Nowadays, we hear a lot from people that eating fish is good for us... but I also get a lot of questions from my patients on whether there is such a thing as too much fish.
Well, a recent study came out from the American Journal of Medicine that looked at fish consumption and acute coronary syndrome (5). It was a "meta-analysis," which takes a look at prior studies and gives a summary of the findings to see what prior studies have found on this topic.
Based on the recent article by Yinko and associates, they saw that there is an inverse association between fish consumption and the risk of acute coronary syndrome (5). It appears that eating fish helps with primary prevention of heart disease and higher consumption is associated with greater protection (5).
In this meta-analysis, Yinko and associates looked at studies from 1966 to June 2013, and they pulled enough studies to get about a total of 408,305 participants in these prior study reports. It seems based on their research that the highest category of fish consumption of more than or equal to four times per week showed the greatest risk reduction in acute coronary syndrome. (5)
Based on the study, it seems that age and sex do not appear to influence association between fish consumption and acute coronary syndrome. They also found that each additional 100-gram serving of fish per week is associated with a 5 percent reduction in risk of acute coronary syndrome. (5)
These authors chose to do this study because there has been controversy about eating fish and protection from heart attacks both before the first attack or in helping prevent future heart attacks after someone has had one already.
There was a landmark study DART (Diet and Reinfarction) Trial that demonstrated that fish consumption was beneficial for the secondary prevention of myocardial infarction (heart attacks) with greater than or equal to two servings of fish per week (1). This means that eating fish helped to prevent future heart attacks after someone already had one. So, these researchers wanted to also see if fish consumption would help with primary prevention of acute coronary syndrome, not just with secondary prevention (5). That means that the meta-analysis wanted to look at whether eating fish protects people from having their first heart attack. Based on this study, apparently it seems that it does (5).
How This Affects Our Life
Well, it tells us that eating fish is a good thing for our heart health. But I frequently get questions from my patients in my integrative medicine clinic in San Jose, California about whether fish oil supplements are just as good. While this study was looking at people eating real fish and not fish oil supplements, there are prior studies that looked at whether taking fish oil supplements are just as good for the heart as eating fish.
Unfortunately, some earlier studies suggest that fish oil from supplement doesn't get into our body as well as fish in food form (2-4). A six-week study showed that active ingredients of EPA and DHA in fish oil capsules were not as effectively incorporated into our body's blood plasma fat particles (3) and another study showed that the EPA content in red blood cells increased more rapidly from eating fish rather than supplements (4).
Is Fish Oil a Thing of the Past?
What we know is that more studies need to get done for more definitive answers. But what we do know is what I've always been telling my patients. Vitamins and nutrients and even the active ingredients that help with inflammation found in fish and fish oil are always going to be better in the real food form. Our body is programmed to be able to more efficiently take in the nutrients from real food and as good as our abilities are nowadays with making supplements, supplements are still not real food. And at the end of the day, our body is always going to be better at incorporating food nutrients into our system for our health than in pill/supplement form... and that's what these studies seem to suggest in what they found (that the EPA and DHA levels were better absorbed into our cells using fish form rather than fish oil supplement form) (2-4).
Fish Oil Can Still be OK
Having said that, I am not opposed to fish oil because it's better than nothing, since the studies still showed absorption of the EPA and DHA into cells but just not as good as with the real food form (2-4). But overall, food form is better than supplement form for the active anti-inflammatory components of EPA and DHA. Ultimately, more studies need to be done to further clarify this issue about fish oil supplement consumption and our concerns about mercury when consuming fish.
Based on this meta-analysis, though, what we can suggest to ourselves is that eating fish a few times per week is a good idea for your heart health, so is there such as thing as clean fishes and dirty fishes?
I generally recommend eating wild fish and not farmed primarily for the goal of keeping our food intake as clean as possible. Also, if you are concerned about mercury, the best is to keep it to smaller fishes and less to bigger predatory fishes so that the accumulated mercury levels in any given fish you eat is less in the smaller fishes.
So, What's the Takeaway Point?
At the end of the day, if you are open to eating fish, you should. The wild forms are cleaner and smaller fishes which are lower on the predatory chain would be your best bet for keeping mercury levels lower.
So, while there are a million and one ways to prep for your dinner meal, the main thing to keep in mind if you have concerns about heart health for yourself or your loved ones is to make sure that you and your loved ones get fish into your diet four or more days out of the week (5) but a minimum of two days out of the week based on the DART trial (1); because apparently eating fish should help keep the heart of your loved ones safer and healthier... but we all kind of knew that right? We just needed confirmation and these studies seem to suggest we knew what was good for us all along.
References:
1. Burr ML, et al. Effects of changes in fat, fish, and fiber intakes on death and myocardial infarction: diet and reinfarction trial (DART). Lancet. 1989;2:757-761.
2. Kris-Etherton PM, Hill AM. N-3 fatty acids: food or supplements? J Am Diet Assoc. 2008;108(7):1125-1130.
3. Visioli, F, et al. Dietary intake of fish vs formulations leads to higher plasma concentrations of n-3 fatty acids. Lipids. 2003;38:415-418.
4. Harris WS, et al. Comparison of effects of fish and fish-oil capsules on the n-3 fatty acid content of blood cells and plasma phospholipids. Am J Clin Nutr. 2007;86:1621-1625.
5. Yinko SSLL, et al. Fish Consumption and Acute Coronary Syndrome: A Meta-Analysis. Am J Medicine. 2014;127(9):848-857.