One Major Side Effect of Taking Fish Oil, Says New Study
What supplement bottles do you see when you open your medicine cabinet? Maybe you have fish oil for reduced risk of heart disease, probiotics for gut health maintenance, and vitamin D for a strong immune system. According to new research, those fish oil pills may actually be a waste of money.
A new study conducted by scientists at the University of Georgia suggests that taking fish oil daily could only be effective if you have the right genetic makeup. The study, which was published in the journal PLOS Genetics, included data from 70,000 people who were participants in a large-scale cohort study called U.K. Biobank, which collected genetic and health information from 500,000 participants.
In the sample, the researchers examined four blood lipids—high-density lipoprotein (HDL, aka healthy cholesterol), low-density lipoprotein (LDL, aka unhealthy cholesterol), total cholesterol, and triglycerides—all of which are biomarkers for heart disease. The most shocking finding was that a fish supplement may heighten the risk of heart disease in some individuals. (Related: The 7 Healthiest Foods to Eat Right Now).
"We've known for a few decades that a higher level of omega-3 fatty acids in the blood is associated with a lower risk of heart disease," Kaixiong Ye, lead study author and assistant professor of genetics in the Franklin College of Arts and Sciences, said in a statement.
"What we found is that fish oil supplementation is not good for everyone; it depends on your genotype," Ye added. "If you have a specific genetic background, then fish oil supplementation will help lower your triglycerides. But if you do not have that right genotype, taking a fish oil supplement actually increases your triglycerides."
The data sample was divided into two groups: those who took fish oil supplements (which was about 11,000) and those who did not. The researchers then performed a genome-wide scan for each group, which involved testing for 8 million genetic variants. Sixty-four million tests later, the results showed a significant genetic variant in the GJB2 gene. Those who took fish oil and had the AG genotype experienced a decrease in their triglyceride levels, whereas individuals with the AA genotype who took the supplement had a slight increase in their levels.
Previous clinical trials have indicated that fish oil isn't effective at preventing heart disease, which Ye believes may have to do with the absence of genotype consideration. But this new study pinpointed a specific gene that can modify a person's response to fish oil supplementation.
"Personalizing and optimizing fish oil supplementation recommendations based on a person's unique genetic composition can improve our understanding of nutrition," Ye said in the press release, "and lead to significant improvements in human health and well-being."
In the interim, why not stick to incorporating more heart-healthy fish like salmon and mackerel into your diet once or twice a week? Your heart could benefit from the omega-3 fatty acids that are rich in these food sources. For more, be sure to read These Two Supplements May Reduce Your Heart Disease Risk, New Study Says.