Marine fat, particularly in the form of fish oil rich in omega-3 polyunsaturated fatty acids (such as EPA and DHA), has been scientifically studied for its effects on the reproductive system. There is moderate evidence supporting its role in reproductive health, especially regarding male fertility and female reproductive function. Several studies have shown that omega-3 fatty acids can improve sperm count, motility, and morphology in men, potentially by reducing oxidative stress and inflammation. In women, omega-3 supplementation has been linked to improvements in oocyte quality and may help regulate menstrual cycles, as well as support fetal development during pregnancy.

The mechanisms by which marine fat influences reproductive health are thought to involve modulation of prostaglandin synthesis, improvement of blood flow to reproductive organs, and anti-inflammatory effects. However, most studies have focused specifically on fish oil or omega-3s, and not on "marine fat (unspecified)" more broadly. While there is supportive evidence, it is not conclusive for all forms of marine fat or for all reproductive issues. Therefore, the evidence is rated as moderate (3/5), with the strongest support for omega-3-rich sources.

References:

• Yeste, M. (2018). Fish oils and male fertility. Reproduction, 155(2), R47–R64.
• Gaskins, A.J. et al. (2018). Dietary patterns and fertility. Current Opinion in Obstetrics & Gynecology, 30(3), 173–179.