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Does fish oil really cause prostate cancer? Find in this episode
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Welcome to another episode of the Super Nutrition Academy Health Class. Today we’re going to be discussing some recent controversy with respect to fish oil. If you’ve paid attention to the news over the last couple weeks perhaps, you’ve probably heard that fish oil increases the risk of prostate cancer in men, quite significantly in some cases.
Today I want to explore this topic a little bit more. And if you’re a man who’s a little bit worried about taking your next fish-oil tablet or spoonful of fish oil, hopefully this will maybe bring some peace of mind to you. The thing I want to get across here is that this is a tough one.
I’m going to present some different studies that are going to show some conflicting results with the recent one, but I want to turn back to what we’ve talked about in the past. I can’t remember which episode we discussed this, but looking at how science emerges in the media. Remember how there’s this kind of window of opportunity that media outlets have and these scientific papers will only release their latest study at a certain time, and then all these news outlets get it at the same time? It’s just like a fire hose of information out in these media outlets.
As I’m recording this, if I were to type in fish oil and prostate cancer, the only searches that will come up in Google for the first two pages or so are news-related articles, which are all pretty much saying the same thing, just summaries of this study. I can’t tell you how many questions I’ve been asked about this. People on my Facebook page and in e-mails, everything.
I’ve been really espousing the benefits of fish oil and omega-3s for quite some time because they really are powerful. When you think about a lot of the diseases of modern man, a lot of it is lifestyle-related, and a lot of that is due to a higher presence of omega-6 fatty acids primarily in processed foods and due to our overconsumption of vegetable oils, which we’ve discussed as well.
Omega-3 is important because our body requires the properties that they provide in terms of antiinflammation. They give off EPA and DHA. DHA, specifically, is very helpful for brain function. They also yield antiinflammatory prostaglandins, which are very important for reducing inflammation. We know that inflammation is correlated with heart disease, with cancer, with dementia, with pretty much every sickness and disease we know of. Reducing inflammation in the body is important.
Having said that, though, nothing really compares to having a clean overall diet. We’re going to look at some interesting things here, and I’ll talk more specifically about diet as we get into specific studies.
First of all, let’s look at this recent study that was published in the Journal of the National Cancer Institute. What they looked at was they looked at 834 men who were diagnosed with prostate cancer. Of those, 156 had high-grade prostate cancer. They essentially wanted to see what was the difference between those who had prostate cancer and those who didn’t.
What the results showed is that compared with the men in the lowest quartile of omega-3 fatty acids inside their body, men in the highest quartile had increased risks for low-grade prostate cancer, high-grade prostate, and total prostate cancer. These associations were similar for individual long-chain omega-3 fatty acids, so EPA or DHA or stuff like that. What’s really interesting is that higher levels of omega-6 fatty acids was associated with reduced risks of low-grade and total prostate cancer.
This study goes against everything we think of as making sense because we see, for whatever reason here, the beneficial effects of preventing prostate cancer comes, in this case, from omega-6 fatty acids, which we know are not necessarily the greatest because of their proinflammatory properties. It really throws this interesting question out there. I think this has a lot to say about supplements in general. There’re a lot of confounding variables, first of all, because just within this area of prostate cancer and omega-3 fatty acids specifically, there’ve been a lot of inconsistent results, and I’m going to show you a couple of them in a moment.
It’s really something to consider because we, as a society, tend to look at we have a problem, we take a pill. We have a problem, we take a supplement as opposed to looking at our overall diet as the most important factor. I think this is really important to remember because we don’t necessarily know the potential issues that might arise by taking fish oil, for instance, or high levels of some other supplement down the road.
For instance, this is a theory that I have. I have no idea whether this is substantiated or not. We know that omega-3 fatty acids are very unstable; that’s why they should not be exposed to oxygen or heat or light. Those are the three factors that really make them rancid. Let’s just say that we had higher levels of omega-3 fatty acids in our body, and somehow those very susceptible fatty acids somehow became oxidized by other free radicals or other processes in our body, which actually made what was initially supposed to be a healthy oil coming into our body, what makes it dangerous inside our body.
There’re a lot of questions here, and the thing is that what I don’t like—and I’ve mentioned this before—what I don’t like about, and that’s why I’m hoping these podcasts bring some light to this, is that it’s very black-and-white in the sense of what the media puts out. Obviously this is a very shocking finding, so it’s beautiful from a marketing perspective, but it’s very confusing because this is not the whole picture.
Having a correlation—these are men already with prostate cancer, and they essentially looked at their blood levels of omega-3 fatty acids. The fact that they had higher levels of omega-3 fatty acids in relation to their prostate cancer is not cause-and-effect, right? It’s correlational. It’s very easy to go down the path of saying fish oil causes prostate cancer or increases the risk of prostate cancer. And it might. We don’t know for sure.
