Breastfeeding protects against type 1 diabetes but cow’s milk raises risk

New research presented at the Annual Meeting of the European Association for the Study of Diabetes (EASD), held online this year, shows that breastfeeding is associated with a lower risk of developing type 1 diabetes (T1D).  Drinking more than two or three glasses of cow’s milk a day in childhood, however, is linked with higher odds of developing T1D.

In T1D, the immune system attacks and destroys the insulin-producing cells in the pancreas.  This prevents the body from producing enough of the hormone to properly regulate blood sugar levels.

What triggers the immune system’s attack is unknown but is thought to involve a combination of a genetic predisposition and an environmental trigger such as a virus or foodstuff. In some cases, the condition may develop in people without a genetic predisposition. 

Incidence of T1D, the most common form of diabetes in children, is increasing worldwide.  The number of diagnoses in young people is rising by an estimated 3.4% annually in Europe and 1.9% in the U.S.

“Type 1 diabetes is a serious condition that requires lifelong treatment,” says Ms Anna-Maria Lampousi of Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden, who led the research. “Over time, high blood sugar levels can damage the heart, eyes, feet and kidneys and can shorten life expectancy.

 

“Learning more about the causes is key to preventing the type 1 diabetes – and its complications. 

 

“The identification of foodstuffs and other environmental triggers which can be modified would be particularly valuable.”

Numerous foodstuffs have been linked to islet autoimmunity – the attack on the insulin-producing cells – and T1D but none of the associations have been firmly established and the existence of a link remains controversial.

In the first study of its kind, Ms Lampousi and colleagues at the Karolinska Institutet carried out a systematic review and meta-analysis of the existing research to identify which foods have been consistently linked to T1D.

The Medline, Embase and Cochrane Library databases were searched from formation until October 2020, for studies on diet, T1D and islet autoimmunity.

Of the 5,935 studies identified, 152 were eligible for inclusion. The analysis produced estimates for how much 27 dietary components increased or reduced the risk of developing T1D.  This included foods eaten by the mother in pregnancy and foods consumed in infancy and childhood, as well as being breastfed.

Babies that were breastfed for longer and those that were breastfed exclusively were less likely to develop T1D.

Those breastfed for at least 6-12 months were less than half as likely (61% less likely) to develop T1D than those breastfed for less.  Those given only breast milk for the first 2-3 months were 31% less likely to develop the condition than those who weren’t exclusively breastfed.

The researchers say that breastfeeding promotes the maturation of baby’s immune system.  Plus, breast milk enhances the baby’s gut microbiota – the bacteria, fungi and other microorganisms that live in the digestive tract and help regulate the immune system.

Higher consumption of cow’s milk and dairy products such as butter, cheese, yoghurt and ice-cream during childhood (under 15 years old) was associated with a higher risk of islet autoimmunity and T1D.

For example, those who drank at least two to three glasses of cow’s milk (one glass = around 200ml) a day were 78% more likely to be develop T1D than those who consumed less than this amount of milk.

It isn’t known what is behind the association but some research has suggested that amino acids (the building blocks of proteins) in cow’s milk can trigger the immune system’s attack on the insulin-producing cells of the pancreas.

Early introduction of cow’s milk to the diet was also associated with a higher risk of T1D.  Those who started drinking cow’s milk at two or three months old were 31% less likely to develop T1D than those who started consuming it earlier.

Later introduction of gluten to the diet more than halved the odds of developing T1D. Infants who started eating gluten-containing foods, such as cereal, bread, pastries, biscuits and pasta, at 3-6 months old were 54% less likely to develop T1D than those introduced to the foods earlier.

Waiting until a child was four to six months old to introduce fruit to their diet was associated with a 53% reduction in their likelihood of developing T1D.

The study’s authors say it isn’t clear if delaying introduction to these foods directly protects against T1D or if the infants are benefiting from being breastfed for longer.

Age at introduction to formula milk, meat and vegetables was not linked to risk of T1D.  Nor were there any associations between a mother’s intake of gluten and vitamin D in pregnancy and her child’s odds of the condition.

Ms Lampousi concludes: “Diet in infancy and childhood may influence the risk of type 1 diabetes. The strongest findings were for the beneficial effects of breastfeeding and the harmful effects of early introduction to cow’s milk, gluten and fruit.

“However, most of the evidence to-date is of limited quality and further high-quality research is necessary before any specific dietary recommendations can be made.”

Study highlights the importance of heart health for preventing diabetes

 Heart healthy middle-aged adults are less likely to develop type 2 diabetes during their lifetime, according to a study published on World Heart Day in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).1

The research found that the importance of favourable cardiovascular health was apparent regardless of an individual’s genetic likelihood of developing type 2 diabetes. Favourable cardiovascular health was defined as having a healthy body weight, blood pressure, and cholesterol, not smoking, eating a balanced diet, and being physically active.

It is estimated that 463 million adults have diabetes and that 10% of global health expenditure is spent on the condition (USD 760 billion).2

Study author Dr. Fariba Ahmadizar of Erasmus University Medical Centre, Rotterdam, the Netherlands, said: “While genetics do contribute to the probability of developing type 2 diabetes, the findings indicate that maintaining healthy lifestyle habits, and especially having a healthy body weight, can help lower the lifetime risk of the condition.”

The study included 5,993 participants of the population-based Rotterdam Study who were free of type 2 diabetes at baseline. The average age was 69 years and 58% were women. Participants received a cardiovascular health score of 0 to 12 according to body mass index, blood pressure, blood cholesterol, smoking status, diet and physical activity at baseline, with higher scores corresponding to better cardiovascular health. Participants were then divided into three categories of cardiovascular health according to their score: poor (0-5), intermediate (6-7) and ideal (8-12).

To assess genetic predisposition to type 2 diabetes, the researchers used 403 independent genetic variants related to the condition to calculate a genetic risk score. Participants were then categorised as low, intermediate or high genetic risk according to their score.

A total of 869 individuals developed type 2 diabetes during 69,208 person-years of follow-up. The researchers estimated and compared the lifetime risk for type 2 diabetes within the cardiovascular health and genetic risk categories.

Looking at cardiovascular health alone, the researchers found that the remaining lifetime risk of type 2 diabetes was lower in those with better heart health. For example, at age 55, participants with ideal cardiovascular health had a 22.6% risk of developing type 2 diabetes in their lifetime, compared to 28.3% and 32.6% risks for those with intermediate and poor cardiovascular health, respectively.

