What Happens To Your Prostate When You Take Fish Oil Every Day

Many people endure the fishy burp often associated with taking fish oil every day to get the health benefits of omega-3 fatty acids. Research shows that taking fish oil supplements can reduce inflammation in the muscles, heart, and brain, according to a 2019 article in Critical Reviews in Food Science in Nutrition.

It might seem logical that fish oil might also reduce any inflammation associated with your prostate. However, there is significant debate about whether high levels of omega-3 might increase your risk of prostate cancer. A 2020 review in the British Journal of Cancer found that consuming high amounts of omega-3 fatty acids and alpha-linolenic acid might slightly increase your risk of prostate cancer. On the other hand, a 2021 study in Nutrients tracked more than 5,000 men for five years and found no significant connection between omega-3 levels in the blood and the risk of developing prostate cancer. 

With that said, taking fish oil every day might also improve the health of those who already have prostate cancer.

The two types of omega-3 fatty acids that reduce inflammation are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). It might be the EPA that could block the growth of prostate cancer, according to a 2021 study in Molecular Cancer Research. Using both clinical trials and mouse models, a monoacylglyceride (MAG)-conjugated EPA reduced the blood supply to prostate tumors to limit their ability to spread.

A prostate cancer screening usually involves a prostate-specific antigen (PSA) blood test. Higher levels of PSA in the blood might require additional screening for prostate cancer or benign prostatic hyperplasia (an enlarged prostate). In a 2016 review in Integrative Cancer Therapies, men with prostate cancer didn’t see any changes in their prostate-specific antigen levels (PSA) if they took a fish oil supplement. The review also found that fish oil supplements might not only reduce inflammation and other cancer markers but also reduce your risk of dying of prostate cancer. The researchers said more research is needed.

Supplementing your diet with fish oil might also improve the quality of life when you go through prostate cancer surgery. A 2023 study in Nutrients had some men take 3.75 grams of fish oil with 75% MAG-EPA seven weeks before prostate cancer surgery and continue taking it for a year after surgery. Compared to the control group, the men who took fish oil had improved their urinary function.

Not all fish oil supplements are alike. Some have higher ratios of EPA to DHA. It might be the DHA that pointed to an increase in prostate cancer. An older study in 2011 in the American Journal of Epidemiology didn’t find a link between fatty acids and prostate cancer risk. However, the men who had high levels of DHA in their system were associated with an increased risk of developing a more aggressive form of prostate cancer. It might be wise to consult with your doctor about your risk of prostate cancer before taking fish oil or an omega-3 supplement.

You could also look to the Mediterranean diet to reduce your risk and mortality of prostate cancer. A 2017 review in Frontiers in Nutrition looked closely at how the foods in the Mediterranean Diet work together to control obesity and, subsequently, the risk of prostate cancer. The Mediterranean Diet leans more towards plant-based foods while allowing for moderate consumption of fish and poultry and limiting red meat. Rather than taking a fish oil supplement, the Mediterranean Diet’s primary source of omega-3 fatty acids comes from olive oil. Because obesity factors heavily into your risk of prostate cancer, adhering to the Mediterranean diet can be protective against your cancer risk.