"Link Between Omega-3 Fatty Acids and Increased Prostate Cancer Risk Confirmed."
"Study confirms link between high blood levels of omega-3 fatty acids and increased risk of aggressive prostate cancer."
These are scary headlines for men who worry about getting prostate cancer. But is this what the study published online in July 2013 from the Fred Hutchinson Cancer Research Center really showed? Did they demonstrate a real link between consuming oily fish and taking fish oil supplements and an increased risk of prostate cancer? The short answer is “No.”
There are a number of problems with this study.
Okinawan elders consume large amounts of vegetables and beans (including high concentrations of fermented soy), oily fish rich in omega-3 fatty acids several times per week, minimal meat and dairy, and virtually no processed food. They have the lowest incidence of prostate cancer in the world; their rate is 80% lower than the average rate of prostate cancer in North America! (The Okinawan Program, Willcox, Willcox and Suzuki, 2001).” For the Japanese, the incidence of prostate cancer is a full 10 times lower than it is for Americans.
Furthermore, Duffy MacKay, N.D., vice president, scientific and regulatory affairs, Council for Responsible Nutrition (CRN), the leading trade association representing the dietary supplement industry stated in a press release in response to the study: “Hundreds of studies over the past two decades have shown omega-3 fatty acids to have positive effects associated with cardiovascular health, perinatal health, inflammation, cognitive function, or cancer. Collectively, this body of research serves as the basis for numerous recommendations from respected organizations, scientific boards and health care practitioners that Americans get omega-3 fatty acids in their diets.”
The World Health Organization (WHO) and the U.S. Institute of Medicine's Food Nutrition Board recommend consuming Omega 3 oils. The American Heart Association and the American Diabetes Association both encourage eating 2 servings of oily fish like salmon each week. This is because Omega 3 fats reduce inflammation, reduce insulin resistance, and improve lipids. All of these are underlying causes of cardiovascular disease and diabetes. Omega 3 fats also favorably alter gene expression which reduces the chance a cell will become a cancer cell. This and inflammation are underlying causes of cancer. Surprisingly, the American Cancer Society has no mention of eating fish on their website.
In other words, based on previous research, we would predict that fish oil and omega 3 fatty acids would be more likely to prevent cancer than cause it.
Now let’s talk about the study itself. It follows an earlier study in 2011 from the Fred Hutchinson Cancer Research Center which suggested that Omega 3 fats contribute to prostate cancer. Alan Kristal, Dr.P.H. senior author stated “This (second) study confirms previous reports of increased prostate cancer risk among men with high blood concentrations of LCω-3PUFA (omega 3 fats). The consistency of these findings suggests that these fatty acids are involved in prostate tumorigenesis.”
Dr. Stephen Sinatra points out in his blog the entire conclusion of the study was based on a mere 0.2% difference in the participants' omega-3 levels.
Another concern, the study used plasma samples which only reflect the Omega 3’s that someone has consumed in the last 24-48 hours. A single fish oil dose (or hearty serving of fish) results in over 100% increase in plasma Omega 3 levels. A better test for ongoing effect of essential fats is a red blood cell Omega 3 (RBCO3) analysis, not plasma. RBCO3 reflect intake over the past several months.
“The difference in blood (plasma) concentrations of omega-3 fatty acids between the lowest and highest risk groups was about 2.5 percentage points (3.2 percent vs. 5.7 percent), which is somewhat larger than the effect of eating salmon twice a week” according to the author Kristal.
He did not criticize eating fish. Instead, Kristal pivoted and condemned taking fish oil supplements: "We've shown once again that use of nutritional supplements may be harmful."
No, they did not show that supplements are harmful.
The study did not ask about dietary intake. Or supplement intake. They did not collect this information. Maybe the patients with cancer heard from their hairdresser or physician or spouse that Omega 3 fats are good for you, and figured why not take some--or maybe they just had a nice Alaskan salmon steak the night before. Or maybe they were trying to eat a “healthier” diet since they had cancer. Eggs, leafy greens, grass fed beef, poultry, walnuts and flax seeds all contain Omega 3s.
The article’s conclusion that Omega 3s cause cancer (tumerigenesis) is speculative at best, and alarmist and confusing at worst. It is certainly not helpful.
The press didn’t help either. It frightened patients and caught physicians off guard. The media misled the public and sensationalized the results before the scientific community could respond. It is wise for all to not jump to conclusions and make abrupt changes based on any single study. If a therapy is working for you, don’t stop it because someone reports that it is “bad for you.”
So what are reasonable recommendations concerning fish oil supplementation or intake of oily fish? Just do it. Most of us are deficient. Our ancestors used to have a ratio of Omega 6 (vegetable oil)/Omega 3 (walnuts, flax and fish oil) of 1/1. We are now closer to 16/1. Unless you are told otherwise, 1200-2400 mg (EPA+DHA) Omega 3 fats/day is reasonable. If you have heart disease, autoimmune disease, depression or manic depressive illness you may require much higher doses. But too much fish oil isn’t good either. It can calm down inflammation too much. Work with someone and test red blood cell, not plasma, levels of essential fats.
Choose safe healthy fish oils. The product must be distilled to remove dioxins and PCBs. We have contaminated the seas with these toxins and bigger fish concentrate them in their fats. Oils made from sardines, anchovies and herring are the least polluted. To achieve the dose mentioned above consider buying a more expensive oil that has a higher concentration of EPA and DHA and swallowing fewer pills. Less expensive pills may only contain 200-300 mg EPA+DHA. One would have to take 10 of these a day.
If you prefer eating fish, eat oily fish. Farm raised Atlantic salmon does not have Omega 3 fats. It has Omega 6 fats from the corn that it is being fed in the salmon farm. Alaskan and Pacific salmon have good levels of Omega 3s and relatively low levels of pollutants. Two-three servings per week are enough. Sardines are an excellent source of Omega 3s.
If you are vegan, take flax oil. But you will have to take eleven grams of flax oil to make 1000 mg of fish oil. And if you eat any trans fats or have B vitamin deficiencies or drink alcohol or are “older”, you may not convert sufficient amounts of flax oil into DHA, the fish oil that makes up 25% of your brain. So take at least 400 mg DHA from algae in addition to the flax oil. That’s where the fish get it from.
If you use Krill oil take 300mg 1-2 x daily. Krill is EPA and DHA already attached to phospholipid which is their functional unit in the body. The phospholipids are more easily incorporated into cell membranes, which are where they reduce inflammation. Do not use Krill if you are sensitive to shrimp. Krill is especially good for lowering blood triglycerides.
When we take Omega 3 supplements, we must protect them from getting rancid by having sufficient antioxidants available. Omega 3 fats are the most unsaturated fats in the body. They need the most antioxidants. Be certain to take Vitamin E 400 IU with gamma and other tocopherols. Do not take synthetic dl alpha tocopherols alone. Or take ¼ cup sunflower seeds daily. Add selenomethionine 200mcg daily or a small handful of Brazil nuts and Vitamin C 1-2 1000mg twice a day.
Lastly, if you eat a lousy diet, taking fish oil doesn’t make up for eating a lousy diet. Supplements are supplementary to a great diet.
For more information, read the following resources.
Dr. Murray: http://doctormurray.com/how-a-selected-bad-study-became-big-news/
Dr. Hoffman: http://www.drhoffman.com/page.cfm/1213