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Saturday, April 20, 2024
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A study finds that when people crave company, the same part of their brain lights up as when they crave food. The research supports the intuitive notion that socializing is a basic human need, akin to eating.

There is ample evidence that chronic loneliness is bad for our physical and mental health.

Studies reported by Medical News Today in the past few years suggest that loneliness weakens the immune system, and has links to diabetes, dementia, and mental illness.

As people worldwide forego meeting friends and family to combat the spread of COVID-19, it is more important than ever to look out for signs of loneliness and stay connected.

Research in social animals has found that positive social interaction is an inherently rewarding activity, similar to eating and sleeping.

A previous study led by the Massachusetts Institute of Technology (MIT) in Cambridge, MA, found that when isolated mice “crave” the company of other mice, a cluster of dopamine neurons in a region of their brains called the dorsal raphe nucleus becomes active.

However, researchers knew little about the neuroscience of acute loneliness in people.

Another study team at MIT has now compared the brain activity of people after they fasted for 10 hours with activity after being deprived of social contact of any kind for 10 hours.

“It’s a stronger intervention of social isolation than anyone had tried before,” says the study’s senior author Rebecca Saxe, from the Department of Brain and Cognitive Sciences at MIT.

Favorite food and social activities

The neuroscientists used functional magnetic resonance imaging (fMRI) to identify any changes in the volunteers’ brain activity, compared with a normal day, when they looked at pictures of their favorite food or people enjoying socializing.

They discovered that a tiny region in the middle of the brain called the substantia nigra, which shares evolutionary roots with the dorsal raphe nucleus in mice, was involved in craving both food and human contact.

The substantia nigra, which contains dopamine neurons, has previously been linked to cravings for addictive drugs.

The region became more active not only when socially isolated participants looked at images of socializing, but also when hungry subjects looked at pictures of food. Neutral images of flowers, used as a control condition, failed to activate the substantia nigra.

“People who are forced to be isolated crave social interactions similar to the way a hungry person craves food,” says Saxe. “Our finding fits the intuitive idea that positive social interactions are a basic human need, and acute loneliness is an aversive state that motivates people to repair what is lacking, similar to hunger.”

The research appears in Nature Neuroscience.

Personalized images

For their study, the researchers recruited 40 participants aged 18–40 years, who were mostly college students.

The scientists asked each participant to list their top 20 favorite foods and social activities, which they then used to find pictures that would provoke cravings during scanning sessions.

To create feelings of social isolation, the volunteers had to surrender their cell phones and laptops to the researchers before spending 10 hours alone in a windowless room without email or social media access.

“There were a whole bunch of interventions we used to make sure that it would really feel strange, different and isolated […] They had to let us know when they were going to the bathroom so we could make sure it was empty. We delivered food to the door and then texted them when it was there so they could get it. They really were not allowed to see people.” – Rebecca Saxe

To occupy themselves, the volunteers could solve puzzles, play simple computer games, or read pre-agreed written texts that contained no social content.

Periodically, they filled out questionnaires rating their social craving, loneliness, discomfort, happiness, and how much they disliked isolation.

The researchers used fMRI to scan participants’ brains after 10 hours of social isolation. They were also scanned on two other occasions: on a normal day, and after 10 hours of fasting.

Craving and the substantia nigra

The amount of activation in the participants’ substantia nigra correlated with how much they reported craving social interaction or food.

Interestingly, after 10 hours of isolation, subjects who said they felt chronically isolated months before the study reported weaker social cravings during the isolation session. There was also less activation in their substantia nigra while looking at the pictures of people socializing.

“For people who reported that their lives were really full of satisfying social interactions, this intervention had a bigger effect on their brains and on their self-reports,” says Saxe.

In contrast to the substantia nigra, craving food or social contact was associated with two distinct patterns of activation elsewhere in the brain, for example, in the striatum and cortex.

“That suggests that those areas are more specialized to respond to different types of longings, while the substantia nigra produces a more general signal representing a variety of cravings,” the authors write.

They now plan to investigate how social isolation affects behavior and whether virtual contact, such as video calls, can ease cravings for social interaction.

The scientists are also interested in discovering how isolation affects different age groups. One of the limitations of the current study was that subjects were generally healthy young adults who were well-connected socially.

Chronic loneliness is known to disproportionately affect older people and adolescents.

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Although obesity is common, there are many misconceptions associated with it — and these myths often fuel social stigma. In this edition of Medical Myths, we tackle five of the most common misunderstandings about obesity.

According to the Centers for Disease Control and Prevention (CDC), in the United States, 42.4% of adults have obesity. Globally, the World Health Organization (WHO) estimate that around 650 million adults have obesity.

People are growing increasingly aware of the health issues associated with obesity. However, despite public health campaigns, myths continue unabated. Many of the most common myths drive stigma that can impact the mental health of people with obesity.

For instance, the results of one 2020 meta-analysis on the subject indicate “a stronger association between weight stigma and diminished mental health with increasing body mass index [BMI].”

Addressing the myths that surround obesity is important. With this in mind, this article will tackle five of the most prevalent misunderstandings around this condition.

1. To reduce obesity, just eat less and move more

In many cases, consuming more calories than the body needs for a prolonged amount of time is the direct cause of obesity. Indeed, the vast majority of measures for reducing obesity aim to lower caloric intake, increase physical activity, or both.

Although diet and exercise are important factors, several unrelated factors can also play a significant part in obesity.

