The Enduring Myth: Why Cholesterol is Wrongly Blamed for Heart Attacks

🩺 Why Doctors Still Believe the Theory That Cholesterol Causes Heart Attacks

For over half a century, doctors around the world have been taught that cholesterol is the main cause of heart attacks. Textbooks, medical lectures, and even public health campaigns have repeated the message: “Eat less fat to save your heart.”

But where did this theory come from — and why does it persist despite conflicting evidence? To understand, we have to go back to the 1950s and one very influential man: Ancel Keys.

🧠 The Birth of the Lipid Hypothesis

In the early 1950s, Keys proposed the “lipid–heart hypothesis”, which asserted that high intakes of total fat, saturated fat, and cholesterol lead to atherosclerosis and heart disease (Newport & Dayrit, 2023). He analysed international data and in 1953 published a chart using only six countries, showing a strong positive association between fat intake and coronary heart disease (Keys, 1953 as cited in Newport & Dayrit, 2023). However, when a broader set of countries was later included in reanalysis, the correlation weakened substantially (Newport & Dayrit, 2023; Teicholz, 2017).

Later, in 1958, Keys launched the famous Seven Countries Study (SCS), choosing only seven of the original candidate countries (U.S., Finland, Netherlands, Italy, Greece, Yugoslavia, Japan) purportedly for logistical and scientific feasibility (Seven Countries Study website, n.d.; Scientific & medical review, 2018). Critics assert that countries such as France and Germany — with relatively high fat intake but lower heart-disease rates — were omitted, raising questions about selection bias (Teicholz, 2017; Wikipedia contributors, 2025).

🏛️ How the Theory Gained Power

In 1955, U.S. President Dwight D. Eisenhower suffered a major heart attack, which shocked the nation and heightened public attention to diet and cardiovascular risk. Keys and others used this context to promote the view that saturated fat and cholesterol were the culprits (Wikipedia contributors, 2025). The theory spread rapidly: governments, medical schools, and food industries aligned behind it. Medical students were trained on the premise that cholesterol causes heart disease; official guidelines promoted low-fat diets; the food industry shifted to processed vegetable oils and refined carbohydrates (Newport & Dayrit, 2023; AOCS, n.d.).

🧩 The Minnesota Coronary Experiment: The Study That Changed Everything

Between 1968 and 1973, Keys and colleagues conducted the Minnesota Coronary Experiment (MCE), a controlled dietary trial of over 9,000 participants, replacing saturated fats with vegetable oils rich in linoleic acid (omega-6) (Ramsden et al., 2016). The findings, when recovered and analysed decades later, were surprising: lowering cholesterol did not reduce deaths from coronary heart disease or all causes; in some cases, higher mortality was observed in the group whose cholesterol dropped most (Ramsden et al., 2016; Teicholz, 2017). The full dataset was largely unpublished for decades, only resurfacing around 2016 (Ramsden et al., 2016).

⚖️ What This Means Today

The persistence of the cholesterol-heart disease axis is less about fraud and more about institutional inertia — once an idea becomes medical “truth,” it takes generations to reverse. Doctors today were trained on decades of guidelines that linked cholesterol with heart disease, even though:

• Many heart attack patients have normal cholesterol levels.

• Modern research emphasizes inflammation, oxidized lipoproteins, and metabolic dysfunction more than total cholesterol alone (Newport & Dayrit, 2023).

• The focus has shifted from total cholesterol to details like LDL particle size and function, HDL function, and the broader metabolic context (AOCS, n.d.).

🩸 The Real Culprit: Inflammation and Metabolic Damage

Modern evidence suggests that the main drivers of atherosclerosis are chronic inflammation, oxidative damage to lipoproteins, insulin resistance and metabolic dysfunction — not simply eating cholesterol or saturated fat. Whole-food diets rich in healthy fats (e.g., olive oil, eggs, nuts) can support heart health when consumed within balanced lifestyle patterns.

🔍 In Summary

The cholesterol–heart hypothesis was built on incomplete and selective data, amplified by authority, and reinforced by repetition. Although later analyses — including Keys’s own Minnesota experiment — failed to confirm it conclusively, the theory became medical dogma and shaped decades of clinical training and guideline writing.

References

AOCS. (n.d.). Big fat controversy: changing opinions about saturated fats. AOCS. Retrieved from https://www.aocs.org/resource/big-fat-controversy-changing-opinions-about-saturated-fats/
Newport, M. T., & Dayrit, F. M. (2023). The lipid–heart hypothesis and the Keys equation defined the dietary guidelines but ignored the impact of trans-fat and high linoleic acid consumption. Lipids in Health and Disease, 22(…), Article … https://doi.org/…
Ramsden, C. E., et al. (2016). Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from the Minnesota Coronary Experiment (1968-73). The BMJ, 353, i1246. https://doi.org/10.1136/bmj.i1246
Scientific review. (2018). A short history of saturated fat: The making and unmaking of a public health paradigm. …, …
Seven Countries Study website. (n.d.). About the study. Retrieved from https://www.sevencountriesstudy.com/about-the-study
Teicholz, N. (2017). Fat and politics – how the Seven Countries Study built the case against saturated fat. diabetes.co.uk. Retrieved from https://www.diabetes.co.uk/in-depth/fat-politics-nina-teicholz-seven-countries-study-dietary-policy/
Wikipedia contributors. (2025, March). Seven Countries Study. In Wikipedia. Retrieved from https://en.wikipedia.org/wiki/Seven_Countries_Study