Saturated fats not so bad after all - June 2016
Friday, June 24, 2016
New analysis of old data on human health raises doubts about the wisdom of replacing saturated fat that's found mainly in animal products with vegetable oils.
Research by the U.S. National Institutes of Health (NIH) that appeared recently in BMJ, the British medical journal, even warns of hazards from eating too much vegetable oil high in linoleic acid.
A study headed by NIH investigator Christopher Ramsden and 10 others reviewed previously unpublished raw data from a large-scale, 40-year-old Minnesota study that compares health effects from traditional and low-fat diets. Respected researchers Ancel Keys and Ivan Frantz, both deceased, conducted
the study among 2,355 psychiatric hospital patients over a five-year period which ended in 1973. The trial was among the largest conducted.
As expected, Keys and Frantz found reduced blood cholesterol levels in subjects who were fed the low-fat diet. However, the NIH analysis of complete unpublished findings shows "no mortality benefit" from the low-fat diet, the BMJ article says.
Clinical benefits of serum cholesterol lowering diets have "never been demonstrated in a randomized, controlled trial," the article maintains. Earlier, Ramsden and his colleagues analyzed data from a smaller Australian study which reached a similar conclusion.
Their report also warns about the potential health effects, particularly in susceptible populations, of consuming too much linoleic acid in vegetable oils.
"High linoleic acid intakes from vegetable oils are a recent and atypical nutritional phenomenon," the BMJ article says. The report cites links between oxidized derivatives of linoleic acid and coronary heart disease, chronic pain and fatty liver disease.
Dietary guidelines in the United States and Canada recommend limiting calories from saturated fats. However, NIH researchers warn that higher consumption of concentrated vegetable oils among industrialized populations over the past 100 years has more than doubled the consumption of linoleic acid. BF