These factors, which people often forget about, include insufficient sleep, psychological stress, chronic pain, endocrine (hormone) disruptors, and the use of certain medications.

In these cases, overeating, for instance, may be a symptom rather than a cause.

Also, some of these factors work together to increase the chance of obesity. As an example, stress can increase the chance of obesity. Due to the prevalence of weight stigma, obesity can be stressful for some people, thereby increasing stress levels and sparking a negative feedback loop.

Added to this, stress can impact sleep quality, and this, in turn, might cause sleep deprivation, which is another factor in the development of obesity. Sleep deprivation also appears to increase stress levels. As one paper explains, “stress hormone levels correlate positively with decreased sleep duration.”

Sleep apnea, wherein a person stops breathing for short periods during sleep, is more prevalent in people with overweight or obesity. Again, a cycle can form: As they gain weight, their sleep apnea may worsen, which can lead to sleep deprivation, which can lead to further weight gain.

As another example, there appears to be an association between chronic pain and obesity. The reasons for this relationship are sure to be complex and differ from person to person, but they likely include chemical factors, sleep, depression, and lifestyle.

It is not difficult to see how chronic pain would both increase stress levels and impact sleep, adding to the negative loops outlined above.

Stress, sleep, and pain are just three interlinking factors that can drive obesity. Each person’s case will be different, but simply receiving an instruction to “move more and eat less” might not be an adequate intervention.

As this article will continue to reiterate, calorie intake and exercise are vital factors in reducing obesity, but they do not tell the whole tale.

2. Obesity causes diabetes

Obesity does not directly cause diabetes. It is a risk factor for type 2 diabetes, but not everyone with obesity will develop type 2 diabetes, and not everyone with type 2 diabetes has obesity.

Obesity is also a risk factor for gestational diabetes, which occurs during pregnancy, but it is not a risk factor for type 1 diabetes.powered by Rubicon Project

3. People with obesity are lazy

An inactive lifestyle is a factor in obesity, and becoming more active can aid weight loss, but there is more to obesity than inactivity.

One 2011 study used accelerometers to measure the activity levels of 2,832 adults, aged 20–79 years, for 4 days. Their step counts reduced as their weight increased, but the differences were not as significant as one might predict, particularly for women.

The list below shows the women’s weights and how many steps they took per day during this study:

  • those with a “healthy” weight: 8,819 steps
  • those with overweight: 8,506 steps
  • those with obesity: 7,546 steps

When one considers that someone with overweight or obesity expends more energy with each step, the difference between the groups’ overall energy expenditures may be even more slight.

This does not mean that physical activity is not essential for good health, but the story is more complex.

Another factor to consider is that not all people are able to perform physical activity. For instance, some physical disabilities can make moving challenging or impossible.

Also, certain mental health issues can severely impact motivation — and there appears to be a relationship between depression and obesity, which further deepens the complexity.

Aside from physical and mental health issues, some people with obesity may also have a negative body image, which might make leaving their home a more daunting prospect.

4. If your close relatives have obesity, so will you

The relationship between obesity and genetics is complex, but someone whose relatives have obesity will not necessarily develop the condition themselves. However, their chance of doing so is higher.

Understanding the role of genes and the environment in isolation is difficult; people who share similar genes often live together and, therefore, may have similar dietary and lifestyle habits.

In 1990, a group of researchers published a study that helped split genes from the environment. The results appeared in The New England Journal of Medicine.

The scientists investigated twins who had been brought up apart and compared them with twins who had been brought up together. In this way, they hoped to tease apart the impact of genetics and the environment. Overall, they conclude:

“[G]enetic influences on [BMI] are substantial, whereas the childhood environment has little or no influence.”

One twin study from 1986 reached similar conclusions. The researchers found that the weights of adopted children correlated with the weights of their biological parents, but not with those of their adoptive parents.

Although more recent studies have identified a more significant role for the environment, genetics do appear to play an important part in obesity.

In recent years, scientists have searched for the genes that influence the chance of obesity. As the CDC explain, in most people with obesity, “no single genetic cause can be identified. Since 2006, genome-wide association studies have found more than 50 genes associated with obesity, most with very small effects.”

One gene that is linked to obesity is a variant of a gene called FTO. This variant, according to one 2011 study, is associated with a 20–30% increased chance of obesity.

Although genetics are important, this does not mean that obesity is inevitable for someone whose relatives have the condition. The above study, which involved individuals with the FTO gene variant, looked at the role of exercise. As the paper explains:

“Using data from over 218,000 adults, the authors found that carrying a copy of the susceptibility gene increased the odds of obesity by 1.23-fold. But the size of this influence was 27% less in the genetically susceptible adults who were physically active.”

A review and meta-analysis that investigated the same gene variant came to a similar conclusion. The authors explain that people with the FTO variant “respond equally well to […] weight loss interventions and thus genetic predisposition to obesity associated with the FTO minor allele can be at least partly counteracted through such interventions.”

However, it is important to reiterate the point that these interventions alone may not be helpful for some people.

5. Obesity does not impact health

This is a myth. There are several conditions associated with obesity. For instance, obesity increases the risk of diabetes, high blood pressure, cardiovascular disease, osteoarthritis, sleep apnea, and some mental health conditions.

That said, even modest weight loss can provide health benefits. According to the CDC, “weight loss of 5–10% of your total body weight is likely to produce health benefits, such as improvements in blood pressure, blood cholesterol, and blood sugars.”

