I’m not the one making an extraordinary claim. But in all the years since Ansel Keyes proposed the lipid hypothesis(who, yes, had an advanced degree — but it was in fish physiology) there have been no convincing studies — and many that do not support that hypothesis. I would suggest that continuing to believe a hypothesis not supported by research for decades is the extraordinary position.
For instance, the The Tecumseh Community Health Study (longitudinal) 2,000 men and women 1959–1979 was an attempt to demonstrate that cholesterol levels were influenced by fat consumption in the previous 24 to 48 hrs. Based on data that included the composition of over 2.700 foods, it concluded that blood cholesterol and triglyceride levels were unrelated to the quality, quantity, or proportions of fat, carbohydrate, or protein consumed. Those who ate the least amount of saturated fat had the highest blood cholesterol levels.
Maybe check out google scholar and do your own research. The 59–69 data is available here if you have ICPSR access.
The challenge is that there is good science in studies of animal nutrition, but it’s not clear how applicable those results are to humans — and not-so-good science in human nutrition.
Aaaages ago there was a study that seemed to support a connection between SFA intake and arteriosclerosis — but that was in rabbits — that don’t normaly consume any SFAs. Use google if you want to find that one.
Aaaand here’s some anecdata: I’d been a strict-ish vegeterian for 30+ years. I had slightly elevated LDLs and super-low HDLs. I introduced meat (mostly chicken — still won’t eat cow) into my diet and HDLs came up into the normal range.
The other side of the lipids hypothesis (elevated blood lipids cause arteriosclerosis) is similarly unproven. I’d point out that statin usage is associated with lower CHD, but other methods of lowering lipids (or raising HDL) (eg bile sequestration, niacin) do modify lipid levels — without the same relative risk redustion shown in statin usage, so statins seem to be doing something in addition. There’s been some work indicating inflammation might be the factor.
