This is in response to the recent study on fish oil and prostate cancer.
And the wall-to-wall media coverage this has received.
Does fish oil cause prostate cancer?
Subjects in this study were not given fish oil. So, no!
Surprised? Read on.
The lead author of the study said so himself: “These results do not address the question of whether Omega-3s play a detrimental role in prostate cancer,” noted Dr. Theodore Brasky of The Ohio State University.
I will share documented facts in bold (and my opinions in italics.) If you know how to interpret scientific publications, I suggest you read the study yourself and come to your own conclusions. Or take this blog to your doctor for interpretation.
Obvious disclaimer: yes, I have a dog in this fight
To the cynical, it should come as no surprise that I hold these views. I don’t blame you for feeling this way. After all, we sell fish oil.
You should take my opinion with a grain of salt. You should question everything you read on the internet. (I do!)
But I’ve been tracking near-universal condemnation of this study by scientists, academics and those who are neither selling fish oil nor have a buck to gain.
What other scientists are saying:
Drs. Mehmet Oz and Michael Roizen: ‘Those fishy reports from a new study didn’t pass the smell test, did they?’
Omega-3 Centre (Non-profit Australia/New Zeland Govt Institution): ‘Conclusions are irresponsible and blatantly ignores the totality of evidence.’
Mark Hyman, M.D.: ‘This type of study does not prove cause and effect. If I did a study on sunrise and humans waking up, I would find 100 percent correlation, but that doesn’t mean that the sun came up because you woke up. Correlation, yes; causation, no. I’ll be eating sardines in my salad for lunch tomorrow, and I’ll be taking my daily fish oil supplement with my dinner tonight. And I hope you will be too!‘
Dr. Gerald Chodak, M.D. Author of ‘Winning The Battle Against Prostate Cancer‘: ‘The bottom line is that we cannot determine from this study design whether the intake of omega-3 fatty acids will cause prostate cancer and raise a man’s risk for high-grade disease. The media has taken this and sensationalized the risk associated with omega-3 fatty acid intake, but I believe that the attention is overplayed and the concerns about the study design were not mentioned at all. At the end of the day, this study does not prove that intake of omega-3 fatty acids causes prostate cancer or increases a man’s risk for high-grade disease.‘
Oregon State University: ‘The authors and news outlets highlighted a purported 70% increased risk of high-grade prostate cancer, but looking at the original data indicates that this finding was not statistically significant. The magnitude of the difference is likely too small to have any meaningful biological effect on prostate cells or any other cells in the body. It cannot establish cause-and-effect relationships.’
Prostate Cancer Institute: ‘Study flawed – don’t believe all you read.‘
Dr. Antony D’Amico, Professor of Oncology, Harvard Medical School: ‘The study cannot really make the conclusion it is trying to. The thing that concerns me the most is that you can associate almost anything with aggressive prostate cancer. You can find driving a Cadillac is associated.‘
Dr. Michael Murray, GreenMedInfo: ‘Bad study became big news. It shows a clear axe to grind in light of a great deal of scientific evidence on the value of dietary supplementation.‘
Prof. Gopinath Paliyath, University of Guelph: ‘I have no idea how this paper got accepted for publication.‘
Alliance for Natural Health: ‘Flawed study of fish oils leaps to wildly unsupported conclusions.‘
Dr. Barry Sears: ‘Having decades of experience of doing fatty acid analyses, I can tell that these numbers are clinically insignificant…analysis is meaningless. If the conclusion of the article was correct that higher levels of omega-3 fatty acids increase prostate cancer, then the Japanese male population should be decimated with prostate cancer. So what are the facts? The Japanese have one of lowest rates of prostate cancer incidence in the world.’
Michael Savage, Ph.D.: ‘There is a very, very dangerous report out there that many of you have panicked over…the media immediately jumped on this assistant professor’s opinion that fish oil is somehow related to prostate cancer…nothing could be further from the truth.‘
Denise Minger: ‘Obviously, fish is only bad for you if you’re American. The current fish-condemning media coverage is a load of hooey. All in all, this study is just another drop in the sea of misinterpreted nutritional research. Don’t take the bait!‘
Petro Dobromylskyj, Prostate cancer and Citrate and maybe Omega 3s: ‘Do PUFA, particularly omega 3 PUFA, give you prostate cancer? Probably not. No more than butter gives you prostate cancer.‘
Dr. Michael Lewis, M.D. Brain Health Education and Research Institute.: ‘What is really sad is how many people will decrease their intake of fish or stop their supplementation because of ridiculous studies/reporting like this. How much additional suffering will occur because of it?’
