But dig a little deeper and the story becomes clearer. In fact, it’s more obvious than most nutrition issues. And the story is that sedentary fat is bad.
For a long time that was the general idea, but then the question arose. I trace the backlash to Mark Bittman’s 2014 New York Times column.butter is back” pinned the headline. meta-analysis They conclude that saturated fat intake is not associated with increased heart disease risk.
since then, others. And that evidence has spawned quite a few reckless contrarians.
On this, I believed we should limit our intake of saturated fats because we believe in two things:
1. Saturated fat raises LDL (aka “bad”) cholesterol.
2. LDL cholesterol increases the risk of heart disease.
I spoke with a few like-minded professionals: cardiologists Ethan Weiss, formerly at the University of California, San Francisco, and is currently a resident entrepreneur at Third Rock Ventures, a biotechnology venture capital firm.and Kevin Klatt, registered dietitian and research scientist at the University of California, Berkeley. But I also wanted to speak to the smartest, most knowledgeable person I could find who disagreed with my opinion. Ronald Krause Professor at the University of California, San Francisco, and co-author of: 2020 paper file a complaint with the Department of Agriculture dietary guidelines It is recommended to limit saturated fat to 10 percent of calories. “Recommendations to limit dietary saturated fat (SFA) intake persist despite mounting evidence to the contrary,” the paper argued.
My conversation with Klaus didn’t go as planned. Because we started out in complete agreement that you can’t figure out saturated fat from observational studies.
Many of the studies that prove saturated fat innocence (including the relevant portion of the study cited by Bittman) track large groups of people, ask them what they eat, and what diseases they have. It was obtained from a researcher who investigated whether I’ll spare you the rant about how terrible a tool I believe this is, but with inaccurate data and billions of confounding factors, it’s hard to figure out how to solve the saturated fat problem or the causal relationship between food and health. Let me just say that I don’t think you can discover relationships. the effect is small.
Once those studies are off the table, all that’s left is clinical trials. many of them.
Consider first the relationship between saturated fat and LDL.
At least two things can influence whether and to what extent saturated fats raise LDL. One is the type of saturated fat and the other is the type of food that contains saturated fat.
4 saturated fats we eat normally (they have names, but are often referred to by the number of carbon atoms they contain) are C12 (lauric acid), C14 (myristic acid), C16 (palmitic acid), and C18 (stearic acid) is.According to Klaus and Kratt, C14 and C16 (together, Most saturated fats found in meat and dairy) definitely raises LDL. C12 ( main fat found in coconut oil) and C18 (which our bodies quickly break down into monounsaturated fats) are slightly different.
The actual diet is also important. Two foods containing the same saturated fat may have different effects on cholesterol. Some dairy products have cheese and YogurtFor example, they don’t raise LDL as much as other saturated fat-rich foods, and in some cases they may even lower it. No one really knows why (Klaus points out that food may have other compensatory properties), but the difference has been observed in a wide range of studies.
Not all saturated fats are the same. Not all foods with saturated fat are the same. Ultimately, though, some saturated fat foods (e.g., coconut oil and some dairy products) don’t seem to be that harmful, but I think it’s perfectly supportable that saturated fat raises LDL cholesterol. .
But if elevated LDL actually increases the risk of heart disease, then of course it only hurts, and everyone I’ve spoken to agrees that’s the case. Weiss calls this a “borderline fact,” and Krause states that “LDL causes cardiovascular disease.” And there’s a ton of evidence to back it up. It is very clear that lowering LDL reduces the risk of heart disease.a 2016 meta-analysis We found that lower LDL levels are associated with a lower incidence of major coronary events.like that another So was 2020. 2012 was the same Mendelian randomization analysis. I was able to continue.
However, even here there are some nuances. Dr. Weiss explains that some in the field of cardiology emphasize different types of LDL, which are small and dense and may be more harmful than large and fluffy ones, while others ( Krause), others have described their focus on apoB, the protein that coats LDL particles. It is a better indicator of disease risk. While aware of these issues, he calls them “distractions.” LDL cholesterol is not the absolute best indicator, but it is still a good indicator of risk. It is easy and cheap to evaluate and is a good alternative to other potentially more accurate measurements.
When I asked Mr. Kratt and Mr. Weiss about the extent of the agreement, beyond just fat and cholesterol, both said the agreement was broad. Kratt called the science “very solid,” but don’t ask too much about nutrition. To be clear, this does not mean that there are no tests that show something different. It’s just that the overwhelming majority of evidence points in the same direction.
Now back to Klaus, I was very disappointed because he had no objection to this as the person I chose to represent Team Sat Fat. His objection to the recommendation to limit saturated fat is not because he thinks it is beneficial. …no reason why we need it in our diet. ’ And when he sees patients at high risk for heart disease, he says to limit heart disease.
“But,” he says, “if you want to advise people who need to lower their risk of heart disease, they should limit foods high in saturated fat. That’s not the same as population guidelines.” He gave me several reasons against restrictions. He believes that not everyone needs to lower their risk, that the 10 percent cutoff is arbitrary, and that guidelines should focus on food rather than nutrients — especially That’s because foods with saturated fat are important.
Any reasonable person may disagree with certain recommendations. There are so many strong claims about the harm of saturated fat that I generally agree that it is better to recommend foods and dietary patterns rather than focusing on specific nutrients, but I would rather avoid saturated fat. I agree with keeping it.
But I don’t think a sensible person would have much objection to saturated fat itself. Many of them, found in most foods, raise LDL cholesterol and increase the risk of heart disease.
That should solve it, right?
