherapy is one of the methods used in the past to take care of influenza, among others. In aromatherapy practice, the patients place various herbal plants inside a big pot, boil the herbs with water, cover themselves with cloths and inhale the steam coming out from the pots. This gives relief to the patient and builds their immune system. One of the tactics of viral infections is to attack the immune system. Some people who got our message on aromatherapy called to commend our efforts.

We have been working in the area of product development. We have been able to come out with a tea form of herbal remedy for the management of blood sugar in the system for people battling with diabetics. We found out that those with underlying ailment like diabetes are more at risk of COVID-19. The tea has been listed by NAFDAC. We also have a tea that can be used by those who suffer from malaria. The product has the capacity to reduce the level of malaria parasite in the blood, reduce the fever and improve the appetite of the patient. We have got NAFDAC listing for the tea too.

We also have a mosquito repellant product, but there are a few tests remainito NAFDAC for listing.

Another malaria-focused product is our indoor spray, which performs the dual function of killing mosquitoes and other household insects, as well as serves as air freshener. The advantage of this herbal product is that you can stay indoors while it is being applied. This is unlike what is obtainable with other chemicalised ones. We are also working on developing larvasical spray that can kill mosquito larvae within the environment.

It appears the agency is focusing more attention on malaria fever?
Statistics have shown that malaria causes more deaths than COVID-19 and HIV/AIDS. With abundant medicinal plants in the country, if we are able to do a lot in this direction, we would have improved the health of Nigerians and the nation’s economy. This is because we would have healthier people who would be economically active.

One other product that we have been successful with is a product to manage breast cancer. The development of the product has gone far and the potential is very high. We do not want to blow our horns unnecessarily until we finish all our scientific analyses. After that, we will go for NAFDAC listing. After the listing, other steps like clinical trial will now come in. If we are able to pass all the stages of the clinical trials, it means we can throw it open to the world.

We also have a product to treat erectile dysfunction. At times, when we go for exhibition, we find it difficult to meet the demand for it. In addition, we have a cream for women that are experiencing vaginal discharge.

We have published nine books on medicinal plants of Nigeria because we are fully aware that documentation is key if we really want to promote local production of our traditional medicine.

Another critical job that we are doing is the training of traditional medicine practitioners, which has remained the flagship duty of the agency since its formative years. We encourage the practitioners to do documentation because we have noticed that old practitioners are dying with their knowledge. So, we are encouraging the younger ones to documen encouraging the younger ones to document their therapy, just as we train them on how to preserve their intellectual property rights.

We have also reached out to people who sell agbo (herbal concoctions) around the country to see how they can improve the packaging of the products they hawk. Even if whatever they are hawking does not cure, it should not also cause harm because it will take time for us to convince everybody not take agbo.

Assortment of fresh vegetables and fruit

A recent review and meta-analysis have investigated whether a plant pigment called quercetin could reduce the risk of cardiovascular disease. In particular, the authors identified that quercetin reduced blood pressure.

Chopped red onion
A compound that occurs naturally in a range of fruits and vegetables, including red onion, may help reduce blood pressure.

Globally, cardiovascular disease is responsible for about 17.3 million deaths each year. As the population’s average age increases, experts expect cardiovascular disease to rise in step.

Researchers have identified a range of lifestyle factors that increase the risk of cardiovascular disease, such as poor diet, low physical activity, smoking, and consuming alcohol. Certain biological markers, including high blood pressure, raised serum lipids, and high blood glucose levels, also predict cardiovascular disease.

Although lifestyle and medical interventions benefit most individuals, they do not work for everyone. For this reason, some researchers are focused on identifying novel ways to reduce cardiovascular risk.

Introducing quercetin

Researchers from Dongguan Shilong People’s Hospital of Southern Medical University in China are interested in quercetin. Quercetin is a flavonoid that naturally occurs in a range of foods, including vegetables, fruits, wine, nuts, red onions, kale, and black tea.

According to the authors of the recent review, “Accumulating evidence indicates that quercetin possesses protective anti-inflammatory as well as antioxidant effects and may be useful in treating a myriad of chronic conditions.”

However, despite some encouraging results, human studies — rather than animal studies or experiments on tissues — have produced inconsistent results. To date, researchers have carried out few meta-analyses to examine the pooled findings of these studies.

To address this issue, the authors of the current paper analyzed studies that investigated quercetin’s influence over a range of cardiovascular risk factors, including blood pressure, lipid profiles, and glucose levels. They published their findings in the journal Nutrition Reviews.

Reanalyzing recent studies

In their analysis, the scientists only included research papers that met certain criteria. All of the studies were randomized placebo-controlled clinical trials that had investigated the effect of quercetin for 2 weeks or more and had involved adults.

The scientists identified 17 relevant papers, which involved a total of 896 participants. The studies took place in six countries: Iran, United States, United Kingdom, Germany, Italy, and Korea.

Overall, they identified no significant effect of quercetin on glucose levels or lipid profiles. However, when they only analyzed data from trials that used a parallel design and lasted 8 weeks or longer, quercetin did appear to improve levels of high-density lipoprotein (HDL or “good”) cholesterol and triglycerides.

A study with a parallel design is one in which researchers compare two or more treatments; for instance, comparing the effects of quercetin against those of a control.

The greatest benefit of quercetin, however, was its effect on blood pressure. The findings showed that quercetin lowered both systolic and diastolic blood pressure. The authors write:

“The main conclusion was that dietary intake of quercetin significantly lowered [blood pressure].”

Benefits for blood pressure

Systolic blood pressure is the pressure in the arteries as the heart contracts, and diastolic blood pressure is the blood pressure when the heart is resting between beats. As an example, if someone’s blood pressure is 120/80 millimeters of mercury (mm Hg), the first number refers to systolic pressure, and the second number denotes diastolic pressure.

On average, quercetin reduced systolic blood pressure by 3.09 mm Hg and diastolic blood pressure by 2.86 mm Hg.

The authors explain that “a reduction in [blood pressure] of more than 10 mm Hg lowers cardiovascular risk by 50% for heart failure, by 35–40% for stroke, and by approximately 20–25% for myocardial infarction.”

The authors believe that “[t]he favorable effects of quercetin on [blood pressure] found in the current investigation support the use of quercetin as an adjunctive therapy in patients with hypertension.”

In other words, quercetin might enhance the benefits of taking hypertension medication and making lifestyle changes, thus helping reduce cardiovascular risk.

Limitations and holes

As the authors explain, the results are not yet conclusive, and many questions remain. They note that the changes in blood pressure varied depending on the type of quercetin formulation and how long the trials lasted.

The authors also noticed substantial differences among the findings of the studies. These differences might be, in part, due to the size of the trials in the analysis: Four of the 17 trials included fewer than 30 participants.

There were also differences in the design of the studies and the age, sex, and body mass index (BMI) of the participants. These differences make it difficult to generalize and compare among experiments.

Overall, the results are promising, but scientists need to conduct larger, longer-term clinical trials before they can confirm the full benefits of quercetin. If the compound eventually proves to reduce cardiovascular risk, it could benefit vast swathes of the population.