Testicular function may improve with use of fish oil supplements
Young Danish men without any indication of infertility who regularly consumed fish oil supplements had better sperm quality and overall testicular function than their peers who used less or no fish oil supplements, according to findings published in JAMA Network Open.
“Young healthy men with intake of fish oil supplements have better semen quality and testosterone,” Tina Kold Jensen, PhD, professor at the University of Southern Denmark and Copenhagen University Hospital, told Healio, adding that this association was unexpected. “Many men have poor semen quality, and if this simple intervention may improve semen quality, it is of public health importance.”
Jensen and colleagues evaluated semen volume, sperm count, sperm motility and spermatozoa in the semen samples of 1,679 men (median age, 18.9 years). The researchers also evaluated the size of testes as well as follicle-stimulating hormone, luteinizing hormone, sex hormone-binding globulin, testosterone and estradiol levels in blood samples and 3-month supplement consumption habits via questionnaires that were completed by the participants.
Fish oil supplement use was reported by 5.8% of the cohort.
Mean testes size was elevated by 1.3 mL (95% CI, 0.5-2.1) among men who consumed fish oil supplements vs. those who did not, whereas semen volume was elevated by 0.49 mL (95% CI, 0.18-0.8), cubic root-transformed total sperm count was elevated by 0.39 million (95% CI, 0.03-0.76) and the ratio of free testosterone to luteinizing hormone was elevated by 8% (95% CI, 0-17). In addition, mean follicle-stimulating hormone levels were reduced by 20% (95% CI, –31 to –9) among men who consumed fish oil supplements vs. those who did not, whereas luteinizing hormone levels were reduced by 16% (95% CI, –24 to –8).
The researchers also found that more fish oil supplement use may have amplified the potential benefits. Mean testes size was elevated by 1.5 mL (95% CI, 0.2-2.8) among men who consumed fish oil supplements for at least 60 days vs. those who did not consume any, whereas semen volume was elevated by 0.64 mL (95% CI, 0.15-1.12) and cubic root-transformed total sperm count was elevated by 0.76 million (95% CI, 0.19-1.33). Mean testes size was elevated by 0.8 mL (95% CI, –0.2 to 1.9) among men who consumed fish oil supplements for less than 60 days vs. those who did not consume any, whereas semen volume was elevated by 0.38 mL (95% CI, –0.03 to 0.8) and cubic root-transformed total sperm count was elevated by 0.22 million (95% CI, –0.27 to 0.72).
“We found that intake of fish oil supplements during the past 3 months was associated with higher semen volume, total sperm count and testis size; lower follicle-stimulating hormone and luteinizing hormone levels; and a higher free testosterone to luteinizing hormone ratio among young men compared with no supplement intake,” the researchers wrote. “Interestingly, a dose-response association was found, as men with intake of fish oil supplements on 60 or more days had higher semen volume, higher total sperm count, lower luteinizing hormone level, higher free testosterone level and a lower free testosterone to luteinizing hormone ratio than men with fish oil intake on fewer than 60 days.”
‘Meaningful and insightful’ findings
In an accompanying commentary published in JAMA Network Open, Albert Salas-Huetos, MSc, PhD, postdoctoral fellow in the andrology and IVF laboratory at the University of Utah School of Medicine in Salt Lake City, wrote that “the study is meaningful and insightful,” although more specifics about the questionnaire used in the study would be beneficial.
“It is important that future studies consider phenotypic and lifestyle characteristics, including but not limited to diet, obesity, medications, smoking and physical activity, as Jensen et al did,” Salas-Huetos wrote. “Much work is still required to examine the complex association between dietary supplements and semen quality and to determine whether such an association could help to improve fecundity or fecundability and the results of assisted reproductive techniques.” – by Phil Neuffer
For more information:
Tina Kold Jensen, PhD, can be reached at firstname.lastname@example.org.
Disclosures: The authors report no relevant financial disclosures.