Ccognitive and behavioral efforts to manage stressor are related to longevity in older men

 

Coping is defined as cognitive and behavioral efforts to manage stressors that people believe exceed their ability and resources to respond to effectively. While previous research has linked stressor characteristics, such as the type of event and its duration, and how stressed people feel in response to them, to higher mortality risk, far fewer studies have considered the long-term health consequences of how we manage stressors (coping) in large-scale studies.

 

In a new study from Boston University Chobanian & Avedisian School of Medicine, researchers have determined that in older men, the overall effort put into coping was generally more important for longevity than the specific coping strategies used, or how stressful they considered the problem to be shortly after it had happened.

 

“How much older men did in response to stressors mattered more for their survival than what they did. Our finding held up even after we considered individual differences in demographics, marital status, major health conditions, and lifestyle factors at study baseline,” said senior and corresponding author Lewina Lee, PhD, clinical psychologist at the National Center for Posttraumatic Stress Disorder at the VA Boston Healthcare System and associate professor of psychiatry at the school. “Studying coping is important because this is an aspect of the stress-health equation that is within our control yet it is very much overlooked.”

 

The researchers followed 743 men who were part of the Veterans Affairs Normative Aging Study. Between 1993 and 2002, each man completed a stress and coping assessment that involved naming the most stressful thing that had happened to them in the past month, rating how stressful the problem was for them, and indicating how much they used specific strategies to deal with the problem. The researchers then analyzed the data looking at the extent to which the stressfulness of their problems, the specific types of coping strategies they used, and the overall effort put into coping related to the risk of dying over a span of 27 years.

 

According to the researchers, prior studies in psychological aging show that people gain tremendous expertise in coping with stressors across the life span. By the time they reach later life, people tend to be able use fewer coping strategies than younger adults while achieving the same level of success in managing difficult situations. “Our findings suggest that if an older adult deviates from this pattern by using a lot of energy to deal with stressors, it may be a sign that they are struggling and do not have what they need to manage the problem at hand,” said first author Victoria Marino, PhD, a postdoctoral fellow at the school. “These findings behoove us to pay more attention to how the aging process may pose challenges to individuals and to signs that older people may need resources to help preserve their health, sense of independence, and well-being,” added Lee.

 

Cranberries provide runners with an all-natural boost

 Competitive athletes are always looking for an extra edge that can help them improve performance. According to a new study by Concordia researchers published in the journal Physical Activity and Nutrition, they can find one in the common cranberry.

In a series of trials involving trained distance runners, the researchers found that ingesting a cranberry supplement for 28 consecutive days led to noticeable improvements in both performance and muscle fatigue following 1,500-metre time trials. Reoxygenation rates were faster and running speeds improved by 1.5 per cent.

“When it comes to elite athletes, any advantage can make the difference between finishing fifth or on the podium,” says Andreas Bergdahl, an associate professor in the Department of Health, Kinesiology and Applied Physiology and the paper’s senior author.

Effects of different energy systems

The researchers recruited 14 high-level runners from Concordia’s varsity track and field team and from two Montreal running clubs, who are performing at least five hours of endurance training a week.

The athletes ran two time trials over three separate visits, one a 1,500-metre, the other a 400-metre. The first visit was used as a baseline. At the second, they were given a single large dose of cranberry extract two hours before running. The athletes were then instructed to consume a small dose of cranberry extract daily for 28 days, after which they repeated the runs for a third time.

“We selected these distances to test the effects the cranberry extract had on different energy systems,” says Francis Parenteau, a PhD candidate and the paper’s lead author. “The 400-metre is shorter and of higher intensity and involves the anaerobic system. The 1,500-metre uses the aerobic system but is shorter than what the athletes usually run. Since they do not train to run that distance, we were able to isolate training effects as a variable.”

