Wednesday, November 30, 2022

The secret to waking up alert: Sleep longer and later, get exercise the day before, eat a low sugar, high carb breakfast

 Do you feel groggy until you’ve had your morning coffee? Do you battle sleepiness throughout the workday?


You’re not alone. Many people struggle with morning alertness, but a new study demonstrates that awaking refreshed each day is not just something a lucky few are born with. Scientists at the University of California, Berkeley, have discovered that you can wake up each morning without feeling sluggish by paying attention to three key factors: sleep, exercise and breakfast.

The findings come from a detailed analysis of the behavior of 833 people who, over a two-week period, were given a variety of breakfast meals; wore wristwatches to record their physical activity and sleep quantity, quality, timing and regularity; kept diaries of their food intake; and recorded their alertness levels from the moment they woke up and throughout the day. Twins — identical and fraternal — were included in the study to disentangle the influence of genes from environment and behavior.

The researchers found that the secret to alertness is a three-part prescription requiring substantial exercise the previous day, sleeping longer and later into the morning, and eating a breakfast high in complex carbohydrates, with limited sugar. The researchers also discovered that a healthy controlled blood glucose response after eating breakfast is key to waking up more effectively.

“All of these have a unique and independent effect,” said UC Berkeley postdoctoral fellow Raphael Vallat, first author of the study. “If you sleep longer or later, you're going to see an increase in your alertness. If you do more physical activity on the day before, you're going to see an increase. You can see improvements with each and every one of these factors.”

Morning grogginess is more than just an annoyance. It has major societal consequences: Many auto accidents, job injuries and large-scale disasters are caused by people who cannot shake off sleepiness. The Exxon Valdez oil spill in Alaska, the Three Mile Island nuclear meltdown in Pennsylvania and an even worse nuclear accident in Chernobyl, Ukraine, are well-known examples.

“Many of us think that morning sleepiness is a benign annoyance. However, it costs developed nations billions of dollars every year through loss of productivity, increased health care utilization, work absenteeism. More impactful, however, is that it costs lives — it is deadly,” said senior author Matthew Walker, UC Berkeley professor of neuroscience and psychology. “From car crashes to work-related accidents, the cost of sleepiness is deadly. As scientists, we must understand how to help society wake up better and help reduce the mortal cost to society’s current struggle to wake up effectively each day.”

Vallat, Walker and their colleagues published their findings last week in the journal Nature Communications. Walker, the author of the international bestseller, Why We Sleep, runs one of the world’s preeminent sleep research labs, the Center for Human Sleep Science, and is a member of the Helen Wills Neuroscience Institute at UC Berkeley.

A personalized approach to eating

Walker and Vallat teamed up with researchers in the United Kingdom, the U.S and Sweden to analyze data acquired by a U.K. company, Zoe Ltd., that has followed hundreds of people for two-week periods in order to learn how to predict individualized metabolic responses to foods based on a person’s biological characteristics, lifestyle factors and the foods’ nutritional composition.

The participants were given preprepared meals, with different amounts of nutrients incorporated into muffins, for the entire two weeks to see how they responded to different diets upon waking. A standardized breakfast, with moderate amounts of fat and carbohydrates, was compared to a high protein (muffins plus a milkshake), high carbohydrate or high sugar (glucose drink) breakfast. The subjects also wore continuous glucose monitors to measure blood glucose levels throughout the day.

The worst type of breakfast, on average, contained high amounts of simple sugar; it was associated with an inability to wake up effectively and maintain alertness. When given this sugar-infused breakfast, participants struggled with sleepiness.

In contrast, the high carbohydrate breakfast — which contained large amounts of carbohydrates, as opposed to simple sugar, and only a modest amount of protein — was linked to individuals revving up their alertness quickly in the morning and sustaining that alert state.

“A breakfast rich in carbohydrates can increase alertness, so long as your body is healthy and capable of efficiently disposing of the glucose from that meal, preventing a sustained spike in blood sugar that otherwise blunts your brain's alertness,” Vallat said

“We have known for some time that a diet high in sugar is harmful to sleep, not to mention being toxic for the cells in your brain and body,” Walker added. “However, what we have discovered is that, beyond these harmful effects on sleep, consuming high amounts of sugar in your breakfast, and having a spike in blood sugar following any type of breakfast meal, markedly blunts your brain’s ability to return to waking consciousness following sleep.”

