Omega-3 fatty acids


John DiTraglia M.D. - Contributing Columnist



The answer to the question posed at the end of the last article is yes. Eating palm oil is ok. It was especially beneficial when it replaced trans fat in margarine decades ago. Apart from trans fat, that increases atherosclerotic heart disease and strokes by a lot, there is a more complicated but probably not that important choice between any other oils or fats – saturated, monounsaturated, polyunsaturated, or total fat intake. (1) Though there is some evidence that eating much more polyunsaturated fats might be better and in whole diet studies it seems like the Mediterranean diet is better for you, and that means olive oil, among too many other things. Plus olive oil tastes better. But that may be my bias since I was weaned on it.

Then there is the further debate about a certain kind of unsaturated fat type, the omega-3 fats, that we last wrote about back in January of last year. (2)

In the December 8 issue of The Journal of the American Medical Association there is another report of a double-blind placebo controlled, randomized, multi-center (AKA careful) trial of omega-3 fatty acids’ effects on major adverse cardiovascular events in high-risk patients.(3) This study found no significant difference in the outcome of major cardiovascular events of omega-3 fats.

Why does there continue to be these debates about fats in our diet? That’s a big discussion (4) that I should devote a whole column to because it’s so complicated. In the case of omega-3 fats, some of the issues include which omega-3 fats are we talking about. There’s docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and a close relative of EPA, icosapent ethyl (IPA) and other derivatives and other omega-3 fats. There is the theoretical point of these omega-3 fats – the reduction of blood triglyceride levels mostly – that doesn’t matter as much as the blood cholesterol. There’s the problem of the smallness of effect. When an effect is 19% reduction in bad events that sounds like a lot but if a 19% reduction means 2.8% instead of 3.5% well that’s not the same number of affected lives as a 19% reduction in a 50% risk. It’s also easy for that kind of small effect to disappear in the next more careful study. And the rate of adverse effects, mostly gastrointestinal but also atrial fibrillation, was 22.2% in the omega-3 group compared to 12.9% with the placebo (corn oil) group. And this difference is impacting half of the patients, so potentially way higher numbers of patients than the predicted positively affected. Also the dose or placebo may make a difference. And the quibbling goes on like that.

But the bottom line is good and easy – it doesn’t matter what you eat as long as you don’t eat more obvious poisons like trans fatty acids. The other good news is all of you all can stop taking fish oil supplements.

1. Zhu YJ et al. Dietary total fat, fatty acids intake, and risk of cardiovascular disease: a dose-response meta-analysis of cohort studies. PMID: 30954077 PMCID: PMC6451787 DOI: 10.1186/s12944-019-1035-2

2. Me Dueling reports about omega-3 fats. Portsmouth Daily Times. 2019; January 22.

3. Nicholls SJ et al. Effect of high dose omega-3 fatty acids vs corn oil on major adverse cardiovascular events in patients at high cardiovascular risk. JAMA. 2020;324(22):2268-80.

4. Sharma G et al. Effects of omega-3 fatty acids on major adverse cardiovascular events. JAMA. 2020;324(22):2262-4

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John DiTraglia M.D.

Contributing Columnist

This writer’s opinion is their own and not the opinion of this newspaper

John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- jditrag@zoomnet.net or phone-354-6605.

This writer’s opinion is their own and not the opinion of this newspaper

John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- jditrag@zoomnet.net or phone-354-6605.