I’m going to bring up some other studies to show you some differing points of view. This recent study was published in late July of 2013. I’m going to just show you some other recent studies that have come out as well. This one here was entitled “Consumption of Fish Products Across the Life Span and Prostate Cancer Risk.” This was in the journal PLOS One; that’s the journal in this case.
What they did here was, the study was they looked at just about 2300 men ages 67 to 96. This was done in Iceland, in Reykjavik. This was done between 2002 and 2006. They looked at their dietary habits in early life, midlife, and later in life using a questionnaire. And then participants were followed through prostate cancer diagnosis and mortality through 2009. That’s kind of how this study was designed. They looked for fish and fish-oil consumption together.
What they found was that high fish consumption in early and midlife was not associated with overall or advanced prostate cancer. That’s fish consumption by itself. High intake of salted or smoked fish was associated with a twofold increase of advanced prostate cancer both in early life and later in life. Again, smoked or salted fish, different properties there. There could be nitrates involved; there could be other compounds involved that are different than eating fresh fish. It increased the risk of prostate cancer in that case.
And then here’s the kicker. Men consuming fish oil in later life had a lower risk of advanced prostate cancer. No association was found for early life or midlife consumption. Based on this, we can only say that if you are 67 years old or older, consuming fish oil can help prevent prostate cancer. However, if you use fish oil in your 30s, well, there’s no association based on this one study.
Each study has very specific recommendations where you can only draw certain conclusions based on the specificity of that one study. It would be irresponsible to say that based on the fact that older men consuming fish oil later in life was beneficial for preventing advanced prostate cancer. It would be irresponsible to say based on that finding that fish oil for all men is beneficial at preventing prostate cancer, because we don’t know that for sure. The research is conflicting.
That’s one study and I want to show you another one. This one is actually a review of the literature. A bunch of studies about, this one was called “Omega-3 Fatty Acids and Cancers: A Systemic Update Review of Epidemiological Studies.” This was published in 2012. This is all recent. This is not stuff from the 1960s that’s been invalidated now. This is all within the last year and a half or so.
This one here was interesting because they looked at colorectal cancer, they looked at breast cancer, they looked at prostate cancer, and some interesting findings were found. Let’s look at, I’ll get to prostate cancer in a second. Let’s look at, first of all, colorectal cancer. Again, colorectal cancer, part of the issue there is that it’s inflammation-related due to stuff that builds up in the colon. You’re thinking fish oil might reduce the inflammation and might prevent colorectal cancer. Well, let me share the results here.
I’m just going to give you some quotes here. This one showed for colorectal cancer, there was basically no association between fish-oil consumption and preventing colorectal cancer, although one of the studies did suggest a probably causal relationship between fish intake and colorectal cancer, although the amount of evidence here was really too limited to draw any real solid conclusions.
Again, a smaller case-control study, again, with colorectal cancer, showed a decreased risk associated with the highest, I guess, consumption of omega-3 fatty acids. A bunch of other studies were conflicting with colorectal cancer. There’s a real conflict even just within colorectal cancer.
Let’s look at breast cancer. Breast cancer seems to be one of the ones that was significantly benefited from the use of omega-3 in fish oils, as well as fish in general. A lot of this stuff came out of Asian countries, where they fond that the cases of breast cancer were dramatically reduced or there was a dramatically reduced reduction to breast cancer associated with an intake of omega-3 oils, omega-3 fats. That was also seen in the U.S. Very positive stuff with respect to omega-3 fatty acids and reduction of breast cancer.
Now, let’s turn our attention to the topic at hand, which is prostate cancer. It’s the second most common cancer in men, and some people say if you live long enough and you’re a man, you’ll eventually have prostate cancer. Maybe that’s true; maybe it’s not. Basically, what they found is the following. There’s a higher incidence of prostate cancer in African-American men. That’s been, for whatever reason, scientifically shown conclusively. For instance, in some studies prostate cancer in African-American men is tenfold higher than in non-African-Americans. That’s significant.
The present study that that I was talking about didn’t really display or they didn’t talk about what was the ethnic makeup of the men in the group, not that I’m aware of, at least. There were a number of studies done with respect to looking at the ethnicity of the individual, as well as their risk for prostate cancer. And then, obviously, there were a number of studies that looked at omega-3 fatty acids and the risk of prostate cancer.
A number of studies have shown that there’s no association between omega-3 fatty acid consumption and the risk of prostate cancer. Some others have shown a slight risk. But the real conclusion here is that we don’t know for sure. We don’t know for sure. It’s very mixed and it’s very confusing.
