Tag: nutrition

Fruit and Vegetable Consumption Directly Increases Happiness

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Fruit and vegetable consumption and exercise can directly increase levels of self-reported happiness, according to findings from a new study.

Public health campaigns encourage healthier diets and exercise by virtue of the well-studied link between lifestyle and wellbeing, and will benefit from new findings published by the Journal of Happiness Studies showing that there is also a positive causation from lifestyle to life satisfaction.

This research is the first to identify the causation of happiness, the consumption of fruit and vegetables and exercising are related, rather than generalising a correlation. The researchers, Dr Adelina Gschwandtner (Kent’s School of Economics), Dr Sarah Jewell and Professor Uma Kambhampati (both from the University of Reading’s School of Economics), used an instrumental variable approach to filter out any effect from happiness to lifestyle. This approach revealed that it is the effect of fruit and vegetables and exercising that makes people happy and not the other way round.

The findings show individuals’ ability to delay gratification and apply self-control plays a major role in influencing lifestyle decisions, which in turn has a positive impact on wellbeing. The research also shows that men appear to exercise more, and women eat more fruit and vegetables.

Dr Gschwandtner said: ‘Behavioural nudges that help the planning self to reinforce long-term objectives are likely to be especially helpful in maintaining a healthy lifestyle. If a better lifestyle not only makes us healthier but also happier, then it is a clear win-win situation.’

Professor Kambhampati said: ‘There has been a bigger shift in recent years for healthier lifestyle choices. To establish that eating more fruit and vegetables and exercising can increase happiness as well as offer health benefits is a major development. This may also prove useful for policy campaigns around environment and sustainability.’

Source: University of Kent

Surprising Finding Links Asthma Risk to Meat Consumption as Infants

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Researchers looking for post-breastfeeding dietary patterns in two prospective birth cohorts, were surprised to discover meat consumption as a predictive factor.

Alexander Hose, MA, MPH, of Ludwig Maximilian University in Munich presented the study’s findings at the virtual European Respiratory Society annual meeting

After switching from breast milk, babies up to age 1 whose protein intake came largely from meat products, rather than dairy, fish, or egg proteins, had a more than eight-fold greater chance of developing asthma by age 6 versus non-meat protein consumption. Asthma prevalence reached 30% in some subgroups.

Wheezing was more common in this diet pattern, which Hose and colleagues termed “unbalanced meat consumption” (UMC); this continued up to age 10, with a five times higher odds.

The duration of breastfeeding was an important factor, likely because switching to baby foods prolonged the exposure. Odds of developing asthma by age 6 increased nearly 12-fold in UMC-fed infants whose breastfeeding stopped by week 19, versus about four-fold in those continuing longer on breast milk.

In addition, UMC was also linked to a certain intestinal microbiome profile featuring unusually high levels of Lactococcus, Granulicatella, and Acinetobacter species.

This type of microbiome scavenges iron in the gut, Hose said, which could explain why the children became especially susceptible to asthma. Additionally, milk proteins may exert an opposite effect on asthma risk by generating a type of “nutritional immunity.”

While the mechanism connecting the gut microbiome to respiratory disease is unknown, the existence of a ‘gut-lung axis‘ is well established; a recent trial showed that probiotics can prevent coughs and wheezing in older adults. The phenomenon has also been considered for COVID’s gastrointestinal symptoms.

A pair of European birth cohort studies, PASTURE and LUKAS2, provided the data for the study. In these, about 1400 infants were followed through age 10 and parents kept detailed records of their infants’ feeding, and other environmental factors, and children’s medical records were accessed as well.

However, a key limitation is the cohorts being from rural areas since investigating asthma’s relationship to animal exposure was a key goal for the studies. Partly because of this, Hose and colleagues were able to separate out ‘industrial’ meat, milk, and yoghurt from that produced at home. A trend toward greater asthma risk was observed with store-bought protein products.

Source: MedPage Today

Healthy Diets Reduce COVID Risk

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A study based on self-reported app data showed that people who eat a high quality, gut friendly diet are less likely to develop COVID-19 or become severely ill. Those eating poorer quality diets are more at risk, especially if they live in a more socioeconomically deprived area.

The study, presented in GUT, analysed data from almost 600 000 ZOE COVID Study app contributors. Participants completed a survey about the food they ate before the pandemic, in February 2020, making it the largest study in this space. 19% of these contributors contracted COVID-19.

People with the highest quality diet were around 10% less likely to develop COVID than those with the lowest quality diet, and 40% less likely to fall severely ill.

This is the first longitudinal study of diet and COVID and the first to show that a healthy diet cuts the chances of developing the disease in the first place.