Also, a review of existing literature in the BMJ concludes that weight loss interventions “may reduce premature all-cause mortality in adults with obesity.”

Obesity is highly prevalent. Currently, the stigma surrounding the condition is unhelpful and can be damaging. We need to address it whenever we encounter it.

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Encouraging people to eat more dried fruit — without added sugar — could be an effective way to boost their intake of vital nutrients, researchers have concluded.

Low consumption of fruit in the United States and other countries is a major contributor to diet-related disease and disability, according to a recent analysis.

Fruit is a good source of nutrients, such as fiber and potassium, that many people lack in their diet. It also contains bioactive nutrients that provide extra health benefits, including polyphenols and carotenoids.

Research suggests that eating fruit is associated with a lower risk of cardiovascular disease, cancer, and type 2 diabetes.

However, only about 24% of females and 14% of males in the U.S. eat the recommended daily amount of fruit, according to the National Cancer Institute.

Several factors might contribute to people’s low intake of fresh fruit, including limited availability, high cost, and perishability.

Recommending that people eat more dried fruit could be one solution.

Healthful snack?

Dried fruit offers several advantages over fresh fruit in terms of cost, availability, and ease of storage and transport. It could also replace more unhealthful snack food that is high in sugar, salt, and saturated fat.

At the same time, however, there are concerns about overconsumption leading to excess calorie intake because dried fruit is such an “energy dense” form of fruit.

Previous observational studies have found that eating dried fruit is associated with health benefits. However, the evidence is inconclusive because people who eat more dried fruit may tend to have a more healthful diet and lifestyle overall.

The new study by researchers at Pennsylvania (Penn) State University in University Park aimed to get around this difficulty by comparing days when particular participants reported eating dried fruit with days when they ate none.

They found that people tended to consume more key nutrients on the days they ate dried fruit, including dietary fiber and potassium. However, they also consumed more calories.

“Dried fruit can be a great choice for a nutritious snack, but consumers might want to be sure they’re choosing unsweetened versions without added sugar,” says Valerie Sullivan of Johns Hopkins Bloomberg School of Public Health in Baltimore, MD, who was a grad student at Penn State when she led the study.

“Portion sizes can also be tricky because a serving of dried fruit is smaller than a serving of fresh since the water has been taken out. But the positive is that dried fruit can help people potentially consume more fruit because it’s portable, it’s shelf-stable, and can even be cheaper.”

The research appears in the Journal of the Academy of Nutrition and Dietetics.

Health and nutrition survey

For their analysis, the scientists drew on survey responses from 25,590 individuals who took part in the National Health and Nutrition Examination Survey (NHANES) 2007–2016.

The respondents provided information about the food they had consumed in the past 24 hours (called “dietary recalls”).

Dried fruit accounted for only 3.7% of all the fruit consumed. However, a total of 1,233 participants reported consuming dried fruit on one out of two dietary recalls, allowing the scientists to compare their intake on these days.

Data were also available on the participants’ health, including their body mass index (BMI), waist circumference, and seated resting blood pressure.

Even after adjusting for demographic and lifestyle factors, the participants who ate significant amounts of dried fruit tended to have better diets, a lower BMI, a smaller waist circumference, and lower systolic blood pressure compared with those who did not.

When the researchers compared the days when a participant ate dried fruit with those when they did not, they found that the average intake of total carbohydrate, dietary fiber, potassium, and polyunsaturated fat was greater on the days they ate dried fruit.

Active lifestyle

Taken together, the findings suggest that people who ate dried fruit expended more energy, compensating for the extra calories.

“In our study, people who consumed dried fruits had a higher calorie intake but a lower BMI and waist circumference, which suggests they were more physically active,” says co-author Penny Kris-Etherton, Evan Pugh University Professor of Nutritional Sciences at Penn State.

“So, when incorporating dried fruits, pay attention to calories and be sure to substitute out calories from low nutrient foods for dried fruits to get the greatest benefit of eating dried fruits,” she adds.

The researchers write that eating dried fruit tended to increase total fruit consumption, rather than replacing other forms of fruit. “Thus, increasing dried fruit consumption might help Americans achieve greater fruit intakes.”

The authors acknowledge that their study did not prove that eating dried fruit improves health, only that there seems to be an association. People who are likely to eat dried fruit may have better health for other reasons, such as taking more exercise or leading less stressful lives.

In addition, they note that the survey relied on the participants’ recollection of what they had eaten over the past 24 hours and their ability to estimate quantities accurately.

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A newly released study found that people with heart failure who received the diabetes drug empagliflozin showed significant improvements in heart structure and function, with many experiencing a reversal of the disease.

Approximately 6.2 million adults in the United States have heart failure. As a result of its high prevalence, the national cost of healthcare services, medicines, and missed workdays related to this disorder reached an estimated $30.7 billion in 2012.

Globally, the disease affects approximately 23 million people.

What is heart failure?

Heart failure occurs when the heart cannot pump blood effectively to other parts of the body, causing symptoms that include shortness of breath, difficulty breathing, weakness and tiredness, and weight gain and swelling in the legs, ankles, feet, or stomach.

It may progress to congestive heart failure due to the buildup of fluids in the lungs, liver, and lower extremities.

