SEARCH HEALTH STUDIES

Low-Carb Diet Not Well Suited for Those Without Diabetes, Pre-Diabetes

While there is no one-size-fits-all weight loss plan that works for everyone, it seems that a low Glycemic Load or low carbohydrate diet makes little difference for most people who don’t have diabetes (or pre-diabetes). Researchers analyzed data from 3 different experiments (high Glycemic load vs low Glycemic Load, lots of whole grains vs few whole grains, and low fat vs. low carbohydrate) and noted whether the weight change differed between people with insulin sensitivity issues (such as diabetes or pre-diabetes). Eating a high Glycemic Load diet resulted in significantly more weight gain in people whose bodies don’t respond well to insulin (the hormone that helps control blood sugar), compared to those without insulin sensitivity issues. Similarly, people with insulin sensitivity problems lost more weight on a New Nordic Diet (high in whole grains) or a high-fat, low-carbohydrate diet. However, people without diabetes or pre-diabetes lost more weight on a high-carbohydrate, low-fat diet.  
American Journal of Clinical Nutrition. 2017 July 5. [Epub ahead of print.] (Hjorth MF et al.)

 

Healthy Diets (Like Med Diet) Associated with Longer Lives

Can an apple a day keep the grim-reaper away – at least for a while? To find out how diet relates to mortality, researchers analyzed the diets of 47,994 women and 25,745 men. They used scores from the Alternate Healthy Eating Index, the Alternate Mediterranean Diet, and the Dietary Approaches to Stop Hypertension (DASH) diet to determine diet quality. They found that a 20-percentile increase in any of these three diet-quality scores was associated with a reduced risk of death from any cause. Specifically, a 20-percentile increase in diet-quality score was associated with a 25% reduced risk of death from cardiovascular disease when assessed by the Alternate Healthy Eating Index, 7% when assessed by the Mediterranean Diet score, and 4% when assessed by the DASH score. Overall, a healthful diet full of whole grains, vegetables, fruit, and fish is linked with a longer life.
New England Journal of Medicine. 3 July 2017;377(2):143-153. (Sotos-Prieto M et al.)

Vegetable Protein Linked with Lower Risk of Early Menopause

Early menopause is linked with health risks, like heart disease, so strategies to prolong fertile years in women are an important area of research. In a study of 85 women, women with the highest plant protein intake had a 16% lower risk of early menopause (defined as menopause before age 45) compared to women with the lowest intake in the group. Plant foods with protein include beans, peas, nuts, seeds, lentils, whole grains and soy foods. Overall animal protein intake was unrelated to risk of early menopause, but red meat intake was associated with a 12% higher risk of early menopause. Additionally, one serving per day of pasta, dark bread, or cold cereal was also associated with lower risk of early menopause, at 36%, 7%, and 18%, respectively.
American Journal of Epidemiology. 2017 June 24. [Epub ahead of print] (Boutot ME et al.)

Whole Grain Foods Improve Blood Sugar Management After Meals

Whole grains are thought to help prevent type 2 diabetes, but researchers want to learn more about this protective effect. In a review of 14 randomized controlled studies, scientists found that whole grain foods led to better post-meal blood sugar management than refined grain foods. However, the medium- and long-term effects (6 weeks or more) on fasting blood sugar were not significantly different between whole grain and refined grain meals. 
Nutrients. 2017 Jul 19;9(7). pii: E769. (Marventano S et al.)

Workplace Mediterranean Diet Program Improves Food Choices among Workers

Even in Italy, workers are starting to opt for unhealthy Western food choices, in place of traditional Mediterranean meals. To combat this trend, researchers in Italy piloted a health program within worksite cafeterias of a large industrial corporation. Handouts, posters, and other promotional material decorated the cafeteria to encourage consumption of healthy foods like vegetables and whole grains. Nutritionists also worked with the food service staff to modify recipes to make them healthier. At the end of the pilot, after analyzing food choices from 738 employees (half office workers, half plant workers) there was a higher purchase rate of dishes based on whole grains, legumes, fish, and poultry and a lower purchase rate of dishes based on refined grains, red meats, eggs and cheese. This trend persisted up to three years after the intervention. There was also better adherence to the national Italian recommendations for saturated fat, cholesterol, sugars and fiber after the study. The authors conclude that this could be a good model for other workplace nutrition programs, especially given that it cost the employer very little, and did not take up too much of the foodservice employees’ time.
International Journal of Food Sciences and Nutrition. 2017 Jun;69(1):117-124. (Vitale M et al.)

Substituting Refined Grains with Whole Grains During Gestational Diabetes Linked with Less Childhood Obesity

Foods that moms choose during pregnancy may have an impact on their children’s health down the line. In a study of more than 500 mother-child pairs in Denmark, in which all of the moms were diagnosed with gestational diabetes (diabetes during pregnancy), Harvard researchers found that substituting 1 serving of refined grains per day with whole grains in the mom’s diet during pregnancy was associated with a 10% lower risk of the child being overweight or obese at age 7. They also found that eating more than 4.3 servings of refined grains per day during pregnancy was linked with nearly double the risk of children becoming overweight or obese at age 7 compared to those who ate fewer than 1.8 servings of refined grains per day. These results were especially strong in kids who were breastfed for less than 6 months.
American Journal of Clinical Nutrition. 2017 June 7. [Epub ahead of print.] (Zhu Y et al.)