It wasn’t all about food, however. Sleep mattered significantly. In particular, Vallat and Walker discovered that sleeping longer than you usually do, and/or sleeping later than usual, resulted in individuals ramping up their alertness very quickly after awakening from sleep. According to Walker, between seven and nine hours of sleep is ideal for ridding the body of “sleep inertia,” the inability to transition effectively to a state of functional cognitive alertness upon awakening. Most people need this amount of sleep to remove a chemical called adenosine that accumulates in the body throughout the day and brings on sleepiness in the evening, something known as sleep pressure.

“Considering that the majority of individuals in society are not getting enough sleep during the week, sleeping longer on a given day can help clear some of the adenosine sleepiness debt they are carrying,” Walker speculated.

“In addition, sleeping later can help with alertness for a second reason,” he said. “When you wake up later, you are rising at a higher point on the upswing of your 24-hour circadian rhythm, which ramps up throughout the morning and boosts alertness.”

It's unclear, however, what physical activity does to improve alertness the following day.

“It is well known that physical activity, in general, improves your alertness and also your mood level, and we did find a high correlation in this study between participants' mood and their alertness levels,” Vallat said. “Participants that, on average, are happier also feel more alert.”

But Vallat also noted that exercise is generally associated with better sleep and a happier mood.

“It may be that exercise-induced better sleep is part of the reason exercise the day before, by helping sleep that night, leads to superior alertness throughout the next day,” Vallat said.

Walker noted that the restoration of consciousness from non-consciousness — from sleep to wake — is unlikely to be a simple biological process.

“If you pause to think, it is a non-trivial accomplishment to go from being nonconscious, recumbent and immobile to being a thoughtful, conscious, attentive and productive human being, active, awake, and mobile. It's unlikely that such a radical, fundamental change is simply going to be explained by tweaking one single thing,” he said. “However, we have discovered that there are still some basic, modifiable yet powerful ingredients to the awakening equation that people can focus on — a relatively simple prescription for how best to wake up each day.”

It's not in your genes

Comparisons of data between pairs of identical and non-identical twins showed that genetics plays only a minor and insignificant role in next-day alertness, explaining only about 25% of the differences across individuals.

“We know there are people who always seem to be bright-eyed and bushy-tailed when they first wake up,” Walker said. “But if you’re not like that, you tend to think, ‘Well, I guess it's just my genetic fate that I'm slow to wake up. There's really nothing I can do about it, short of using the stimulant chemical caffeine, which can harm sleep.

“But our new findings offer a different and more optimistic message. How you wake up each day is very much under your own control, based on how you structure your life and your sleep. You don’t need to feel resigned to any fate, throwing your hands up in disappointment because, ‘… it's my genes, and I can't change my genes.’ There are some very basic and achievable things you can start doing today, and tonight, to change how you awake each morning, feeling alert and free of that grogginess.”

Walker, Vallat and their colleagues continue their collaboration with the Zoe team, examining novel scientific questions about how sleep, diet and physical exercise change people’s brain and body health, steering them away from disease and sickness.

Diet can lower risk of cardiovascular disease by 10 percent

 

 Cardiovascular disease (CVD) remains the leading cause of death in the United States, claiming more than 800,000 lives annually. A healthy diet is one key lifestyle strategy to reduce CVD risk factors, including high blood pressure and cholesterol levels, and ultimately prevent atherosclerotic heart disease — or the hardening and narrowing of the arteries caused by fatty build up that can lead to heart attack and stroke. However, there is scarce data to guide patients' decisions as to which heart-healthy diet to adopt.

In a new study, researchers at Beth Israel Deaconess Medical Center (BIDMC) compared the effects of three eating patterns on patients' risk of experiencing a cardiovascular event within in the next ten years — the Dietary Approaches to Stop Hypertension (DASH) diet, a diet rich in fruits and vegetables, and the Western diet that is typically low in fruits and vegetables while high in fat and sodium. The team's findings suggest that while the DASH and fruit/vegetable diet each reduced risk scores by about 10 percent over an eight-week period, the DASH diet conferred additional benefits for women and Black adults compared to Western Diet. The results are published in the American Journal of Cardiology.

"While physicians and patients rely on the extensive data available when choosing appropriate pharmacologic therapy to prevent atherosclerotic cardiovascular disease, there's limited evidence to inform expectations for risk reductions from established lifestyle interventions," said corresponding author Stephen P. Jurashcek, MD, PhD, a clinician-researcher in the Department of Medicine at BIDMC. "Our study suggests that the benefits associated with these diets may vary by sex and race. While a diet rich in fruits and vegetables produced reductions in risk for woman and Black participants, the effect with the DASH diet was twice as large in women and four times as large in Black adults."

