Today, omega-3 fatty acids are well-known for offering multiple health benefits, the most notable of which is helping prevent heart disease and stroke. Other benefits associated with these healthy fats include helping control lupus, eczema and rheumatoid arthritis; alleviating anxiety and depression symptoms; helping prevent age-related eye diseases; supporting brain development and function; and protecting against some types of cancer.
According to a recent study, the health benefits of consuming omega-3 fatty acids does not end there. Researchers from Iran and Australia investigated the effects of omega-3 fatty acid supplementation in infertile men and found that these fats can also improve sperm parameters that impact fertility. They discussed their findings in an article published in the Journal of Dietary Supplements.
There are three main types of omega-3 fatty acids: alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). ALA, the most common type of omega-3 found in Western diets, is present in vegetable oils, nuts, flaxseed, leafy vegetables and the fat of grass-fed animals. DHA and EPA, on the other hand, come mainly from fatty fish, such as salmon, mackerel, sardines and cod.
Recent studies have associated ALA with better cardiovascular disease outcomes and lower risks of Type 2 diabetes and bone fractures. Although ALA is converted into EPA and DHA inside the body, the efficiency of this conversion is very low. This means that while foods rich in ALA are poor alternative EPA and DHA sources, ALA nevertheless offers substantial health benefits all on its own.
EPA and DHA, the so-called marine omega-3s, are important for fetal development and healthy aging. They act as precursors of several metabolites that serve as lipid mediators; as such, they are beneficial for the prevention and treatment of many diseases. For instance, a study published in the American Journal of Clinical Nutrition reported that higher intake of EPA and DHA via fish oil supplementation decreased the expression of more than 1,000 genes in older adults. These genes were found to be involved in inflammatory pathways as well as signaling pathways that lead to atherosclerosis.
For their study, the Iranian-Australian team evaluated the effects of EPA and DHA supplementation on sperm parameters in infertile men. They searched different databases for relevant literature published between January 1, 1990 and December 20, 2017. The researchers then conducted a systematic review and meta-analysis of randomized controlled trials involving infertile men who were treated with DHA or EPA alone or in combination with other micronutrients.
The sperm parameters considered in the study included total sperm concentration, sperm motility, sperm DHA and seminal plasma DHA concentration. The researchers found three studies that met the inclusion criteria. A total of 147 patients comprised the intervention group, while 143 patients comprised the control group. (Related: Can probiotics reverse male infertility?)
Data analysis showed that omega-3 supplementation significantly increased sperm motility and seminal DHA concentrations in infertile men. Increased DHA levels in sperm is associated with better antioxidant status and reduced DNA damage. Compared with the controls, however, both DHA and EPA did not affect sperm concentration. The researchers confirmed the absence of publication bias through a funnel plot.
Based on these findings, the researchers concluded that DHA and EPA supplementation benefits infertile men by increasing sperm motility and DHA concentration in seminal plasma.