When genetic risk was taken into account, the lifetime risk for type 2 diabetes was still lower in those with better cardiovascular health. At age 55, for example, the remaining lifetime risk of diabetes in the high genetic risk group was 23.5% for those with ideal cardiovascular health, compared to 33.7% and 38.7% for those with intermediate and poor cardiovascular health, respectively. The same relationships were seen within the low and intermediate genetic risk groups.

Dr. Ahmadizar said: “Our results highlight the importance of favourable heart health in preventing type 2 diabetes among middle-aged adults regardless of whether they are genetically at high or low risk of the condition. In other words, a healthy lifestyle is associated with a significantly lower risk of type 2 diabetes within any genetic risk category. The findings applied equally to men and women and indicate that healthy habits in midlife are an effective strategy for avoiding diabetes later on.”

Healthy obesity is not a harmless condition

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Adults who are obese but appear healthy (without common metabolic abnormalities such as high blood pressure, abnormal blood fats, or diabetes) are not at greater risk of heart attack, stroke, or cardiovascular death than healthy individuals of normal weight, but they are around 33% more likely to develop heart failure and the heart rhythm condition, atrial fibrillation, according to a nationwide study from France that followed nearly 3 million hospital patients (aged 18 and older) for at least 5 years.

The findings, being presented at the Annual Meeting of the European Association for the Study of Diabetes (EASD), held online this year (27 Sept-1 Oct), also indicate that heart failure risk was especially high in metabolically unhealthy individuals, regardless of their weight.

“This new and best available evidence tells us that on a population level, the idea that large numbers of people can be obese but metabolically healthy is simply untrue”, says lead author Dr Laurent Fauchier from Centre Hospitalier Universitaire Trousseau, Tours, France. “Encouraging weight loss in people with obesity, regardless of whether or not they are metabolically healthy, will help prevent atrial fibrillation and heart failure. Our findings also highlight the importance of preventing poor metabolic health, and suggest that even normal weight individuals may benefit from early behavioural and medical management to improve their diet and increase physical activity in order to guard against stroke.”

Obesity (BMI of more than 30kg/m²) affects almost all of the cardiovascular disease risk factors, particularly those related to metabolic syndrome including high blood pressure, poor blood sugar control or diabetes, and abnormal blood fats, which double the risk of cardiovascular disease such as heart attacks and stroke. However, some people with obesity seem to be free of these metabolic abnormalities—estimates suggest as many as a third of obese people might be metabolically healthy.

Whether this so called ‘metabolically health obesity’ is associated with a higher risk of cardiovascular disease has been debated for many years, and research so far has produced conflicting results. It remains unclear how weight and metabolic status affect the development of different cardiovascular events in both healthy and obese individuals, due to limitations of previous studies including: lack of analyses of different cardiovascular disease events and the lack of adjustment for confounding factors such as age, sex and history of smoking.

To investigate this further, researchers analysed medical records of all patients admitted to French hospitals between January and December 2013 with at least 5 years of complete follow-up data. Around 2.9 million adults (of whom 272, 838 [9.5%] had obesity) who had not had a major cardiovascular event (ie, heart attack, ischaemic stroke, or heart failure) and were not underweight at the start of the study were divided into groups by BMI category and metabolic health (whether they had three metabolic abnormalities—high blood pressure, unusually high levels of cholesterol and other fats in the blood, or diabetes). Participants who had none of these abnormalities were classed as having ‘metabolically healthy obesity’. The researchers adjusted for several factors that could have influenced the results including age, sex, and smoking status.

During an average follow-up of 5 years, 510,439 new major cardiovascular events were recorded, including 77,924 heart attacks, 391,637 cases of heart failure, 84,042 strokes, and 100,633 cardiovascular disease deaths. In addition, 257,287 patients developed atrial fibrillation.

The analysis found that people with metabolically healthy obesity had a 22% higher risk of having a new major cardiovascular event than people of normal weight with no metabolic abnormalities. They also had a 34% increased risk of developing heart failure and 33% greater likelihood of developing atrial fibrillation – which can substantially impair quality of life and lead to stroke. However, they did not have a higher risk of heart attack, stroke, or cardiovascular death then metabolically healthy people of normal weight.

Importantly, the analysis also showed that men face higher risks than women—compared to normal weight men with no metabolic abnormalities, men with metabolically healthy obesity had a 61% higher risk of cardiovascular events; while women with metabolically healthy obesity were 50% less likely to suffer heart attack than those of normal weight.

Higher fruit and veg intake linked to better mental health in secondary schoolchildren

Nutritious breakfast and lunch linked to emotional wellbeing in pupils across age spectrum
Include good nutrition in public health strategies for kids’ mental health, urge researchers

Higher fruit and veg intake is significantly associated with better mental health in secondary schoolchildren, while a nutritious breakfast and lunch is linked to emotional wellbeing in pupils across the age spectrum, finds research published in the online journal BMJ Nutrition Prevention & Health.

The findings prompt the researchers to call for the inclusion of good nutrition in public health strategies to maximise kids’ mental health.

Poor mental health is a major issue for young people, with survey data indicating that its prevalence is rising. The evidence suggests that teen mental health problems often persist into adulthood, leading to poorer life outcomes and achievement.

It’s not clear if school pupils’ dietary choices might be linked to their mental health. To explore this further, the researchers drew on responses from over 50 schools in Norfolk, England, to The Norfolk Children and Young People Health and Wellbeing Survey 2017.

In total, 10,853 pupils completed the survey on their mental health and nutrition: 9% of Norfolk primary school children in the target year groups (9-11 year olds); 22% of secondary school pupils; and around 6% of young people in years 12 and 13 (17-18 year olds).

Dietary questions aimed to explore fruit and vegetable intake, as well as type of breakfast and lunch eaten; alcohol intake; eligibility for free school meals; and satisfaction with weight.

Background and general health information was also collected; as well as a range of other factors, ranging from whether they had their own bedroom and bed to whether they felt safe at school and at home, including whether they had witnessed violence or arguing at home. Mental health was assessed using validated age appropriate measures.