Underlying causes of heart failure include coronary artery disease, high blood pressure, obesity, heart valve disease, and diabetes. Over time, these diseases may result in “adverse modeling,” which is the heart’s attempt to compensate for its added workload by getting larger, developing thicker walls, and pumping more frequently.

Among people with heart failure, about 50% present with heart failure with reduced ejection fraction (HFrEF). The lowered ejection fraction occurs when the heart’s left ventricle cannot pump blood effectively, decreasing the amount of blood that leaves the ventricle to circulate the body after each contraction.

Treatment options for heart failure include taking prescription drugs, reducing the amount of sodium in the diet, consuming a lower volume of liquids, and making any necessary lifestyle changes, such as reaching a moderate weight, quitting smoking, and eating a heart-healthy diet.

New study shows promising results

With limited heart failure treatment options available, researchers from the Icahn School of Medicine at Mount Sinai set up a clinical trial called EMPATROPISM to investigate the use of empagliflozin, a diabetes drug, for treating HFrEF in people without diabetes.

The researchers presented the trial results on November 13 at the American Heart Association (AHA) Scientific Sessions 2020, with a pre-proof appearing in the Journal of the American College of Cardiology.

In the double-blind, placebo-controlled, randomized study, the scientists divided the 84 participants, who were 18–85 years of age, into two groups. One group received 10 milligrams (mg) of empagliflozin daily, and the other took a placebo.

At the trial’s onset, all of the participants underwent baseline evaluations, which included cardiac MRI, a 6-minute walk test, and a cardiopulmonary exercise test to determine their oxygen levels. They also completed questionnaires regarding their quality of life.

After 6 months of receiving either the placebo or empagliflozin, the participants completed the same tests again.

The researchers found that approximately 80% of those who received the medication showed significant improvement in their condition, with a 16.6% improvement in left ventricle ejection fraction.

They also experienced a reduction in heart size and thickness and had less congestion, indicating that their heart failure had become less severe.

Remarkably, the investigators note that the heart returned to near normal in this group of participants.

Additionally, those who received empagliflozin experienced no severe side effects and saw improvements in their exercise levels and quality of life, which occurred relatively quickly after beginning the medication.

Although empagliflozin is an antidiabetes drug, the investigators noted no adverse blood sugar-related side effects, such as hypoglycemia, in the study participants, despite them not having diabetes.

Conversely, the study participants who took the placebo showed no improvements. Their condition either stayed the same or worsened, with a further reduced ejection fraction, increased heart size and thickness, and an abnormal change in the heart’s overall shape.

According to the researchers, the study results also explain why this medication effectively treats heart failure. They explain that it essentially reverses the adverse modeling that occurs when the heart attempts to restructure itself to compensate for changes associated with other chronic conditions.

Supporting evidence

The EMPEROR-Reduced trial, a slightly earlier study that featured in the New England Journal of Medicine, saw similar results. In this double-blind trial, 3,730 people with HFrEF took either empagliflozin (10 mg once daily) or a placebo, in addition to recommended therapy.

The results concurred with the EMPATROPISM findings, showing that people both with and without diabetes in the empagliflozin group experienced a lower risk of cardiovascular death or hospitalization for heart failure than those in the placebo group.

Researchers look to the future

The EMPATROPISM study’s first author, Carlos Santos-Gallego, a postdoctoral fellow at the Icahn School of Medicine, explains the implications of these findings.

He says, “Our clinical trial’s promising results show this diabetes drug can ameliorate lives of heart failure patients with reduced ejection fraction, enhance their exercise capacity, and improve their quality of life with little to no side effects.”

“We expect this work will help lead to U.S. Food and Drug Administration [FDA] approval of empagliflozin for this patient population in the coming months.”

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New research has found that short bursts of exercise may significantly improve levels of metabolites that are indicators of key physical health issues.

The research, published in the journal Circulation, offers scientists a better understanding of the beneficial effects exercise can have on a person’s health.

Health and physical activity

Scientists have known for a long time that there is a link between physical activity and better health. As the Centers for Disease Control and Prevention (CDC) say, “Regular physical activity is one of the most important things you can do for your health.”

The CDC note that regular exercise can improve a person’s brain health; help them better manage their weight; reduce their chances of developing various diseases, including diabetes, some cancers, and cardiovascular disease; strengthen their muscles and bones; and improve mental health.

While scientists are well aware of these links, they do not fully understand the precise molecular mechanisms that help explain the link between being physically active and maintaining better health.

Metabolites

In this context, the researchers wanted to look at the association between metabolites that are indicators of health and exercise.

A person’s metabolism describes the chemical reactions that take place in their body. Metabolites either facilitate these reactions or are the end result of them. Scientists have identified relationships between exercise and certain changes in metabolites.

Dr. Gregory Lewis, section head of Heart Failure at Massachusetts General Hospital (MGH) and senior author of the study, says, “Much is known about the effects of exercise on cardiac, vascular, and inflammatory systems of the body, but our study provides a comprehensive look at the metabolic impact of exercise by linking specific metabolic pathways to exercise response variables and long-term health outcomes.”

He continues:

“What was striking to us was the effects a brief bout of exercise can have on the circulating levels of metabolites that govern such key bodily functions as insulin resistance, oxidative stress, vascular reactivity, inflammation, and longevity.”

Burst of exercise

The researchers made use of the Framingham Heart Study (FHS), a long-term study directed by the National Heart, Lung, and Blood Institute.

