Eating more omega-3 and omega-6 fatty acids may reduce your risk of developing 14 different types of cancer

Consuming omega-3 and omega-6 fats (acids often found in plant foods and fatty fish) may affect your risk of cancer, according to an October study published in The Hill. International Journal of Cancer.

The study found that the more omega-3 and omega-6 fats circulating in the blood of study participants, the lower their overall likelihood of developing cancer. The association focuses on 14 different types of cancer, including colon, stomach, lung, brain, bladder and others.

According to study author Kaixiong “Kelvin” Ye, PhD, of the University of Georgia’s Department of Genetics, these results confirm what previous studies had hinted at. “Previous reports have suggested the potential benefits of omega-3 and omega-6 fatty acids in reducing cancer incidence and mortality,” he said.

However, he noted that the new study tried to avoid some of the limitations of earlier studies, such as relying on self-reported data, using small sample sizes and limiting the number of cancer types studied.

Here’s a look at exactly what the new study found, as well as what the study means for diet and cancer risk.

Omega-3 and omega-6 fats are polyunsaturated fats, meaning they have more than one double carbon bond in their chemical chain. In omega-3 this bond is located three carbons from the end of the chain, while in omega-6 it is six carbons from the end.

Although these two fats have many similarities in their chemical structure and biological pathways, they affect health in unique ways. “Omega-3 fatty acids are known to be more involved in brain development, cognitive function and cardiovascular health,” Ye said. “Omega-6 fatty acids are more involved in immune function and skin health.”

Since the body does not produce omega-3 and omega-6 fats naturally, they can only be obtained from food. Some of the best sources of omega-3 are fatty fish, while vegetable oils, nuts and seeds are rich in omega-6.

Many studies have focused on the effects of omega-3s on cancer prevention, but not many studies have focused on the effects of omega-6s. The latest study looked at both options.

For their analysis, the researchers looked at cancer incidence and blood levels of omega-3 and omega-6 fats in more than 250,000 people registered in the UK Biobank, a large biomedical database that has been running since 2006.

Over an average follow-up of 12.9 years, the researchers found that of the 250,000 participants, about 30,000 developed any of 19 “site-specific” cancers (those that occur in specific parts of the body such as the colon, lung, breast or pancreas) gland). They then compared blood samples from these participants with blood samples from people without cancer.

After crunching the numbers, they found that higher levels of omega-3 and omega-6 in the blood were associated with a lower risk of developing multiple types of cancer. Specifically, higher levels of omega-3 were associated with a reduced risk of colon, stomach and lung cancers, while higher levels of omega-6 were associated with a lower risk of brain, bladder, kidney, thyroid and other cancers. body parts. .

However, some results differed by age. “For cancer in general, the protective associations of omega-3s are stronger in younger age groups and in women,” Ye noted. “On the other hand, the protective association of omega-6 with cancer is generally stronger in older age groups, in men and in current smokers.”

Other differences emerged between the sexes. Three of the four cancer types that were not associated with omega-3 or omega-6 levels affected women—breast, ovarian, and uterine cancer. And there was another notable gender-specific phenomenon: prostate cancer. For unknown reasons, men with higher levels of omega-3 had a higher risk of developing this form of cancer.

The study also found that a higher ratio of omega-6 to omega-3 is associated with an increased overall risk of cancer, with the strongest association between the two being in colorectal, colon and lung cancers.

Although omega-3 fatty acids have received a lot of good press over the years, omega-6 fatty acids do not have such a stellar reputation. In fact, some social media accounts are full of anti-omega-6 messages, claiming that these fats cause inflammation or contribute to the development of heart disease. However, public health authorities such as the American Heart Association say that omega-6s are healthy for the heart and even necessary in appropriate amounts.

What appears to be critical in cancer and other diseases is the ratio of omega-3 to omega-6. “The study shows that while higher levels of omega-6 and omega-3 in the blood were associated with a lower risk of cancer, the (higher) ratio of omega-6 to omega-3 actually appeared to increase cancer risk ” Taylor Janulewicz, RDN, founder of My Cancer Dietitian, said Health. “This suggests that the balance between omega-6 and omega-3 may be more important than we thought.” Some studies suggest that a 1:1 to 2:1 ratio of omega-6 to omega-3 may be optimal for disease prevention.

If you’re looking to add more polyunsaturated fats to your diet, omega-6 rich options include:

And for getting more omega-3, the following foods are good sources:

To increase your intake, Janulewicz recommends starting with food rather than supplements. “The foods contain a number of additional nutrients that support overall health,” she said. “Whole foods help the body absorb these nutrients more efficiently, while supplements may not provide the same benefits or bioavailability.”