Besides their running time, the researchers measured their post-exercise blood lactate, a marker for potential muscle fatigue and lack of oxygen. They also attached a portable near-infrared spectroscopy device to the runners to measure muscle oxygenation levels before, during and after their runs.

Following data analysis, the researchers found that 28 days of cranberry extract consumption demonstrated a trend toward increased speed in the 1,500-metre time trial but not in the 400-metre. However, they did notice that lactate buildup was reduced following the 400-metre but not the 1,500-metre compared to baseline.

The data also indicated that the cranberry extract promoted better oxygen extraction by the muscle, improved lactate clearance and slower muscle deoxygenation.

Cranberries are extraordinarily rich in polyphenols, a natural compound with antioxidant properties. These characteristics help protect the body from the harmful effects of free radical molecules produced by strenuous exercise.

Low-carb diets are backed by science and support health equity

What was once a subject of public health debate is now a matter of clear scientific consensus: low-carb diets can be safe, nutritious, and should be included as an option within the Dietary Guidelines for Americans. A group of experts, including leading nutrition and health researchers and healthcare professionals, reviewed the evidence and arrived at more than 15 areas of unanimous scientific agreement on the benefits, opportunities and considerations around lower carbohydrate dietary patterns.

A review of the state of science and summary of the consensus statements are now published in the peer-reviewed journal Frontiers in Nutrition. Importantly, the experts agreed on a consensus definition of low-carbohydrate diets as those containing 50 – 129 gram of carbohydrates per day. Until now, no standard definition existed.

The established range of 50-129 grams of carbohydrates per day is lower than the current dietary reference intake (DRI), which recommends 45-65% of daily calories come from carbohydrates. Based on a 2,000-calorie diet, consuming 50-129 grams of carbohydrate per day would provide about 10-26% of daily calories. The scientific basis for DRI for carbohydrates is currently being reevaluated to take more recent research into account.

“This is a milestone achievement for the public health and scientific communities,” said lead author Jeff Volek, PhD, The Ohio State University. “Now that we have a clear definition of what constitutes a low-carb diet, and a shared agreement on the evidence-based benefits of a low-carb diet, this information should be included in dietary recommendations and accessible to the broader public.”

Other key takeaways about low-carb diets

The experts also agreed on several other important points.

• Low-carb diets are safe for the general public, though initial medical supervision may be necessary for some people, like those living with more medically complex conditions or taking certain medications.
• Low-carb diets are helpful for addressing insulin resistance within the general population and in those with or at risk of diet-related diseases, like obesity, type 2 diabetes, heart disease, and more.
• Well-planned low-carb diets can provide adequate nutrition and support high-quality diets similar to the healthy eating patterns currently recommended in the Dietary Guidelines for Americans.
• Including guidance around a healthy, lower-carb eating pattern within the Dietary Guidelines could help address health disparities and advance health equity.

“We’ve reached a critical mass of scientific evidence at this point,” said Volek. “And nutrition experts now agree, low-carb diets provide benefits beyond disease management. In other words, they’ve been shown to not only help people with diet-related diseases, like heart disease and type 2 diabetes, they can also help generally healthy people reduce their risk of developing those diseases in the first place.”

Federal agencies reevaluating scientific basis for low-carb diet

The newly published consensus statements come at a time when the U.S. Departments of Agriculture and Health and Human Services are considering potential changes to the Dietary Guidelines for Americans, with particular emphasis on the importance of health equity. The Dietary Guidelines for Americans provide a set of evidence-based nutrition recommendations that broadly inform public health and nutrition activities, including food and nutrition labeling, federal nutrition assistance programs, and education initiatives, all of which are foundational to addressing persistent health disparities in America.

Today’s body of research suggests that lower-carb diets can have a beneficial effect on weight, insulin sensitivity, and heart disease risk – diseases that disproportionately affect people from historically marginalized backgrounds, like Black and Hispanic Americans – and the expert group agreed the inclusion of a lower-carbohydrate eating pattern in the Dietary Guidelines could enhance health equity across the country.

