Search Health Studies

Moderate Alcohol Intake Linked with Lower Risk of Heart Disease

In the UK, moderate alcohol intake is defined by up to 3 drinks per day for men and up to two drinks per day for women. To see how drinking alcohol relates to heart disease risk, British researchers analyzed the drinking habits and health outcomes of nearly 2 million adults (although they did not differentiate between beer, wine, and other alcoholic beverages). They found that, compared to moderate drinking, both nondrinkers and heavy drinkers (exceeding the guidelines described above) were significantly more likely to suffer from heart failure, stroke, and death from heart disease, among other (but not all) heart problems. The scientists caution that “there are safer and more effective ways of reducing cardiovascular risk,” than taking up drinking (such as diet, exercise, and quitting smoking), and suggest that “a more nuanced approach to the role of alcohol in prevention of cardiovascular disease is necessary.”
BMJ. 2017 Mar 22;356:j909. (Bell S 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.) 

Healthy Diets (Such as Mediterranean Diet) Linked with Better Sperm Quality

For couples trying to get pregnant, a healthy diet may help tilt the odds in their favor. To see what types of foods are associated with better male fertility and healthy sperm quality, researchers analyzed data on eating patterns and male fertility in 35 observational studies from around the world. They found that a healthy diet (e.g. a Mediterranean diet) with lots of seafood, poultry, vegetables, fruits, low fat dairy, and grains is associated with better sperm quality. They also found that in some studies, processed meat, soy foods,  potatoes, full fat dairy, coffee, alcohol, sugary drinks, and sweets were linked with poor sperm quality and male infertility.
Human Reproduction Update. 2017 Mar 10:1-19. (Salas-Huetos A et al.)

Low Gluten Diet Linked with Diabetes

For those without a medically diagnosed gluten issue (such as celiac disease), the support for gluten-free and low-gluten diets appears to be more fad than fact. In a study of nearly 200,000 health professionals, researchers at Harvard found that eating lower amounts of gluten is related to a higher risk for type 2 diabetes. In fact, those in the top 20% of gluten intake were 13% less likely to get type 2 diabetes over the 30-year study period, even after adjusting for family history, exercise habits, weight, and calorie intake. (Note that research presented at meetings is considered preliminary until published in a peer reviewed journal.)
Presented at the American Heart Association’s Epidemiology and Prevention / Lifestyle and Cardiometabolic Health 2017 Scientific Sessions. Portland, OR. March 9, 2017. (Zhong G et al.)

Some Neanderthals (Relatives of Early Humans) were Vegetarian

Despite heavy marketing of the Paleo diet and lifestyle, very little is known about what our early human ancestors actually ate. To learn more about their diets, scientists in Australia studied the DNA of dental plaque from the teeth of Neanderthals (relatives of early humans) who went extinct about 40,000 years ago. While there was evidence of a meat-based diet (including wooly rhinoceros and sheep) in what is today Belgium, the Neanderthal diet in what is today Spain indicated a vegetarian diet, including mushrooms pine nuts, and moss.
Nature. 2017 Mar 8. [Epub ahead of print] (Weyrich LS et al.)

Inadequate Vegetables, Fruits, Whole Grains, Omega 3’s Linked with Cardiometabolic Death

Researchers created models to estimate the percentage of US cardiometabolic deaths (deaths from heart disease, stroke, or type 2 diabetes), that can be attributed to specific aspects of a poor diet. After analyzing decades of eating pattern data from large, nationally representative surveys (NHANES), the researchers estimated that nearly half of all cardiometabolic deaths can be attributed to poor diet. Specifically, they found that high sodium diets, low nut & seed intake, high intake of processed meats (like sausage or bacon), low seafood omega-3 fats, low vegetable intake, low fruit intake, high intake of sugar sweetened beverages (like soda), and low intake of whole grains contributed the most to cardiometabolic deaths, at about 5.9-9.5% each. The researchers note that the importance of eating more healthy foods (like whole grains or vegetables) is very important, in addition to decreasing less healthy foods (like soda or bacon).
JAMA. 2017 Mar 7;317(9):912-924. (Micha R et al.)

