Consumption of fish oil during pregnancy does not benefit babies’ cognitive development or mothers’ mood, according to a new study in the Journal of the American Medical Association. Pregnant women who consumed 800 mg of a DHA-rich fish oil supplement each day during pregnancy showed no benefits for depression, and their babies did not differ cognitively from children born from women who consumed a vegetable oil (rapeseed, sunflower, and palm) supplement. A team of researchers in Australia evaluated depression in 2,320 women six months postpartum and cognitive scores including memory, problem solving, and language for 694 children at 18 months.

Makrides M, Gibson RA, McPhee AJ, et al. Effect of DHA Supplementation During Pregnancy on Maternal Depression and Neurodevelopment of Young Children. JAMA. 2010;304:1675-1683.

New evidence contradicts the notion that early humans were mainly hunters. Archeological findings recently unearthed in Italy, Russia, and the Czech Republic show evidence that grains were ground into flour as far back as 30,000 years ago. The findings were presented in the Proceedings of the National Academy of Sciences.

Revedin A, Aranguren B, Becattini R, et al. Thirty thousand-year-old evidence of plant food processing. Proc Natl Acad Sci. 2010. Published ahead of print October 19, 2010: doi: 10.1073/pnas.1006993107.

Women consuming more vegetables have a decreased risk of breast cancer, according to a new study published in the American Journal of Epidemiology. Researchers followed the diets of 51,928 participants in the Black Women’s Health Study. Participants who ate two or more servings of vegetables per day had a 43 percent decreased breast cancer risk, compared with those who ate less than four servings per week. Cruciferous vegetables (e.g., broccoli, cauliflower, and kale) and carrots had the largest impact on breast cancer risk.

Boggs DA, Palmer JR, Wise LA, et al. Fruit and Vegetable Intake in Relation to Risk of Breast Cancer in the Black Women’s Health Study. Am J Epidemiol. Published ahead of print October 11, 2010. doi: 10.1093/aje/kwq293.

A low-carbohydrate diet based on animal food sources increases mortality risk, according to a new study funded by the National Institutes of Health. The study included 85,168 women from the Nurses’ Health Study and 44,548 men from the Health Professionals’ Follow-Up Study with an average of 23 years of follow-up. Researchers found that a high-animal-food, low-carbohydrate diet was linked with higher all-cause mortality, including a higher rate of cancer deaths. A high-vegetable-food, low-carbohydrate diet was associated with lower mortality, especially reducing the risk of death from cardiovascular events.

Fung TT, van Dam RM, Hankinson SE, Stampfer M, Willett WC, Hu FB. Low-carbohydrate diets and all-cause and cause-specific mortality: two cohort studies. Ann Intern Med. 2010;153:289-298.

Renowned Cleveland Clinic researcher Caldwell Esselstyn, M.D., highlights the need to change standard approaches to heart disease in an article to be published next week in the American Journal of Cardiology. Dr. Esselstyn explains why common methods of treating heart disease, such as stent and bypass surgeries, may have their place among a minority of patients, but for the vast majority, they are not as effective as low-fat, plant-based diets. The author acknowledges that physicians’ time constraints can limit the ability to provide information to patients. But ultimately, educated patients experience weight loss, blood pressure normalization, and improved or resolved diabetes, angina, and heart disease.

Esselstyn CB. Is the present therapy for coronary artery disease the radical mastectomy of the twenty-first century? Am J Cardiol. 2010;106:902-904.

McDougall shows how you can identify the bad guys: “But my guess is that Avandia will, unfortunately, remain on the market. The people keeping this medication on the market do so because of profits, and disregard the harms caused by it. Most of them work directly or indirectly for the drug maker, GlaxoSmithKline. Investors are worried because the company could face even more lawsuits than they currently have if the drug is pulled from the market by the FDA.”

McDougall debates fats versus carbs again: “Pointing the guilty finger away from fat and towards carbohydrates is self-serving for those diet-experts who themselves refuse to give up their high-fat diet.”

And, of course, recipes: Baco-yuba, Edamame Surprise, Chipotle Sauce, Mushroom Sauce, Gallo Pinto, Pico de Gallo, Fresh Corn Tortillas, and Costa Rican Mango-Avocado Salad.

Consumption of red and processed meats increases the risk of bladder cancer, according to a new study. Researchers looked at 300,933 men and women and found that those who consumed the most red meat had a 22 percent increased risk of bladder cancer, compared with those who ate the least. Consumption of nitrites and nitrates, compounds used for preserving, coloring, and flavoring processed meats, was associated with a 28 to 29 percent increased risk at highest intake levels. PhIP, a chemical commonly found in grilled chicken and other meats heated to a sufficient degree, was associated with a 19 percent increased risk of bladder cancer. Participants were part of the NIH-AARP Diet and Health Study and were included in a 7-year follow up.

PhIP has been linked to numerous cancers in humans, including breast, colon, and prostate. Nitrites and nitrates have long been recognized as potent carcinogens.

Ferrucci LM, Sinha R, Ward MH, et al. Meat and components of meat and the risk of bladder cancer in the NIH-AARP Diet and Health Study. Cancer. Published ahead of print August 2, 2010. doi: 10.1002/cncr.25463.

McDougall weighs in on the 2010 Dietary Guidelines Advisory Committee: “Except for a few hopeful sentences, the committee presents a report filled with fear mongering, doubletalk, omissions of major topics, consistently biased views of the scientific literature, and inexcusable factual errors that favor the livestock industries.”

Lack of physical activity is not the cause of weight gain in children, according to a study in Archives of Diseases in Childhood. Researchers measured physical activity and body fat percentage in 202 children annually from age 7 to age 10. The amount of physical activity did not result in changes in body fat. Although physical activity is important, the researchers concluded that focusing on food intake may have a larger impact on weight loss.

Metcalf BS, Hosking J, Jeffery AN, Voss LD, Henley W, Wilkin TJ. Fatness leads to inactivity, but inactivity does not lead to fatness: a longitudinal study in children (EarlyBird 45). Arch Dis Child. Published ahead of print June 23, 2010. doi: 10.1136/adc.2009.175927.

Dr. McDougall challenges claims by Dr. Andrew Weil in a recent Huffington Post article: “Pointing the guilty finger away from fat and towards carbohydrates is self-serving for those diet-experts who themselves refuse to give up their high-fat diet. Food industries buy scientific research published in respectable journals because it is one of their most effective marketing tools.”