Data from 7570 secondary school and 1253 primary school pupils were included in the final analysis. The average mental health score was 46.6 out of 70 for secondary school pupils and 46 out of 60 for primary school pupils.

Only around 1 in 4 (25%) secondary school pupils and 28.5% of primary school pupils reported eating the recommended 5 portions of fruit and veg a day, with 10% and 9%, respectively, eating none.

Around 1 in 5 (21%) secondary school pupils and 1 in 8 (12%) primary school pupils consumed only a non-energy drink or nothing at all for breakfast, while around 1 in 8 secondary school children (11.5%) ate no lunch.

Higher combined fruit and veg intake was significantly associated with higher mental health scores; the higher the intake, the higher was the score.

Compared with secondary school pupils eating no fruit or veg, eating one or two daily portions was associated with a score 1.42 units higher, while eating 3 or 4 portions was associated with a score 2.34 units higher. Eating 5 or more portions was associated with a score 3.73 units higher.

Breakfast type was also significantly associated with mental wellbeing. Compared with a conventional breakfast, such as toast, porridge, cereal, yoghurt, fruit, or a cooked breakfast, eating only a snack or breakfast bar was associated with a score that was 1.15 units lower.

Consumption of energy drinks as a breakfast substitute was associated with particularly low mental health scores, and lower than those for children eating no breakfast at all.

Just having nothing more than an energy drink was associated with a score 3.14 units lower; not eating any breakfast at all was associated with a score 2.73 units lower.

Similarly, lunch type was also significantly associated with mental health scores. Not eating any lunch was associated with a score 2.95 units lower than when eating a packed lunch.

Among primary school pupils, eating only a snack for breakfast was associated with a score 5.50 units lower while consuming only a non-energy drink was associated with a score 2.67 units lower than those eating a conventional breakfast. Not eating any breakfast was associated with a score 3.62 units lower. 

And compared with eating a packed lunch, eating school food was associated with a score 1.27 units lower, although this wasn’t statistically significant; having no lunch was associated with a score 6.08 units lower, although there were only a few children in this group, caution the researchers.

This is an observational study, and as such, can’t establish cause, added to which there was no detailed nutritional information in the survey data and the study relied on children’s subjective assessments.

But, the researchers argue: “The importance of good quality nutrition for childhood growth and development is well established. Our study adds to this prior evidence the finding that nutrition is also highly relevant to childhood mental wellbeing. 

The difference in mental wellbeing between children who ate the most fruit and vegetables and those who ate the least was of a similar scale to those children who reported daily, or almost daily, arguing or violence at home, they point out.

“As a potentially modifiable factor, both at an individual and societal level, nutrition may therefore represent an important public health target for strategies to address childhood mental wellbeing.”

"This study provides the first insights into how fruit and vegetable intake affects children's mental health, and contributes to the emerging evidence around ‘food and mood’," comments Sumantra Ray, executive director of the NNEdPro Global Centre for Nutrition and Health.* 

“The findings are timely, not only because of  the impact the pandemic has had on mental wellbeing, food security, and diet quality, especially in school children, but also in light of the recently published National Food Strategy for England, which highlighted gaps in school meal provision.” 

Drinks that contain the artificial sweetener sucralose may increase food cravings and appetite

A synthetic aftertaste might not be the only side effect of switching to diet soda, especially if you’re trying to lose weight.

Drinks that contain the artificial sweetener sucralose may increase food cravings and appetite in woman and people who are obese, according to a new study by led by researchers at the Keck School of Medicine of USC.

Just published in JAMA Network Open, the study is one of the largest to-date to examine the effects of an artificial sweetener, also called a nonnutritive sweetener (NNS), on brain activity and appetite responses in different segments of the population. 

Artificial sweeteners: A controversial topic

More than 40 percent of adults in the U.S. currently use NNSs as a calorie-free way to satisfy a sweet tooth, and, in some cases, accomplish weight loss goals. Despite their prevalence, the health consequences of artificial sweeteners are still highly debated, with no clear consensus on their effects on appetite, glucose metabolism and body weight. 

“There is controversy surrounding the use of artificial sweeteners because a lot of people are using them for weight loss,” said Kathleen Page, MD, the study’s corresponding author and an associate professor of medicine at the Keck School of Medicine. “While some studies suggest they may be helpful, others show they may be contributing to weight gain, type 2 diabetes and other metabolic disorders. Our study looked at different population groups to tease out some of the reasons behind those conflicting results.”

To study the effects of NNSs, Page and her colleagues studied 74 participants who, during the course of three different visits, consumed 300 milliliters of a drink sweetened with sucrose (table sugar), a drink sweetened with the NNS sucralose or water as a control. In the two hours that followed, the researchers measured three things: activation of regions of the brain responsible for appetite and food cravings in response to pictures of high calorie foods like a burger and donut using an imaging technique called functional magnetic resonance imaging (fMRI); levels of glucose (blood sugar), insulin, and other metabolic hormones in the blood; and the amount of food consumed at a snack buffet provided at the end of each session. The study group comprised an equal number of male and females who were identified as healthy weight, overweight, or obese, allowing researchers to explore potential differences between population groups.

Artificial sweeteners may make certain people feel more hungry

Imaging studies showed increased activity in regions of the brain responsible for food cravings and appetite in both women and people who were obese after they consumed sucralose-containing drinks when compared to drinks containing real sugar. 

The study also showed an across-the-board decrease in levels of hormones that tell the body ‘I feel full’ after participants drank the sucralose-containing drink compared to the sucrose-containing drink, suggesting artificially sweetened beverages may not be effective in suppressing hunger.

Finally, after female participants drank the sucralose-containing drink they ate more at the snack buffet than after they drank the sucrose-containing drink, whereas snack food intake did not differ for male participants. Page recommended interpreting these finding with caution, since all participants fasted overnight before the study and were likely more hungry than usual.

“Our study starts to provide context for the mixed results from previous studies when it comes to the neural and behavioral effects of artificial sweeteners,” Page said. “By studying different groups we were able to show that females and people with obesity may be more sensitive to artificial sweeteners. For these groups, drinking artificially sweetened drinks may trick the brain into feeling hungry, which may in turn result in more calories being consumed.”

Intense workouts before bedtime won’t guarantee a good night’s rest, new research shows

Exercise is often associated positively with a good night’s sleep. But if done at certain times of day, or shortly before bedtime, it can also alter how we sleep. And yet despite years of study, there is still much we do not know about how the two are linked.

