Hardly a day, or at most a week, goes by without a new headline advising one eating pattern or another. In a world where heart disease, obesity, diabetes mellitus and other chronic diseases are serious drains on health, happiness and national budgets, reliable information on sound nutritional patterns is crucial to turn the tide on these food borne illnesses. The contrast between the good and the bad of "nutrition experts" was highlighted this week providing a lesson in the care it takes to obtain reliable health information in a digital world where anyone can be an expert.
The "good" side of nutrition advice comes from a new scientific report derived from data on 131,342 participants in the Nurses' Health Study and the Physicians Health Study (85,013 women and 46,329 men) who were followed from as early as 1980 until 2012 (http://archinte.jamanetwork.com/article.aspx?articleid=2540540). Participants had baseline and repeat questionnaires every two years on dietary intake. There were 36,115 deaths with 8,851 due to cardiovascular disease (CVD), 13,159 from cancer, and 14,105 from other causes. The researchers found that the higher the intake of dietary animal protein (eggs, dairy, and any meat, fish or fowl) the higher the CVD mortality. In contrast, the higher the plant derived protein intake (grains, cereals, pasta, nuts, and legumes) the lower the mortality, particularly CVD deaths. The association of increased death rates in those that consumed more animal protein sources was stronger in participants with diabetes mellitus. The researchers calculated that substituting plant protein sources in place of animal protein primarily would reduce CVD deaths. Substituting plant proteins for eggs however was predicted to drop cancer deaths by 17%.
The authors concluded that "high animal protein intake was positively associated and mortality and high plant protein intake was inversely associated with mortality, especially among individuals with at least 1 lifestyle risk factor. Substitution of plant protein for animal protein, especially that from processed red meat, was associated with lower mortality."
On the other hand, the "ugly" side of nutrition advice showed up as an article in the lay press interviewing an interventional cardiologist just back from the small Italian village of Pioppi on the Mediterranean (http://www.standard.co.uk/lifestyle/health/the-big-fat-fix-meet-the-diet-doctor-changing-the-way-we-eat-a3303726.html). The article reports that butter is in style along with all other fats while sugar is the overlooked evil ingredient that has poisoned Western culture. This is the same story that rises periodically since Robert Atkins MD popularized his diet decades ago.
By good fortune, I too am an interventional cardiologist and I visited Pioppi within the last month. Conveniently omitted from the 'butter is back" article is the fact that Dr. Ancel Keys, the famous researcher and lead author of the Seven Countries Study that established a strong relationship between saturated fats and cardiovascular disease, lived in Pioppi for 40 years (http://www.sevencountriesstudy.com). In fact, there is a museum honoring his work that promotes largely plant based food, not butter. In both Pioppi and neighboring Accioroli (full of centenarians who eat garden to table emphasizing the healing power of rosemary), butter was not a staple of their diet.
All reasonable observers agree that residents in Western societies have been eating too much sugar and refined carbohydrates. But over 3 decades of research indicates that the optimal heart diet is based on predominantly on "good" carbs (fruits, vegetables, whole grains, legumes, soy in their natural, unrefined forms, preferably organic). While it's true that Americans have been advised to eat less fat since the 1970s, the data indicates that they never listened. The reality is since 1950, Americans have been consuming 67% more added fats, 39% more sweeteners, 800 calories more per capita and 57 pounds more meats (http://www.usda.gov/factbook/2002factbook.pdf). In addition, Americans have been exercising steadily less since 1950.
Thus, while Americans have been told to eat less fat, they have been consistently consuming more fat, more sugar and refined carbohydrates, more calories, and more meats -- and exercising less. So, it's not at all surprising why Americans are fatter than ever -- but it's not because we're eating too little fat or too adding too little butter to our plates.
In addition to the new study cited above, there is additional evidence that animal protein plays an important role in chronic diseases, including obesity and diabetes (http://www.ncbi.nlm.nih.gov/pubmed/24606898). For example, diets high in animal protein were associated with a 75% increased risk of premature death from all causes, a 400% increased risk of cancer, and a 500% increased risk of type 2 diabetes. These associations were either abolished or attenuated if the proteins were plant derived. The authors also reported that among those without type 2 diabetes at baseline, those in the high animal protein group had a 73-fold increased risk of developing diabetes during the study.
Overall, the comments by the butter promoting cardiologist are irresponsible and not supported by major medical societies or research. Decades ago, reductions in butter where central to health measures that reduced rates of heart attacks by over 80% in North Karelia, Finland (http://www.ncbi.nlm.nih.gov/pubmed/24606898). The message from this week's science (not swagger) can be distilled into the familiar: eat real food, not too much, and mostly plants (not smothered in butter).