Tag: nutrition

Categories : Diet and NutritionTags :

Eating Grapes Protects against Sunburn

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Compounds found in the humble grape may offer a protective effect against the sun’s damaging UV radiation, a new study has found.

Researchers from University of Alabama at Birmingham’s (UAB) Department of Dermatology found that healthy adult participants who ate freeze-dried powdered grapes for 14 days achieved a 74.8% increase in natural skin protection. 

The number of sunburns experienced over a lifetime increases the risk of skin cancer. Sunburns also cause skin damage, which has a cosmetic effect. Sunburns are marked by DNA damage triggering cell apoptosis, as well as the release of inflammatory markers such as prostaglandins, reactive oxygen species, and bradykinin in response to dimers formed by UV radiation. Prostaglandin E2 and histamine levels also rise after a sunburn.
Research in mouse models has shown that polyphenols, found in grapes as well as other fruits and vegetables, can reduce UV radiation damage, as well as reducing the production of inflammatory compounds. As such, this is the first research that shows the consumption of table grapes has a photoprotective effect against the sunburn response in adult humans. The subjects were also given a polyphenol compound, proanthocyanidin, as a topical extract to apply on their skin.

“Study results indicate that oral consumption of grapes has systemic beneficial effects in healthy adults,” said lead author Allen Oak, MD, a dermatologist in the UAB School of Medicine. “These benefits include inhibition of inflammation and repair of DNA damage.”

The preliminary findings also indicated that grapes may help reduce the risk of skin cancer as well, although this requires further research. 
“Grape consumption may act as an ‘edible sunscreen,'” Oak said. “This does not mean that grapes should be used in lieu of sunscreen, but they may offer additional protection which we are eager to continue learning more about. This research is exciting because our current findings provide building blocks for additional studies that may eventuate in an oral photoprotective product from a natural source.”

Source: Medical Xpress

Journal information: Allen S.W. Oak et al. Dietary table grape protects against UV photodamage in humans: 1. clinical evaluation, Journal of the American Academy of Dermatology (2021). DOI: 10.1016/j.jaad.2021.01.035

Categories : Diet and Nutrition GastrointestinalTags :

Eating Saturated Fats can Cut Symptoms of Pancreatitis

On By ModernMedia


A study has found that symptoms of pancreatitis are less severe when foods with saturated fats are eaten.

The study, by researchers from Mayo Clinic, the Saint Louis University School of Medicine and the Washington University School of Medicine, examines the obesity paradox in which obese patients had better results when being treated for certain conditions, compared to non-obese patients.

Pancreatitis is the leading cause of hospitalisation from gastrointestinal disorders in the United States. It can have a variety of causes, such as gallstones, having abdominal surgery or overconsumption of alcohol.
Saturated fats are found in meat and dairy, while unsaturated fats are found in plants and fish, and in general consumption of unsaturated fats over saturated fats is encouraged as it is associated with reduced risk of heart disease and other conditions. However, exceptions such as the obesity paradox exist.

To delve into this question, the researchers examined 20 clinical reports from 11 countries, where fat intake in obese patients was monitored. They found that among obese patients who developed pancreatitis, those who ate a diet heavy in saturated fats had less severe symptoms than those who did not. 

To determine the cause of this protective effect, the researchers fed mice a diet rich in either saturated or unsaturated fats, and then induced pancreatitis in them. Those fed saturated fats developed less severe symptoms. On closer examination, they found that saturated fat did not interact well with pancreatic triglyceride lipase, reducing production of long-chain non-esterified fatty acids, which reduced the symptoms of pancreatitis.  

Source: Medical Xpress

Journal information: Biswajit Khatua et al. Adipose saturation reduces lipotoxic systemic inflammation and explains the obesity paradox, Science Advances (2021). DOI: 10.1126/sciadv.abd6449

Categories : Cancer Diet and NutritionTags :

Breast Cancer in Mice Inhibited by Restricted Feeding Times

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Restricting calorie intake to an eight-hour window coinciding with physical activity reduced breast cancer risk in female mouse models.

Researchers from University of California San Diego School of Medicine, Moores Cancer Center and Veterans Affairs San Diego Healthcare System (VASDSH) found that the restricted feeding times, which are kind of circadian rhythm-linked intermittent fasting, enhanced metabolic health and tumour circadian rhythms in female mice with obesity-driven postmenopausal breast cancer. Breast cancer is the second most common cancer in US women, after skin cancer.

“Previous research has shown that obesity increases the risk of a variety of cancers by negatively affecting how the body reacts to insulin levels and changing circadian rhythms,” explained senior author Nicholas Webster, PhD. professor at UC San Diego School of Medicine and senior research career scientist at VASDSH. “We were able to increase insulin sensitivity, reduce hyperinsulinemia, restore circadian rhythms and reduce tumor growth by simply modifying when and for how long mice had access to food.”