To determine the effect of the different diets on an individual's risk of atherosclerotic cardiovascular disease, Juraschek and colleagues acquired data from 459 adults aged 22 to 75 who participated in the original DASH trial between 1994 and 1996. Participants — who were roughly half women and half Black – were randomized to one of three diets for eight weeks. The control diet was high in total fat, saturated fat and cholesterol. The fruit and vegetable diet provided more produce, but did not otherwise significantly differ from the control diet. The DASH diet also provided more fruit and vegetables, but emphasized more whole grains, lean proteins, nuts and low-fat dairy while reducing fat, saturated fat, cholesterol and sugar. First published in 1997, the DASH trial demonstrated that, among adults with elevated blood pressure and hypertension, the DASH diet not only reduced systolic blood pressure but also reduced HDL cholesterol levels, compared to the control diet. As diet high in fruits and vegetables was shown to reduce systolic blood pressure to a lesser degree, but to improve HDL cholesterol levels as well.

When Juraschek and colleagues compared the data, they found that both the DASH diet and the fruit and vegetable diet had lowered participants' 10-year risk for atherosclerotic cardiovascular disease by about 10 percent overall. However, the effect was not consistent across demographics. The DASH diet reduced the 10-year risk score among women by nearly 13 percent, compared to just over six percent among men. Moreover, DASH reduced the 10-year risk score by nearly 14 percent among Black adults, versus just three percent among non-Black adults.

"The findings could have major implications for clinical practitioners and policy makers alike," said first author Sun Young Jeong, MD, MPH, an internal medicine resident at BIDMC. "Cardiovascular disease is the leading cause of death in women and hypertension is also more strongly linked with heart failure and death in women than men. We also know women are less likely to receive risk factor modification therapies, such as statins, so our finding that DASH may be more efficacious among women are relevant for lifestyle counseling in this group."

"Similarly, disparities in access to healthy foods has been a major focus of policy efforts to promote higher intake of fruits and vegetables among Black adults," said Juraschek, who is also an assistant professor of medicine at Harvard Medical School. "Our study suggests that the DASH dietary pattern may offer Black adults more prevention benefits than the emphasis on fruits and vegetables alone. This is particularly relevant as dietary pattern has been identified as one of the most important mediators of hypertension risk among Black adults."

Grape consumption helps counter UV damage to skin

A recent human study published in the scientific journal Antioxidants found that consuming grapes protected against ultraviolet (UV) damage to the skin.[1]  Study subjects showed increased resistance to sunburn after consuming 2 ¼ cups of grapes every day for two weeks.  Additionally, subjects displaying UV resistance demonstrated unique microbiomic and metabolomic profiles suggesting a correlation between the gut and skin.  Natural components known as polyphenols found in grapes are thought to be responsible for these beneficial effects.  

This new study reinforces previous research in this area.  In this investigation with 29 human volunteers, researchers examined the impact of consuming whole grape powder – equivalent to 2 ¼ cups of grapes per day – for 14 days against photodamage from UV light.  Subjects’ skin response to UV light was measured before and after consuming grapes for two weeks by determining the threshold dose of UV radiation that induced visible reddening after 24 hours – the Minimal Erythema Dose (MED).  Additionally, metabolomic analysis of the gut microbiome, blood, and urinary samples was undertaken. 

Ultimately, one-third of the subjects demonstrated UV resistance following grape consumption, and these same subjects displayed significant differences in the microbiome and metabolome compared with the non-responders.  Notably, the same three urinary metabolites were depressed in the UV-resistant group.  One metabolite in particular (2’-deoxyribose) is a strong indicator of reduced photodamage and suggests unique genetic profiles of relevance for personalized medicine.

Furthermore, three of the UV resistant subjects showed a durable response where UV protection remained after reverting back to no grape consumption for four more weeks.  This work suggests that a segment of the population is capable of resisting sunburn following grape consumption, and that there is a correlation between the gut-skin axis and UV resistance.

Over 3 million Americans are affected by skin cancer each year, largely as a result of exposure to sunlight.  It is estimated that one in five Americans will develop skin cancer by the age of 70.[2]  Most skin cancer cases are associated with exposure to UV radiation from the sun:  about 90 percent of nonmelanoma skin cancers and 86 percent of melanomas, respectively.   Additionally, an estimated 90 percent of skin aging is caused by the sun.