Volek added, “If we really want to make sure federal nutrition guidance is keeping up with the science and serving America’s diverse populations with different health needs, priorities and preferences, then the Dietary Guidelines should be updated to include a lower-carbohydrate approach to eating.”

Sugary drinks, fruit juices linked to higher risk of developing Type 2 diabetes among boys

 

AMERICAN HEART ASSOCIATION

Research Highlights:

• Preliminary findings from a long-term study of children in Massachusetts have potentially linked regularly drinking sugary drinks and fruit juices (8 ounces or more daily) during childhood and adolescence to a higher risk of developing Type 2 diabetes, based on glycemic markers, among boys but not girls.
• The researchers also found that eating fresh fruit in childhood and adolescence was not associated with an increase or reduction in markers for Type 2 diabetes risk.

A small, long-term study of almost 500 children in Massachusetts has found that regularly drinking sugary drinks and 100% fruit juices during childhood and adolescence may be linked to a higher risk of developing Type 2 diabetes among boys than girls, according to preliminary research to be presented at the American Heart Association’s Epidemiology and Prevention│Lifestyle and Cardiometabolic Scientific Sessions 2024, March 18- 21, in Chicago. The meeting offers the latest science on population-based health and wellness and implications for lifestyle.

“While these findings are preliminary, they support the existing evidence about the potential relationship between beverages with added sugar and long-term risk of Type 2 diabetes in children,” said lead investigator Soren Harnois-Leblanc, Ph.D., a registered dietitian and postdoctoral researcher in the department of population medicine at Harvard Pilgrim Health Care Institute and Harvard Medical School, both in Boston. “Pediatricians and other health care professionals should caution young patients and their parents about sugary drinks and fruit juices when discussing healthy eating habits.”

According to a 2022 American Heart Association fact sheet about sugary drinks, nearly two-thirds of children and adolescents in the U.S. consume at least one sugary drink, such as soda, lemonade or an energy drink, each day. It also notes that in addition to weight gain, eating too many foods with added sugars, especially from sugary drinks, raises the risk of developing heart disease, high blood pressure, Type 2 diabetes and tooth decay.

Using data from Project Viva, an ongoing long-term study of women and their children in eastern Massachusetts that began in 1999, researchers explored whether drinking sugary drinks, 100% fruit juices and eating fresh fruits were associated with markers for developing Type 2 diabetes. Researchers calculated the average consumption of sugary drinks, 100% fruit juices, and fresh fruits over childhood and adolescence based on dietary records and assessed their potential associations to three markers of Type 2 diabetes: insulin resistance, fasting blood glucose level and HbA1c levels. These markers were measured by a single blood test while fasting in late adolescence (approximately age 17).

The analysis found:

• Each daily serving of sugary drinks (approx. 8 ounces) during childhood and adolescence among boys was associated with a 34% increase in insulin resistance; a 5.6 milligrams per deciliter (mg/dl) increase in fasting glucose levels; and a 0.12% increase in HbA1c levels in late adolescence.
• Drinking 100% fruit juice throughout childhood and adolescence was linked to a 0.07% increase in HbA1c levels in late adolescence per daily serving of 100% fruit juice among the boys in the study, with only a slight increase in girls of 0.02%.
• Eating fresh fruit during childhood and adolescence did not appear to have a positive or negative effect on the risk of developing Type 2 diabetes among the boys or girls in the study, according to Harnois-Leblanc.

The associations between regularly drinking sugar-sweetened beverage and insulin resistance, fasting blood glucose levels and elevated HbA1c levels among boys persisted when other health, family and social factors were considered. These factors included socioeconomic status; child’s and mother’s body mass index; mother’s age at time of child’s birth; maternal and paternal history of Type 1 or Type 2 diabetes; overall diet quality and other lifestyle behaviors.

