Mercury is generally concentrated in the meat, not the fat. (It has an affinity for the thiol groups on certain amino acids in protein.) There's certainly other fat-soluble pollutants like PCBs to worry about, but I'd never heard of any fish oil products having significant mercury contamination. I'd love to see the info you've been looking at?
Worth noting that canned "sardines" can be any of a multitude of unrelated fish, so it's not a good differentiator. Although they tend to be small fish, which is probably a reasonable predictor for lower mercury content.
Good advice. Additionally, I’d recommend that with any supplement you evaluate the source you’re buying from. I typically use Nootropics Depot (avoiding linking so this doesn’t look like a full blown add - check my history though, not a shill) and they use 3rd party lab testing to back up claims.
Overlooked one major benefit of salmon though: it tastes great and I would rather eat salmon than krill oil caps ;)
To be fair, there’s low heavy metal contamination salmon on the market; a few sibling comments mentioned wild Alaskan salmon, but I also think farmed salmon tends to be lower in Hg content that the “average” wild salmon.
Flax is also really easy to add to a smoothie if you have a decent blender, my recipe: almond milk (any type of milk or yogurt), frozen berries, oats, flax seeds. Just blend it up and eat it for breakfast. Washing blenders after you finish is often easy as you can just add water and a drop of dish soap and then run it once more and then pour it out.
Some skimming of Wikipedia suggests that our total annual krill harvest is about 1/950th of the amount that predators eat of the main krill species per year.
Also usually the smaller the animal / the farther down the food chain, the faster they reproduce. And some more reading of Wikipedia suggests that krill can reproduce very quickly.
For the most complete analysis of the evidence for Omega 3 (and other miconutrients) the very best resource I've found is Dr Rhonda Patrick: https://www.foundmyfitness.com/topics/omega-3
> It is unclear how omega-3 fatty acids increase the AF risk. Omega-3 fatty acids stabilize the cardiac membrane and protect against arrhythmias, including ventricular arrhythmias, through both direct electrophysiologic actions and positive effects on biological processes involved in atrial remodeling. However, omega-3 fatty acids have direct effects on the activity of cardiac calcium, sodium, and potassium ionic currents, which can alter the duration of the ventricular action potential. Therefore, omega-3 fatty acids may promote re-entrant arrhythmias, despite being anti-arrhythmic in therapeutic conditions. Several previous studies have evaluated the electrical characteristics of the ventricular wall; few studies have evaluated how omega-3 fatty acids influence the atria.
It sounds to me like that short quote is saying (paraphrasing here) that 'studies seems to show omega-3 is beneficial, but theoretically apart from the beneficial mechanisms there could be a harmful mechanism so we're not sure why we don't see that happening'
The academic paper this story is based on is here: https://nature.com/articles/s43587-024-00793-y
Despite the linked story title only mentioning omega3, the paper was about 3 interventions, that, vitamin D, exercise and found reduced epigenetic age from the interventionts, with bigger anti-aging benefit as they were combined.
With respect to vitamin D specifically, this isn't by itself good evidence vitamin D reverses aging. But it is consistent with the totality of evidence that being vitamin D deficient probably (causally) speeds aging. And it mildly increases the overall weight of evidence of a connection.
As with much vitamin D research, it would have been better for the intervention to have been titrate vitamin D supplement amount to achieve an optimal target range (eg 30-60ng/ml) rather than using a fixed relative moderate dose (2000IU).
The problem with a fixed dose is that surely some subjects started severely deficient, some mildly, and some had sufficient levels. The moderate but not very high fixed dose will have helped many in the middle group climb out of deficiency, not been enough for many in the 1st group to bring them fully out of deficiency, and been unnecessary for those in the 3rd group, so the study ends up seeing a weaker overall effect averaged over all subjects. This is well known within the vitamin D world, eg see https://x.com/KarlPfleger/status/1732514710715514883, but somehow has not permeated to be widely enough understood, even within the scientific community (or the Hacker News community).
A book I read a couple years ago (I think Peter Attia's) said one of the clearest nutritional studies just sent a weekly bottle of olive oil to half the participants, who had better health results than the control group. They didn't track exactly what people ate, but figured they probably used recipes with olive oil and ended up closer to a Mediterranean diet.
Of course that doesn't necessarily mean it translates to extreme longevity.
I haven't read the study itself, but normal practice is to give the control group some kind of attention that doesn't include the intervention you're testing.