A new meta-analysis by Concordia researchers published in the journal Sleep Medicine Reviews assessed data from 15 published studies to see how a single session of intense exercise affects young and middle-aged healthy adults in the hours prior to bedtime.

And while no two bodies are the same, the researchers did find that the combination of factors would interact to enhance or modulate the effects of exercise on sleep.

“When we reviewed the literature on this work, we found that there were a lot of mixed results,” says Melodee Mograss, a cognitive neuropsychologist and researcher at the PERFORM Sleep Lab. “Some depended on the time of exercise, others on the fitness level of a study’s participants, or even the type of exercise.”

Timing is (almost) everything

Emmanuel Frimpong, a postdoctoral fellow at the Sleep, Cognition and Neuroimaging Laband the study’s lead author, says their principal goal was to assess whether high-intensity exercise affected sleep afterwards and to see which factors might influence that sleep.

The researchers combined data from the 15 studies and ran a statistical analysis that examined variables such as the timing of exercise — early evening or late evening — and the hours between the cessation of exercise and bedtime — less than two hours, around two hours, and two to four hours.

Additional variables included the fitness level of the participants (sedentary or physically active), the threshold intensity and the duration of the exercises. They also analyzed how specific types of exercise influenced sleep.

“Overall, our analysis showed that when exercise ended two hours before bedtime, there were sleep benefits, including the promotion of sleep onset and increased sleep duration,” says Frimpong.

“On the other hand, when exercise ended less than two hours before bedtime, sleep was negatively impacted. It took longer for participants to fall asleep and sleep duration decreased.”

Further analysis provided the following results:

• Early evening high-intensity exercise promoted sleep onset and improved sleep duration, especially when performed by sedentary subjects.
• High-intensity exercise performed between 30 and 60 minutes also improved onset and duration.
• Cycling exercises were found to benefit participants most in terms of onset and deep sleep.
• However, high intensity exercise, regardless of timing, contributed to a slight decrease in the rapid-eye-movement (REM) stage of sleep, the sleep stage which is commonly associated with dreaming experiences. Studies suggests that decreases in REM sleep can impact cognitive tasks negatively if the information is complex and emotionally stimulating but not if the information is easy or neutral.

Different effects for early risers and night owls

“Based on our review, for healthy, young and middle-aged adults with no history of sleep disorders, evening exercises should be performed in the early evening if possible,” concludes Frimpong.

“Individuals should also keep to a consistent exercise schedule, as exercising at different times of the evening could cause sleep disturbances. Individuals should also consider whether they are morning people or evening people. High intensity exercise performed late in the evening can result in sleep disturbance for morning-type people.

“And lastly, sleep hygiene strategies should also be carried out, such as taking a shower between the cessation of exercise and bedtime and avoiding eating heavy meals or drinking a lot of water before going to bed.”

Low-carb diet improves cardiometabolic risk profile

 Low-carbohydrate diets are popular for weight loss and diabetes control. However, for most of the past 50 years, medical and public health experts have instead embraced low-fat diets, concerned about the health effects of saturated fats on cardiovascular risk factors like LDL cholesterol. As a result, low-fat and fat-free foods have proliferated — many of them high in processed carbohydrates.

A clinical trial led by Boston Children’s Hospital, one of the largest and most rigorous study of its kind, now challenges that thinking. It demonstrates that low-carb diets — even though higher in saturated fat — produce better cardiovascular and metabolic profiles than low-fat, higher-carb diets. The findings were published online September 28 by the American Journal of Clinical Nutrition.

“Surprisingly, the low-carb diet did not adversely affect LDL (“bad”) cholesterol, despite having saturated fat levels far in excess of current recommendations,” says David Ludwig, MD, PhD, who led the study together with first author Cara Ebbeling, PhD.

Carbohydrates, insulin resistance, and disease

While high LDL cholesterol is the traditional risk factor for heart disease, a group of other risk factors is increasingly being tied to both heart disease and diabetes: high triglycerides, low HDL (“good”) cholesterol, high blood pressure, high blood sugar, chronic inflammation, a tendency toward blood clotting, and fatty liver.

These factors are hallmarks of metabolic syndrome, also known as insulin resistance syndrome because the body’s cells lose their sensitivity to signals from insulin to take up sugars from the blood. Mounting evidence implicates increased consumption of carbohydrates, especially highly processed carbs like refined grains and added sugars.

As people switch to low-fat diets, carbohydrates make up more and more of what we eat. This is one reason why metabolic syndrome is rising — while obesity remains an epidemic.

Comparing low-carb and low-fat diets

Ebbeling and Ludwig wanted to test the idea that a low-carb diet would improve people’s cardiometabolic risk profiles as compared with a low-fat diet. In partnership with Framingham State University, they enrolled 164 adults with overweight or obesity who had lost 10-14 percent of their body weight on a reduced-calorie diet.

The participants then followed one of three weight-loss maintenance diets for five months, assigned at random:

• Low-carb diet (20 percent carbs, 60 percent fat, 20 percent protein)
• Moderate-carb diet (40 percent carbs, 40 percent fat, 20 percent protein)
• High-carb diet (60 percent carbs, 20 percent fat, 20 percent protein)

All participants received fully prepared, customized meals that they could eat in cafeterias or take to go. This protocol ensured that they stuck to the diets, unlike many other studies that just give people nutritional guidelines.

“We had a commercial food service provide more than 100,000 meals, tailored to each participant’s caloric needs,” says Ebbeling. “The meals were designed to keep participants at the same weight throughout the five months, so that everything we saw in this study would be independent of weight loss.”

In all three diets, 35 percent of the fat consumed was saturated fat. This meant that the low-carb diet had three times the saturated fat of the high-carb diet (21 vs. 7 percent), well above the range of current recommendations.

But of note, the low-carb diet wasn’t a ketogenic diet — a restrictive very-low-carb, very high-fat diet in which carbs typically constitute less than 10 percent of calories.  

“The less restricted low-carb diet we studied is pragmatic,” says Ludwig. “There’s still room for whole fruits, all the non-starchy vegetables you want, beans, and small amounts of grains.”

