How You Cook Makes a Difference

Source: J Am Diet Assoc. 2010 Jun

In the past, studies of diet focused on nutrition (what we eat), but recent research strongly suggests that food preparation (how we eat), including preservative methods, has health effects as significant as the food itself. Glycation is a normal metabolic process that binds sugars to proteins or fats, but when the pool of Advanced Glycation End-products (AGEs) becomes excessive in blood and tissues, serious problems can result. Dietary AGEs (dAGEs) are also known as glycotoxins and have been implicated in the inception and progress of chronic diseases such as diabetes, atherosclerosis, and kidney disease. Many foods, particularly animal-based foods (meat and dairy), are already rich in dAGEs, but the way we prepare them is key—dAGEs increase with broiling, grilling, roasting, searing, and frying, but decrease with stewing, boiling, and steaming. Dry heat makes the difference. Because many modern food preservation techniques involve dry heat, large numbers of dAGEs may be present even before the food is actually cooked, giving some consumers a double dose of these glycotoxins.

Transplant Rejection Drug Benefits

Source: Annals of the New York Academy of Sciences, 1346

Much of biology is about communication between body systems. Key among these is the autoimmune system, the body’s way of recognizing and disposing of potentially dangerous “alien” cells. But the autoimmune system also attempts to “protect” the body against intentional medical interventions, such as organ transplants, which may be attacked as if they were invading cells. The medication Rapamycin was developed to suppress autoimmune response to organ transplantation, but since its discovery, its molecular target, “mTOR” (mechanistic Target Of Rapamycin), has been identified as a key regulator of metabolic communication, promoting or inhibiting the reproduction of genes that control carbohydrate metabolism and production of fats. These mTORs also aid in the production of proteins that inhibit the autoimmune process known as autophagy (when autoimmune cells eat” cells they recognize as alien invaders”). Thus, Rapamycin and similar inhibitors may not only prevent transplant rejection, but they have the potential to treat obesity and various forms of cancer, extending human lifespans.

Source: J Intern Med. 2016 Mar 16

Should we seek out sunlight or avoid it? A Swedish study shows that sun exposure confers both risks and benefits. The effects of sunshine vary with skin pigmentation, season, and physical distance from the equator. In Sweden, a region that receives little sunlight for more than half the year, women who spent more time in the sun were at lower risk for cardiovascular disease but showed an increased risk for skin cancer (investigators assessed the increased risk as approximately the same as that from smoking).

The study’s authors also discussed how regional and seasonal variations in sun exposure, melanin production, and vitamin D may contribute to risk factors for diabetes, multiple sclerosis, and cardiovascular disease. They concluded that ultraviolet exposure may have different effects on different health issues. Because of this, they question the uncritical use of sunscreen, noting that over-reliance on sunblockers may paradoxically lead to overexposure to the sun and an increased risk for skin cancer. 

Source: JAMA August 01, 2016

This study analyzed data from more than 130,000 participants over 32 years to identify associations of different animal and plant protein sources with risks for mortality. After they adjusted for dietary and lifestyle factors, researchers found that higher animal protein intake was associated with higher risk for mortality, particularly from cardiovascular disease, while higher consumption of plant protein was associated with lower mortality from all causes. These associations were true only for participants with at least one of the following risk factors: smoking, heavy alcohol intake, obesity, and physical inactivity.

When participants substituted plant protein for animal protein, their mortality risk decreased, especially when the participant had been a heavy consumer of processed red meat. Overall, the reduction of processed red meat consumption showed a much stronger association with reduced mortality than reduction of fish and poultry consumption. When protein was substituted for other nutrients (for example, carbohydrates), the source of that protein appeared to be even more important. It is clear that the choice of protein sources may be a key determinant in health outcomes and that public health recommendations should emphasize improvement of protein sources.

Source: Br J Nutr. 2014 Nov; 112(10)

Motivations guide real-world dietary choices and lead to different health consequences. We all know that not all vegetarians are alike: there are vegans, lacto-ovo-vegetarians, pesco-vegetarians, and so-called flexitarians. They may have different primary motivations for being vegetarian, including ethical, health, ecological, or religious concerns. But only some vegetarian patterns are associated with reduced consumption of added fats, sweets, snack foods, and refined grains; cultural motivations are still influential in dietary choice. An example would be a vegetarian whose primary motivation is to decrease animal suffering. This hypothetical person will consume more plant foods and less meat than a non-vegetarian but may not avoid soft drinks and snacks that contain added fats, sweets, and refined grains. When evaluating scientific information about the health effects of vegetarian diets, we should keep the motivations of the study population in mind. While all vegetarians will avoid the consumption of meat, their motivation for doing so influences their choice of foods, which in turn influences the nutritional consequences of their diet. 


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