Instead of looking at specific foods, the survey aimed to broadly capture people’s diets. A ‘diet quality score’ reflected the overall merit of each person’s diet. Diets with high quality scores were found to contain plant-based foods such as fruits, vegetables and whole grains, as well as oily fish, less processed foods and refined carbohydrates. A low diet quality score is associated with diets high in ultra processed foods and low amounts of plant based foods.

The researchers found that people who ate the highest quality diet were around 10% less likely to develop COVID-19 than those with the least nutritious diet and 40% less likely to become severely ill if they developed COVID.

The link between diet quality and COVID risk persisted after accounting for all potential confounding factors such as age and BMI. Mask-wearing habits and population density were also considered.

The effect of diet was amplified by individual life situations, with people living in low-income neighbourhoods with the lowest quality diet being around 25% more at risk from COVID than people in more affluent communities eating the same kind of diet.

Based on these results, the researchers estimate that nearly a quarter of COVID cases could have been prevented if these differences in diet quality and socioeconomic status had not existed. The study also showed that improved access to better food is an important public health consideration.

Dr Sarah Berry, study co-lead and Reader in nutritional sciences at the School of Life Course Sciences said: “For the first time we’ve been able to show that a healthier diet can cut the chances of developing COVID, especially for people living in the more deprived areas. Access to healthier food is important to everyone in society, but our findings tell us that helping those living in more deprived areas to eat more healthily could have the biggest public health benefits.”

Professor Tim Spector, professor of genetic epidemiology at the School of Life Course Sciences, said: “These findings chime with recent results from our landmark PREDICT study, showing that people who eat higher quality diets (with low levels of ultra-processed foods) have a healthier collection of microbes in their guts, which is linked to better health. You don’t have to go vegan, but getting more diverse plants on your plate is a great way to boost the health of your gut microbiome, improve your immunity and overall health, and potentially reduce your risk from COVID.”

Source: Kings College London

Supermarket Layout Change Encourages Healthy Food Purchases

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A study into food purchasing behaviours shows that placing fruit and vegetables near store entrances and removing confectionery and other unhealthy products from checkouts and the end of nearby aisles prompts customers to make healthier food purchases.

The study, led by Dr Christina Vogel, Principal Research Fellow in Public Health Nutrition and Janis Baird, Professor of Public Health and Epidemiology at the University’s MRC Lifecourse Epidemiology Centre, was conducted in partnership with the national supermarket chain Iceland Foods Ltd. The trial took place in a number of Iceland stores in England, monitoring store sales as well as dietary patterns of sample customers.

The results showed confectionery sales decreased throughout the store while fruit and vegetable sales increased when non-food items and water were placed at checkouts and at the end of the opposite aisles, and an expanded fruit and vegetable section was repositioned near the store entrance. Beneficial effects were also observed for household fruit and vegetable purchasing and individual dietary quality. The findings are presented in the open-access journal PLOS Medicine.

Discussing the results of the study Dr Vogel said “Altering the layouts of supermarkets could help people make healthier food choices and shift population diet towards the government’s dietary recommendations. The findings of our study suggest that a healthier store layout could lead to nearly 10 000 extra portions of fruit and vegetables and approximately 1500 fewer portions of confectionery being sold on a weekly basis in each store.”

This research is more comprehensive than previous studies testing whether placement strategies can promote healthier food purchasing which have been limited in scope, for example including only a single location (ie at checkouts) or placing healthy and unhealthy products together. This study further aimed to reduce exposure of customers to calorie opportunities by placing non-food items at checkout and aisle-ends opposite and measuring effects on store sales, purchasing patterns on customer loyalty cards and the diets of more than one household member.

Matt Downes, Head of Format Development at Iceland, said:   “We have been pleased to support this long-term study and the evaluation of how product placement in supermarkets can affect the diets of our customers. We know that childhood obesity is a growing issue and the retail industry has its part to play in tackling this. We hope that the outcomes of the study provide insights for the wider retail industry and policy makers about the impact of store merchandising on purchasing decisions.”

Prof Baird added “These results provide novel evidence to suggest that the intended UK government ban on prominent placement of unhealthy foods across retail outlets could be beneficial for population diet, and that effects may be further enhanced if requirements for a produce section near supermarket entrances were incorporated into the regulation.”

Source: University of Southampton

Body Clock Disruption on High-fat Diet Leads to Obesity

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According to a new study, when rats are fed a high fat diet, this disturbs the body clock in their brain that normally controls satiety, leading to over-eating and obesity. 

This new research, published in the Journal of Physiology, may be a cornerstone for future clinical studies that could restore the proper functioning of the body clock in the brain, to avoid overeating.