“Although several aspects of biology and behaviors differ between boys and girls, I would have expected to also find an association between sugar-sweetened beverages and fruit juice intake and the increases in insulin resistance, glycemia and HbA1c levels in late-adolescent girls. I was also surprised that eating whole fruits did not reduce the levels of these markers of Type 2 diabetes,” Harnois-Leblanc said.

“The next steps are to use more advanced statistical tools to enable us to better understand the potential causal role of sugary drinks and fruit juices, and to examine whether the relationships may also differ among children by race and/or ethnicity.”

Study background and details:

• Researchers analyzed data of children of the 2,128 pregnant women who had children while enrolled in Project Viva. 972 of the children met criteria for inclusion in this study (parent-completed questionnaires at the child’s age-3 examination and no personal or parental history of Type 1 or Type 2 diabetes, assessed separately from parental history of Type 2 diabetes). Of the 972 children, 455 had a fasting blood sample collected at a research visit in late adolescence, Harnois-Leblanc noted.
• 240 of the children in the study were girls and 215 were boys.
• Project Viva is a long-term study of women and their children in eastern Massachusetts that began enrollment in 1999. The study is focused on improving maternal and child health by examining the potential impact of various life and health factors during and after pregnancy on the mother’s health and their children’s health, including a review of diet and nutrition. Children were followed from birth to late adolescence, up to age 20 at most recent follow-up.
• Researchers evaluated the frequency of drinking sugary drinks, fruit juices and eating fresh fruit (based on standard serving sizes) from questionnaires completed by the parent at the child’s age of approximately 3, 8 and 13 years old; and measured fasting blood glucose, insulin and HbA1c levels in late adolescence (average age of 17.4 years).

The study had several limitations. Although it found an association between regularly drinking sugary drinks and fruit juices and the development of markers for Type 2 diabetes, it could not prove that the drinks caused Type 2 diabetes. Additionally, the relatively small number of study participants may have affected the strength of the association found between sugary drinks and fruit juices and the increased risk of developing Type 2 diabetes.

“Diet and cardiometabolic health are complex, with many factors varying over time and interacting in different ways, and this study represents one small piece of this puzzle,” Harnois-Leblanc said.

American Heart Association nutrition committee member Penny M. Kris-Etherton, Ph.D., R.D., FAHA, said, “This study has shown that greater sugar sweetened beverage intake, including fruit juice, throughout childhood and adolescents is associated with higher markers of diabetes risk in late adolescents in boys but not girls. It is striking that many measures of Type 2 diabetes risk were increased in boys at such an early age.”

Kris-Etherton, an emeritus professor of nutritional sciences at Penn State University, was also a co-author of the Association’s 2018 science advisory on low-calorie sweetened beverages and cardiometabolic health.

“Importantly, although fruit intake did not appear to be protective, it nonetheless was not associated with increased Type 2 diabetes risk,” she said. “These findings support the current dietary recommendations of the Association, and many organizations, to limit or eliminate drinking sugar sweetened beverages and instead consume whole fruits, which are high in so many nutrients especially the shortfall nutrients in the average American diet.” (Shortfall nutrients are the vitamins and nutrients that people are missing each day from the foods they eat; long-term deficiencies in some vitamins and nutrients have been linked to adverse health outcomes.)

The health care resource called Know Diabetes by Heart, developed by the American Heart Association and the American Diabetes Association, provides information about preventing heart disease and stroke while living with Type 2 diabetes. The initiative aims to raise awareness and understanding of the link between Type 2 diabetes and cardiovascular disease, provide resources and support to help people better manage their risk for heart disease and stroke, support health care professionals by sharing the latest clinical guidelines and science and engage health systems to improve quality of care for people with Type 2 diabetes.

Co-authors, their disclosures and funding sources are listed in the abstract.