Female mouse models mimicking postmenopausal hormone conditions were used to investigate if time-restricted feeding of obese mice affected the tumour growth and development, and reduced metastasis to the lungs. The mice were split into three groups, one with constant access to food, one with access for eight hours at night when they have the greatest activity, and the last was fed an unrestricted low-fat diet.

Obesity and menopause disrupt the circadian rhythm, with increased risk of insulin resistance and thereby chronic diseases such as cancer. A number of cancers are known to be associated with insulin resistance, such as breast cancer and pancreatic cancer. High insulin levels in obese mice drive tumour growth. Artificially increasing insulin levels has been shown to accelerate tumour growth whilst lowering them is similar to the effect of limiting eating.
Manasi Das, PhD, postdoctoral fellow in the Webster lab and first author, said: “Time-restricted eating has a positive effect on metabolic health and does not trigger the hunger and irritability that is associated with long-term fasting or calorie restriction. Through its beneficial metabolic effects, time-restricted eating may also provide an inexpensive, easy to adopt, but effective strategy to prevent and inhibit breast cancer without requiring a change in diet or physical activity.”

Webster believes that time-restricting eating warrants further investigations as it may present a way to reduce breast cancer risk, or that of cancer in general.

“The increase in risk of breast cancer is particularly high in women who are overweight and have been through menopause. For this reason, doctors may advise women to adopt weight loss strategies to prevent tumor growth,” said Das. “Our data suggests that a person may benefit from simply timing their meals differently to prevent breast cancer rather than changing what they eat.”

Source: Medical Xpress

Journal information: Manasi Das et al. Time-restricted feeding normalizes hyperinsulinemia to inhibit breast cancer in obese postmenopausal mouse models, Nature Communications (2021). DOI: 10.1038/s41467-020-20743-7

Categories : Diet and NutritionTags :

High-carb and High-fat Diets Compared

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Plant-based diets high in carbohydrates and meat-centred diets high in fats have become increasingly popular in recent years, and a new small, tightly controlled study has investigated their effects.

A myriad of health benefits ascribed to plant-based diets, while high-fat, low-carb diets have been proposed as a way to counteract overweight and diabetes risk. But there has been little understanding on how exactly the two diets compare, given that they restrict either fats or carbohydrates.

The answers to these questions were sought by a team at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).”High-fat foods have been thought to result in excess calorie intake because they have many calories per bite. Alternatively, high-carb foods can cause large swings in blood glucose and insulin that may increase hunger and lead to overeating,” said the study’s lead author, NIDDK Senior Investigator Kevin Hall, PhD. “Our study was designed to determine whether high-carb or high-fat diets result in greater calorie intake.”

The study took 11 male and 9 female non-diabetic participants and housed them in a facility for four weeks. For two weeks, they were served either a low-fat, high-carb, plant-based diet or a low-carb, high-fat meat-based diet. They were then changed to the other diet for the next two weeks. The food was minimally processed, contained equivalent amounts of non-starchy vegetables and participants were allowed snacks and to eat as much as they wanted.

The participants ate 550 to 700 fewer calories per day than when they ate the low-carb diet. Despite this difference, participants reported no hunger, and the same level of fullness and satisfaction with both diets. The participants lost weight on both diets, but more so on the low-fat diet.

“Despite eating food with an abundance of high glycemic carbohydrates that resulted in pronounced swings in blood glucose and insulin, people eating the plant-based, low-fat diet showed a significant reduction in calorie intake and loss of body fat, which challenges the idea that high-carb diets per se lead people to overeat. On the other hand, the animal-based, low-carb diet did not result in weight gain despite being high in fat,” Hall said.

The results add to a growing body of evidence that shows that diet is much more complex than just total calories. Hall’s previous research found that participants who ate highly processed food let to overeating and weight gain compared to a minimally processed carbs and fat-matched diet.

In this case, however, there were benefits observed in both diets.

“Interestingly, our findings suggest benefits to both diets, at least in the short-term. While the low-fat, plant-based diet helps curb appetite, the animal-based, low-carb diet resulted in lower and more steady insulin and glucose levels,” Hall commented. “We don’t yet know if these differences would be sustained over the long term.”

However, weight loss was not a goal of the study, and that may have influenced participants’ eating behaviours and the outcome of the study. The inpatient setting of the study also controlled what foods were available, unlike daily life where a variety of options, costs, preparation and availability concerns influence food choices. 

Source: Medical Xpress

Categories : Diet and Nutrition ExerciseTags :

Poor Diet is an Important Factor of Childhood Obesity

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A Baylor University study has shown that market-bought food in addition to the traditional diet reliably predicted obesity in Amazonian children, a result that has important insights into the global childhood obesity epidemic.