John Pezzuto – lead author of the paper and professor and dean at Western New England University in Springfield, MA – notes “'Let thy food be thy medicine and medicine be thy food' dates back to the time of Hippocrates.  Now, after 2500 years, as exemplified by this human study conducted with dietary grapes, we are still learning the reality of this statement.”

 


Consuming a high sodium, low potassium diet can increase the risk of cognitive decline


Peer-Reviewed Publication

KEAI COMMUNICATIONS CO., LTD.

Association of average sodium, potassium, sodium/potassium and salt intake, and self-reported memory. 

IMAGE: ASSOCIATION OF AVERAGE SODIUM, POTASSIUM, SODIUM/POTASSIUM AND SALT INTAKE, AND SELF-REPORTED MEMORY. MODEL 1 IS ADJUSTED FOR AGE, SEX, LOCATION OF RESIDENCE, AREA OF RESIDENCE, EDUCATIONAL LEVEL, WORKING STATUS, MARITAL STATUS, PHYSICAL ACTIVITY LEVELS, AND SMOKING AND DRINKING HABITS. MODEL 2 IS ADJUSTED FOR ENERGY, CARBOHYDRATE, PROTEIN AND FAT INTAKE (ADDITIONALLY ADJUSTED POTASSIUM INTAKE FOR THE MODEL OF SODIUM AND SODIUM INTAKE FOR THE MODEL OF POTASSIUM) BASED ON MODEL 1. MODEL 3 IS ADJUSTED FOR BMI, SLEEP TIME, CARDIOVASCULAR AND CEREBROVASCULAR DISEASES, AND COGNITION TEST SCORES AT BASELINE BASED ON MODEL 2. ABBREVIATIONS: Q1-Q4, QUARTILE 1-QUARTILE 4; OR, ODDS RATIOS; CI, CONFIDENCE INTERVAL; AND BMI, BODY MASS INDEX. ORANGE SQUARES DENOTE SIGNIFICANT ASSOCIATION (P < 0.05). view more 

CREDIT: XIAONA NA

Dementia impairs sufferers’ ability to remember, think and make decisions to the point where their everyday activities are affected. The condition has become one of the leading causes of death and disability among the elderly globally. As China is not only home to the largest elderly population, but also one of the fastest ageing, dementia poses great economic, health and social challenges for the country.

Dementia is irreversible and there is a lack of effective treatments available, which makes prevention and early detection of age-related cognitive function vital. Research has found that several lifestyle choices are linked to cognitive function; for example, physical activity, diet and sleep. However, the effects of dietary sodium and potassium on cognitive function have not been explored in detail.

In a prospective study published in the KeAi journal Global Transitions, a group of researchers from China looked at the impact of dietary sodium, potassium, sodium to potassium ratio, and salt on the cognitive function of a group of elderly people in China. Participants numbered 4,213 and were aged at least 50 years at baseline. Results are based on cognitive tests and participants’self-reporting.

The research team found that a high intake of sodium (> 5593.2 mg/day) and a high sodium to potassium ratio (> 3.8/day) increased the risk of memory impairment in the elderly. Conversely, higher levels of potassium intake (> 1653.3 mg/day) were associated with a higher cognitive score; the average cognitive test score (13.44 at baseline, total score was 27.00) increased by ~1 point when 1000 mg/day of sodium was replaced with an equal intake of potassium. In addition, the researchers built on previous studies by demonstrating that the effects of dietary sodium, sodium to potassium ratio, and potassium on cognitive function have the potential to be mediated by cardiovascular and cerebrovascular disease (CCVD), while the link between salt and cognitive function can be mediated by sleep.  

Although China has attempted to restrict salt and sodium in people’s diets for over a decade, the population’s intake remains alarmingly high, outstripping many other countries and the World Health Organization’s recommendation of a maximum of 1400 mg/day of sodium for people aged 50—79 years and 5 g/day of salt. This high salt intake is commonly accompanied by insufficient consumption of potassium (1499.0 mg/day in this study vs. the Chinese recommended level of 3600 mg/day).

The study’s results also confirm previous findings that dietary sodium to potassium ratio could provide a better measure of how these elements impact cognitive function, than looking at separate sodium or potassium values.

Corresponding author, Ai Zhao, adds: “Based on our findings, it is reasonable to suggest that decreasing sodium intake, and properly increasing potassium intake, is beneficial to cognitive function. Given our results, and the nutritional situation of the Chinese, it will be important for future studies to focus on determining the optimal ratio of dietary sodium and potassium in the elderly. In addition, the development of strategies to improve the sodium to potassium ratio in Chinese diets should be a priority.”

