Over the past couple years or so I have been focusing a lot on further improving & optimising my health, from a more holistic pov which basically mostly entails the diet aspect. I’ve probably tried every “fad diet” promising you to be the cure, and to no one’s surprise not being it. The list includes but is not limited to keto, intermittent fasting (IF), OMAD, veganism (no comments pls - idiotic I know), paleo and there’s probably more but they just escape my mind at present. Of course, you may argue that each person is different and what is suited for me won’t be suited for X, which I completely agree with and not arguing against. Sidenote, a fun fact is that the keto diet actually started as a treatment for epilepsy in the 1920s, and was highly successful.
I’ll try to not divert to much esp when considering diets for males vs females, how they simply can’t be the same. But anyways, a big aspect of health nowadays is not complete without the intake of various supplements also promising longevity. I do agree with supplements in some cases, e.g., vitamin D, considering I’ve barely seen the sun in months in London it is v much needed! However, the endless promise that if you take 20+ pills a day everything will be solved and working at 200% is purely not the case. One of the most famous one and most consumed is fish oil, aka, Omega-3 fatty acids (FAs).
Omega-3s are very good for your body, sadly our body doesn’t make them naturally so we need to get them from food or, you guessed it, supplements. The main benefits are around heart health as they lower your cholesterol and triglycerides, which is basically the fats in your blood. So, less fat in the blood, less “blockage”, less chance of a heart issue occurring, pretty straight forward, right? Outside of heart, it’s also been linked with improved autoimmune disease symptoms, brain development, depression and more.
Now, there are three main types:
Eicosapentaenoic acid (EPA) - found in fish
Docosahexaenoic acid (DHA) - also found in fish
Alpha-linolenic acid (ALA) - found in plant foods
Fish is the main source of these FAs, and it includes salmon, tuna, anchovies, trout, sardines, and many more fishes. Plant foods containing them are flaxseeds, chia seeds, edamame, walnuts, and some seed oils, namely canola and soybean oil - which I would far from recommend as a “health food”, but seed oils are a completely different discussion for another day.
Omega-3 FAs are polyunsaturated fatty acids (PUFAs) - this is also what seed oils are, but I’ll try not to digress too much but there are many similarities with their issues. Now you may be still wondering what the issue is, well when the fish oil is just in capsules or liquid or whichever form it is in, it’s very susceptible to oxidation when exposed to heat, light, or oxygen. So, if you’re getting a supplement that has been in transit for a while, or you’re also not “storing” it properly it will most likely be oxidised. The oxidation itself creates compounds that are not the best for our health and also causes inflammation, which is the no 1 cause of most disease.
Another aspect of PUFAs is that they affect the thyroid by suppressing the signaling of hormones. The thyroid is important for metabolic health, growth and development, as well as fertility. So, if your thyroid is already not working as it should, say it’s under-active the addition of fish oil will just make it worse. Studies in rats did show that in rats with underactive thyroid, LDL cholesterol did decrease but body and blood fat did not, and there was no positive effect on the thyroid. Simply, not much positive effect.1
If that doesn’t make you think, remember the promise of reduced heart disease? Well, a 2021 meta analysis showed that those who took fish oil supplements in comparison to a placebo had a significantly increased risk of atrial fibrillation2, which simply means irregular and sometimes fast heart rate. Atrial fibrillation over the years causes the heart muscles to weaken and also may not provide adequate blood flow to your body and organs.
And if you’re wondering why it is still recommended, the simple answer is money. The global fish oil market size is to set grow to USD 3.6 billion by 2030 and was valued at USD 2.37 Billion in 2023.3 Although there is some regulation around the creation of supplements and recommended intake, it is entities like the FDA that approve so in the US. (Do note that in the UK since Brexit, they’ve been developing their own framework for the authorisation of health claims of supplements.) Also, I’m not assuming excessive consumption of fish oil would cause this but the standard recommended ones. There’s many studies that have shown even in people with high cholesterol, there was no improvement shown when comparing to a placebo but rather their cholesterol levels worsened.4 So, I guess for the first time I am truly advocating against something which is probably highly controversial! I acc remember when I was younger my father had made a similar remark about how we should never consume fish oil, don’t recall much of the details as to the why but yeah…
As usual, I’ve added some links below. I hope you enjoyed - see you next week! :)
Souza, L. L., Cordeiro, A., Oliveira, L. S., Paula, G. S. M. d., Faustino, L. C., Ortiga-Carvalho, T. M., Oliveira, K. J., & Pazos-Moura, C. C. (2011). Thyroid hormone contributes to the hypolipidemic effect of polyunsaturated fatty acids from fish oil: in vivo evidence for cross talking mechanisms. Journal of Endocrinology, 211(1), 65-72. Retrieved Mar 26, 2024, from https://doi.org/10.1530/JOE-11-0142
Omega-3 supplementation linked with atrial fibrillation risk: a meta-analysis. Cardiovasc J Afr. 2021;32(3):167. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8756005/
Fish Oil Market: Industry Analysis and Forecast (2023-2030). stellarmr.com/report/Fish-Oil-Market/1602
Demke, D., Peters, G., Linet, O., Metzler, C., & Klott, K. (1988). Effects of a fish oil concentrate in patients with hypercholesterolemia.. Atherosclerosis, 70 1-2, 73-80 . https://doi.org/10.1016/0021-9150(88)90101-3.