You may want to listen to this interview by Dr. Michael Savage, Ph.D in epidemiology & nutrition with prostate cancer researcher and professor of oncology at Harvard Medical School, Dr. Anthony D’Amico, MD, PH.D about this Study.
FACT: Omega-3 has NEVER been shown to cause prostate cancer.
Neither this study nor anything published prior has ever proven that Omega-3s cause prostate cancer.
FACT: this was an observational population study and by definition, you cannot establish causality from population studies. You can only infer associations. There are literally thousands of variables and Omega-3 is just one of them.
My opinion: This is like blaming the ambulance driver for the crime…since ambulances are always found at the scene of the crime. People who do not understand the difference between correlation and causation should not go on TV to talk about science.
FACT: This study also found that smoking and heavy drinking reduced prostate cancer.
My opinion: Thought you might like to know.
FACT: this study was NOT DESIGNED to look for a relationship between Omega-3 and prostate cancer. It was a study aimed to study Selenium and Vitamin E, not Omega-3.
FACT: they measured Omega-3 levels once.
My opinion: Once?! Just once?
FACT: they measured Omega-3 as % of total fatty acids.
My opinion: this is a lousy indicator of your Omega-3 status. This is like measuring your blood alcohol level an hour after a tequila shot. It’s not a good predictor of your long-term blood alcohol level. And you certainly cannot be charged with DUI two days later! If you eat salmon for lunch, your blood plasma Omega-3 levels will spike. Then drop.
Omega-3 as percent of total fatty acids is different than the Omega-3 Index, a far more reliable marker of your Omega-3 status.
FACT: the average Omega-3 level for people with cancer was 4.66%. People without cancer had 4.48%.
EPA+DHA levels of the three groups of people studied:
- No-cancer group: 3.62%
- Low-grade cancer: 3.67%
- High-grade cancer: 3.74%
My opinion: So the difference was within normal variation. Eating just 6 oz. of farmed salmon twice a week can double the Omega-3 level to 8%.
The scary news reports are about a minor difference when eating salmon can bump you up from 4% to 8%, with just one meal. It spikes about 6-8 hours after eating fish and washes out after a day or two.
If having 3.74% level of Omega-3 in your blood plasma can give you prostate cancer, then all Japanese should be long dead. And Kiwis (New Zealanders, with their low Omega-3 intake,) should live forever.
FACT: The study does not say if the people ate fish or took fish oil supplements. The authors did not ask. And we may never know. Yet the senior author, Dr. Alan Kristal was quoted as saying “We’ve shown once again that use of nutritional supplements may be harmful.”
My opinion: Really? Seriously, Doc, really? Where’s the proof? Your own data showed no such evidence. Where I come from, there is a word for this: bias.
Axe, meet grind.
In the Framingham Study, those NOT taking fish oil supplements measured in at 5.2% Omega-3 level. And those taking supplements had 7.5%.
Given that in other population studies, those not taking fish oil had Omega-3 levels of 5.2% and those in this study with ‘high grade’ cancer had only 3.74%, tells me that the participants in this study were almost certainly not taking fish oil supplements.
It is also entirely possible that the people who got cancer started taking fish oil in an effort to get healthy – nobody knows since this is not something the study controlled.
If you’re a prostate cancer researcher, you may want to know that:
- the study did not account for how often patients had a prostate-specific antigen (PSA) test
- did not account for how that PSA test was managed
- did not account for whether they had a prostate biopsy, or how the prostate biopsy was done
When the control group is invalid, the results are invalid.
You’re supposed to start with an open mind, then develop a hypothesis, you isolate variables and test your hypothesis/prove causality. The authors have done none of the above.
“We’ve shown once again that use of nutritional supplements may be harmful.”
|– Dr. Alan Kristal, senior author of the study implicating supplements even though supplements were not part of the study. There is no data in the study to indicate where the blood Omega-3 came from. Omega-3 levels of study participants were much lower than populations who do not take fish oil supplements.|
The media circus around this study plays along with this researcher’s irresponsibility and contradicts statements made by a slightly less irresponsible coauthor (Dr. Brasky.)
I don’t think the authors are unaware that they cannot make these statement. It’s not ignorance. It’s just career advancement. This kind of media attention brings funding and ensures job promotions, tenure-ship and all-around back-slapping.
And the media? Well, fear-mongering sells. And in a media circus, it’s always the supplement that gets taken out back and shot.
For what it’s worth, it is much better to get your Omega-3 from fish than from supplements.
A press release…for a scientific paper?!
