Fish oil is a nutritional source of omega-3 fatty acids and one of the most commonly consumed supplements. The World Health Organization (WHO) recommends eating 1-2 servings of fish per week, as the omega-3 fatty acids in fish offer many health benefits, such as: Such as helping heart health, helping you lose weight, and even reducing inflammation. New research from a team led by a University of Georgia scientist now reports that fish oil ingestion will only bring health benefits if you have the right genetic makeup.
The results were published in the journal PLOS Genetics in an article titled “Genome-Wide Association Study of Supplementation of Fish Oil with Lipid Characteristics in 81,246 Individuals Reveals New Locations of Interaction Between Genes and Diet” led by Kaixiong Ye, PhD, Assistant Professor of Genetics at Franklin College of Arts and Sciences.
“Fish oil supplements are widely used to reduce serum triglycerides (TAGs), but have mixed effects on other circulating cardiovascular biomarkers,” the researchers write. “Many genetic polymorphisms have been associated with blood lipids, including high and low density lipoprotein cholesterol (HDL-C, LDL-C), total cholesterol, and TAGs. Here, the gene-diet interaction effects of the fish oil supplement on these lipids were analyzed in a discovery cohort of up to 73,962 British biobank participants using a 1 degree of freedom test (1df) for interaction effects and a 2 degree test (2df) for the test of freedom joint analysis of interaction and main effects. “
“We have known for several decades that higher levels of omega-3 fatty acids in the blood are linked to lower risk of heart disease,” Ye added. “We have found that supplementing with fish oil is not good for everyone. it depends on your genotype. If you have a certain genetic background, a fish oil supplement will help lower your triglycerides. But if you don’t have the right genotype, taking a fish oil supplement will actually increase your triglycerides. “
Researchers looked at four blood lipids – high-density lipoprotein, low-density lipoprotein, total cholesterol, and triglycerides – that are biomarkers of cardiovascular disease. The data for their sample of 70,000 people were taken from the UK biobank.
After over 64 million tests, their results showed a significant genetic variant of the GJB2 gene. People with the AG genotype who took fish oil decreased their triglycerides. Those with the AA genotype who ingested fish oil increased their triglycerides slightly.
The new findings could also shed light on previous studies that reported that fish oil was of no benefit in preventing cardiovascular disease.
“One possible explanation is that these clinical trials didn’t take into account the genotypes of the participants,” Ye said. “Some participants may benefit from it, others may not. So if you mix them up and do the analysis, you won’t see the effects.”
In the future, researchers will test the effects of fish oil on cardiovascular disease directly.
“Our study identifies novel gene-diet interaction effects for four genetic loci whose effects on blood lipids are altered by fish oil supplementation. These results underscore the need for and possibility of personalized nutrition, ”the researchers concluded.