The researchers measured 588 metabolites in 411 middle-aged people before and immediately after 12 minutes of physical activity on an exercise bike. This allowed them to see the effect that exercise has on the metabolome.

In general, the researchers found that the short burst of exercise significantly altered 80% of a participant’s metabolites. In particular, they found that metabolites associated with adverse health outcomes when resting were reduced.

For example, high levels of glutamate have been linked to diabetes, heart disease, and hypertension, and the researchers found that these levels fell by 29% following exercise. The levels of dimethylguanidine valerate (DMGV), which are associated with liver disease and diabetes, fell by 18% following exercise.

Marker of fitness?

The researchers note that their findings may be valuable in helping doctors determine a person’s fitness levels.

Dr. Matthew Nayor, a cardiologist in the Heart Failure and Transplantation section of the MGH Cardiology Division, explains, “Intriguingly, our study found that different metabolites tracked with different physiologic responses to exercise, and might therefore provide unique signatures in the bloodstream that reveal if a person is physically fit, much the way current blood tests determine how well the kidney and liver are functioning.”

He adds, “Lower levels of DMGV, for example, could signify higher levels of fitness.”

By combining the information they gained from this analysis with blood samples taken during previous rounds of the FHS, the researchers were also able to determine the longer-term effects of exercise on a person’s metabolome.

Dr. Ravi Shah of the Heart Failure and Transplantation section of the MGH Cardiology Division notes, “We’re starting to better understand the molecular underpinnings of how exercise affects the body and use that knowledge to understand the metabolic architecture around exercise response patterns.”

He adds, “This approach has the potential to target people who have high blood pressure or many other metabolic risk factors in response to exercise, and set them on a healthier trajectory early in their lives.”

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More than four billion people could be overweight by 2050, with 1.5 billion of them obese, if the current global dietary trend towards processed foods continues, a first-of-its-kind study predicted Wednesday.

Warning of a health and environmental crisis of “mind-blowing magnitude”, experts from the Potsdam Institute for Climate Impact Research (PIK) said that global food demand would leap 50 percent by mid-century, pushing past Earth’s capacity to sustain nature.

Food production already hoovers up three-quarters of the world’s freshwater and one-third of its land — and accounts for up to a third of greenhouse gas emissions.

Providing a long-term overview of changing global eating habits between 1965 and 2100, the researchers used an open-source model to forecast how food demand would respond to a variety of factors such as population growth, ageing, growing body masses, declining physical activity and increased food waste.

They found that “business as usual” — a continuation of current trends — will likely see more than four billion people, or 45 percent of the world’s population, overweight by 2050.

The model predicted that 16 percent would be obese, compared with nine percent currently among the 29 percent of the population who are overweight.

“The increasing waste of food and the rising consumption of animal protein mean that the environmental impact of our agricultural system will spiral out of control,” said Benjamin Bodirsky, lead author of the study published in Nature Scientific Reports.

“Whether greenhouse gasses, nitrogen pollution or deforestation: we are pushing the limits of our planet — and exceeding them.”

While trends vary between regions, the authors said that global eating habits were moving away from plant- and starch-based diets to more “affluent diets high in sugar, fat, and animal-source foods, featuring highly-processed food products”.

At the same time, the study found that as a result of increasing inequality along with food waste and loss — food that is produced but not consumed due to lack of storage or overbuying — around half a billion people will still be undernourished by mid-century.

“There is enough food in the world — the problem is that the poorest people on our planet have simply not the income to purchase it,” said co-author Prajal Pradhan.

“And in rich countries, people don’t feel the economic and environmental consequences of wasting food.”

The UN’s Intergovernmental Panel on Climate Change warned in a special report last year that humanity will face increasingly painful trade-offs between food security and rising temperatures within decades unless emissions are curbed and unsustainable farming and deforestation are halted.

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A new study comparing a vegan diet with a mixed diet has found no difference in vitamin B12 levels. However, one-third of the vegan participants were iodine-deficient.

There are many benefits to a vegan diet, including a lower risk of heart disease, cancer, and type 2 diabetes.

However, a growing concern is the lack of dietary nutrients that are mainly present in animal foods. Two important nutrients are vitamin B12 and iodine.

Vitamin B12 is essential to the body

Vitamin B12, also known as cobalamin, helps the body form nerves, red blood cells, and DNA. Maintaining adequate vitamin B12 levels is also crucial for cell metabolism and supporting the nervous system.

According to the National Institutes of Health (NIH), the average adult needs about 2.4 micrograms (mcg) of vitamin B12. The only natural sources of vitamin B12 are animal-based. They include various types of meats and fish, as well as dairy products, clams, and eggs.

As vitamin B12 does not occur naturally in plant-based foods, those eating only these foods are at risk for vitamin B12 deficiency. A 2017 study in the journal Nutrients found that 69.9% of males and 83.4% of females who were under the age of 55 years and identified as vegan lacked sufficient vitamin B12.

Since vitamin B12 is vital in making red blood cells, insufficient levels can increase the risk of anemia. Also, without vitamin B12, the brain cannot function correctly, which can lead to cognitive impairments. There is also evidence of a link between this vitamin deficiency and depression, Alzheimer’s, Parkinson’s disease, and dementia.

Importance of iodine in the diet

Iodine is another essential nutrient for the body. Iodine is crucial to making thyroid hormones, and the recommended intake for an adult is 150 mcg. However, about 38% of the world’s population lack adequate iodine levels.