Fiber Linked with Less Knee Pain Worsening and Less Symptomatic Osteoarthritis

Osteoarthritis is a painful joint condition in which the flexible tissues at the ends of bones get worn down. To see how eating patterns might relate to joint pain in this condition, scientists analyzed the diets of 5,227 US adults (average age = 61) with (or at risk of) osteoarthritis. Those eating 20.6 grams of fiber per day were 30% less likely to develop symptomatic osteoarthritis than those eating only 8.6 grams of fiber per day, and scientists noted a dose-response relationship (meaning that higher fiber intakes are correlated with a lower risk of symptomatic osteoarthritis). Similarly, the researchers found that those eating the most cereal fiber (the type of fiber in whole grains) had a 14% lower risk of knee pain worsening than those eating the least (8.4 grams vs 2.8 grams). However, results were not statistically significant for other types of fiber (such as fiber from fruit or nuts).
Annals of the Rheumatic Diseases. 2017 May 23. [Epub before print.] (Dai Z et al.) 

Gluten Not Related to Heart Disease, but Avoiding Whole Grains Is

Unless you have celiac disease, you might want to rethink that gluten-free diet. In a study of more than 100,000 US adults without celiac disease, followed for more than 25 years, researchers found that eating gluten was not related to heart disease risk. In fact, the researchers caution that avoiding gluten may result in eating fewer whole grain foods, which may in turn pose a risk for heart disease.
BMJ. 2017 May 2;357:j1892. (Lebwohl B et al.)

Very Low Carb Diet May Impair Athletic Performance

Very low carbohydrate “keto” diets can increase oxygen uptake (VO2 peak). However, this doesn’t necessarily translate to an improvement in athletic performance, and may be detrimental. In this study of 21 race walkers, researchers assigned them to a very low carb “keto” diet, or 2 different types of high carb diets. In the keto diet, the participants experienced reduced economy, meaning their bodies required more oxygen at a given speed, despite their increased VO2 peak. This translated to no improvement in the keto diet group speed, with 5.3-6.6% improvements in speed for the high carb diet groups.
The Journal of Physiology. 2017 May 1;595(9):2785-2807. doi:10.1113/JP273230. (Burke LM et al.)

Whole Grains Linked with Lower Circulating Insulin in Kids

Whole grains have long been associated with chronic disease prevention in adults, but research suggests that children may benefit as well. In this study, researchers analyzed the 7-day food records of more than 700 Danish children and confirmed whole grain intake by also taking biomarkers of whole wheat and rye intake. They found that whole grains and fiber were linked with lower levels of serum insulin, indicating healthier blood sugar management. Additionally, oats were linked with less body fat, and lower systolic blood pressure (the first number in your blood pressure reading), insulin, and LDL (bad cholesterol).
Journal of Nutrition. 2017 May 1;147(5):816-824. (Damsgaard CT et al.)

Mediterranean-Based Diets Associated with Better Cognitive Function

Dementia is a serious neurological disease, so preventive measures are an important area of research.  In a study of 5,907 adults, researchers analyzed whether the Mediterranean diet and/or the MIND diet  (a diet similar to the Mediterranean diet, full of “brain-healthy” foods like leafy greens, nuts, berries, beans, whole grains, seafood, poultry, olive oil, and wine) have an effect on cognitive performance. Researchers found that those most closely following the Mediterranean Diet had 35% lower odds of having poor cognitive performance (assessed through tests of memory and attention), when compared to those not following a Mediterranean Diet. Results were similar for the MIND diet, probably because there is so much overlap in these two eating patterns.
Journal of the American Geriatrics Society. 25 April 2017. [Epub ahead of print.]  (McEvoy CT, et al.)

Few Patients with Suspected Non-celiac Gluten Sensitivity Actually Show Gluten-Specific Symptoms

Many patients who respond well to a gluten free diet, but don’t test positive for celiac disease, are thought to have non-celiac gluten sensitivity. However, a closer look at this population is raising some doubts. Researchers in Spain analyzed data from 10 studies comprising 1312 adults, all of which were double blind, placebo controlled gluten challenges (meaning that neither the researchers nor the participants knew if they were getting a gluten-free diet or the gluten-containing placebo).  Only 16% of the non-celiac gluten sensitivity patients showed gluten-specific symptoms when exposed to the gluten-containing diet, and 40% of them had similar or increased symptoms when on the gluten-free control diet. The researchers conclude that these results “cast doubt on gluten as the culprit food component in most patients with presumptive [non-celiac gluten sensitivity].”  
Perspectives in Clinical Gastroenterology and Hepatology. 2017 Mar:15(3):339-348. (Molina-Infante J et al.) 

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