The benefits of restricting carbs

As compared with higher-carb, lower-fat diets, the low-carb diet improved the profiles of a range of blood lipids related to cardiovascular disease and insulin resistance. It also increased adiponectin, a hormone made by fat cells that promotes sensitivity to insulin and protects against atherosclerosis (the formation of fatty plaques in the arteries).

“We also found that the low-carb diet reduced lipoprotein(a), an under-appreciated risk factor for atherosclerosis, heart disease, and stroke that previously was not thought to be influenced by diet,” says Ludwig.

Specifically, lipoprotein(a) fell by an average of nearly 15 percent with the low-carb diet, versus a 2 percent reduction with the moderate-carb diet and a slight increase of 0.2 percent with the high-carb diet.

In a related, recently published commentary, Ludwig, Ebbeling, and their colleagues specifically implicate refined carbohydrates — not excess calories — as fueling the obesity epidemic. Foods like white bread, white rice, most breakfast cereals, and highly-processed snack foods cause spikes in blood sugar and insulin that slow metabolism, increase hunger, and set the stage for weight gain, the authors write. 

What about children?

Although the clinical trial was done in adults, low-carb diets are appropriate for children, says Ludwig. Children coming to the Optimal Wellness for Life (OWL) clinic at Boston Children’s may be prescribed diets with reduced proportions of carbohydrates depending on their individual needs. Pediatric cardiologists are also starting to embrace low-carb diets.

“The roots of heart disease are planted in childhood,” Ludwig says. “A moderate change now could lead to a huge benefit when kids reach middle age, and if you establish healthy habits early, they’re more likely to stick. We’re trying to shift the lifetime trajectory of heart disease risk.”

Walking is good. But moderate-vigorous exercise boosts fitness three times more

With help from 2,000 Framingham Heart Study participants, BU researchers studied how much being sedentary, walking, and routine exercise impacts fitness

Peer-Reviewed Publication

Exercise is healthy. That is common knowledge. But just how rigorous should that exercise be in order to really impact a person’s fitness level? And, if you sit all day at a desk, but still manage to get out and exercise, does that negate your six, seven, or eight hours of sedentary behavior? 

These were the sort of questions Matthew Nayor and his team at Boston University School of Medicine set out to answer in the largest study to date aimed at understanding the relationship between regular physical activity and a person’s physical fitness. 

Their findings, which appear in the European Heart Journal, came from a study of approximately 2,000 participants from the Framingham Heart Study. They found that bouts of moderate to vigorous exercise—working out with more intensity than, say, walking 10,000 steps over the course of a day—drastically improved a person’s fitness, compared to milder forms of exercise.

“By establishing the relationship between different forms of habitual physical activity and detailed fitness measures,” Nayor says, “we hope that our study will provide important information that can ultimately be used to improve physical fitness and overall health across the life course.” 

Nayor, a BU School of Medicine assistant professor of medicine, is also a cardiologist specializing in heart failure at Boston Medical Center, BU’s primary teaching hospital and the city of Boston’s safety net hospital. In the Q&A below, Nayor explains the results of the study and discusses what people should know about exercise in relation to fitness.

 

People might see a study that finds that moderate to vigorous activity is the best way to improve fitness, and think, isn’t that obvious? But your research is more specific than that, so can you tell us what was surprising or perhaps revealing about your work?

Matthew Nayor: While there is a wealth of evidence supporting the health benefits of both physical activity and higher levels of fitness, the actual links between the two are less well understood, especially in the general population (as opposed to athletes or individuals with specific medical problems). Our study was designed to address this gap, but we were also interested in answering several specific questions. 

First, we wondered how different intensities of physical activity might lead to improvements in the body’s responses during the beginning, middle, and peak of exercise. We expected to find that higher amounts of moderate-vigorous physical activity, like exercise, would lead to better peak exercise performance, but we were surprised to see that higher intensity activity was also more efficient than walking in improving the body’s ability to start and sustain lower levels of exertion.

We were also uncertain whether the number of steps per day or less time spent sedentary would truly impact peak fitness levels. We found that they were associated with higher fitness levels in our study group. These findings were consistent across categories of age, sex, and health status, confirming the relevance of maintaining physical activity [throughout the day] for everyone.

Second, we asked, how do different combinations of the three activity measures contribute to peak fitness? Intriguingly, we observed that individuals with higher-than-average steps per day, or moderate-vigorous physical activity, had higher-than-average fitness levels, regardless of how much time they spent sedentary. So, it seems that much of the negative effect that being sedentary has on fitness may be offset by also having higher levels of activity and exercise.

Our third question was, are more recent physical activity habits more important than previous exercise habits in determining current levels of fitness? Interestingly, we found that participants with high activity values at one assessment and low values at another assessment, performed eight years apart, had equivalent levels of fitness, whether or not the high value coincided with the fitness testing. This suggests that there may be a “memory effect” of previous physical activity on current levels of fitness.

 

A lot of people wear Fitbits or their Apple Watch to track their daily step counts these days, and they might think, hey, I did 10,000 steps today! But it sounds like your research suggests that while walking is valuable, it’s not the same as exercise?

Well, I think we need to be a little careful with this interpretation. It is important to note that higher steps were associated with higher fitness levels in our study, which is reassuring, especially for older individuals or those with medical conditions that may prohibit higher levels of exertion. There is also ample evidence from other studies that higher step counts are associated with a host of favorable health outcomes. So, I would not want to dissuade people from following their step counts. 

However, if your goal is to improve your fitness level, or to slow down the inescapable decline in fitness that occurs with aging, performing at least a moderate level of exertion [through intentional exercise] is over three times more efficient than just walking at a relatively low cadence.

 

Where is that line? When does exercise go from moderate to rigorous, for people who might be wondering if they are doing enough?

We used definitions from prior studies that categorized a cadence of 60-99 steps/minute as low-level exertion, while 100-129 steps/minute is generally considered to be indicative of moderate physical activity and greater than 130 steps/minute is considered vigorous. These step counts may need to be a bit higher in younger individuals. The Physical Activity Guidelines for Americans recommend 150-300 minutes/week of moderate intensity or 75-150 minutes/week of vigorous intensity exercise. However, this upper limit is really a guidance meant to encourage people to exercise. In our study, we did not observe any evidence of a threshold beyond which higher levels of activity were no longer associated with greater fitness.

