One compelling study examining the link between genetics, diet, and heart health claims that the cardiovascular benefits often associated with taking fish oil supplements may only be seen in people of a certain genotype. The association study suggests that in the future, nutritional recommendations can be optimized taking into account a person’s unique genetic makeup.
In recent years, a growing body of research has begun to question the longstanding recommendations recommending omega-3 fish oil supplements as beneficial for people at high risk for cardiovascular disease. Several large-scale meta-analyzes found little benefit from taking the popular dietary supplement, and a phase 3 clinical trial testing a purified, concentrated form of a specific fatty acid in fish oil was discontinued after preliminary data showed no benefit.
A new study published in the journal PLOS Genetics wanted to investigate whether a new gene-diet interaction might be responsible for the apparent discordance in previous research. A genome-wide association study was carried out with over 70,000 UK biobank participants.
A specific genetic variant that affects a gene called GJB2 was identified in the study as being significantly reduced in triglycerides in subjects who took fish oil supplements.
While this beneficial variant, called AG, resulted in triglyceride reductions in those who took the fish oil supplements, another variant, called AA, was associated with slightly higher triglyceride levels in those who took the supplements.
“We found that fish oil supplementation isn’t good for everyone; it depends on your genotype, ”says Kaixiong Ye, head of the new study. “If you have a certain genetic background, supplementing with fish oil will help lower your triglycerides. But if you don’t have the right genotype, taking a fish oil supplement will actually increase your triglycerides. ”
Of course, the researchers point out the limitations inherent in this type of association study. While a plausible mechanism can be traced back to this gene and its effect on blood lipids, more focused work is needed to understand how fish oil supplementation could interact with these genetic variants and affect cardiovascular health.
However, Ye says this novel association result could explain why a large number of previous studies on fish oil supplements and cardiovascular health have produced conflicting results.
“One possible explanation is that these clinical trials did not take into account the genotypes of the participants,” notes Ye. “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. “
If confirmed by further research, this type of gene-diet interaction gives credibility to the emerging field of precision nutrition. The idea is that there may not be one-size-fits-all recommendations for nutritional strategies and that in the future, nutritional advice could be tailored specifically to individuals based on a variety of physiological factors, including genetics.
“Personalizing and optimizing fish oil supplement recommendations based on a person’s unique genetic makeup can improve our understanding of nutrition and lead to significant improvements in human health and well-being,” Ye concludes.
The new study was published in the journal PLOS Genetics.
Source: University of Georgia