Share on PinterestIf you are taking a fish oil supplement to improve your health, it may not have as much of an effect as you think it is. Getty Images
- New research has shown that fish oil may have little benefit in preventing cancer.
- However, it can slightly lower the risk of cardiovascular disease or death.
- Fish oil contains omega-3 fatty acids, which are important for health and must be sustained through diet.
- It is believed that the benefits of omega-3 fatty acids could result from their effects on inflammation, oxidative stress, or the composition of the cell membrane.
- It is important to consult your doctor about whether a fish oil supplement is right for you.
According to researchers at the University of East Anglia in Norwich, England, supplementing with fish oil offers little to no cancer benefit.
In fact, it appears to be linked to a slightly increased risk of a specific type of cancer: the prostate.
However, a group of researchers from China and the United States found that habitual fish oil use was associated with a lower risk of death from cardiovascular disease (CVD), as well as death from all causes.
In addition, it appeared to offer a small advantage over CVD events in the general population.
Fish oil supplements contain omega-3 fatty acids, which are important for health.
It is available both over-the-counter and on prescription.
Omega-3 fatty acids are also found in foods like nuts, seeds, and oily fish like salmon or mackerel.
These fatty acids have been thought to potentially protect against various diseases, including cancer and cardiovascular disease, possibly due to their effects on inflammation, oxidative stress, or cell membrane composition.
The researchers used the data from 47 different randomized controlled trials that included 108,194 people.
The studies included adults who did not have cancer, who were at increased risk of cancer, or who had previously been diagnosed with cancer.
In all studies, the higher consumption of omega-3, omega-6 or polyunsaturated fatty acids (PUFA) was compared with the normal intake.
Omega-3 and omega-6 fatty acids are types of PUFAs.
Both are essential fatty acids, which means the human body cannot make them. Instead, they have to be sustained through diet.
Proper proportions of omega-3 and omega-6 fatty acids are considered important for health.
In addition to examining fatty acid uptake, the studies examined cancer over a period of at least 1 year.
The studies looked at how many people either died or were diagnosed with cancer at the end of their respective studies.
After statistical analysis of the data, the team found that increased consumption of omega-3 fatty acids was associated with little or no positive effects on cancer prevention.
However, it was linked to a slight increase in prostate cancer risk.
According to lead author Lee Hooper, PhD, RD, Professor of Research Synthesis of Nutrition and Hydration at Norwich Medical School, if 1,000 people took omega-3 supplements for 4 years, three additional people would develop prostate cancer, otherwise.
The researchers involved in this study used data from the UK Biobank, a large population-based study that included 427,678 British women and men between the ages of 40 and 69.
The study participants who had neither CVD nor cancer took part in the study between 2006 and 2010.
Everyone completed a questionnaire related to the use of supplements such as fish oil.
The team used death certificates and hospital records to track deaths from cause or CVD, as well as heart attacks or strokes that occurred through 2018.
The researchers found during the follow-up period that those who had taken fish oil regularly at the start of the study had a 13 percent lower risk of death from all reasons.
They also had a 16 percent lower risk of death from CVD.
They also had a 7 percent lower risk of a heart attack or stroke.
The association between fish oil consumption and CVD appeared to be strongest in patients with high blood pressure.
Hooper states that because of their work, both the cancer risk and the benefit for CVD are very small.
“In general, as individuals, we are interested in staying healthy,” she said. “Whether we have cardiovascular disease or cancer is not the key, it is about preventing both.”
If you’re at increased risk for cardiovascular disease, these small perks may make it worthwhile to take fish oil supplements, Hooper says.
However, if you are at high risk of cancer it would not make sense to take them.
“Talking to your doctor is a good idea,” she added.
Timothy Richard Rebbeck, PhD, a researcher at the Dana-Farber Cancer Institute who was not involved in either study, agrees with the idea that certain high-risk populations could benefit from a fish oil supplement.
However, it is not yet possible to make strong recommendations, he notes.
So far, the data does not provide unequivocal evidence that fish oil supplementation has beneficial effects on CVD or cancer death.
In addition, he was not sure whether the risk of prostate cancer had actually increased, and found that none of the individual studies showed a statistically significant effect.
Based on these studies, it appears that a fish oil supplement has little to no benefit in preventing cancer. In fact, it can slightly increase your risk of prostate cancer.
However, a fish oil supplement may offer some benefit to people at risk for cardiovascular disease.
It is important to speak to your doctor about what is best for you as an individual.