The real benefits of walking in a winter wonderland

The woodland in Silesia, Poland, where the research took place 

IMAGE: THE WOODLAND IN SILESIA, POLAND, WHERE THE RESEARCH TOOK PLACE view more 

CREDIT: NONE

Research has shown for the first time that spending time in snowy surroundings can improve how you feel about your body.

Previous studies have found that green spaces, such as parks and forests, and ‘blue environments’, such as being at the coast or close to a river, can improve body image.

Now new research, published this month in the International Journal of Environmental Research and Public Health, has discovered that white spaces, in this case a snow-covered woodland, can have a similar effect.

Led by academics from the Medical University of Silesia, in Katowice, Poland, and Anglia Ruskin University (ARU) in the UK, the research was carried out last winter and involved 87 women, with an average age of 24, who took part in small groups.

Before and after walking in a snowy woodland in the Silesia region of Poland, the participants completed a measure of their body appreciation. Before the walk, they also completed measures of connectedness to nature and self-compassion.

The study found that spending a short amount of time in nature – in this case approximately 40 minutes – results in greater body appreciation. Additionally, people who scored highly in the trait of self-compassion displayed greater improvement in body appreciation.

As well as being the first study to examine the body image benefits of spending time in a snowy landscape, it is also the first to show that these benefits can be achieved when being in nature in small groups, rather than individually.

Lead author Dr Kamila Czepczor-Bernat, of the Medical University of Silesia, said: “A body of evidence now exists showing that nature exposure – living close to, frequenting, or engaging with environments such as forests and parks – is associated with a range of physical and psychological wellbeing benefits.

“However, in contrast to previous studies which have focused on the impact of blue and green natural environments on body image outcomes, ours is the first to show the positive impact on body appreciation from spending time in snow-covered environments.”

Senior author Viren Swami, Professor of Social Psychology at Anglia Ruskin University (ARU), said: “Natural environments help to restrict negative appearance-related thoughts and shift attention away from an aesthetic view of the body and toward greater appreciation of the body’s functionality. Positive body image is important not only in its own right, but has other beneficial effects, including more positive psychological wellbeing.

“Our findings demonstrate the importance of ensuring that everyone can access restorative natural environments, which may be a cost-effective way of promoting healthier body image, and highlight that there are significant benefits of being outside in nature, whatever the weather.”

The full open access study is available at https://www.mdpi.com/1660-4601/19/21/14548

 

Tuesday, November 29, 2022

Eating more kale, spinach, broccoli, green beans. prunes, kiwi, avocado = 31 per cent less likely to have any fracture


Breaking bones can be life changing events — especially as we age, when hip fractures can become particularly damaging and result in disability, compromised independence and a higher mortality risk.

But research from Edith Cowan University’s Nutrition and Health Innovation Research Institute has revealed there may be something you can do to help reduce your risk of fractures later in life.

In collaboration with the University of Western Australia, the study looked at the relationship between fracture-related hospitalisations and vitamin K1 intake in almost 1400 older Australian women over a 14.5-year period from the Perth Longitudinal Study of Aging Women.

It found women who ate more than 100 micrograms of vitamin K1 consumption — equivalent to about 125g of dark leafy vegetables, or one-to-two serves of vegetables — were 31 per cent less likely to have any fracture compared to participants who consumed less than 60 micrograms per day, which is the current vitamin K adequate intake guideline in Australia for women.

There were even more positive results regarding hip fractures, with those who ate the most vitamin K1 cutting their risk of hospitalisation almost in half (49 per cent).

Study lead Dr Marc Sim said the results were further evidence of the benefits of vitamin K1, which has also been shown to enhance cardiovascular health.

“Our results are independent of many established factors for fracture rates, including body mass index, calcium intake, Vitamin D status and prevalent disease,” he said.

“Basic studies of vitamin K1 have identified a critical role in the carboxylation of the vitamin K1-dependant bone proteins such as osteocalcin, which is believed to improve bone toughness.

“A previous ECU trial indicates dietary vitamin K1 intakes of less than 100 micrograms per day may be too low for this carboxylation.

“Vitamin K1 may also promote bone health by inhibiting various bone resorbing agents.”

So, what should we eat — and how much?

Dr Sim said eating more than 100 micrograms of vitamin K1 daily was ideal — and, happily, it isn’t too difficult to do.

“Consuming this much daily vitamin K1 can easily be achieved by consuming between 75-150g, equivalent to one to two serves, of vegetables such as spinach, kale, broccoli and cabbage,” he said.