It was believed that the body clock resided only in the hypothalamus, but research over the years has clarified that some control of our body’s daily rhythms (hormone levels, appetite etc) lies in several other parts of the brain and body, including a group of neurons in the evolutionary ancient brainstem, called the dorsal vagal complex (DVC).

Specifically, the DVC has been shown to moderate food intake by inducing satiety. In obesity, research has shown that daily rhythms in food intake and the release of hormones related to eating, are blunted or eliminated. It is unclear if the malfunctioning of brain centres controlling appetite is a cause or the result of obesity.

This new study found that rats on a high-fat diet, before they started to gain weight, showed changes in the DVC’s daily neuronal rhythms and its response to appetite hormones. Thus, the researchers proposed that DVC disruption causes obesity.

Two groups of rats were used: those fed a well-balanced control diet (10% kcal from fat) and a high-fat diet (70% kcal from fat). To mimic the impact of unhealthy diet on humans, the researchers introduced the new diet to adolescent rats and monitored their food intake over 24h for four weeks.

Using multi-electrode arrays, the researchers measured DVC changes over 24h, simultaneously monitoring around a hundred DVC neurons from each brainstem slice. With this, circadian changes of neuronal activity could be assessed as well as neuronal responses to metabolically-relevant hormones in each of the diet groups.

Rats being nocturnal animals is a limitation of the study. The DVC activity peaked at the end of day, the rest phase for rodents, but an active phase for humans. Thus, it remains to be established if the phase of the brainstem clock is set to day and night, or whether it depends on patterns of rest and activity. These findings however could lead to understanding how to reset the body clock and tackle obesity.

First author Dr Lukasz Chrobok said:

“I’m really excited about this research because of the possibilities it opens up to tackle the growing health issue of obesity. We still do not know what are the time cues which are able to reset or synchronise the brainstem clock. Hopefully, the restoration of daily rhythms in this satiety centre before or after the onset of obesity may provide new therapeutic opportunities.”

Source: The Physiological Society

GPs Should Aim for Diabetes Remission Through Weight Loss

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A large-scale review of clinical evidence concluded that achieving ‘remission’ for people with type 2 diabetes through dietary approaches and weight loss should be the primary treatment goal of GPs and healthcare practitioners.

Corresponding author Dr Duane Mellor at Aston University said: “Accounting for all the evidence, our review suggests remission should be discussed as a primary treatment goal with people living with type 2 diabetes. There are multiple dietary approaches that have been shown to bring about T2DM remission though at present meal replacements offer the best quality evidence. Low carbohydrate diets have been shown to be highly effective and should also be considered as a dietary approach for remission.”

Lead author, Dr Adrian Brown, UCL Division of Medicine said: “Traditionally T2DM has focussed on managing a person’s blood glucose with medication, however the approach doesn’t address the underlying causes of T2DM. There is now a growing body of research that shows losing significant weight, 10-15kg, either through weight loss surgery or dietary approaches, can bring about type 2 diabetes remission (non-diabetic blood sugar levels).”

Expert reviewers analysed over 90 research papers covering international clinical trials and clinical practice data of dietary methods used to treat T2DM. Their findings were published in the Journal of Human Nutrition & Dietetics.

The study found that meal-replacement diets helped 36% people successfully achieve remission, while low carbohydrate diets were able to help 17.6 % of people achieve and maintain remission for at least two years. People who lost the most weight and kept the weight off using both of these dietary approaches were able to stay in remission.

Calorie restricted and Mediterranean diets were somewhat less effective, with only about 5% of people on calorie restricted diets and 15% of people on a Mediterranean diet staying in remission after one year.

There were multiple definitions of ‘remission’: one is a return to non-diabetic blood sugar levels (glycated haemoglobin less than 48mmol/mol), without diabetes drugs. Other definitions however say weight (especially fat around the midsection) must be lost to achieve remission, and others allow medication to be used.

Some reports also suggested low-carbohydrate diets can normalise blood sugar levels even without weight loss, since carbohydrates cause blood sugar levels to rise. A low-carbohydrate diet means reduced blood sugar, leading to improved blood sugar control. However, if weight is lost without blood glucose being non-diabetic, the authors are suggesting this should instead be called mitigation, as the underlying mechanisms of T2DM are not being addressed.

Dr Brown said: “The evidence is clear that the main driver of remission remains the degree of weight loss a person achieved. Therefore, for those not achieving weight loss but achieving a non-diabetic blood glucose we are suggesting this isn’t remission per se, but rather ‘mitigation’ of their diabetes.”

