Fish Oil Supplementation May Reduce Genetic Risk of High Cholesterol

Fish oil and other omega-3 supplements may reduce the genetic risk of high total cholesterol and low-density lipoprotein (LDL) cholesterol, according to data published in The American Journal of Clinical Nutrition. The authors’ findings indicate that individuals who reported regular supplementation of fish oil had lower blood lipid levels, especially for total cholesterol, LDL cholesterol, and triglycerides.¹

Participants who consumed fish oil were more likely to be older, female, current alcohol drinkers, statin users, engaged in high physical activity, and have higher concentrations of total cholesterol, LDL cholesterol, and HDL cholesterol. Image Credit: © khamkula - stock.adobe.com

Many patients turn to fish oil supplements, and they are frequently suggested by pharmacists as a method for increasing omega-3 fatty acid intake. Studies indicate that omega-3s have anti-inflammatory properties that may provide relief from mild inflammation or joint pain, and fish oil supplementation, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), may protect the heart by reducing triglyceride concentrations. It is important to know which patients may benefit from omega-3 supplements the most, the supplements’ proper dosage, and the benefits that can be expected. Pharmacists can be essential sources of education for patients, offering them guidance on safe use, proper dosage, and the reasonings behind these recommendations to ensure positive outcomes.^2,3

The authors examined whether fish oil supplementation modifies the association between genetically predicted and observed concentrations of total cholesterol, LDL cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides. Using UK Biobank, they collected and assessed complete genetic and phenotypic data from 441,985 individuals aged 37 to 73. Participants provided blood samples, as well as sociodemographic, lifestyle, and medical records information via questionnaires at baseline.¹

Fish oil supplementation was determined through a touchscreen questionnaire that asked about consumption of specific supplements; however, it did not collect the dose, frequency, or duration of supplementation. The study included the primary outcomes of 4 serum lipid parameters including total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides. Using multivariable linear regression models, the authors assessed the modifying impacts of fish oil supplementation on the associations between the polygenic scores of the 4 lipids and their observed concentrations. These analyses were performed separately for each lipid across 4 ancestry groups: European, African, Central/South Asian, and East Asian.¹

According to the data, 31.8% of the participants reported habitual use of fish oil, of which 56% were female with a mean age of 59 years. Participants who consumed fish oil were more likely to be older, female, current alcohol drinkers, statin users, engaged in high physical activity, and have higher concentrations of total cholesterol, LDL cholesterol, and HDL cholesterol. Among other ancestry groups, 2,289 (34.8%) African, 1,942 (22.5%) Central/South Asian, and 845 (31.6%) East Asian participants used fish oil.¹

Overall, the data indicated that fish oil supplementation weakened the association between genetically predicted and observed circulating concentrations of total cholesterol, LDL cholesterol, and triglycerides while strengthening the corresponding association for HDL cholesterol. This suggests the ability of fish oil to lower specific lipid levels, thereby reducing their influence on genetic risk, as well as enhance the body’s ability to maintain higher HDL levels.¹

“Our study shows that considering lifestyles will improve genetic prediction,” Kaixiong Ye, BS, PhD, corresponding author of the study and an assistant professor of genetics in Franklin College of Arts and Sciences at the University of Georgia in Athens, said in an interview with UGA Today. “Our findings also support that fish oil supplements may counteract the genetic predisposition to high cholesterol.”⁴

The study had some potential limitations, such as unreliable self-reported fish oil intake, lack of dosage information, and the inability to evaluate the effects of fish oil for an extended duration of use. Studies with larger sample sizes and accurate dose information are needed to further expand the findings. However, the initial data supports the hypothesis that genetic effects on blood lipid concentrations could be modified by habitual fish oil supplementation.¹

REFERENCES

1. Sun Y, McDonald T, Baur A, et al. Fish oil supplementation modifies the associations between genetically predicted and observed concentrations of blood-lipids: a cross-sectional gene-diet interaction study in uk biobank. Am J Clin Nutr. July 15, 2024. doi: 10.1016/j.ajcnut.2024.07.009

2. Mason PR. What pharmacists need to know about omega-3 fatty acids and fish oil supplements. Pharmacy Times. May 17, 2022. Accessed August 22, 2024. https://www.pharmacytimes.com/view/what-pharmacists-need-to-know-about-omega-3-fatty-acids-and-fish-oil-supplements

3. Cole B. Omega-3 recommendations: counseling points for pharmacists. Pharmacy Times. April 27, 2020. Accessed August 23, 2024. https://www.pharmacytimes.com/view/omega-3-recommendations-counseling-points-for-pharmacists

4. Hataway L. At risk of high cholesterol? Taking fish oil may help. UGA Today. August 5, 2024. Accessed August 22, 2024. https://news.uga.edu/fish-oil-supplements-fight-risk-of-high-cholesterol/