Tag Archives: Diets

Science: American Indian Covid-19 Cases, Healthy Heart Diets (Podcast)

First up, host Meagan Cantwell speaks with Abigail Echo-Hawk, director of the Urban Indian Health Institute and chief research officer for the Seattle Indian Health Board. Echo-Hawk shares what inspired her journey in public health and explains the repercussions of excluding native people from health data. 

This story was originally reported by Lizzie Wade, who profiled Echo-Hawk as part of Science’s “voices of the pandemic” series. Next, host Sarah Crespi interviews Danielle Murashige, a Ph.D. student at the University of Pennsylvania, about her Science paper that attempts to quantify how much fuel a healthy heart needs. 

Healthy Diet Podcasts: “Spoon-Fed” Author & Professor Tim Spector

According to a recent study, obesity increases the risk of dying of Covid-19 by nearly 50%. Governments around the world are now hoping to encourage their citizens to lose weight. But with so much complex and often contradictory diet advice, as well as endless food fads, it can be hard to know what healthy eating actually looks like. 

How many pieces of fruit and vegetables should you eat a day? Will cutting out carbs help you lose weight? Is breakfast really the most important meal of the day? Speaking to Tim Spector, professor of genetic epidemiology at King’s College London about his new book Spoon-Fed, Madeleine Finlay asks why we’re still getting food science wrong, and explores the current scientific evidence on snacking, supplements and calorie labels. 

Tim Spector is a Professor of Genetic Epidemiology and Director of the TwinsUK Registry at Kings College, London and has recently been elected to the prestigious Fellowship of the Academy of Medical Sciences. He trained originally in rheumatology and epidemiology. In 1992 he moved into genetic epidemiology and founded the UK Twins Registry, of 13,000 twins, which is the richest collection of genotypic and phenotypic information worldwide. He is past President of the International Society of Twin Studies, directs the European Twin Registry Consortium (Discotwin) and collaborates with over 120 centres worldwide. He has demonstrated the genetic basis of a wide range of common complex traits, many previously thought to be mainly due to ageing and environment. Through genetic association studies (GWAS), his group have found over 500 novel gene loci in over 50 disease areas. He has published over 800 research articles and is ranked as being in the top 1% of the world’s most cited scientists by Thomson-Reuters. He held a prestigious European Research Council senior investigator award in epigenetics and is a NIHR Senior Investigator. His current work focuses on omics and the microbiome and directs the crowdfunded British Gut microbiome project. Together with an international team of leading scientists including researchers from King’s College London, Massachusetts General Hospital, Tufts University, Stanford University and nutritional science company ZOE he  is conducting the largest scientific nutrition research project, showing that individual responses to the same foods are unique, even between identical twins. You can find more on https://joinzoe.com/ He is a prolific writer with several popular science books and a regular blog, focusing on genetics, epigenetics and most recently microbiome and diet (The Diet Myth). He is in demand as a public speaker and features regularly in the media.

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Studies: 4- And 6-Hour Time-Restricted Eating (TRE) Diets, No Food Limits Result In Weight Loss

UIC Chicago Illinois
University of Illinois, Chicago (July 15, 2020)

“The findings of this study are promising and reinforce what we’ve seen in other studies — fasting diets are a viable option for people who want to lose weight, especially for people who do not want to count calories or find other diets to be fatiguing,” Varady said. 

…participants in both daily fasting groups reduced calorie intake by about 550 calories each day simply by adhering to the schedule and lost about 3% of their body weight. The researchers also found that insulin resistance and oxidative stress levels were reduced among participants in the study groups when compared with the control group.

4- And 6-Hour Time Restricted Eating TRE DietsTwo daily fasting diets, also known as time-restricted feeding diets, are effective for weight loss, according to a new study published by researchers from the University of Illinois at Chicago.

The study reported results from a clinical trial that compared a 4-hour time-restricted feeding diet and a 6-hour time-restricted feeding diet to a control group.

“This is the first human clinical trial to compare the effects of two popular forms of time-restricted feeding on body weight and cardiometabolic risk factors,” said Krista Varady, professor of nutrition at the UIC College of Applied Health Sciences and corresponding author of the story.

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Diet Infographic: Most “Macronutrient Diets” Reduce Weight & Blood Pressure In 6 Months (BMJ)

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From a BMJ Study article (April, 2020):

Compared with usual diet, moderate certainty evidence supports modest weight loss and substantial reductions in systolic and diastolic blood pressure for low carbohydrate (eg, Atkins, Zone), low fat (eg, Ornish), and moderate macronutrient (eg, DASH, Mediterranean) diets at six but not 12 months. Differences between diets are, however, generally trivial to small, implying that people can choose the diet they prefer from among many of the available diets (fig 6) without concern about the magnitude of benefits.

Introduction

The worldwide prevalence of obesity nearly tripled between 1975 and 2018.1 In response, authorities have made dietary recommendations for weight management and cardiovascular risk reduction.23 Diet programmes—some focusing on carbohydrate reduction and others on fat reduction—have been promoted widely by the media and have generated intense debates about their relative merit. Millions of people are trying to lose weight by changing their diet. Thus establishing the effect of dietary macronutrient patterns (carbohydrate reduction v fat reduction v moderate macronutrients) and popular named dietary programmes is important.

