Browse evidence-based analysis of health-related claims and assertions
The emergence of atherosclerotic cardiovascular disease as a leading cause of death occurred only in the 20th century, despite consistent human consumption of animal-based diets throughout evolutionary history.
Assertion
Atherosclerotic plaque development requires prolonged exposure to pathogenic stimuli and does not occur within short-term dietary interventions of less than one year.
Multiple large-scale meta-analyses of prospective cohort studies demonstrate no statistically significant association between dietary saturated fat intake and incidence of coronary heart disease or cardiovascular disease.
Domesticated carnivores fed ultraprocessed diets develop atherosclerotic plaque and cardiovascular disease, whereas those fed species-appropriate meat-based diets do not.
Wild obligate carnivores consuming natural prey-based diets exhibit minimal to no atherosclerotic plaque buildup in arterial vasculature.
A comprehensive meta-analysis of epidemiological evidence concludes that LDL cholesterol does not satisfy the Bradford Hill criteria for causality in the development of cardiovascular disease.
The Seven Countries Study selectively reported data from only seven of 22 analyzed countries to falsely imply a causal relationship between saturated fat intake and cardiovascular disease, omitting data from 15 countries showing no association.
Historical human populations consuming diets high in saturated fat from animal sources likely had higher circulating LDL cholesterol levels than contemporary populations, yet exhibited negligible rates of atherosclerotic cardiovascular disease.
Prior to the widespread consumption of industrial seed oils and refined carbohydrates in the early 20th century, clinical cases of atherosclerotic cardiovascular disease were exceptionally rare in human populations consuming diets high in animal fats.
A substantial proportion of patients hospitalized with acute coronary artery disease have LDL cholesterol levels below 100 mg/dL, challenging the assumption that elevated LDL is a necessary precursor to clinical events.
Quantitative
Low-density lipoprotein (LDL) functions as a transport particle that delivers cholesterol and other essential lipids to peripheral tissues via the bloodstream.
Atherosclerotic plaque buildup in arterial walls is a common pathological mechanism underlying both myocardial infarction and ischemic stroke.
There isn’t strong enough proof to say that eating less saturated fat and more vegetable oils will definitely prevent heart disease, according to this big review.
Descriptive
Even though eating trans fats seems bad for your heart, the amount of trans fat found in your blood doesn’t clearly link to heart disease risk in these studies.
Correlational
People with more omega-3 fats in their blood don’t clearly have lower heart disease risk, even though the numbers hint at a possible benefit.
The amount of saturated fat found in your blood doesn’t seem to predict whether you’ll get heart disease, based on blood tests from many people.
Taking flaxseed or walnut oil supplements doesn’t seem to help prevent heart disease, based on clinical trial results.
Taking omega-6 supplements, like those from sunflower or corn oil, doesn’t appear to protect against heart disease, according to clinical trial data.
Taking fish oil supplements doesn’t seem to lower your risk of having a heart attack or other heart disease, according to this review of many clinical trials.
Eating more omega-6 fats—like those in vegetable oils—doesn’t appear to increase or decrease your risk of heart disease, based on this large review.
People who eat more fish or other sources of omega-3s don’t seem to have much lower risk of heart disease, according to this review of many studies.
Eating more saturated fat—like in butter or red meat—doesn’t seem to make people more likely to get heart disease, based on this big review of studies.
People who eat a lot of trans fats (like in fried or processed foods) are more likely to have heart problems than those who eat very little.
The studies didn’t seem to be hiding negative results, but the smaller ones showed odd patterns that might mean some results weren’t fully reported.