Statements and conclusions of studies that are presented at the American Heart Association’s scientific meetings are solely those of the study authors and do not necessarily reflect the Association’s policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. Abstracts presented at the Association’s scientific meetings are not peer-reviewed, rather, they are curated by independent review panels and are considered based on the potential to add to the diversity of scientific issues and views discussed at the meeting. The findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.

The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers and the Association’s overall financial information are here.

Additional Resources:

• AHA news release: “Gateway” foods like candy, pastries and frozen treats may lead to unhealthy teen eating (Sept. 2022)
• AHA news release: California study finds drinking sugary drinks daily may be linked to higher risk of CVD in women (May 2020)
• AHA health information: Rethink Your Drink: Reducing Sugary Drinks in Your Diet
• AHA health information: What is Diabetes?

What really works to reduce anger

 Venting about a source of anger might feel good in the moment, but it’s not effective at reducing the rage, new research suggests.

Instead, techniques often used to address stress – deep breathing, mindfulness, meditation, yoga or even counting to 10 – have been shown to be more effective at decreasing anger and aggression.

Researchers analyzed over 150 studies involving more than 10,000 participants and found that what really works to reduce anger is lowering physiological arousal – in other words, turning down the heat. Activities that increased arousal overall had no effect on anger, and some activities made it worse – particularly jogging.

“I think it’s really important to bust the myth that if you’re angry you should blow off steam – get it off your chest,” said senior author Brad Bushman, professor of communication at The Ohio State University. “Venting anger might sound like a good idea, but there’s not a shred of scientific evidence to support catharsis theory.

“To reduce anger, it is better to engage in activities that decrease arousal levels,” Bushman said. “Despite what popular wisdom may suggest, even going for a run is not an effective strategy because it increases arousal levels and ends up being counterproductive.”

The study was led by first author Sophie Kjærvik, who completed the review for her Ohio State dissertation. It was published online March 11 in the journal Clinical Psychology Review.

Kjærvik, now a postdoctoral fellow at Virginia Commonwealth University, said the work was inspired in part by the rising popularity of rage rooms that promote smashing things (such as glass, plates and electronics) to work through angry feelings.

“I wanted to debunk the whole theory of expressing anger as a way of coping with it,” she said. “We wanted to show that reducing arousal, and actually the physiological aspect of it, is really important.”

The meta-analytic review was based on 154 studies involving 10,189 participants of different genders, races, ages and cultures. The study selection and analysis were guided by the Schachter-Singer two-factor theory, which assumes that all emotions, including anger, consist of physiological arousal and mental meanings. To get rid of anger, you can work on either of those.

Several previous meta-analytic reviews have focused on changing mental meanings using cognitive behavioral therapy, which works. However, Kjærvik and Bushman said a meta-analytic review on the role of arousal would fill an important gap in understanding how to resolve anger. Their analysis focused on examining both arousal-increasing activities (e.g., hitting a bag, jogging, cycling, swimming) and arousal-decreasing activities (e.g., deep breathing, mindfulness, meditation, yoga).

Results showed that arousal-decreasing activities were effective at fending off the fury in labs and field settings, using digital platforms or in-person instruction, and in group and individual sessions across multiple populations: college students and non-students, people with and without a criminal history, and individuals with and without intellectual disabilities.

Arousal-decreasing activities that were effective at lowering anger across the board included deep breathing, relaxation, mindfulness, meditation, slow flow yoga, progressive muscle relaxation, diaphragmic breathing and taking a timeout.

“It was really interesting to see that progressive muscle relaxation and just relaxation in general might be as effective as approaches such as mindfulness and meditation,” Kjærvik said. “And yoga, which can be more arousing than meditation and mindfulness, is still a way of calming and focusing on your breath that has the similar effect in reducing anger.

“Obviously in today’s society, we’re all dealing with a lot of stress, and we need ways of coping with that, too. Showing that the same strategies that work for stress actually also work for anger is beneficial.”