Biological and physiological mechanisms have been proposed to explain why some dietary macronutrient patterns and popular dietary programmes should be better than others. A previous network meta-analysis, however, suggested that differences in weight loss between dietary patterns and individual popular named dietary programmes are small and unlikely to be important.4 No systematic review and network meta-analysis has examined the comparative effectiveness of popular dietary programmes for reducing risk factors for cardiovascular disease, an area of continuing controversy.

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Medical Podcasts: A Clinical Review Of “The Pritikin Diet” (JAMA)

JAMA Clinical Reviews LogoNathan Pritikin was a college dropout who became an entrepreneur. While doing research for the government during World War II, he observed that populations that had extremely limited food availability because of the war had substantially reduced mortality from cardiovascular disease—something unexpected at a time when cardiovascular disease was thought to be due to stress. 

After the war when food became more available CVD death rates went back up, resulting in Pritikin concluding that CVD was related to diet. Pritikin devised his own very low-fat diet that bears his name and the diet is still in use 65 years later.

Health Studies: “Habitual” Supplementation Of Fish Oil (Omega-3) Lowers “All Cause Mortality” (BMJ)

From a BMJ Research study (March 4, 2020):

The BMJ podcastHabitual fish oil supplementation is associated with a 13% lower risk of all cause mortality, a 16% lower risk of CVD mortality, and a 7% lower risk of CVD events among the general population

Fish oil is a rich source of long chain omega 3 fatty acids, a group of polyunsaturated fats that primarily include eicosapentaenoic acid and docosahexaenoic acid. Initially, these compounds were recommended for daily omega 3 fatty acid supplementation for the prevention of cardiovascular disease (CVD). Consequently, the use of fish oil supplements is widespread in the United Kingdom and other developed countries.

Omega-3 Fatty Acids Cardiovascular Protection

Several mechanisms could explain the benefits for clinical outcome derived from fish oil supplementation. Firstly, the results of several studies have indicated that supplementation with omega 3 fatty acids has beneficial effects on blood pressure, plasma triglycerides, and heart rate, all of which would exert a protective effect against the development of CVD. Secondly, several trials have shown that omega 3 fatty acids can improve flow mediated arterial dilatation, which is a measure of endothelial function and health. Thirdly, omega 3 fatty acids have been shown to possess antiarrhythmic properties that could be clinically beneficial. Finally, studies have reported that fish oil can reduce thrombosis. Additionally, studies have reported that the anti-inflammatory properties of fish oil could have a preventive role in the pathophysiology of CVD outcomes. Other mechanisms could also be involved to explain the effect of fish oil on CVD outcomes.

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Diet: “Skeptical” NY Times Health Writer Endorses Numerous Health Benefits Of 16+ Hour Fasting

From a New York Times article by Jane E. Brody (Feb 17, 2020):

“It takes 10 to 12 hours to use up the calories in the liver before a metabolic shift occurs to using stored fat,” Dr. Mattson told me. After meals, glucose is used for energy and fat is stored in fat tissue, but during fasts, once glucose is depleted, fat is broken down and used for energy.

The Benefits of Intermittent Fasting Jane E Brody New York Times February 17 2020I was skeptical, but it turns out there is something to be said for practicing a rather prolonged diurnal fast, preferably one lasting at least 16 hours. Mark P. Mattson, neuroscientist at the National Institute on Aging and Johns Hopkins University School of Medicine, explained that the liver stores glucose, which the body uses preferentially for energy before it turns to burning body fat.

For example, human studies of intermittent fasting found that it improved such disease indicators as insulin resistance, blood fat abnormalities, high blood pressure and inflammation, even independently of weight loss. In patients with multiple sclerosis, intermittent fasting reduced symptoms in just two months, a research team in Baltimore reported in 2018.

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Mayo Clinic Health: “Obesity Epidemic And Popular Diet Trends”

On the Mayo Clinic Radio program, Dr. Donald Hensrud, director of the Mayo Clinic Healthy Living Program, discusses the obesity epidemic and talks about popular diet trends, including intermittent fasting.

This interview originally aired Feb. 8, 2020.

Learn more about intermittent fasting: https://www.mayoclinic.org/healthy-li…

Weight Loss: Medical Review Of “Keto, Atkins, and Pritikin Diets” (JAMA)

JAMA Clinical Studies PodcastThere are many named diets that receive a great deal of attention. But what are they and do they work? David Heber, MD, PhD, from the UCLA Center for Human Nutrition explains these diets.

Healthy Diets: “The Science Behind Fasting – Ketosis” (Infographic)

The Science Behind Fasting - Ketosis
Cellular Cleanup Crew Fasting and caloric restriction both can ramp up autophagy, a kind of cellular housekeeping. When cells are in famine mode and don’t have to break down food, they pause their usual tasks and stop dividing. Instead, they work on repairing and recycling damaged components, and cleaning out dead or harmful cell matter. Alison Mackey/Discover

…It seems fasting triggers a dramatic switch in the body’s metabolism, according Discover Magazine logoto a paper Mattson and colleagues published in February in the experimental biology journal FASEB. In humans, fasting for 12 hours or more drops the levels of glycogen, a form of cellular glucose. Like changing to a backup gas tank, the body switches from glucose to fatty acids, a more efficient fuel. The switch generates the production of ketones, which are energy molecules that are made in the liver. “When the fats are mobilized and used to produce ketones, we think that is a key factor in accruing the health benefits,” says Mattson.

Read more at Discover Magazine