The Science Behind Saturated Fat and Health

"That should settle it, don't you think?" @TamarHaspel asks.

My answer, not surprisingly, no.

As I've said before about nutrition research in this context (and others), let's pretend this is science.

Read on.

1/21 https://t.co/RUMTagXTP8

— gary taubes (@garytaubes) June 11, 2023

Yes S(aturated)FAs raise LDL--compared to carbs or U(nsaturated)FA's -- but that doesn't mean eating SFA-rich foods will kill us prematurely.

I discussed this issue in the journal Science in 2001: https://t.co/U7N48qawKp

2/21

— gary taubes (@garytaubes) June 11, 2023

Not entirely irrelevant aside: that Science article constituted a year of work and was based on both reading the literature and interviews with over 160 researchers and administrators.

It won the National Association of Science Writers Science in Society Award.

3/21

— gary taubes (@garytaubes) June 11, 2023

Foods do many things when consumed. Influencing blood lipids (LDL, HDL, Trigs...) is only one of them.

Just as drugs do many things when taken.

Hence, RCTs are required to know the actual balance of benefits and risks: effects on both morbidity & mortality.
4/21

— gary taubes (@garytaubes) June 11, 2023

Looking at effects on cholesterol alone -- let alone LDL cholesterol alone, as Tamar suggests -- is insufficient.

That was the case when I wrote my Science article and it still is.

This issue cannot be dismissed merely because it's inconvenient.
5/21

— gary taubes (@garytaubes) June 11, 2023

Unlike drugs, the effects of foods are always compared to what else we might have eaten instead. Tamar neglects this point, too.

Eating less of one food implies eating more of another.

SFA's raise LDL compared to carbs, but they also raise HDL and lower Trigs.
6/21

— gary taubes (@garytaubes) June 11, 2023

SFA's raise LDL compared to UFAs from vegetable oils without the HDL or Trig benefits.

But can vegetable oils be deleterious for other reasons?

What's the trade-off

How would we find out?
7/21

— gary taubes (@garytaubes) June 11, 2023

To settle the issue, as Tamar suggests she has, requires RCTs showing (unambiguously) that subjects live longer and healthier lives by replacing SFA-rich foods (cheese and butter, say) with P(oly)UFA or MUFA-rich foods (seed oils, olive oil).

8/21

— gary taubes (@garytaubes) June 11, 2023

Here's Tamar's primary source, Ron Krauss (whom I know and respect immensely) as the last author of an article JUST TWO YEARS AGO making the opposite point to what she now argues:https://t.co/F2cPv8ELAc
9/21

— gary taubes (@garytaubes) June 11, 2023

Why are Ron and his co-authors making the opposite point?

Because the handful of meaningful RCTs that tested SFA/PUFA trade-offs are half a century old and the results can charitably be called ambiguous.
10/21

— gary taubes (@garytaubes) June 11, 2023

With one notable exception: the $.5 billion (most expensive diet trial ever) Women's Health Initiative, which in 2006 reported NO benefits of avoiding SFA-rich foods.

Hmm, maybe they're harmless for women and not men. RCTs are needed to clarify. https://t.co/wQtZyP3uFi
11/21

— gary taubes (@garytaubes) June 11, 2023

So I'd say the jury is still out.

Meanwhile, a couple of thought experiments:

1. If you ate more like the French & Swiss (copious SFAs from butter, cheese and meats) and less like the AHA prescribes (low fat/SFA) -- should you expect to die prematurely?

Thoughts?
12/21

— gary taubes (@garytaubes) June 11, 2023