Taking omega-3 fish oil supplements can increase your risk of aggressive prostate cancer by 70%
- The supplement also increased the risk of low-grade prostate cancer by 44%
- One theory is that pills can suppress the immune system
- Omega-3 fish oils are one of the most popular nutritional supplements in the UK
Fish oil supplements, which are believed to have a number of health benefits, could trigger prostate cancer.
Experts found that omega-3 fatty acids can increase your risk for the most deadly form of the disease by more than 70 percent.
Researchers warned against omega-3 pills and recommended eating only one or two meals of fatty fish a week.
Fish oil supplements are said to protect against heart attacks and strokes, ward off arthritis, increase brain performance and prevent behavioral disorders in children.
Ingesting omega-3 fatty acids, which are derived from fish oils, can increase a man’s risk of high-grade prostate cancer by 71 percent
However, scientists found that those with the highest levels of omega-3 in their blood were 71 percent more likely to develop fast-growing, difficult-to-treat prostate tumors.
They were also more likely to get the slower, less fatal form of the disease, with the overall risk of prostate cancer increasing 43 percent.
The team at the Fred Hutchinson Cancer Research Center in Seattle warned, “There really is no evidence that dietary supplement use is beneficial, and there is growing evidence that high doses are harmful.”
Dr. Alan Kristal said the omega-3 levels associated with increased cancer risk would be achieved by taking just one supplement a day or three or four meals a week of fish like salmon and mackerel.
About meals, he said, “There are good things in fish, so the message is moderation. It’s probably not bad for you and it tastes good. ‘
Omega-3 intake was also linked to a 44 percent higher chance of developing low-grade prostate cancer
However, he emphasized that compared to the fatty acids ingested from eating oily fish, the amount consumed via pills was “huge”.
It’s unclear how fish oil could cause tumors, but omega-3s can limit the immune system or damage our DNA. It’s also unclear whether it helps tumors grow and spread.
The result came from a broader research project involving more than 2,000 men looking at whether nutritional supplements containing vitamin E and the mineral selenium could help prevent prostate cancer – the most common cancer in British men that kills more than 10,000 people . Selenium was of no benefit, and vitamin E increased the likelihood of developing the disease.
Dr. Kristal said, “As we do more and more of these studies – and I’ve been involved in them for most of my career – we find that high doses of supplements have no effect or increase the risk of the disease you are trying to prevent.
“There isn’t really a single example that taking a dietary supplement reduces the risk of chronic disease.”
Professor Malcolm Mason of Cancer Research UK said, “The results of this study are surprising and we clearly need more research to understand what is behind it.”
Although he stressed that researchers might not be sure whether the study participants ate oily fish or took omega-3 supplements, he said the results “show how complex the effects of dietary supplements could be”.
Dr. Prostate Cancer UK’s Iain Frame agreed that “Larger and more complex studies must be done before we understand how the risks of high omega-3 diets are weighed up” [its] Services’.
Several recent studies have also questioned the benefits of omega-3s for the heart. One that looked at 20 studies involving nearly 70,000 people found that those who took omega-3s were no less likely to die from a heart attack or stroke than others