Iodine is in fish, eggs, and dairy products. Unlike vitamin B12, iodine is naturally available to vegans in seaweed.

Despite some natural sources, getting sufficient iodine can still be challenging for vegans. A 2011 study in The Journal of Clinical Endocrinology & Metabolism found vegans to be at high risk for iodine deficiency.

Low iodine levels can force the thyroid to absorb iodine from the blood, which may lead to hypothyroidism. Iodine deficiency during pregnancy or in young children may also impair cognitive development and increase the risk of intellectual disabilities.

A growing trend for vegan diets

Despite the nutritional concerns, eating plant-based foods remains increasingly popular. For instance, a 2017 study in the Journal of Nutrition Education and Behavior found that in 2012, 1.9% of people in the U.S. followed a vegan or vegetarian diet for health reasons. This was an 18.8% increase from 2002.

In response to the rising interest in veganism, researchers at the German Federal Institute for Risk Assessment sought to find any updates regarding the average vegan’s nutritional health.

The study appears in the journal Deutsches Ärzteblatt.

Study design

The researchers selected a total of 72 participants aged 30–57 years from Berlin, of whom 36 were vegan, and 36 were eating an omnivorous diet consisting of both plant and animal foods.

The team used questionnaires to collect demographic information from these individuals, including their age, education level, and lifestyle factors.

Using the German Nutrient Database, the researchers used a 3-day dietary protocol to measure nutrient intake in both groups. They excluded dietary supplement use from the calculations.

The researchers also took 60-milliliter blood samples and 24-hour urine samples to observe vitamin and mineral levels. They identified some of these, such as vitamin B12, through biomarkers. For example, high concentrations of holotranscobalamin indicate a vitamin B12 deficiency.

Key research findings

During the 3-day recording, those on a vegan diet showed lower concentrations of cholesterol than the omnivores.

The vegan group also consumed more fiber, vitamin E, vitamin K, and folate. However, these participants did not eat as many foods high in vitamin B12, vitamin D, and iodine as the omnivores.

In the blood, the vegan participants had lower levels of vitamin B2, vitamin B3, vitamin E, vitamin A, selenoprotein P, and zinc than the omnivores. However, they had high levels of folate and vitamin K1.

In the urine samples, iodine and calcium levels were low in those following a vegan diet.

A surprising finding was the lack of vitamin B12 deficiency in vegans. The researchers attribute this to a growing knowledge of the lack of vitamin B12 in plant-based diets.

“Most vegans are aware that a vegan diet is associated with the risk of vitamin B12 deficiency, and vitamin B12 is by far their most frequently taken supplement,” write the authors.

Another interesting finding was that both groups had low iodine levels, although this was more apparent in vegans. Only 8% of vegans achieved adequate iodine levels compared with 25% of omnivores.

Study limitations to consider

Understanding the study’s recruitment process is important when interpreting the data. The authors note that participants were most likely a convenience sample. This means that they chose people who were easy to reach, as they enrolled people who responded to their announcement.

A convenience sample may have created bias in the results, as the people who took the time to respond may already have been health conscious. However, the subjectiveness in recruitment remains debatable.

“Since the same recruitment strategy was used for vegans and omnivores, and a BMI ≥ 30 kg/m2 was chosen as an exclusion criterion, it can be assumed that the level of health consciousness was similar in both groups,” note the authors.

The study also used a small sample size of 72 participants, which is unlikely to be representative of the general population in Germany.

Final thoughts

“Consequently, the results of our study provide first insights into the current vitamin and mineral status in vegans versus omnivores in the German population,” write the authors.

This updated nutritional information could help guide vegans toward prioritizing iodine in addition to vitamin B12 supplementation.

Doing so may help circumvent the health risks associated with following a plant-based diet.

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Asian female buying some wine at a supermarket

Doctors have warned that people in the United States may be drinking excessively as a way to cope with the COVID-19 pandemic.

In a new viewpoint article, two doctors have warned that more people in the U.S. may be turning to alcohol as a way of coping with the “myriad stressors” of the COVID-19 pandemic.

The article, published in the Journal of General Internal Medicine, proposes a series of interventions to try to minimize this behavior and better support people with alcohol use disorder.

Coping strategy

It is well documented that drinking alcohol is one way that people cope with stressful situations. For example, research has shown that in the U.S., people tend to drink more alcohol following terrorist attacks.

Furthermore, if a person has alcohol use disorder, they are more likely to use alcohol to cope with the stress of a traumatic event.

In this context, the current COVID-19 pandemic is a particular cause for concern. The authors of the current article point out that rather than being a single event, the effects of the COVID-19 pandemic are prolonged over time, potentially exposing people to ongoing trauma.

Further, the pandemic has caused various potential stressors that a person may cope with by drinking alcohol.

As well as the catastrophic effect on people’s health and the loss and grief experienced by many, the pandemic has also disrupted economies and social and cultural life, threatening people’s jobs, disrupting their interpersonal support structures, increasing barriers to health care, and forcing many people into isolation.

Before the pandemic, researchers had noted that people in the U.S. were tending to drink more. This was particularly the case for females.

Recent research suggests that people in the U.S. increased their alcohol consumption in the early phase of the pandemic. This is in line with similar findings from studies in the United Kingdom and Australia.

Alcohol health effects

This matters because well-documented links exist between increased alcohol consumption and adverse health outcomes.