I recommend checking out Gill Carvalho (https://www.youtube.com/@NutritionMadeSimple). He helped me realize that nutrition science isn’t a controversial as it would seem from reading the popular press or the occasional study showing that bacon and Oreo cookies are good for your heart. It took five or ten videos to get a feel for how real scientists interpret new information. He explains the relative power of different types of scientific evidence, etc. Good stuff. He covers the Omega-3 AFib connection. If I remember correctly, Omegas-3s improve several cardiovascular risk factors, but also increase the risk of AFib. So, depending on your current situation, you may want to increase or decrease your intake. Deficiency is definitely bad, but you can also overdo it. I decided that sardines a few times a week is probably safer for me than the fish oil capsules I was taking daily.
There are different variations of Omega 3 fatty acids. For instance, Avocados is rich in Omega 3 ALA which is considered not as effective as EPA and DHA.
>> Now, new research from the Intermountain Healthcare Heart Institute in Salt Lake City finds that higher EPA blood levels alone lowered the risk of major cardiac events and death in patients, while DHA blunted the cardiovascular benefits of EPA. Higher DHA levels at any level of EPA, worsened health outcomes.
>> [...] Based on these and other findings, we can still tell our patients to eat Omega-3 rich foods, but we should not be recommending them in pill form as supplements or even as combined (EPA + DHA) prescription products,” he said. “Our data adds further strength to the findings of the recent REDUCE-IT (2018) study that EPA-only prescription products reduce heart disease events.”
I'm only going to bring up the life expectancy part, but latino people also live longer despite their cuisine not being the healthiest. I'm not saying that all latinos eat a terrible diet, but the cuisine we all know and love is high-carb and high in saturated fats compared to the olive oils, fishies, and veggies we see in the mediterranean diet.
Metabolic diseases are a different story. But I guess love and family cancel that out.
Life expectancy in Latin America ranges from 65 in Bolivia to 80 in Chile and the cuisines, genetics, cultures, and socioeconomic circumstances vary greatly from region to region so it's not very useful to generalize latino people into one cohesive group with regards to diet and life expectancy.
I'm starting to wonder if Vitamin D and Omega 3s are indicators, not drivers. D is an indicator that you spend time outdoors, in the sun, and that is healthy for your body. Similarly, Omega 3 is indicative of other lifestyle choices, not causal for better health.
Or even that being healthier and less frail means you're more likely to go out and enjoy being outdoors.
As I age, I increasingly see the effect that healthy people with great genetics also have all the indicators of being healthy. I think this effect is conflated to an extent even for things like exercise: for people that feel good and strong, exercise feels great. For people that aren't, they go downhill faster anyway.
I have terrible genetics for cardiovascular disease. I've spent my life as an athlete, eating healthy, training, etc. But now in my 30's, I can feel the slow down a lot despite being more disciplined in my training and diet than ever and yet I know people my age that haven't trained in years that can just go for a run and absolutely smoke me.
I'm sure at some point my genetics is going to force me to slow down a bit on the training despite my best efforts and then I'll just end up as someone contributing to the statistics that those who exercise more are healthier.
I know that exercise has benefits nevertheless, but I also think we very often just make the mistake of concluding "healthier people are healthier".
No, ample evidence shows that vitamin D (or vitamin D deficiency at least) is causally related to multiple diseases. The evidence is pretty overwhelming. Eg here's a just published review on D deficiency causality for Covid based on applying Hill's Criteria for causality https://www.mdpi.com/2072-6643/17/3/599 and a prior 2022 paper on the same subject https://pubmed.ncbi.nlm.nih.gov/35308241/
Some vitamin D skeptics claim tat there's insufficient evidence from RCTs but few people question the causality of smoking's influence on cancer despite no RCTs for that---that relationship was established also via Hill's Criteria.
> No, ample evidence shows that vitamin D (or vitamin D deficiency at least) is causally related to multiple diseases.
Both my statement and yours can be true. Having a deficiency in an essential nutrient can be causal for bad outcomes while, at the same time, having the correct amount or excess can be non-causal but correlated with positive health outcomes.
> I'm starting to wonder if Vitamin D and Omega 3s are indicators, not drivers.
That is not true. AFAIK there have been several studies using supplements of Vitamin D3 & Omega-3 that showed that it improved biomarkers of various diseases.
Those are different claims. I don't exactly know what frailty means technically, but this was a 5 year study on the elderly. Preserving organ health with a lifetime of omega 3 consumption is totally different.
Instead, you should get your omega-3 from krill oil, which is low on the food chain does not concentrate Mercury is all around better