Whole Plant Foods, Not Fads, Best for Heart Health

Magazines and news articles often jump from one “superfood” or fad diet to the next, but not all nutrition advice is backed up by substantial evidence. In this review, researchers analyzed the scientific support for various trending “heart healthy” foods and diets. Eating berries, nuts, extra virgin olive oil, leafy green vegetables, and plant-based diets are all strongly linked with better heart-health based on numerous studies. On the other hand, coconut oil, palm oil, eggs, juicing, and southern diets are linked with potential harm. Additionally, the researchers found no support that gluten-free diets are beneficial for people without gluten related disorders. The authors conclude that “Evidence-based healthy dietary patterns are high in fruits, vegetables, whole grains, legumes, and nuts in moderation, although some may include limited quantities of lean meats (including poultry and seafood), low-fat dairy products, and liquid vegetable oils.”
Journal of the American College of Cardiology. 2017 March 7;69(9):1172-87.

Eating More Soy Linked with Less Breast Cancer Death

Soy foods (like tofu, edamame, or soy milk) have a complicated relationship with breast cancer, since soy has estrogen-like properties. To see if eating isoflavones (the major estrogen-like compound in soy) relates to breast cancer outcomes, researchers analyzed the eating habits and health outcomes of more than 6,000 newly-diagnosed breast cancer patients (all women) in the US, Canada, and Australia. Scientists found that women eating the most isoflavones (the amount in at least ¼ cup soymilk per day) were less likely to die over the 9-year study period, but the results were only statistically significant in women with hormone-receptor-negative breast cancers (the breast cancers unlikely to respond to hormonal therapy).
Cancer. 2017 Mar 6. [Epub ahead of print] (Zhang FF et al.)

Healthier Diet May Reduce Greenhouse Gas Emissions & Cut Healthcare Costs

Healthy diets nourish both people and the planet, and the savings can be quite impressive. Scientists in California created models to analyze how greenhouse gas emissions and healthcare costs might change if we decrease red & processed meat and refined grains in our standard US diet, and shift to eat more beans and peas, whole grains, fruits, and vegetables. The researchers found that opting for the healthier diets can reduce risk of heart disease, colorectal cancer, and type 2 diabetes by 20-40%, saving the US $77-93 billion per year in healthcare. These shifts can also lower greenhouse gas emissions by 222-826 kg CO2, which is equivalent to 6-23% of the US Climate Action Plan’s target. Climatic Change. 2017 Mar 6. [Epub] (Hallstrom E et al.)

Mediterranean Diet Linked with up to 40% Lower Risk of Breast Cancer

About ⅓ of breast cancer cases are hormone-receptor-negative, meaning that they are unlikely to respond to hormonal therapy. To see if diet relates to breast cancer risk, researchers analyzed the eating habits and health outcomes of more than 62,500 post-menopausal Dutch women for about 20 years. Those most closely following a Mediterranean diet were 40% less likely to develop estrogen-receptor-negative breast cancer, although overall breast cancer risk and the risk for other types of breast cancer were not significantly lower. Nut intake was the only food significantly associated with a lower risk of estrogen-receptor-negative breast cancer. For total and estrogen-receptor positive breast cancer, whole grain intake contributed the most to the lower risk, although not significantly.
International Journal of Cancer. 2017 Mar 5. [Epub ahead of print] (van den Brandt PA).

Home-cooked Family Meals Enjoyed Without TV On Linked with Less Obesity

Home-cooked meals enjoyed with others are good for the heart, the soul, and even the waistline. Researchers analyzed the eating habits and body mass index (based on height and weight) of 12,842 adults in Ohio. They found that adults eating all home-cooked family meals were 26% less likely to be obese than those who only ate some or no home-cooked family meals (relying on takeout, microwave dinners, or fast food instead). Additionally, those who never watched TV or movies while eating dinner were 37% less likely to be obese than those who always did. However, the frequency of eating family meals together was not linked to obesity, meaning those eating 6-7 family meals each week were just as likely to be obese as those eating just 1-2 family meals.
Journal of the Academy of Nutrition and Dietetics. 2017 Feb 24. pii: S2212-2672(17)30069-2. [Epub ahead of print] (Tumin R et al.)

Cheese Not Associated with Body Fat or Blood Cholesterol Levels

Dairy has a complicated relationship with nutrition, as it contains essential nutrients (like calcium, protein), but also ones that we are told to cut back on (saturated fat and sodium). To see how eating different dairy foods relates to health, researchers analyzed the eating patterns and health markers of 1,500 healthy Irish adults. They found no significant health differences (fatness, cholesterol, etc.) among people who eat different amounts of cheese, except that higher cheese intake is linked with C-peptide (a sign of healthy insulin sensitivity). Researchers also found that total dairy is linked with less body fatness and lower blood pressure, and that cholesterol appears to be higher among those who prefer reduced fat milk and yogurt, because they also eat more refined grains.
Nutrition & Diabetes. 2017 Feb 20;7(2):e243. (Feeney EL et al.)