Globally, 6% of girls and 8% of boys in 2016 were obese, compared to 1% in 1975. In South Africa, 13% of children under the age of five are obese.

“The importance of a poor diet versus low energy expenditure on the development of childhood obesity remains unclear,” said lead author Samuel Urlacher, PhD, of Baylor University. “Using gold-standard measures of energy expenditure, we show that relatively lean, rural forager-horticulturalist children in the Amazon spend approximately the same total number of calories each day as their much fatter peri-urban counterparts and, notably, even the same number of calories each day as children living in the industrialised United States.”

Factors such as income and access to running water were used to establish market integration. Children’s physical activity was measured with wearable devices and immune activity by measuring biomarkers obtained from minimally invasive finger-prick blood samples. Most importantly, children’s daily energy expenditure was measured with the “doubly labeled water” stable isotope-tracking method and children’s resting energy expenditure using respirometry. These are both participant-friendly, gold-standard techniques.

A third of peri-urban children were overweight, while zero rural children were, and peri-urban children on average had 65% more body fat than rural children. Peri-urban and rural children had similar levels of physical activity, and market integration, immune activity and physical activity had no effect on expenditure between rural and peri-urban children’s energy expenditure, in common with previous studies. Compared to rural children, peri-urban children spent 108 less calories while at rest, which is thought to be due to lower immune activity. Most importantly, variation in market foods was related to children’s level of body fat.

“Our findings are in line with a growing body of research pointing toward poor diet being the most important factor underlying the development of childhood obesity,” Urlacher said. “Exercise is absolutely still a critical part of this equation and is essential for living a healthy life, but diet increasingly appears to be most directly related to children’s adiposity and long-term energy balance.”

The researchers plan to follow the children longitudinally to record any development obesity and cardiovascular problems.

Source: News-Medical.Net

Categories : Ageing Diet and Nutrition Mental HealthTags :

Mediterranean-type Diets Protect Against Parkinson’s Disease

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Researchers at the University of British Columbia have shown that the Mediterranean diet and another diet based on it, have a strong link in protecting against Parkinson’s disease (PD). 

These two diets had previously been shown that they could protect against other neurodegenerative diseases. The Mediterranean‐DASH Intervention for Neurodegenerative Delay (MIND) diet combines aspects of the Mediterranean diet and the DASH diet which protects against hypertension. The MIND diet emphasises consumption of berries, as research shows that they protect against mental decline, eating leafy greens and poultry. The MIND diet also mostly does away with potato, milk and fruit (excluding berries).

Senior author Dr Silke Appel-Cresswell said, “There is a lack of medications to prevent or delay Parkinson’s disease yet we are optimistic that this new evidence suggests nutrition could potentially delay onset of the disease.”
Following the diets delayed the average onset of PD by 17.4 years in women, and 8.4 years in men.

Since PD already has a notable sex difference, with 60% of sufferers being men, despite their shorter average lifespan, the sex difference in response to the diets opens new avenues of research
“It drives home the connection between the gut and the brain for this disease,” Dr Brett Finlay said. “It also shows it’s not just one disease that healthy eating can affect, but several of these cognitive diseases.”

Source: Medical Xpress

Journal information: Avril Metcalfe‐Roach et al, MIND and Mediterranean Diets Associated with Later Onset of Parkinson’s Disease, Movement Disorders (2021). DOI: 10.1002/mds.28464

Categories : Diet and NutritionTags :

Meat-free Diets Increase Risk of Fracture

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Research conducted on one of the largest dietary and health studies has revealed that people eating vegan, and to a lesser extent, vegetarian and pescetarian, diets are at higher risk for fractures.

This is in line with earlier studies that had indicated that vegan diets had weaker bones, but it had been unclear if this translated to an increased fracture risk.

Participants eating a vegan diet had a more than doubled increase of hip fracture risk; those on vegetarian and pescatarian diets also had an increase in hip fracture risk of 25%. Vegans, but not vegetarians and pescetarians, were also at increased risk of other fractures.

The research was done using data from the EPIC-Oxford trial, which followed over 65 000 participants from 1993 onwards, and controlled for a number of variables such as age, gender and level of physical activity.

The presence of protein helps to absorb calcium, and vegans are unlikely to be getting enough calcium without supplementing their diet. It is notable that after the 1990s, plant-based milk substitutes began to be fortified, which may have affected the results. 

A vegan diet also resulted in other health benefits as well as risks. Compared to an omnivorous diet, a vegan diet conferred a 10% reduction in cancer rates, 20% reduction in heart disease but also increased stroke risk by 20%.

The article is available to read at BMC Medicine.

Source: New Scientist