As the National Institute on Alcohol Abuse and Alcoholism point out, alcohol consumption can change mood and behavior, damage a person’s heart, liver, and pancreas, increase the risk of several types of cancer, and weaken a person’s immune system.

Research has also linked excessive alcohol consumption to mental health disorders, such as anxiety and depression, which may worsen during the pandemic.

Consequently, it is important to encourage people to find alternative coping strategies in response to the stressors of the pandemic. Effective support should also be available for people experiencing the effects of increased alcohol consumption or people with alcohol use disorder.

Interventions

The authors of the present study offer various suggestions for interventions that may help reduce people’s dependence on alcohol during the pandemic. Other suggestions focus on better preparing clinical services to support people with substance abuse issues.

According to Dr. Shelly F. Greenfield, director of the Alcohol, Drug, and Addiction Clinical and Health Services Research Program at McLean Hospital in Belmont, MA, “[i]ncreasing identification of harmful alcohol use in patients and intervening early are key components of addressing this problem.”

“In addition, recognition of the problem from policymakers could lead to changes in federal regulations — such as we have seen with telehealth — and improvements in access to healthcare,” she notes.

The authors suggest that public health messaging should raise awareness of the potential for increased drinking during the pandemic, as well as giving advice on alternative coping strategies for the stressors of the pandemic.

They also suggest that primary care practitioners should offer increased screening for alcohol use disorder when people contact primary care services.

Technologies, such as telehealth — that enable clinical information to pass between doctors and individuals at a distance — may also be valuable for people who are isolating or where the pandemic has forced a reduction in the enrolment for some face-to-face clinical services.

Finally, the authors highlight that ensuring people have access to health insurance to cover medical treatment costs is crucial. This is particularly important given the number of people who depend on work-place health insurance and the significant number of people who have lost their jobs during the pandemic.

Co-author Dr. Dawn E. Sugarman, a research psychologist in the Center of Excellence in Alcohol, Drugs, and Addiction at McLean Hospital, notes that:

“We hope this article will call attention to the pandemic’s effects on alcohol use and offer mitigating approaches to this under-recognized public health concern.”

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A study suggests an intensive exercise program boosts cognitive performance and physical fitness in United States Air Force personnel. A nutritional supplement may also have some additional benefits.

While exercise is known to improve health and cognition, combining it with a nutritional supplement that mimics a Mediterranean diet may provide further advantages.

Scientists at the University of Illinois in Urbana-Champaign, Abbott Nutrition, and the U.S. Air Force Research Lab found that volunteers who consumed the supplement before and after training sessions had an edge in some measures of fitness and cognition 3 months later.

However, intensive exercise alone improved strength and endurance more than intensive training with the supplement.

On two cognitive performance measures, both the placebo group and the supplement group showed a slight reduction in performance, while other measures improved.

“The physical and mental health benefits of exercise are well known, but this study demonstrates how optimal nutrition can help boost brain function as well,” says study leader Chris Zwilling, a postdoctoral researcher at the University of Illinois.

“We are excited by the results because they provide critical insights into how simple dietary changes can make a big difference in helping people be as efficient and productive as possible in today’s world,” he adds.

The research appears in the journal Scientific Reports.

Strength and fitness training

The scientists recruited 148 active-duty male and female Air Force personnel from Wright Patterson Air Force Base in Dayton, OH, and randomly assigned them to two groups.

Both groups underwent a 12-week exercise program involving five daily sessions of 45 minutes, including rotating sessions of high-intensity interval training, aerobic fitness, and strength training each week.

One group drank the specially formulated nutritional supplement 30 minutes before and 1 hour after each session, while the second group consumed a placebo drink that looked and tasted the same. The supplement contained 267 calories of energy, while the placebo contained 100 calories.

Neither the researchers nor the participants knew who drank the special supplement and who drank the placebo.

The high-protein supplement contained a wide range of nutrients, including:

  • lutein, a carotenoid vitamin related to beta-carotene and vitamin A found in kale, spinach, avocados, and eggs
  • omega-3 fatty acids, found in oily fish such as mackerel and sardines
  • phospholipids, an essential component of cell membranes
  • beta-hydroxy beta-methylbutyrate, a supplement that helps increase muscle mass and aids recovery after exercise
  • folic acid
  • B vitamins
  • vitamin D

Participants took a series of cognitive and physical fitness tests before and after the exercise program. The cognitive tests assessed their memory, fluid intelligence — the ability to solve novel reasoning problems, executive function, and reaction time.

The exercise-only group had positive improvements in 5 out of 6 physical fitness measures and 4 out of 8 cognitive functioning measures. The research team recorded cognitive functioning increases in:

  • short-term memory
  • episodic memory
  • executive function reaction time
  • fluid intelligence and processing efficiency

The group who also took the supplement had improvements in all six fitness measures and 6 out of 8 cognitive measures. Compared with exercise alone, taking the supplement was associated with significant additional enhancements:

  • working memory increased
  • fluid intelligence reaction time decreased
  • lean muscle mass increased
  • resting heart rate, a measure of physical fitness, decreased

However, some of the figures in the study abstract were inaccurate. The authors have provided updated figures to Medical News Today and the journal.

Furthermore, the figures in the abstract were determined using raw data, which the paper did not provide. There were also some errors in rounding. Therefore, MNT is cautious about the study’s findings while the authors and the journal update the figures.

