New research suggests the health benefits of omega-3s are offset by increased prostate cancer risk. But that research doesn't make sense when put against the backdrop of everything else we know about omega-3s.
In recent years a study was released by the Fred Hutchinson Cancer Research Center linking omega-3 fish oil and prostate cancer. One headline I saw even read, “Taking omega-3 fish oil supplements may increase the risk of aggressive prostate cancer by 70 percent.” These types of headlines definitely sell newspapers, but the science is not that simple—or accurate.
No Real Connection Made Between Omega-3 Fish Oil and Prostate Cancer
First off, this wasn’t a double-blind study purely on omega-3s. To reach their conclusion, the researchers reanalyzed their findings from the Selenium and Vitamin E Cancer Prevention Trial (SELECT), which accurately warned about the relationship between Vitamin E and prostate cancer. The SELECT researchers discovered a 17 percent increase in prostate cancer among men taking 400 IU of dl-alpha tocopherol—essentially an overdose of a particular form of Vitamin E.
It is true that Vitamin E can have a pro-oxidant effect on HDL cholesterol, which can adversely affect the immune system. In addition, when you take too much of one Vitamin E derivative, as they did in the SELECT study, it will not eradicate the peroxynitrite radical. I personally prefer supplements with gamma tocopherol and mixed tocopherols, which is what I include in my formulas.
Get more of Dr. Sinatra's advice on Omega-3s
But Vitamin E wasn’t the only factor that contaminated the SELECT trial. Some of the the participants were also on prescription medications, and many of them smoked and drank alcohol. We don't know if the participants were taking omega-3 supplements or eating omega-3 rich foods, since the study did not control for these variables. The researchers also failed to report that one of the most important risk factors for prostate cancer in their data was having a first-degree relative with prostate cancer. A study like this would carry much more weight if it didn’t have all of these other confounding variables. Moreover, the entire conclusion of the study was based on a mere .2 percent difference in the participants' omega-3 levels.
What’s also interesting is the reason why these researchers conducted their analysis. The study was conducted to confirm previous research that they had reported from the Prostate Cancer Prevention Trial, which showed that omega-3s were associated with high-risk prostate cancer and that trans-fatty acids and omega-6s are associated with lower rates of high-risk prostate cancer. If you listened to these findings, you would throw out your fish oil and load up on trans-fats.
The Health Benefits of Omega-3s are Real and Supported by Research
This research also doesn’t make sense when you put it against the backdrop of everything we know about the health benefits of omega-3s and prostate cancer. Populations with the biggest intake of omega-3s from fish—such as the Eskimos, the Japanese, and the Inuits of Greenland—have some of the lowest incidences of prostate cancer. The health benefits of omega-3s are clear in Japan, where the incidence of prostate cancer is a full 10 times lower than it is in America.
Plus, there’s a tremendous amount of research showing the health benefits of omega-3s in reducing the risk of prostate cancer:
A 2003 study from the Harvard School of Public Health found that consuming fish - one of the natural sources of omega-3 - more than three times a week was associated with a reduced risk of prostate cancer. Plus, the strongest correlation was for the most aggressive, metastatic cancer.
A 2001 study in the Lancet studied 6,272 Swedish men over three decades and found that men who didn’t eat fish had a two- to three-fold higher risk of prostate cancer than those who ate moderate or high amounts.
A meta-analysis published in the 2010 American Journal of Clinical Nutrition found no protective effect on the incidence of prostate cancer among those who eat fish, but showed a 63 percent reduction in mortality from prostate cancer.
So what’s the bottom line? This research doesn’t change my mind about omega-3s. Your body needs omega-3s for healthy blood pressure, arterial functioning, circulation, eye health, mental processing and more. In fact, omega-3s are called an “essential fatty acid” because your body requires them, but can’t manufacture them—you need to get them from food or supplements. Natural sources of omega-3s include fish, leafy greens, and some seed oils. Taking supplements is just as good, but it is important to be a conscientious consumer when buying supplements. The best omega-3 supplements are pure and contaminant free, come from a sustainable source, and are high in DHA. Algae and calamari oil benefits come from naturally high levels of DHA omega-3s, which are the best form of omega-3 for supporting a healthy body and mind.
Now it's your turn: What do you think of this study linking fish oil and prostate cancer?