“It’s another reason to follow public health guidelines, which advocate higher vegetable intake including one to two serves of green leafy vegetables — which is in-line with our study’s recommendations.”

Vitamin K1-rich foods

Vegetables: Kale, spinach, broccoli, green beans

Fruits: Prunes, kiwi, avocado

Increasing protein and tea or coffee intake could reduce hip fracture risk

How women can reduce the risk of hip fracture

  • Increasing protein intake by 25g a day could reduce hip fracture risk by up to 14% 
  • Every additional cup of tea or coffee is linked with a 4% reduction in risk

Increasing intake of protein and drinking regular cups of tea or coffee is a way women could reduce their risk of suffering a hip fracture, according to new research.  

Food scientists at the University of Leeds in the UK have found that for women, a 25g a day increase in protein was associated with, on average, a 14% reduction in their risk of hip fracture. In a surprise twist, they also discovered that every additional cup of tea or coffee they drank was linked with a 4% reduction in risk. 

Writing in the journal Clinical Nutrition, the researchers noted that the protective benefits were greater for women who were underweight, with a 25g/day increase in protein reducing their risk by 45%. 

The protein could come in any form: meat, dairy or eggs; and for people on a plant-based diet, from beans, nuts or legumes. Three to four eggs would provide around 25g of protein as would a steak or piece of salmon. 100g of tofu would provide about 17g of protein.  

Just over 3% of the women in the study group experienced a hip fracture. 

Observational study 

The investigation - Foods, nutrients and hip fracture risk: A prospective study of middle-aged women - is based on a large observational analysis of more than 26,000 women.  

As an observational study, the researchers were able to identify associations between factors in diet and health. They could not single out direct cause and effect.  

James Webster, a doctoral researcher in the School of Food Science and Nutrition at Leeds who led the study, said: “Across the world, the costs to individuals and societies caused by hip fracture are enormous.  

“Hip fracture can often lead to other chronic illnesses, loss of independence, and premature death. In the UK, the annual cost to the NHS is between £2 to £3 billion. 

“Diet is a factor that people can modify to protect themselves by maintaining healthy bones and muscles. This study is one of the first to investigate relationships between food and nutrient intakes and risk of hip fracture, with hip fractures accurately identified through hospital records.  

“The results highlight which aspects of diet may be useful tools in reducing hip fracture risk in women, with evidence of links between higher protein, tea and coffee intakes and a reduced risk.” 

Proteins are the basic building blocks of life and are needed to keep cells, tissues and muscles working properly as well as contributing to bone health.  

The recommended protein intake in the UK is 0.8g per kilogramme of bodyweight per day, a limit some nutritional experts believe is too low. As the study revealed, people who had a higher protein consumption had a reduction in the risk of hip fracture. However, intakes of protein which are very high - where intake is greater than 2 to 3g of protein/kg body weight/day - can have negative health effects. The study was not able to explore these very high protein intake levels.  

Professor Janet Cade, who leads the Nutritional Epidemiology Group at Leeds and supervised the research, said: “In the UK most people eat an adequate amount of protein, however, certain groups, such as vegetarians or vegans need to check that their protein intakes are high enough for good health.” 

Why underweight women may see greater risk reductions 

Women who are underweight may be more likely to have reduced bone mineral density and muscle mass. Increasing intakes of several foods and nutrients, especially protein, may help reduce hip fracture risk more in underweight women than in healthy or overweight women by helping to establish or restore bone and muscle health. However, the researchers note that this finding needs further research to confirm this.  

Tea and coffee both contain biologically active compounds called polyphenols and phytoestrogens which may help to maintain bone health.  

Professor Cade added: "This is an interesting finding given that tea and coffee are the UK's favourite drinks. We still need to know more about how these drinks could affect bone health but it might be through promoting the amount of calcium present in our bones."

UK Women’s Cohort Study 

The data used in the study came from the UK Women’s Cohort Study, which recruited participants between 1995 and 1998. At the time they entered the study, the women ranged between 35 and 69 years of age. 

At recruitment, they were asked to fill out questionnaires about their diet and lifestyle. This information was then linked with hospital records over the following two decades, which revealed how many had suffered a hip fracture or had a hip replaced.  

Of the 26,318 women involved in the study, 822 cases of hip fracture were identified, that is 3.1%. 

Foods, nutrients and hip fracture risk: A prospective study of middle-aged women by James Webster, Dr Darren C. Greenwood and Professor Janet E. Cade, all from the University of Leeds. 