Big events of commerce and culture get press releases and public relations mangers. But a press release for a scientific paper? Seriously? That’s very
Since lack of proof and scientific protocol would not allow them to say ‘Supplements are bad for you’ in the paper itself, they bought a press release to do so.
FACT (geek alert!): the study used Cox Proportional Hazard method for statistical analysis.
My opinion: I took two courses in statistics while in grad school. I barely passed. I find statistics far less interesting than watching C-SPAN on mute. So I’m no expert. But I know enough to know that Cox analysis is best used for steady-state drug ingredients, not a nutritional component that changes with the wind.
FACT: EPA and DHA were not statistically associated with prostate cancer using the Cox method.
My opinion: but you’d never know that based on senior author, Dr. Kristal’s appearance on CNN, Fox News, etc.
FACT: In 2011, the same group of researchers found no connection between EPA and prostate cancer. But did find a connection between DHA and prostate cancer. But even in that study, the difference in Omega-3 levels of those at ‘risk’ and not, was tiny.
This study also found that artificially created trans-fat decreased prostate cancer risk.
FACT: Going on low-fat diets can increase Omega-3 levels. True. Albeit only a little bit, like the levels found in the study in question.
My opinion: when you cut out fat from your diet, the replacement calories are almost always starchy, processed grains or something sweet. Sugars feed cancer. My point: there are many, many, many things that can trigger growth of tumors and cancer.
FACT: there have been a few studies (that got no media attention) that show that EPA and DHA prevented prostate cancer. See for yourself.
- This study published just last year by Harvard researchers said DHA reduced prostate cancer by 40%.
- This study from the National Cancer Institute also noticed that ‘EPA and DHA intakes may reduce the risk of total and advanced prostate cancer.’
- Another study found that Omega-3 causes prostate cancer cells to self-destruct (apoptosis.)
- This study released around the same time proposes how Omega-3 may prevent prostate cancer. But not a peep out of the media.
Note that these studies were DESIGNED to study Omega-3 effect on prostate cancer.
My opinion: I don’t think these comforting studies are sufficient to say that Omega-3 prevent prostate cancer. We can’t say that. These studies are not conclusive. They don’t establish cause and effect.
But it is worth noting that they suggest mechanisms:
- modulation of phospholipase A2 and oxygenases
- synthesis of their corresponding metabolites
- alteration in cell membrane phospholipid composition and receptor function
- regulation of gene expression and signal transduction
But there’s more…
This study not only suggests Omega-3 helps but it also points a finger at too much Omega-6 for triggering cancer.
A large 2010 meta-analysis showed a LARGE REDUCTION (63% reduction to be exact) in mortality from fatal prostate cancer. It was with fish consumption, not supplement use.
Sure, the vast majority of evidence on Omega-3 and cancer is encouraging – regardless of what the news says – and I can assure you that most scientists involved in this field are focused on how Omega-3 could prevent cancer, not cause it.
If you read this blog regularly, you know that I NEVER talk about cancer on this blog. This is the first time. Why? Because of the mountain of emails I’ve received from you. Glad you asked.
The reason I don’t talk about cancer on this forum is not because it is unimportant or that Omega-3 has no effect on cancer. I don’t talk about it because of FDA regulations. The word ‘cancer’ on any dietary supplement website is an FDA red flag. Fly-by-night supplement people prey on the gullible by making outrageous cancer claims. That is not right and the FDA should come down on them.
Still, FDA does not make distinctions. They will probably find this article and I will probably get in trouble. I will comply with the FDA if they ask me to take this down, but until then, you will have access to this.
But what if the study is right…
According to the CDC, almost 8 times more people die from heart disease than they do from prostate cancer. Just for argument sake, let’s say this study is right, in which case the benefits of fish oil still far outweigh the potential of risk from prostate cancer.
And most people take fish for heart health, not prostate health.
There may be a way that extremely high Omega-3 levels promote carcinogenesis. But there is no proof whatsoever that this happens due to Omega-3 levels noted in this study.
There are several studies – Alpha-Omega, GISSI, JELIS, ORIGIN etc that together combine over 70,000 people who had much higher levels of Omega-3. Yet none of those studies noted any increase in prostate cancer.
Let me be clear: Omega-3 does not prevent, cure or cause cancer. Sorry. The evidence is far from conclusive either way.
Anyone who tells you that Omega-3 cures or causes cancer based on current evidence, does not have the facts or has an agenda other than public health.
The verdict is not in.
Please share this with those you care about.
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About the Author: Vin Kutty, M.S., is OmegaVia’s Scientific Advisor and Chief Blogger. He is a nutritionist, author, and Omega-3 expert with over 20 years of experience.