The review concluded that while weight loss seems to best predict remission success, it assumes fat loss from the pancreas and liver. Future studies should compare how these diets work for different ethnic groups, as T2DM can occur at different body weights in different ethnic groups.

Dr Mellor added: “Not everyone will be able to achieve remission, but people who are younger (less than 50), male, have had type 2 diabetes for less than six years and lose more weight are more likely to be successful.”

Source: Ashton University

Added Potassium Salt Substitute Greatly Cuts CVD Risk

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Replacing table salt with a low-sodium, added potassium ‘salt substitute’ significantly reduces rates of stroke, heart attack and death, one of the largest dietary intervention studies ever conducted.

Presented at the European Society of Cardiology Congress in Paris, and simultaneously published in the New England Journal of Medicine, the results also showed that there were no harmful effects from the salt substitute, such as hyperkalaemia.

High sodium intake and low potassium intake are widespread. Both are linked to hypertension and increased risks of stroke, heart disease and premature death. Using a salt substitute – where part of the sodium chloride is replaced with potassium chloride – addresses both problems at once. Salt substitutes are known to lower blood pressure but their effects on heart disease, stroke, and death were unclear, until now.

Lead researcher, Professor Bruce Neal of The George Institute for Global Health, said that the benefit could prevent millions of early deaths with the widespread adoption of salt substitutes.

“Almost everyone in the world eats more salt than they should.  Switching to a salt substitute is something that everyone could do if salt substitutes were on the supermarket shelves,’’ he said.

“Better still, while salt substitutes are a bit more expensive than regular salt, they’re still very low-cost – just a few dollars a year to make the switch.”

“As well as showing clear benefits for important health outcomes, our study also allays concerns about possible risks.  We saw no indication of any harm from the added potassium in the salt substitute.  Certainly, patients with serious kidney disease should not use salt substitutes, but they need to keep away from regular salt as well,” added Professor Neal.

The Salt Substitute and Stroke Study enrolled 21 000 adults with either a history of stroke or poorly controlled blood pressure from 600 villages in rural areas of China from 2014 to 2015.

Participants in intervention villages were provided enough salt substitute to cover all household cooking and food preservation requirements – a daily amount of 20g per person. Those in the other villages continued using regular salt.

Over five years’ average follow up, more than 3000 participants had a stroke. Use of salt substitute reduced stroke risk by 14 percent, total cardiovascular events (strokes and heart attacks combined) by 13 percent and premature death by 12 percent.

Professor Neal said that as salt substitutes are relatively cheap (US$1.62 per kg vs US$1.08 per kg for regular salt in China), they are likely very cost effective.

“Last year, a modelling study done for China suggested that about 400 000 premature deaths might be prevented each year by national uptake of salt substitute. Our results now confirm this. If salt was switched for salt substitute worldwide, there would be several million premature deaths prevented every year,” he said.    

“This is quite simply the single most worthwhile piece of research I’ve ever been involved with. Switching table salt to salt substitute is a highly feasible and low-cost opportunity to have a massive global health benefit.”

As a result of the study, George Institute researchers are calling for salt manufacturers to embrace salt substitution, the promotion of salt substitutes by governments, and the use of substitute salt by consumers.

Source: George Institute for Global Health

Weight Loss in 80% Following Series of Different Diets

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In a study testing three successive and varying diets, nearly 80 percent of participants in a lost a “clinically significant” amount of body weight in less than two years.

The participants adhered to a sequence of a calorie-restrictive diet, a low-carb/high-fat diet and an intermittent fasting diet, losing 11.1 kilograms on average.

The results were published in the journal Nutrition.

“Almost 80 percent of participants lost a clinically significant amount of weight,” said study leader Rebecca Christensen, a PhD candidate at the Dalla Lana School of Public Health. “This is important because losing just five percent of your body weight is associated with improvements in cardiometabolic function and other health concerns.

“That lets us know that we have a lot of different tools in the toolbox to pick from when initiating a dietary intervention.”

Christensen says that staying on the same diet can be tough, which is why she is pleased that the study’s findings suggest there may be an alternative.

“It can be quite hard for patients to maintain dietary interventions,” she said. “This might be where successive diets have an advantage as changing things up makes it easier to stick to a diet.”

As more people attempt to shed their pandemic weight, Christensen said she also found that there is no right month to start your diet. Rather, it is just about getting started, adding that reaching a very low body mass index (BMI) need not be the goal.

“We know that that’s not necessarily feasible,” she said. “But the very least they are reaching the weight that we know is beneficial for their health which is why we want to do the intervention.”

