Fitting into your genes: do genetic testing-based dietary recommendations work?

Science fiction is full of stories of genetic testing and its potential to revolutionize medicine and human performance. However, it’s not clear if the futurist hopes match scientific reality. Now that consumer genetic testing is both cheap and accessible, researchers have begun to study whether or not these services can actually help assess and manage health risks.

Because it’s such a new field, most of the research on the role of genetic testing for health management has been focused on diseases with known genetic risk factors, such as BRCA mutations, which greatly increase breast cancer risk. As research progresses, more and more genes and gene variants are being identified as risk factors for disease. However, as consumer genetic tests become more common, they’ve been used for a variety of lesser known exposure-disease associations based on more common gene variations.

Genetic testing will likely become more prevalent as it becomes cheaper, and consumers without much knowledge of genetics or disease will have access to information that they may not know how to handle. Genes can affect a variety of nutrition-related areas — everything from how we metabolize different fuel sources to how we absorb different nutrients.

But does it actually help people to have access to this information? Do people who receive advice based on genetic tests change their habits? The researchers in this study assessed whether or not genetic testing and subsequent dietary recommendations had an actual effect on diet, not just in the first days or weeks after being tested, but up to a year afterward.

The most established associations in genetics are for mutations that increase susceptibility to major diseases, such as BRCA for breast cancer. With the advent of direct-to-consumer genetic testing, a variety of lesser known genes have been tested, some of which can impact nutrients.