In contrast, activities that increased arousal were generally ineffective, but also produced a complex range of outcomes. Jogging was the most likely to increase anger, while physical education classes and playing ball sports had an arousal-decreasing effect – suggesting to the researchers that introducing an element of play into physical activity may at least increase positive emotions or counteract negative feelings.

Finding that increasing arousal was not the answer to anger corresponded with previous work led by Bushman that linked venting anger with continued aggression.

“Certain physical activities that increase arousal may be good for your heart, but they’re definitely not the best way to reduce anger,” Bushman said. “It’s really a battle because angry people want to vent, but our research shows that any good feeling we get from venting actually reinforces aggression.”

That being the case, the authors noted that many arousal-decreasing interventions shown to lower the heat of anger are free or inexpensive and easy to access.

“You don’t need to necessarily book an appointment with a cognitive behavioral therapist to deal with anger. You can download an app for free on your phone, or you can find a YouTube video if you need guidance,” Kjærvik said. 

8-hour time-restricted eating linked to a 91% higher risk of cardiovascular death

Research Highlights:

• A study of over 20,000 adults found that those who followed an 8-hour time-restricted eating schedule, a type of intermittent fasting, had a 91% higher risk of death from cardiovascular disease.
• People with heart disease or cancer also had an increased risk of cardiovascular death.
• Compared with a standard schedule of eating across 12-16 hours per day, limiting food intake to less than 8 hours per day was not associated with living longer.

 An analysis of over 20,000 U.S. adults found that people who limited their eating across less than 8 hours per day, a time-restricted eating plan, were more likely to die from cardiovascular disease compared to people who ate across 12-16 hours per day, according to preliminary research presented at the American Heart Association’s Epidemiology and Prevention│Lifestyle and Cardiometabolic Scientific Sessions 2024, March 18- 21, in Chicago. The meeting offers the latest science on population-based health and wellness and implications for lifestyle.

Time-restricted eating, a type of intermittent fasting, involves limiting the hours for eating to a specific number of hours each day, which may range from a 4- to 12-hour time window in 24 hours. Many people who follow a time-restricted eating diet follow a 16:8 eating schedule, where they eat all their foods in an 8-hour window and fast for the remaining 16 hours each day, the researchers noted. Previous research has found that time-restricted eating improves several cardiometabolic health measures, such as blood pressure, blood glucose and cholesterol levels.

“Restricting daily eating time to a short period, such as 8 hours per day, has gained popularity in recent years as a way to lose weight and improve heart health,” said senior study author Victor Wenze Zhong, Ph.D., a professor and chair of the department of epidemiology and biostatistics at the Shanghai Jiao Tong University School of Medicine in Shanghai, China. “However, the long-term health effects of time-restricted eating, including risk of death from any cause or cardiovascular disease, are unknown.”

In this study, researchers investigated the potential long-term health impact of following an 8-hour time-restricted eating plan. They reviewed information about dietary patterns for participants in the annual 2003-2018 National Health and Nutrition Examination Surveys (NHANES) in comparison to data about people who died in the U.S., from 2003 through December 2019, from the Centers for Disease Control and Prevention’s National Death Index database.

The analysis found:

• People who followed a pattern of eating all of their food across less than 8 hours per day had a 91% higher risk of death due to cardiovascular disease.
• The increased risk of cardiovascular death was also seen in people living with heart disease or cancer.
• Among people with existing cardiovascular disease, an eating duration of no less than 8 but less than 10 hours per day was also associated with a 66% higher risk of death from heart disease or stroke.
• Time-restricted eating did not reduce the overall risk of death from any cause.
• An eating duration of more than 16 hours per day was associated with a lower risk of cancer mortality among people with cancer.

“We were surprised to find that people who followed an 8-hour, time-restricted eating schedule were more likely to die from cardiovascular disease. Even though this type of diet has been popular due to its potential short-term benefits, our research clearly shows that, compared with a typical eating time range of 12-16 hours per day, a shorter eating duration was not associated with living longer,” Zhong said.