 

Can you explain in some detail how the results of your study were achieved, studying participants in the Framingham Heart Study?

Thank you for this question and for the opportunity to thank the Framingham Heart Study participants. It is only through their voluntary participation over three generations now that studies such as ours are possible. For our study, we analyzed data from participants of the Third Generation cohort (literally the grandchildren of the original participants, in many cases) and the multiracial sample. At the most recent study visit in 2016–2019, we performed cardiopulmonary exercise tests (CPETs) on stationary cycles for comprehensive fitness evaluations. CPETs are the “gold standard” assessment of fitness and involve exercise testing with a face mask or mouthpiece to measure the oxygen that is breathed in and the carbon dioxide that’s breathed out during exercise. You may have seen professional endurance athletes (such as cyclists) performing similar tests during training sessions. Participants also took home accelerometers, which were worn on belts around their waist for eight days after their study visit. Accelerometers were worn at the recent study visit and at the prior visit eight years earlier, and information was compared.

 

 

 

Older women, younger men more likely to have uncontrolled blood pressure

According to the American Heart Association, nearly half of adults in the U.S. have high blood pressure, which increases their risk for heart attack, stroke, kidney disease and many other health conditions, including severe complications from COVID-19.

“Blood pressure control remains a major public health challenge that impacts even those being treated for the disease,” according to study author Aayush Visaria, M.D., M.P.H., a postdoctoral research fellow at Rutgers Institute for Health, Health Care Policy and Aging Research at Rutgers University in New Brunswick, N.J.   

“Although we know that women tend to have an accelerated increase in blood pressure and cardiovascular disease risk after menopause, we have little information on whether blood pressure control is different by gender and whether it changes with age,” Visaria said.

Researchers used health information from the 1999 to 2018 National Health and Nutrition Examination Survey, a biannual, nationally representative survey conducted by the U.S. Centers for Disease Control and Prevention (CDC). This study included 13,253 adults, ages 20 years and older, who were taking prescription medications to treat hypertension. The average age was 57 years; 52% were women; and 71% were non-Hispanic white.

Researchers looked at rates of hypertension control using both an older and newer definition of high blood pressure: either greater than 140/90 mm Hg, as defined in the 2014 Joint National Commission guideline or greater than 130/80 mm Hg, as defined in the 2017 American Heart Association/American College of Cardiology guideline.

They compared rates of uncontrolled hypertension among men versus women across 10-year age-groups and found:  

• Differences in odds of uncontrolled hypertension were similar regardless of the guideline criteria for high blood pressure.
• Overall, 34% of those in the study had uncontrolled hypertension.
• From ages 20 to 29, the odds of having uncontrolled hypertension was 59% higher for men compared to women, based on the American Heart Association guideline definition of high blood pressure. Among those ages 30-39, men were 70% more likely to be uncontrolled, and for those aged 40-49 men were 47% more likely to be uncontrolled.
• From ages 50 to 69, women and men had similar odds of uncontrolled hypertension.
• For ages 70 and older, using the American Heart Association guideline definition of hypertension, women had 29% (age 70-79) to 63% (age 80+) higher odds of uncontrolled hypertension than men.

“These results indicate that women 70 years and older and men less than 50 years with hypertension may have increased risk of uncontrolled hypertension and may benefit from more frequent blood pressure monitoring,” Visaria said. “In general, there is a need to increase awareness about uncontrolled hypertension among older women and younger men, and further studies need to be done to understand the reasons behind this phenomenon.”

A limitation of the study is that researchers had access to only one blood pressure reading at one time point, which may not accurately depict a person’s blood pressure because it usually fluctuates throughout the day.

“In order to really determine whether uncontrolled hypertension rates are changing in women versus men across age, a prospective study where blood pressure measurements are tracked over time in women and men with hypertension is ideal,” Visaria said.

Spending time outside and getting quality sleep may promote wellbeing during COVID-19 restrictions

For many individuals, restrictions implemented during the COVID-19 pandemic dramatically altered daily routines and limited time spent outdoors. In a study published in the Journal of Sleep Research that included 7,517 adults from many countries who were surveyed during the 2020 COVID-19 restrictions, median levels of sleep quality, quality of life, physical activity, and productivity deteriorated, while screen time increased and time spent outdoors during the day decreased; however, many survey participants reported no changes or even improvements. Longer sleep and decreased alarm-clock use were linked to better sleep quality and quality of life.

Larger reductions in time spent outside in daylight were linked to deteriorations in wellbeing and delayed sleep.

“Our findings suggest that strategies to improve wellbeing under social restrictions should foster more daylight exposure and good sleep,” said lead author Maria Korman, PhD, MSc, of Ariel University, in Israel.

New therapies offer hope for management of menopausal hot flashes

(September 22, 2021) -- Hot flashes are one of the most common symptoms of menopause, affecting roughly 75% of women. They can adversely affect a woman’s quality of life by disrupting sleep and mood and can lead to more serious health consequences. A presentation at The North American Menopause Society (NAMS) Annual Meeting in Washington, DC, September 22-25, 2021, will review several nonhormone therapies currently under investigation for hot flash management.

Recent studies have shown that vasomotor symptoms (the clinical term for hot flashes) can last, on average, 7-10 years, and can sometimes last even longer in women whose symptoms began in perimenopause. While some women only have mild hot flashes, others can have more bothersome symptoms which can lead to problems with lower bone density and subclinical cardiovascular disease.

The good news is that several therapies are currently under investigation for vasomotor symptom management. Dr. Stephanie Faubion, NAMS medical director, will highlight some of the more promising therapies which are already approved for other indications and others that represent novel compounds that are not yet government approved. Newer options include:

• Oxybutynin, an antimuscarinic, anticholinergic agent used for management of overactive bladder symptoms and hyperhidrosis has also been found to reduce vasomotor symptom frequency and severity. Although there are concerns regarding dementia risk with its long-term use, short-term use may provide symptom relief for women with significant or bothersome vasomotor symptoms.
• Neurokinin 3 receptor antagonists which are in phase 3 clinical trials for treatment of vasomotor symptoms represent a promising nonhormone therapy. They appear to rapidly reduce hot flash frequency and severity, although their effects on weight, as well as cardiovascular, bone, brain, and sexual health are unknown. In addition, their long-term safety and efficacy have yet to be established.
• Estetrol (E4) is a naturally occurring estrogen that has been shown in initial studies to reduce vasomotor frequency and severity, as well as improve the vaginal maturation index. E4 was recently approved in the US and Canada for use as a contraceptive and is under investigation currently for vasomotor symptom management.

