Study Subjects Do Not Appear to Have Taken Fish Oil Supplements
Life Extension scientists repeatedly reached out to the authors of the negative report, but did not receive a response as to whether any attempt was made to ascertain the source of the omega-3 in the study subjects’ blood. We wanted to know if these men regularly ate cold-water fish or took at least some fish oil supplements.
Despite our requests, no clarification was made available by study authors as to the level of dietary supplementation with fish oil, and if so, the source of fish oil used in the study.
Based upon the very low plasma percentage levels of omega-3 fatty acids detected in the study, the implication is that dietary supplementation with fish oil likely did not occur. Instead, based upon the low levels of omega-3 plasma phospholipids detected, the source appears to have been primarily (potentially exclusively) diet only. As we will show soon, it appears that none of the men in this study consumed much in the way of cold-water fish either.
Omega-3 Levels Were Low in All Study Subjects
You will be shocked to learn how low the average plasma percentages of omega-3 were in all these study subjects, whether they were in the high or low rate of prostate cancer group.
Plasma phospholipid testing for fatty acids was used in this study. However, this type of fatty acid testing can vary widely depending upon short-term dietary intake. In contrast, long-term uptake by cells and tissues of the body is far less dependent upon short-term changes in diet. For this reason, erythrocyte (red blood cell) fatty acid indices are far better at evaluating cellular uptake over time as a result of fish ingestion and fish oil supplementation.
For example, data indicates that supplementing with about 2 grams of omega-3 fatty acids from fish oil leads to an increase in erythrocyte (red blood cell) omega-3 fatty acid percentage from about 4% at baseline to about 8% at eight weeks.13
In a case analysis conducted by Life Extension staff, a healthy diet that included fish but not fish oil supplementation resulted in an omega-3 red blood cell (RBC) equivalence level of 6.06%.
However, a standard diet supplemented with 3.6 grams of EPA/DHA from purified fish oil resulted in an omega-3 RBC equivalence level of 10.59%. Thus, compared to what can be achieved with a healthy diet alone, adding a high quality fish oil supplement can nearly double a person’s omega-3 RBC equivalence score, which is consistent with the published literature.
Therefore, if participants in the report alleging an association with fish and prostate cancer had been taking meaningful doses of fish oil supplements, their levels should have been substantially higher than what the study authors reported. Instead, for men in the prostate cancer group of this study, the percentage of plasma long-chain omega-3 fatty acids was only 4.66% ... a lower level than historic baselines taking no supplemental omega-3s.13
The numbers below should clarify this glaring flaw that renders conclusions from this report claiming fish or fish oil increases prostate cancer meaningless:
- Omega-3 RBC equivalence percentage when taking 3.6 grams/day EPA/DHA 10.59%
- Omega-3 RBC equivalence percentage of a moderate fish eater 6.06%
- Average long-chain omega-3 plasma percentage in study group with higher prostate cancer rates 4.66%
- Average long-chain omega-3 plasma percentage in study control group (no prostate cancer) 4.48%
There may be no need to provide any more rebuttal than the numbers posted above. They make it clear that the average subject in their groups were consuming very little cold-water fish and certainly no meaningful fish oil supplement. Their entire study population was so negligible in omega-3 that no relevant correlation can be drawn for health conscious people today choosing omega-3-rich foods (like cold-water fish) and high-potency fish oil supplements.
Yet based on this study of men who consumed relatively no omega-3s, frenzied news reporters were advising the public to stop eating cold-water fish and avoid omega-3 supplements.
Virtually No Difference in Omega-3 in Men Who Developed Prostate Cancer
When reading the frantic news reports, you would have thought the omega-3 difference in men with up to 71% increased risk of prostate cancer must have been huge.
At Life Extension, our very first reaction was that the researchers were comparing cardiac patients who gobbled down huge amounts of fish oil supplements to normal individuals who consume relatively little omega-3s. Our initial assumption was that since heart disease patients have higher prostate cancer rates, then that would explain why higher omega-3 could be mistakenly associated with increased prostate cancer risk, since heart disease patients are known to consistently take high-potencies of omega-3s through diet and supplements. How wrong our early conjecture was!