“It’s crucial for patients, particularly those with existing heart conditions or cancer, to be aware of the association between an 8-hour eating window and increased risk of cardiovascular death. Our study’s findings encourage a more cautious, personalized approach to dietary recommendations, ensuring that they are aligned with an individual’s health status and the latest scientific evidence,” he continued. “Although the study identified an association between an 8-hour eating window and cardiovascular death, this does not mean that time-restricted eating caused cardiovascular death.”
Study details and background:

• The study included approximately 20,000 adults in the U.S. with an average age of 49 years.
• Study participants were followed for a median length of 8 years and maximum length of 17 years.
• The study included data for NHANES participants who were at least 20 years old at enrollment, between 2003-2018, and had completed two 24-hour dietary recall questionnaires within the first year of enrollment.
• Approximately half of the participants self-identified as men, and half self-identified as women. 73.3% of the participants self-identified as non-Hispanic white adults, 11% self-identified as Hispanic adults, 8% self-identified as non-Hispanic Black adults and 6.9% of adults self-identified as another racial category, including mixed-race adults and adults of other non-Hispanic races.

The study’s limitations included its reliance on self-reported dietary information, which may be affected by participant’s memory or recall and may not accurately assess typical eating patterns. Factors that may also play a role in health, outside of daily duration of eating and cause of death, were not included in the analysis.

Future research may examine the biological mechanisms that underly the associations between a time-restricted eating schedule and adverse cardiovascular outcomes, and whether these findings are similar for people who live in other parts of the world, the authors noted.

“Overall, this study suggests that time-restricted eating may have short-term benefits but long-term adverse effects. When the study is presented in its entirety, it will be interesting and helpful to learn more of the details of the analysis,” said Christopher D. Gardner, Ph.D., FAHA, the Rehnborg Farquhar Professor of Medicine at Stanford University in Stanford, California, and chair of the writing committee for the Association’s 2023 scientific statement, Popular Dietary Patterns: Alignment with American Heart Association 2021 Dietary Guidance. 

“One of those details involves the nutrient quality of the diets typical of the different subsets of participants. Without this information, it cannot be determined if nutrient density might be an alternate explanation to the findings that currently focus on the window of time for eating. Second, it needs to be emphasized that categorization into the different windows of time-restricted eating was determined on the basis of just two days of dietary intake,” he said.

“It will also be critical to see a comparison of demographics and baseline characteristics across the groups that were classified into the different time-restricted eating windows – for example, was the group with the shortest time-restricted eating window unique compared to people who followed other eating schedules,  in terms of weight, stress, traditional cardiometabolic risk factors or other factors associated with adverse cardiovascular outcomes? This additional information will help to better understand the potential independent contribution of the short time-restricted eating pattern reported in this interesting and provocative abstract.”

Co-authors, their disclosures and funding sources are listed in the abstract.

Statements and conclusions of studies that are presented at the American Heart Association’s scientific meetings are solely those of the study authors and do not necessarily reflect the Association’s policy or position. The Association makes no representation or guarantee as to their accuracy or reliability. Abstracts presented at the Association’s scientific meetings are not peer-reviewed, rather, they are curated by independent review panels and are considered based on the potential to add to the diversity of scientific issues and views discussed at the meeting. The findings are considered preliminary until published as a full manuscript in a peer-reviewed scientific journal.

The Association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific Association programs and events. The Association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and biotech companies, device manufacturers and health insurance providers and the Association’s overall financial information are here.

Additional Resources:

• AHA news release: Reducing total calories may be more effective for weight loss than intermittent fasting (January 2023)
• AHA news release: 10 popular diets scored for heart-healthy elements; some need improvement (April 2023)
• AHA news release: New look at nutrition research identifies 10 features of a heart-healthy eating pattern (November 2021)
• AHA healthy eating tips: Eat Smart

Small amounts of licorice raise blood pressure

 

It is known that large amounts of liquorice cause high blood pressure. A study by researchers at Linköping University, Sweden, now shows that even small amounts of liquorice raise blood pressure. The individuals who react most strongly also show signs of strain on the heart.