What they do know is that…well, I’ll give you one of the theories here. And I’m just going to quote this right out of the study here. I’ll start the quote. “The biological plausibility from experimental studies especially involving the antiinflammatory effects of PUFAs”—the polyunsaturated fatty acids—“possibly through mediation of cyclooxygenase, or COX, a key enzyme in fatty acid metabolism and inflammation, is supported by a case-study showing that the subjects carrying a mutation of the gene COX-2 needed a higher intake of EPA plus DHA to be protected in the subjects carrying the most common gene. Thus, epidemiological studies provide inconsistent results suggesting an inverse association of omega-3 fats and prostate cancer.”
And then it goes on to talk about how this discrepancy in results can be explained by measurement errors, insufficient food-composition tables, high intake of fish possibly contaminated by endocrine disruptors, statistical difficulty at disentangling specific fatty acids, which are correlated in the intake and expressed as a percentage when measured in the blood. There are all sorts of confounding variables. There are so many different things here that it’s so tough to really know what’s happening for sure.
The other thing I would really question with these studies is: What was the source of the fish oil? Were these men taking a triglyceride form of fish oil, or was it an ethyl ester? There are very different forms of fish oils. What was the quality? Were some of them from…there are varying qualities of fish oil, and there are varying qualities of fish. What was the initial quality of that fish oil? Again, even if it was high-quality, we don’t necessarily know if that reduces the risk of prostate cancer or increases it.
Let’s just sum this up. What they found was that… I’m just going to go back to the African-American stuff. Even though African-Americans have a very significant increase in prostate cancer compared to non-African-Americans, what they found was that…and they compared African-Americans with Africans and looked at what are the differences there. They found the biggest difference, really, is in their respective diets. They found that African-Americans had an increased risk in prostate cancer compared to Africans, and the biggest difference there was in respect to their individual indigenous diets.
That’s why I continue to say you can never, never outweigh the overall importance of your diet. You can eat the crappiest diet and supplement with fish oil. Maybe you’re one of these 834 men who have prostate cancer down the road. And then they say, “This individual had high levels of omega-3 fatty acids in his body,” but they’re not accounting for the overall diet that you consumed during your life.
As you can tell, there are so many different things to account for here, and it’s very confusing and it’s very tough to do this conclusively and without a shadow of a doubt. Even as best they try, all this science is very conflicting with respect to this, especially with respect to prostate cancer and colorectal cancer and how fish oil impacts either one of those.
So, what is my basic recommendation? Well, for now I’m going to continue taking my fish oil, but maybe that’s not the right choice for you. Maybe it is. I really believe that fish oil does have a lot of benefits. Heart-disease studies have shown this; dementia studies have shown higher intake of omega-3 fatty acid decreases dementia.
We know that it’s powerful in terms of antiinflammation. I would, as a recommendation, personally I’d take about one to two tablespoons of fish oil per day. That’s just because my body produces a lot of inflammation. I would assume a lot of us do, and we’re, I would say in the most cases, benefited by using a fish oil or, at the very minimum, consuming more fish, but then again, you get into the fish problem of contamination and all that good stuff. Small fish like sardines are obviously the best way to go for that stuff.
I don’t know if this has confused you even more or if it’s given you a little bit more clarity, but I think what I wanted to get across was it would be irresponsible for me to say this is the be all and end all. Fish oil is bad because it increases your risk of prostate cancer, so don’t take fish oil ever again. But if you’re a woman, the study showed that it actually reduces your risk of breast cancer pretty significantly and very consistently across a number of different studies, with very few confounding results.
My message to you here is that when you see this stuff in the media and you see this stuff in the news—and, again, this is the reason I put this podcast together, to cut through the crap and give you the gist of what you need to look at. I’m not saying you have to go in to all these different scientific studies and look at what the differences are. That’s my job; that’s what I’m here to do for you.
But I would question the results because for years and years and years and for thousands of studies, we have seen that fish oil is beneficial for fat loss, for everything else, and all of a sudden, one study comes out and says it increases our risk of prostate cancer. And the quality of that study is even somewhat subject to disapproval, for instance, from many. It’s very confusing, as you probably know, because it’s in all the media, it’s in all the news outlets. Every single news channel probably featured this story at the beginning of July.
Hopefully, this information gives you a bit of a bigger perspective. There are a lot of studies that have been done on this, and a lot of studies show conflicting results. Some are good, some are bad, so there’s not a cut-and-dry answer to this equation.
With that said, if you have any questions about this fish-oil topic or if you have any comments or anything like that, pop over to the blog at SuperNutritionAcademy.com/blog and let me know. Just find the episode here on “Does Fish Oil Cause Prostate Cancer?” and chime in to the conversation.
What do you think about this study? Is it overhyped? Is it bang-on? Do you have any personal experience that you can speak to with respect to this, prostate cancer? It would be great to hear your thoughts, opinions, and/or questions.
That’s all for today. Thank you very much for joining me. I hope you have a great rest of your day. I look forward to seeing you guys in the next episode.
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