This blog post is the fifth in a series I wrote for Skipper Otto's Community Supported Fishery on the high nutritional value of local fish and seafood here in BC. The original blog was posted April 11, 2018 and can be found here.
Like many trends in nutrition, fish oil is still enjoying its time in the limelight. This is because the omega-3 fatty acids in fish oil have been linked to prevention of heart disease and dementia, to name a few. So for those who may not have access to, or enjoy, wild fish and seafood, popping a pill every morning can seem like a viable option to help ward off disease.
But while early research on fish oil was promising, many studies are now showing mixed outcomes, with many not showing any significant impact on health at all. So why is the data so confounding? And why might eating whole fish on a regular basis be the best way to address health and disease prevention?
So you want to make a fish oil supplement. First you’ve got to catch the fish. Then you need to transport it to a processing plant and turn it into fish meal. Next you have to refine, purify and clean the oil. Finally you have you package it and distribute it to the store where it will remain until purchased. Each one of these stages can compromise product quality. And quality control is especially important for fish oil because it is chemically unstable and highly prone to oxidation. Studies have shown 50-83% of the fish oils tested exceeded at least one of the measures of acceptable oxidation. Once oxidized, fish oil can have a “fishy” flavour and odour, reduced shelf life, and lower levels of omega-3s than the labels claim. There is also some evidence that oxidized fish oil may increase risk factors of disease like inflammation. Even so, the effect of oxidized fish oil on human health hasn’t been well studied.
This difference in fish oil quality, and the fact that most clinical trials don’t test the oxidative state of the fish oils, may explain inconsistencies in study results. A study published in 2013 showed that fish oil quality (oxidative state) had significant impacts on heart disease markers (triglyceride and cholesterol levels). In that study fish oil capsules with lower levels of oxidation showed improved heart disease markers compared to highly oxidized omega-3 capsules, which had a negative effect on cholesterol levels. All this to say, unless you are purchasing omega-3 supplements from a reputable manufacturer that tests for oxidative stability, the benefits of taking omega-3 supplements may be questionable.
Omega-3 fish oil supplements contain EPA and DHA, the primary anti-inflammatory fats. But, unlike whole fish and seafood, omega-3 supplements typically don’t contain other micronutrients like vitamin D, selenium, iodine and B vitamins. B vitamins, are especially important because they work with omega-3s to support brain function reducing the likelihood of dementia. The greatest benefit of eating whole fish then, is because it offers a whole range of micronutrients that not only support a broad range of our nutritional needs but also are designed to work together to optimize their use in the body.
Our bodies are designed in a way that efficiently takes and uses nutrients from whole foods. Studies comparing fish to fish oil have shown that omega-3 supplements aren’t used as well by our bodies as those in food form. This may be because of the larger amount of overall fat in whole fish, which can better activate fat absorption in the body. This difference in absorption might explain why eating even low or moderate amounts of fish (1-4 servings/week), can be protective against cardiovascular disease.
BOTTOM LINE: For most of us, eating whole fish, like wild BC salmon and salmon roe (my favourite!), several times a week will provide us with all the protective omega-3 fatty acids our body needs with no ‘fishy’ burps!
© Melissa Evanson 2018. For permission to reproduce or repost this post, email firstname.lastname@example.org