Omega-3 and Health – Cancer

In my last article I wrote about Ω-3 fatty acids, commenting on their potential health benefits. Considering the comments I received saying it seemed like I promote Ω-3 supplements after I mentioned the risks of excess blue fish consumption, I would like to clear the air right away and say it most certainly isn't so.
 

Even though I do not recommend a certain brand of omega-3 supplements, I'm not saying that I wouldn't, because my opinions are based on science, not manufacturers. If scientific data complies with their interests, and it brings me financial benefit, I see no reason not to do it. My point is that the amount of omega-3 that has the proven health benefits is difficult to ingest through fish alone, but not impossible. Also, a higher intake of fish from polluted seas could have negative effects on your health. I repeat, it could. Another thing is, many people don't like the taste of fish. I'm not a huge fan myself so I consume refined fish oil on a daily basis. Oddly enough, oil does not bother me. In any case, the benefits of consuming fish with elevated levels of heavy metals are higher than the risks of not doing so.

To sum it up: 1 g of omega-3 (EPA + DHA) a day, any time, from fish, fish oil, or capsules, with a meal or on an empty stomach.

I overlooked another potential benefit of omega-3 fatty acids – their anabolic effect, which bodybuilders have a special interest in, but also everyone trying to enhance their muscle mass. Research on this topic is relatively new, so I won't go deeper into the subject, but I will soon write more about this.

For the time being, I'll skip the connection between omega-3 and cardiovascular disease and answer the question from the previous article: does higher intake of omega-3 fatty acids reduce the risk of cancer? Another comment I received said I used too many expert phrases (ha ha), so this time I'll try to keep it short and simple.

One of the many benefits associated with omega-3 fatty acids is the inhibition of carcinogenesis – cancer development. Research done on animals and cell cultures showed a low, but significant inhibitory effect of omega-3 consumption when it comes to tumor occurrence and tumor cell proliferation in mammary glands, prostate, pancreas and large intestine. Unfortunately, research done on humans does not affirm these findings. Even though there's research showing a negative correlation to tumor occurrence, there's also research proving the opposite results.

However, for the most part, research shows that omega-3 consumption has no effect on carcinogenesis. The reason for different results in animals and humans is most likely the dosage which in animals exceeds the usual doses used in epidemiological studies. Also, the ratio between omega-6 and omega-3 fatty acids in your diet is most likely the factor responsible for health benefits frequently attributed to Ω-3, but very few studies have been done on this subject so far. Last, and possibly the most important fact, is that omega-3 mechanisms haven't been fully explained yet, which is the case with carcinogenesis as well – all of which makes it hard to identify the reason for aforementioned difference. Even though evidence shows lack of omega-3 protective influence on cancer development in humans, this possibility should not be discarded, considering the positive results from studies done on animals and cell cultures.

Omega-3 fatty acids and their effect on health – Introduction

In my next article I'll cover the better-researched area of Ω-3 fatty acids consumption, which is their influence on risk of cardiovascular disease.


References: 

1. MacLean, Catherine H., et al. "Effects of omega-3 fatty acids on cancer risk: a systematic review." Jama 295.4 (2006): 403-415.
2. Hooper, Lee, et al. "Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review." Bmj 332.7544 (2006): 752-760.
3. Ruxton, C. H. S., et al. "The health benefits of omega‐3 polyunsaturated fatty acids: a review of the evidence." Journal of Human Nutrition and Dietetics 17.5 (2004): 449-459.