Caffeine Gets You to The Finish Line Faster

 At the international level of sport, even the smallest advantage can take an athlete from being a mere participant to a podium finisher. Consequently, athletes try to achieve that competitive edge with the help of performance enhancing training methods and pre-event performance enhancing aids. Caffeine, a nervous system stimulant, is one such performance enhancing aid, most commonly and popularly used by athletes around the world. In fact, the International Association of Athletics Federations(now called World Athletics, WA) recommends caffeine as an ergogenic (or physical performance-enhancing) aid in a consensus statement of nutritional strategy for athletics. However, owing to the absence of research on caffeine’s effects on sprint performance, the recommendation is reflective of evidence from other anaerobic sports rather than sprint running in athletics, like the 100-m sprint event.

To advance research, a team of researchers from Japan investigated the acute effects of caffeine supplementation on sprint running performance. This study, led by Professor Takeshi Hashimoto from Ritsumeikan University in Japan, was subsequently published in the Medicine & Science in Sports & Exercise journal. According to Prof. Hashimoto, “While previous studies have investigated the effects of caffeine on running activity, evidence from these studies is not conclusive enough to support the World Athletics consensus. A majority of them have looked at its effects on single sprint runs of less than 60 meters. Therefore, it was important to study the ergogenic effects of caffeine on the 100-meter sprint performance.”

The researchers recruited 13 male collegiate sprinters for the study. In a preliminary test, the researchers determined the time it takes for each athlete to reach peak blood plasma caffeine concentration after ingesting it. Taking this into account, the athletes were called two more times for 100-meter time trials after ingesting either caffeine or placebo supplements.

As measures of performance, the researchers measured the sprint velocity and calculated the sprint time. On discounting the effects of environmental factors, the corrected sprint time was used to examine the effects of caffeine supplementation.

The results revealed that the corrected 100-m sprint time was shortened significantly for athletes who received caffeine, with a decrease of 0.14 seconds compared to the controls. This decrease in the time was largely associated with a decrease in sprint time for the first 60 meters of the sprint.

The researchers also found that the mean sprint velocity for the 0–10 m and 10–20 m splits was significantly higher in the athletes who received caffeine. Moreover, no significant difference was seen in the sprint time for the last 40 meters of the sprint, despite the shortening of the sprint time in the first 60 meters. Together, these observations suggest that the caffeine supplementation provided more explosive acceleration to the sprinters in the early stage of the race.

In the long term, these results could translate to the enhancement of sports performance for athletes by enhancing the usage of caffeine as an ergogenic aid during sprints.

“The insights gained from this study have given us the first direct evidence of caffeine’s ergogenicity on sprint running in athletics. This also serves as evidence to directly support the recommendations for caffeine usage by World Athletics. The study thus provides one more advantage that athletes can use to inch themselves closer towards victory”, concludes Prof. Hashimoto.

Determined to explore the ergogenic effects of caffeine further, Prof. Hashimoto and his team intend to call to question the mechanisms behind the effects of caffeine on ballistic actions such as sprinting and jumping.

The Green Mediterranean diet reduces twice as much visceral fat as the Mediterranean diet and 10% more than a healthy diet


Reducing visceral fat is the true goal of weight loss

 The green Mediterranean diet (MED) significantly reduces visceral adipose tissue, a type of fat around internal organs that is much more dangerous than the extra "tire" around your waist. The green Mediterranean diet was pitted against the Mediterranean diet and a healthy diet in a large-scale clinical interventional trial- the DIRECT PLUS. Subsequent analysis found that the green Med diet reduced visceral fat by 14%, the Med diet by 7% and the healthy diet by 4.5%. The study was published in BMC Medicine.

Reducing visceral fat is considered the true goal of weight loss as it is a more important indicator than a person's weight or the circumference of their waist. Visceral fat aggregates over time between organs and produces hormones and poisons linked to heart disease, diabetes, dementia and premature death.

The DIRECT-PLUS trial research team was the first to introduce the concept of the green-Mediterranean diet. This modified MED diet is further enriched with dietary polyphenols and lower in red/processed meat than the traditional healthy MED diet. On top of a daily intake of walnuts (28 grams), the participants consumed 3-4 cups of green tea/day and 100 grams (frozen cubes) of duckweed green shake/day. The aquatic green plant duckweed is high in bioavailable protein, iron, B12, vitamins, minerals, and polyphenols and substituted meat intake.