Liquorice is produced from the root of plants of the Glycyrrhiza species and has long been used as a herbal remedy and flavouring. However, it is known that eating liquorice can also raise blood pressure. This is mainly due to a substance called glycyrrhizic acid that affects the body’s fluid balance through effects on an enzyme in the kidney. High blood pressure, in turn, increases the risk of cardiovascular disease.

Both the European Union and the World Health Organization have concluded that 100 mg of glycyrrhizic acid per day is probably safe to eat for most individuals. But some people eat more liquorice than that. The Swedish Food Agency has estimated that 5 per cent of Swedes have an intake higher than this level.

In the current study, published in The American Journal of Clinical Nutrition, researchers at Linköping University wanted to test whether the limit stated as likely safe actually is so or not.

It is not easy to know how much glycyrrhizic acid is in the liquorice you eat, as its concentration in different liquorice products varies greatly. This variation may depend on factors such as origin, storage conditions and liquorice root species. In addition, the amount of glycyrrhizic acid is not indicated on many products. The Linköping University study is the first to have carefully measured the amount of glycyrrhizic acid in the liquorice that was tested, while being randomised and having a control group.

In the study, 28 women and men aged 18–30 were instructed to eat liquorice, or a control product that did not contain any liquorice, over two periods of time. The control product instead contained salmiak, which gives salty liquorice its flavour. The liquorice weighed 3.3 grammes and contained 100 mg of glycyrrhizic acid, that is, the amount indicated as likely safe for most people to eat daily. Participants were randomly assigned to eat either liquorice or the control product for two weeks, take a break for two weeks, and then eat the other variety for two weeks. This enabled the researchers to compare the effect of both varieties in the same person. The study participants were asked to measure their blood pressure at home every day. At the end of each intake period, the researchers measured levels of various hormones, salt balance, and heart workload.

“In the study, we found that a daily intake of liquorice containing 100 mg glycyrrhizic acid raised blood pressure in young healthy people. This hasn’t previously been shown for such small amounts of liquorice,” says Peder af Geijerstam, doctoral student at the Department of Health, Medicine and Caring Sciences at Linköping University, general practitioner, and lead author of the study.

When the participants ate liquorice, their blood pressure increased by an average of 3.1 mmHg. The researchers also measured two hormones that are affected by liquorice and that regulate fluid balance: renin and aldosterone. The levels of both of these decreased when eating liquorice. The quarter of the study participants who were most sensitive, based on their levels of the hormones renin and aldosterone decreasing the most after eating liquorice, also gained slightly in weight, most likely due to an increased amount of fluid in the body. This group also had elevated levels of a protein that the heart secretes more of when it needs to work harder to pump around the blood in the body, N-terminal pro-brain natriuretic peptide (NT-proBNP). This suggests increased fluid volume and heart workload in the individuals most sensitive to the effects of liquorice.

“Our results give reason to be more cautious when it comes to recommendations and labelling for food containing liquorice,” says Fredrik Nyström, professor at the same department, who was responsible for the study.

The study was funded with support from, among others, The Strategic Research Network in Circulation and Metabolism (LiU-CircM) at Linköping University, The National Research School in General Practice at Umeå University, King Gustaf V and Queen Victoria Freemason Foundation and Region Östergötland.

Article: A low dose of daily licorice intake affects renin, aldosterone, and home blood pressure in a randomized crossover trial, Peder af Geijerstam, Annelie Joelsson, Karin Rådholm and Fredrik Nyström, (2024). American Journal of Clinical Nutrition, Vol. 119 No. 3-682-692. Published online 20 January 2024, doi: 10.1016/j.ajcnut.2024.01.011

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