For decades, there’s been a controversial debate over the benefits of taking fish oil as a nutritional supplement. But now, one University of Arizona professor thinks we may be getting close to a definitive — and surprising — answer.
Floyd Chilton, Ph.D., is the director of University of Arizona's center for precision nutrition and wellness. Precision nutrition is a cutting-edge approach to dietary research which looks at nutrition through the lens of evolutionary biology. By using more robust variables — like genetic information -— precision nutritionists believe they can pinpoint hyper-effective treatments for conditions like heart disease that previous studies may have missed.
Chilton joined The Show to discuss his groundbreaking research into the benefits of fish oil supplements.
Conversation highlights
FLOYD CHILTON: It was said early on that nothing makes sense in biology and less in the light of evolution. And in particular precision nutrition is around food sources. So, if you were a foraging population in Africa, what you would have been eating well before organized fishing and animal husbandry would have been very different than what you would have been eating in northern Europe. For a long time we've in the nutrition field have believed that one size fits all. And typically that one size has been built around studies in European ancestry populations.
That brings us to this very remarkable analysis that you did in 2018. There was a five-year clinical trial on the benefits of various nutritional supplements that was released. And initially that the data seemed to suggest that there was not a clear benefit from, in particular, taking fish oil. But then you reanalyzed that data with greater precision, and you got a very striking result.
CHILTON: Yeah, you know, a study was published in the New England Journal of Medicine in 2018; 26,000 people followed over five years. The bottom line was that fish oil had no benefit for cancer or cardiovascular disease. Well, when we went back and looked at the study, there were 5,100 African Americans in the study. And we had complete data when it became publicly available for 3,766. We could then match those African Americans — we had over 16,000 European Americans or non-hispanic whites — and we could match them for covariance. And then we could re-simulate the clinical trial using machine-learning algorithms.
So you looked at this data set and realized that there was an opportunity to rerun it in a way that would correlate a larger number of factors.
CHILTON: Yeah, we call it in science balance the covariance. But that's just a fancy-smancy word for saying, you know, the age BMI, a degree of heart disease, degree of diabetes medication. So we could match 3,766 African Americans with 3,766 whites with all the covariance matched, and then rerun the clinical trial. And what our study indicated was an 83% reduction in heart attacks or myocardial infarction in the African American population, but no effect in the white population.
... It is astounding and it was astonishing to us. I think what's really important about this work is we must identify the populations in which interventions are going to work.
It sounds like to get to that point, we have to start introducing the value across the fields of the type of studies that you're doing. Acknowledging the idea that there may be genetic factors in some populations, and not others, that if focused on we have the opportunity to discover these things. But that it seems like the first step there is acknowledging, as a discipline, the importance of taking these things into consideration.
CHILTON: Absolutely. And we must — because evolution was different for all of these populations — and then we must include them in our clinical trials.
This result that you got when you reran the analysis, while it was startling, it did match up with your suspicions about the potential benefits of fish oil amongst African Americans when it comes to heart disease. What gave you that inkling?
CHILTON: In 1961, the American Heart Association said saturated fatty acids are bad ... eat polyunsaturated fatty acids (PUFAs). We instantly went from 1.5% of our energy as PUFAs to almost 10% of our energy as PUFAs. And we did that because it was reducing cholesterol ... in non-Hispanic whites. The assumption there was that would benefit everyone equally.
Heart disease is a huge concern in the African American community. And hearing a result like this, that sounds like it has just life-trajectory-altering potential. Is that what we're talking about here? Something that could like completely rewrite the story of heart disease in the African American community?
CHILTON: I want to emphasize potential because I don't want — I'm not a physician. I have a Ph.D. in biochemistry, and I study genetics, and I'm an evolutionary geneticist. So I want to emphasize, I'm not an MD.
And this is not necessarily a segment designed to encourage people to run out and buy a bunch of fish oil.
CHILTON: That's right. But if we are correct — we're recently funded with a $4 million grant from NIH. And if at the end of this five years of this ... we're stratifying by ancestry in this trial and we're stratifying by genome characteristic. And then we're giving fish oils to non-Hispanic whites and African Americans. Now, if we come back with a large-scale clinical trial focused in particular at African Americans, then there's tremendous potential. Because you can drink milk or not drink milk, but you cannot get these polyunsaturated fatty acids out of your diet ... they're in our cooking oils. We have no choice but to eat them. I would say this: our work is controversial. There's been a controversy in this field between the epidemiologist and the basic biochemist and geneticist such as myself.
What is that controversy?
CHILTON: Well, you know, in 1961 there was this recommendation by the American Heart Association. It's been doubled down upon several times. You know, my plea is, we must understand these recommendations, whatever they may be, in diverse populations. In populations where their evolutionary genetics or the evolutionary pressures were dramatically different, we must get more sophisticated, because one size fits all does not fit all.