A sedentary lifestyle can lead to more nighttime hot flashes

New study suggests that too many hours sitting on the couch could increase problematic hot flashes in midlife women

(September 22, 2021)—Hot flashes, one of the most common symptoms of the menopause transition, not only interfere with a woman’s quality of life, but are also associated with an array of health problems. A new study suggests that sedentary behavior can increase the likelihood of nighttime hot flashes. Study results will be presented during The North American Menopause Society (NAMS) Annual Meeting in Washington, DC, September 22-25, 2021.

Approximately 80% of women report experiencing hot flashes. Some data suggest that a greater number and severity of hot flashes are related to increased risk for cardiovascular disease. Sedentary behavior, which is often more prevalent as women age, is also related to a greater risk for heart disease. Few studies, however, have evaluated the effect of sedentary behavior on hot flash experience. Those studies that have been conducted were largely based on self-reports and did not consider objective measures of hot flashes or sedentary behavior.

This new study, which includes pre-, peri-, and postmenopausal women, aimed to determine whether objectively measured sedentary behavior is a predictor of objective and subjective hot flash experience. Preliminary results of the study indicate that sedentary behavior does, in fact, predict nighttime objective hot flashes, independently of time spent participating in moderate-to-vigorous activity.

“Since women near the menopause transition spend a large portion of their daily activities in sedentary behaviors, it’s important to understand how such behavior influences menopausal hot flashes,” says Dr. Sarah Witkowski, an exercise physiologist at Smith College and co-author of the study. “Knowledge regarding the influence of sedentary behavior on hot flashes can improve evidence-based lifestyle recommendations for women experiencing hot flashes.”

“With such a large portion of women affected by hot flashes, research that helps identify triggers or risk factors is always valuable,” says Dr. Stephanie Faubion, NAMS medical director. “Healthcare professionals should review a patient’s physical activities and routines when discussing treatment options.”

New therapies offer hope for minimizing hair loss in midlife women

Presentation will discuss common causes and new treatment for women with thinning or lost hair

(September 22, 2021) – Hair loss in middle-aged females is common, affecting up to two-thirds of women after menopause. The exact reasons remain unclear, although evidence suggests a hormonal and genetic predisposition. A presentation at The North American Menopause Society (NAMS) Annual Meeting in Washington, DC, September 22-25, 2021, will address common hair loss problems and review new therapies and treatment approaches to stimulate hair growth and minimize thinning.

There are many different types of hair loss that occur with age. In some (non-scarring), the hair follicle is preserved and hair has the potential to grow back. Others (scarring) are characterized by irreversibly destroyed hair follicles that do not allow hair to be replenished. Today the term most commonly used with women is female pattern hair loss (also known as androgenetic alopecia). Although it’s similar to what happens to men, hair loss patterns in women are typically different. 

With female pattern hair loss, the hair’s growing phase shortens and fewer hairs are in the active growing phase. Hair follicles shrink, leading hair to become thinner and finer with decreased numbers of hairs overall. Women typically report progressive ponytail thinning, increased scalp visibility, and easy sunburn. Usually there is a preservation of the frontal hairline with diffuse central thinning and accentuation of the part-line with a Christmas tree appearance.

Treatment includes daily application of topical 5% minoxidil and may take at least three months before noticeable results. Finasteride is a 5-reductase inhibitor that is FDA-approved for male hair loss. As an off-label indication, it may be effective in females, although higher doses may be required. Additional treatments include drospirenone containing OCP and spironolactone. Newer therapies emerging include platelet-rich plasma injections.

“Since some medical conditions can result in permanent hair loss and be signs of more serious illnesses or dermatologic disease, early diagnosis is important. In some cases, biopsies may be needed for an accurate diagnosis,” says Dr. Alison Bruce from the Mayo Clinic who will be making the presentation.

Nutraceuticals may be the secret to a full head of hair for women at midlife

  Hair thinning is one of the many symptoms that accompanies the menopause transition. Roughly 40% of women over 60 will experience what’s known as female pattern hair loss (also known as androgenetic alopecia). However, a new study suggests that a nutraceutical supplement may improve hair growth and quality. The study results will be presented during The North American Menopause Society (NAMS) Annual Meeting in Washington, DC, September 22-25, 2021.

Hair shedding or thinning is a devastating reality for most women as they age, as it can have a strong impact on self-esteem and emotional well-being. Unfortunately, the therapeutic options on the market are limited.

The new study out of California suggests that a nutraceutical supplement — with nutrient-derived bioactive compounds derived from food sources — may effectively promote hair growth in peri-, menopausal, and postmenopausal women whose hormone changes are associated with decreased hair growth, as well as percentage of hairs and time spent in the anagen phase (when hair follicles form a new hair shaft). These findings offer hope for women near the menopause transition who are experiencing hair shedding or loss.

Researchers compared results at 6 months and 12 months of treatment and found that mean total hair counts increased significantly and progressively. Global hair quality improvements significantly increased by 40% with few or no side effects, along with a decrease in hair shedding.

“With the aging of our society and the fact that women now spend approximately one-third of their lives in the postmenopausal period, research into interventions for menopause symptoms, including hair thinning, is critical, especially with therapeutic options being so limited,” says Dr. Glynis Ablon of the Ablon Skin Institute and Research Center in California and lead author of the study.

“Hair loss is a significant concern for midlife women,” says Dr. Stephanie Faubion, NAMS medical director. “Additional research will help confirm the long-term efficacy of nutraceutical supplements.”

The quality, not quantity, of cardiovascular fat can interfere with memory later in life

 

New study based on SWAN data suggests that a greater radiodensity of perivascular adipose tissue in midlife women is associated with a worse performance in working memory later in life

(September 22, 2021)—A worsening cardiovascular profile after menopause may contribute to the fact that women are disproportionately affected by dementia. A new study identified a link between cardiovascular fat volume and radiodensity and cognitive function, as well as racial differences in this association. Study results will be presented during The North American Menopause Society (NAMS) Annual Meeting in Washington, DC, September 22-25, 2021.