The team has shown in previous studies that the green MED diet has a variety of salutary effects ranging from the microbiome to age-related degenerative diseases.

Two hundred and ninety four participants took part in the 18-month long trial.

"A healthy lifestyle is a strong basis for any weight loss program. We learned from the results of our experiment that the quality of food is no less important than the number of calories consumed and the goal today is to understand the mechanisms of various nutrients, for example, positive ones such as the polyphenols, and negative ones such as empty carbohydrates and processed red meat, on the pace of fat cell differentiation and their aggregation in the viscera," says Prof. Shai.

"A 14% reduction in visceral fat is a dramatic achievement for making simple changes to your diet and lifestyle. Weight loss is an important goal only if it is accompanied by impressive results in reducing adipose tissue," notes Dr. Hila Zelicha.

Monday, November 28, 2022

Shaking less salt on your food at the table could reduce heart disease risk


Researchers found a link between a lower frequency of dietary salt and a reduced CVD risk


Adding additional salt to foods at a lower frequency is associated with a reduced risk of heart disease, heart failure and ischemic heart disease, according to a new study published today in the Journal of the American College of Cardiology. Even among those following a DASH-style diet, behavioral interventions to lessen salt consumption could further improve heart health.

There’s substantial evidence linking high sodium intake to high blood pressure, a major risk factor for cardiovascular disease. However, epidemiological studies investigating this link have produced conflicting results due to a lack of practical methods for assessing long-term dietary sodium intake. Recent studies suggest that the frequency at which an individual adds salt to their foods could be used to predict their individual sodium intake over time.

“Overall, we found that people who don’t shake on a little additional salt to their foods very often had a much lower risk of heart disease events, regardless of lifestyle factors and pre-existing disease,” said Lu Qi, MD, PhD, HCA Regents Distinguished Chair and professor at the School of Public Health and Tropical Medicine at Tulane University in New Orleans. “We also found that when patients combine a DASH diet with a low frequency of adding salt, they had the lowest heart disease risk. This is meaningful as reducing additional salt to food, not removing salt entirely, is an incredibly modifiable risk factor that we can hopefully encourage our patients to make without much sacrifice.”

In the current study, the authors evaluated whether the frequency of adding salt to foods was linked with incident heart disease risk in 176,570 participants from the UK Biobank. The study also examined the association between the frequency of adding salt to foods and the DASH diet as it relates to heart disease risk.

The study used a questionnaire at baseline to collect data on the frequency of adding salt to foods, not including salt used in cooking. Participants were also asked if they had made any major changes to their diet in the last 5 years, as well as complete 1-5 rounds of 24-hour dietary recalls over a three-year period.  

The DASH-style diet was developed to prevent hypertension by limiting consumption of red and processed meats and focusing on vegetables, fruit, whole grains, low-fat dairy, nuts, and legumes. While the DASH diet has yielded benefits in relation to reducing cardiovascular disease risk, a recent clinical trial found that combining the DASH diet with sodium reduction was more beneficial for certain cardiac biomarkers, including cardiac injury, strain, and inflammation. The researchers calculated a modified DASH score that did not consider sodium intake based on seven foods and nutrients that were emphasized or deemphasized in the DASH-style diet.

Data on heart disease events was collected through medical history and data on hospital admissions, questionnaire and death register data.

Overall, study participants with a lower frequency of adding salt to foods were more likely to be women; white; have a lower body mass index; more likely to have moderate alcohol consumption; less likely to be current smokers; and more physically active. They also had a higher prevalence of high blood pressure and chronic kidney disease, but a lower prevalence of cancer. These participants were also more likely to adhere to a DASH-style diet and consumed more fruits, vegetables, nuts and legumes, whole grains, low-fat dietary but less sugar-sweetened drinks or red/processed meats than those with a higher frequency of adding salt to foods.

The researchers found the association of adding salt to foods with heart disease risk was stronger in participants of lower socioeconomic status, as well as in current smokers. A higher modified DASH diet score was associated with lower risk of heart disease events.

In a related editorial comment, Sara Ghoneim, MD, a gastroenterology fellow at the University of Nebraska Medical Center, wrote that the study is promising, builds on previous reports, and alludes to the potential impact of long-term salt preferences on total cardiovascular risk.

“A major limitation of the study is the self-reported frequency of adding salt to foods and the enrollment of participants only from the UK, limiting generalizability to other populations with different eating behaviors,” Ghoneim said. “The findings of the present study are encouraging and are poised to expand our understanding of salt-related behavioral interventions on cardiovascular health.”