Working memory

Matt Kuchan, a research fellow and brain health scientist at Abbott and a co-author of the study, was impressed by the improvement in working memory among participants who took the supplement.

Working memory is a finite, temporary information store that predicts an individual’s ability to multitask and is often impaired in stressful situations. For example, it allows a person to remember a telephone number long enough to dial it or write it down.

“This is a really big deal,” says Kuchan. “First, because working memory is hard to improve. And secondly, because it is relevant to everybody.”

Strangely, two measures of cognitive function were slightly worse after the intervention for both the supplement and the placebo group: short-term memory and executive function accuracy.

It could be that these small performance decreases were due to test anxiety or chance.

The investigators say they did not design the study to determine which nutrients improved physical and cognitive performance. They also remain unsure if the enhanced cognition was due to the supplement, improvements in physical fitness, or a combination of both.

The study also took just 3 months, and therefore, it is not certain that real-life health programs could maintain these enhancements.

The research team discovered a link between the supplements and improvements that could not be explained by exercise in only 5 out of the 23 analyzed measures of cognitive health.

In addition, they made no adjustments in the statistical analysis to assess many variables in a single and relatively small study.

They also believe there may have been further benefits by using whole foods to deliver the nutrients, rather than supplements.

However, this would have presented several challenges in designing the study, for example, how to deliver exact quantities of several different nutrients.

The study provides evidence that intensive cardiovascular and resistance training offer rapid improvement in fitness, and in line with previous research, is associated with improvements in some measures of cognition.

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Image credit: Sellwell/Getty Images

A high fat, low carb diet reversed heart failure in a mouse model of the condition. A 24-hour fast also led to improvements, mimicking the physiological effects of the diet.

In people with heart failure, the muscle on the right or left side of the heart — or on both sides — weakens. This impairment limits the organ’s ability to pump blood around the body, causing fatigue and shortness of breath, among other symptoms.

The leading causes are high blood pressure, diabetes, and ischemic heart disease, in which the heart muscle becomes starved of oxygen.

The National Heart, Lung, and Blood Institute estimate that about 5.7 million people in the United States have heart failure.

There is currently no cure, but medications and lifestyle changes can improve people’s quality of life and increase their lifespan.

Healthy heart muscle can draw upon a variety of chemical energy sources, depending on the circumstances. One of these is a molecule called pyruvate, which the body generates during the breakdown of the sugar glucose.

However, conditions such as heart failure and diabetes reduce this flexibility, starving the muscle of the fuel it needs to function effectively.

Fuel shuttle

Researchers have now traced this loss of flexibility to a transporter protein that shuttles pyruvate into mitochondria — the so-called power stations of cells.

Known as the mitochondrial pyruvate carrier (MPC) complex, it comprises two subunits: MPC1 and MPC2.

Researchers at the Saint Louis University School of Medicine in St. Louis, MO, led a team who discovered that the production of both subunits is reduced in failing human hearts.

The researchers compared heart tissue samples from people undergoing heart surgery with tissue samples from donor hearts that were healthy but unsuitable for transplant.

They then showed that mice that lack the gene for producing MPC2 steadily develop heart failure over time. Their hearts became outsized, or hypertrophied, and the organs’ ability to pump blood diminished.

Crucially, the scientists found that they could reverse the damage to the animals’ heart muscle by simply feeding them a special diet for 3 weeks.

“Interestingly, this heart failure can be prevented or even reversed by providing a high fat, low carbohydrate ‘ketogenic’ diet,” explains Kyle S. McCommis, Ph.D., assistant professor of biochemistry and molecular biology at the university, who led the research.

“A 24-hour fast in mice, which is also ‘ketogenic,’ also provided significant improvement in heart remodeling,” he adds.

Ketogenic diet

The ketogenic diet has been growing in popularity in recent years, with research suggesting that it has a range of possible health benefits. These include supporting weight loss, improving heart health, and preventing seizures in some types of epilepsy.

By severely restricting the intake of carbohydrates, such as glucose and other sugars and starches, the diet forces the body to break down fat, producing molecules called ketones that it can use as fuel. Intermittent fasting may achieve similar effects, though adhering to the regimen can be challenging.

The new research indicates that a ketogenic diet promotes the breakdown of fatty acids in heart muscle cells. This process produces an alternative fuel called acetyl-CoA, which the mitochondria can use as an energy source instead of pyruvate.

“Thus, these studies suggest that consumption of higher fat and lower carbohydrate diets may be a nutritional therapeutic intervention to treat heart failure,” says McCommis.

The scientists showed that the diet reversed heart failure by promoting the breakdown of fatty acids in mitochondria rather than ketones. Supplying the mitochondria with extra ketones only slightly improved heart failure.

Converging evidence

The findings from this study appear in the journal Nature Metabolism.

Two studies by other research groups, which feature in the same issue, independently show that the MPC transporter protein plays a central role in heart failure.

P. Christian Schulze and Jasmine M. F. Wu, who are both cardiologists from the University Hospital Jena in Germany, have written a comment article for the journal about the three papers.

While several questions remain unanswered about the regulation of MPC levels in healthy and failing hearts, they conclude:

“The current findings suggest a role for specific ketogenic diets as a supportive, nonpharmacologic treatment in people with heart failure.”

The cardiologists speculate that the findings could also inspire the development of new drugs for heart failure that work by boosting the breakdown of fatty acids in heart muscle cells.

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