Dietary fat gets personal

In the 39 years since the debut of the U.S. dietary guidelines, Americans have become heavier and increased their risk of certain chronic diseases. For this reason, a growing number of consumers believe that standardized nutrition advice is too broad to be effective. This belief has caused a rise in the popularity of personalized nutrition services that craft nutrition plans unique to an individual’s biological data. A recent study published in The Journal of Nutritional Biochemistry provides some credibility to the concept of personalized nutrition.

In conjunction with researchers at the University of California, Davis, scientists at the U.S. Department of Agriculture’s Agricultural Research Service conducted a study on human subjects to determine how their bodies would respond to a high-fat meal. The objective of the study was to determine the inflammatory response after each participant consumed a standardized meal equivalent to a hamburger, small fries, and an ice cream shake. While inflammation is part of the body’s normal immune response, unresolved chronic inflammation can damage cells, DNA, and normal organ functions and is a risk factor for many chronic diseases.

For each of the study’s 20 participants, the inflammatory response to the high-fat meal was distinct—none of them exhibited the same inflammatory response. Puzzled by the outcome, the researchers administered genetic testing on the subjects to determine whether some discernible patterns emerged among genes that were turned on or off. Still, no consistent pattern was present: For 13,000 genes tested, the results were also different.

While the findings may lead some credence to the concept of personalized nutrition, the study does not provide enough information to design customized nutrition plans. Many of the personalized nutrition tests marketed to consumers are based on DNA testing. This study indicates that no nutritional conclusions can be drawn from gene testing.