Cardiovascular fat deposition, found to be higher in postmenopausal women compared with premenopausal women, is a novel risk factor for cardiovascular disease. It is also believed to affect cognitive function through neuropathological pathways by changing the secretion of inflammatory cytokines and adipokines. The quality of cardiovascular fat is characterized by its radiodensity.

In this new study, researchers aimed to assess associations of cardiovascular fat volume and radiodensity with future cognitive performance among midlife women and check for any racial differences in these associations. Racial differences were specifically analyzed since Blacks paradoxically have lower cardiovascular fat volume but are at a higher risk for heart disease and a higher prevalence of Alzheimer disease compared with Whites.

The study, which was based on SWAN (Study of Women’s Health Across the Nation) data, involved nearly 500 women, of which 30.6% were postmenopausal and 35.9% were Black. Study results suggest a higher perivascular adipose tissue (PVAT) radiodensity is significantly associated with a worse performance in working memory. Researchers additionally identified a significant interaction between PVAT radiodensity and race, noting that a higher baseline PVAT radiodensity at midlife was associated with lower future performance in verbal episodic memory among Blacks, but not White women. The reported associations were independent of volume of PVAT depot, as well as waist circumference and other known confounders.

“Our study suggests that the quality, rather than the quantity, of perivascular adipose tissue at midlife may serve as a novel biomarker of cognitive function status in women later in life. We need more research to understand the underlaying mechanisms of the reported association,” says Dr. Samar R. El Khoudary from the University of Pittsburgh and senior author of the study.

“Studies like these are valuable in helping healthcare providers identify who may be most vulnerable so they can intervene early to help delay disease progression,” says Dr. Stephanie Faubion, NAMS medical director.

Strength training can burn fat too

It’s basic exercise knowledge that to gain muscles, you strength train, and to lose fat, you do cardio – right?

Not necessarily, a new UNSW study published this week in Sports Medicine suggests.

In fact, the study – a systematic review and meta-analysis that reviewed and analysed existing evidence – shows we can lose around 1.4 per cent of our entire body fat through strength training alone, which is similar to how much we might lose through cardio or aerobics. 

“A lot of people think that if you want to lose weight, you need to go out and run,” says senior author of the study Dr Mandy Hagstrom, exercise physiologist and senior lecturer at UNSW Medicine & Health.

“But our findings show that even when strength training is done on its own, it still causes a favourable loss of body fat without having to consciously diet or go running.”

Up until now, the link between strength training and fat loss has been unclear. Studies have investigated this link in the past, but their sample sizes tend to be small – a side effect of not many people wanting to volunteer to exercise for months on end. Smaller sample sizes can make it difficult to find statistically significant results, especially as many bodies can respond differently to exercise programs. 

“It can be really difficult to discern whether there’s an effect or not based on one study alone,” says Dr Hagstrom. “But when we add all of these studies together, we effectively create one large study, and can get a much clearer idea of what's going on.”

Dr Hagstrom and her team pulled together the findings from 58 research papers that used highly accurate forms of body fat measurement (like body scans, which can differentiate fat mass from lean mass) to measure the outcomes from strength training programs. Altogether, the studies included 3000 participants, none of which had any previous weight training experience. 

While the strength training programs differed between the studies, the participants worked out for roughly 45-60 minutes each session for an average of 2.7 times per week. The programs lasted for about five months. 

The team found that, on average, the participants lost 1.4 per cent of their total body fat after their training programs, which equated to roughly half a kilo in fat mass for most participants. 

While the findings are encouraging for fans of pumping iron, Dr Hagstrom says the best approach for people who are aiming to lose fat is still to stick to eating nutritiously and having an exercise routine that includes both aerobic/cardio and strength training. 

But if aerobics and cardio just aren’t your thing, the good news is you don’t need to force it.

“If you want to exercise to change your body composition, you’ve got options,” says Dr Hagstrom.

“Do what exercise you want to do and what you’re most likely to stick to.”

Busting the fat loss myth 

Part of the reason many people think strength training doesn’t live up to cardio in terms of fat loss comes down to inaccurate ways of measuring fat.

For example, many people focus on the number they see on the scale – that is, their total body weight. But this figure doesn’t differentiate fat mass from everything else that makes up the body, like water, bones and muscles.

“More often than not, we don't gain any muscle mass when we do aerobic training,” says Dr Hagstrom. “We improve our cardiorespiratory fitness, gain other health and functional benefits, and can lose body fat.

“But when we strength train, we gain muscle mass and lose body fat, so the number on the scales won’t look as low as it would after aerobics training, especially as muscle weighs more than fat.”

The research team focused on measuring how much the total body fat percentage – that is, the amount of your body that’s made up of fat mass – changed after strength training programs. This measurement showed fat loss appears to be on par with aerobics and cardio training, despite the different figures on the scales.

“A lot of fitness recommendations come from studies that use inaccurate measurement tools, like bioelectrical impedance or scales,” says Dr Hagstrom.

“But the most accurate and reliable way of assessing body fat is through DEXA, MRI or CT scans. They can compartmentalise the body and separate fat mass from lean tissue.”

While this study didn’t show whether variables like exercise duration, frequency, intensity, or set volume impacted fat loss percentage, the team hope to next investigate whether how we strength train can change the amount of fat loss.

A better way of measuring progress

As part of their study, the team conducted a sub-analysis comparing how different ways of measuring fat can influence a study’s findings. 

Interestingly, it showed that when papers used more accurate measurements like body scans, they tended to show lower overall changes in body fat.

“Using accurate fat measurements is important because it gives us a more realistic idea of what body changes to expect,” says lead author of the study Mr Michael Wewege, PhD candidate at UNSW and NeuRA. 

“Future exercise studies can improve their research by using these more accurate body measurements.”

Reframing the way we measure progress doesn’t just apply to sports researchers, but to everyday people, too. 

“Resistance training does so many fantastic things to the body that other forms of exercise don't, like improving bone mineral density, lean mass and muscle quality. Now, we know it also gives you a benefit we previously thought only came from aerobics,” says Dr Hagstrom.

“If you're strength training and want to change how your body looks, then you don't want to focus on the number on the scale too much, because it won’t show you all your results.

“Instead, think about your whole body composition, like how your clothes fit and how your body will start to feel, and move, differently.”