Fish Oil Good for Heart Health in Males—At All Ages!
It has been well documented that high intake of EPA/DHA rich foods and supplements promotes cardiovascular health by reduction of various risk factors including lowering blood pressure, serum triglyceride levels and improving inflammatory markers. What has not been studied as closely is the cardio protective effects and mechanisms of EPA/DHA intake on men in various age groups.
A recent publication from the journal Molecular Nutrition & Food Research aimed to examine the age-related effects of a fish oil supplement on various cardiometabolic markers including fatty acid composition, and serum oxylipin profiles. Male participants in the study were grouped into a “young cohort” aged 18-30 years old and “older cohort” aged 60-74 years of age and were then randomized to a control or a fish oil supplement group for three months.
Patients in the fish oil group were given 2.0 grams of EPA and 1.0 gram of DHA daily while the placebo group received 3.0 grams of olive oil per day. The following parameters were evaluated at baseline and at the end of the three month study: glucose, insulin, triglycerides, total cholesterol, LDL-cholesterol (LDL-c), HDL-cholesterol (HDL-c), high-sensitivity C-reactive protein (hs-CRP), fatty acid composition, oxylipins, RNA quantity and quality and variability of genetic expression in predetermined genes.
Results: At the end of the study, both the young and older men in the fish oil group had a significant reduction of levels of circulating triglycerides of approximately 30%. Serum and red blood cell (RBC) levels of EPA and DHA increased in both groups although there was a significantly smaller increase in the DHA levels in the older men. These findings indicate fish oil supplements can regulate levels of serum and RBC fatty acid in an age-dependent manner providing cardioprotective properties in both groups but through different mechanisms.
Both groups experienced an increase in the Omega-3 Index (O3I) to approximately 8%, a level which has been estimated to offer the greatest degree of cardio protection. However, in young men the increase in O3I was attributed to increases in both EPA and DHA while the older men’s increase in O3I was mainly from an increase in EPA.
Another goal of the study was to look at the age-related effects of supplementation on the serum oxylipin profiles in both age categories. Oxylipins are derived from polyunsaturated fatty acids (PUFAs) and play important roles in health and disease through inflammation modulating actions. The results from this study indicate that the young and older patient groups experienced a similar modification in oxylipin profile with a reduction in 5-HETE level and increase in 17-HDoHE. 5-HETE is typically found to be pro-inflammatory and thus a lowering would support fish oil’s anti-inflammatory effects. There was a small increase in 17-HDoHE whose precursor is DHA. 17-HDoHE is then converted into D series resolvins (RvD) and protectin/neuroprotection D1. Together the changes in levels of 5-HETE and 17-HDoHE promote an improved anti-inflammatory profile in both age groups of male subjects.
Finally gene expression in the studied genes was not significantly different between the young and older groups.
Conclusions: The study’s authors concluded that fish oil supplementation offers cardio protective properties some of which function similarly in both younger and older males such as the triglyceride-lowering benefits while others, such as the remodeling of the fatty acid composition of RBCs, occur in an age dependent manner. Moreover, the changes seen in oxylipin profiles contribute to the cardiovascular protection through anti-inflammatory mechanisms, one of which is an increase in resolvin production. These changes were found to be similar in both age categories.
Further studies are warranted to more specifically understand the mechanisms that are occurring to create the health benefits found from fish oil supplementation in varying ages of men.
Why is this Clinically Relevant?
- Fish oil supplementation provides cardio protective benefits for both young and older males
- The mechanisms underlying the anti-inflammatory properties of fish oil supplementation varies by age
- Fish oil supplementation provides cardiac health benefits through changes in RBC fatty acid composition in both young and older males but the composition modifications vary by age
- Fish oil supplementation influences production of resolvins as part of the anti-inflammatory pathway and is present in both young and older males
Zulyniak, M et al. Fish oil regulates blood fatty acid composition and oxylipin levels in healthy humans: A comparison of young and older men. Mol. Nutr. Food Res. 2016, 60, 631-641.