It turns out that the differences in omega-3 plasma phospholipid levels between groups were slight. In fact they were so close that we at Life Extension would classify them all as being too narrow to extrapolate meaningful data.
Our goal is to get the red blood cell (RBC) omega-3 index values in Life Extension members to 8-11% as this level was shown to offer the greatest protection against sudden myocardial infarction, yet the average quartile for plasma long-chain omega-3 fatty acids in the prostate cancer cases in the report associating fish oil with prostate cancer was only 4.66%.
Now look how narrow the difference is between men with higher prostate cancer rates. In the group whose average baseline blood draw showed 4.48% plasma long-chain omega-3 fatty acids, there was no increased prostate cancer risk. But if the omega-3 percentage average went up to 4.66% (about 1/5 of one percent), prostate cancer rates skyrocketed, according to the report’s authors.
We’re talking here of a difference of 0.18% in the percentage of plasma omega-3 fatty acids that supposedly caused a 43 to 71% increase in prostate cancer incidence. Dedicated fish oil supplement users, on the other hand, have over 100% higher omega-3 levels than seen in this study of men who apparently consumed little cold-water fish and no omega-3 supplements.
To put this into real-world perspective, the trivial difference (0.18%) in plasma omega-3 between men with no prostate cancer and those with prostate cancer could occur if a man ate just a few ounces of a cold-water fish like salmon the night before.
Remember, plasma phospholipid testing for fatty acids was used in this study. However, this type of fatty acid testing can vary widely depending upon short-term dietary intake. In contrast, long-term uptake by cells and tissues of the body is far less dependent upon short-term changes in diet. For this reason, the omega-3 RBC equivalence score is far better at evaluating cellular uptake over time as a result of fish ingestion and fish oil supplementation.
There was only one baseline blood draw. The men were followed for up to six years (low-grade and high-grade cancer), with a smaller group followed up to nine years to see who would get high-grade prostate cancer. Those who developed prostate cancer were then compared against their baseline blood draw done years earlier.
This kind of methodology is open to misinterpretation and errors even if there were large variances in omega-3 fatty acid percentages, but the 0.18% difference is so tiny that it has no relevance to aging humans who choose to include omega-3-rich foods in their diet and supplement with fish oil.
This may be the first study that seeks to discredit a food/supplement (i.e., omega-3s) where the human subjects were not even taking a fish oil supplement nor ingesting significant amounts of an omega-3 food.
A 0.18% difference in plasma omega-3 fatty acids between men who contracted prostate cancer and those who did not is infinitesimally small. To extrapolate a conclusion from this very small difference is false, misleading, and meaningless … but it did generate a lot of news headlines.
Life Extension is concerned that some men will decrease consumption of omega-3s. The result will be sharp elevations of blood triglyceride levels along with increased thrombotic, inflammatory, and atherogenic risks. An epidemic of coronary artery blockage and ischemic stroke will soon follow.
Results Are Completely Inconsistent with the Known Biology, Pathophysiology, and Biochemistry of Prostate Cancer
A fundamental aspect of quality research is consistency and repeatability.
Stated another way, for a medical finding to be considered valid, the results should not contradict well-established facts involving known biology, physiology, biochemistry, etc. Furthermore, the finding should be repeatable by other scientists.
The report attacking omega-3s is inconsistent with a variety of aspects of the well-established scientific and medical literature.
For example, upon close inspection of the data (and not simply a top-line, parroted response by the mainstream media eager to generate headlines), non-smokers had more aggressive prostate cancer, and non-drinkers (alcohol) had higher risk of prostate cancer, and prostate cancer case subjects were less likely to report a history of diabetes than controls.
Based upon these results, the implication is that men who wish to avoid prostate cancer should consume excess calories and develop diabetes, drink alcohol heavily, and abuse tobacco.
This is completely inconsistent with well-established science and utter nonsense.
In fact, numerous scientific studies show fish oil omega-3 fatty acids offer significant protective benefit for prostate health.