Source: University of Toronto

Gut Microbiome Moderates BP Benefits of Flavonoids

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Flavonoid-rich foods, such as berries, apples, pears and wine, seem to reduce hypertension due in part to characteristics of the gut microbiome, according to a new study published in Hypertension.

“Our gut microbiome plays a key role in metabolising flavonoids to enhance their cardioprotective effects, and this study provides evidence to suggest these blood pressure-lowering effects are achievable with simple changes to the daily diet,” said lead researcher Aedín Cassidy, PhD, chair and professor in nutrition and preventive medicine at the Institute for Global Food Security at Queen’s University.

Flavonoids are compounds found naturally in fruits, vegetables and plant-based foods such as tea, chocolate and wine. They have miscellaneous favourable biochemical and antioxidant effects associated with various diseases such as cancer, Alzheimer’s disease, atherosclerosis, etc. Flavonoids are broken down by the body’s gut microbiome. Recent studies found a link between gut microbiota, the microorganisms in the human digestive tract, and cardiovascular disease (CVD). Gut microbiota are highly individual, and seem to be associated with CVD.

With studies suggesting flavonoids may reduce heart disease risk, the researchers investigaged the role of the gut microbiome in this. 
Researchers drew on a group of 904 adults between the ages of 25 and 82, 57% men from Germany’s PopGen biobank. Researchers evaluated the participants’ food intake, gut microbiome and blood pressure levels together with other clinical and molecular phenotyping at regular follow-up examinations.

Participants’ intake of flavonoid-rich foods during the previous year was calculated from a self-reported food questionnaire detailing the frequency and quantity eaten of 112 foods.

Participants’ gut microbiomes were assessed by faecal bacterial DNA in stool samples. After an overnight fast, participants’ blood pressure levels were measured. Researchers also collected participants’ lifestyle information, and measured BMI and other physical characteristics,

The analysis found that:

  • Study participants with the highest intake of flavonoid-rich foods, including berries, red wine, apples and pears, had lower systolic blood pressure levels, as well as greater gut microbiome diversity than the participants with the lowest levels of flavonoid-rich food intake.
  • Up to 15.2% of the association between flavonoid-rich foods and systolic blood pressure could be explained by the diversity found in participants’ gut microbiome.
  • Eating 1.6 servings of berries per day (one serving = 80 grams, or 1 cup) was associated with an average reduction in systolic blood pressure levels of 4.1 mm Hg. 12% of the association was explained by gut microbiome factors.
  • Drinking 2.8 glasses (125 ml of wine per glass) of red wine a week was associated with an average of 3.7 mm Hg lower systolic blood pressure level, of which 15% could be explained by the gut microbiome.

“Our findings indicate future trials should look at participants according to metabolic profile in order to more accurately study the roles of metabolism and the gut microbiome in regulating the effects of flavonoids on blood pressure,” said Cassidy. “A better understanding of the highly individual variability of flavonoid metabolism could very well explain why some people have greater cardiovascular protection benefits from flavonoid-rich foods than others.”

While this study suggests potential benefits to consuming red wine, the American Heart Association suggests that if you don’t drink alcohol already, you shouldn’t start.

Study limitations include not being able to account for all factors, such as genetics and lifestyle. The authors noted the focus of this study was on specific foods rich in flavonoids, not all food and beverages with flavonoids.

Source: Medical Xpress

Extra Vitamin D Does not Boost Muscles

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Vitamin D supplementation does not have beneficial effects on muscle function, strength, or mass, according to a new meta-analysis, and may even have detrimental effects on muscle strength in people with normal levels of the vitamin.

Vitamin D deficiency, causes a generalised decrease in bone mineral density, resulting in osteopenia and osteoporosis. In young children who have little mineral in their skeleton, this defect results in a variety of skeletal deformities classically known as rickets. It is also believed to cause muscle weakness; affected children have difficulty in standing and walking, whereas the elderly have increasing sway and more frequent falls,thereby increasing their risk of fracture.

The analysis, which is published in the Journal of Bone and Mineral Research, included 54 trials involving 8747 individuals. Overall, no benefits of vitamin D over placebo were observed for improving muscle health. On the contrary, vitamin D appeared to have detrimental effects in terms of increased time spent performing what’s called the Timed Up and Go test, a decrease in maximum strength at knee flexion, and a tendency towards a reduced score of the Short Physical Performance Battery.

“Care should be taken recommending vitamin D supplementation to improve muscle strength and function in people with normal or only slightly impaired vitamin D status,” said lead author Lise Sofie Bislev, MD, PhD, of Aarhus University Hospital, in Denmark. “We need to study further whether it may benefit muscles in those with severe vitamin D deficiency, however.”

Source: Wiley