The Diet-Heart Hypothesis: Why It Won’t Die Despite Weak Evidence

For decades, we've been told that saturated fat raises LDL, and LDL causes heart disease—a belief known as the diet-heart hypothesis. But Zoë Harcombe’s PhD thesis (2016) systematically reviewed the evidence and found no significant link between dietary fat, LDL, and CHD mortality.

So why is this idea still alive? 🤔

💡 1. The Power of Early Dogma

🔹 The 1977 U.S. and 1983 U.K. dietary guidelines were introduced without strong RCT evidence, yet they shaped global nutrition policy.

🔹 The Seven Countries Study (Keys, 1970) cemented the belief that saturated fat = heart disease, despite serious methodological flaws (e.g., cherry-picked countries, ignoring confounders).

🧪 2. Reliance on LDL as a "Risk Marker"

🔹 LDL became an easy-to-measure surrogate for CHD risk, even though RCTs show lowering LDL doesn’t always reduce CHD deaths.

🔹 Statins lower LDL and show some benefits, but their positive effects may be due to anti-inflammatory properties rather than LDL reduction alone.

💰 3. Industry and Financial Incentives

🔹 The food industry promoted low-fat, high-carb diets, replacing fat with processed carbs & vegetable oils—coinciding with rising obesity & diabetes.

🔹 The pharmaceutical industry capitalized on cholesterol-lowering medications, making billions from statins and PCSK9 inhibitors.

🔹 Government agencies & health organizations can’t easily reverse decades of public health advice without credibility damage.

📺 4. Media & Public Perception

🔹 The public and even doctors have been conditioned to fear fat for over 50 years.

🔹 New research questioning LDL is often ignored or dismissed because it contradicts the dominant narrative.

🚀 Time to Rethink Heart Disease Prevention!

❌ LDL is NOT the sole cause of CHD – inflammation, metabolic health, triglycerides, and overall diet matter more!

✅ Instead of demonizing fat, let’s focus on whole, nutrient-dense foods, reducing processed carbs, and improving metabolic health.

Harcombe, Z. V. (2016). An examination of the randomised controlled trial and epidemiological evidence for the introduction of dietary fat recommendations in 1977 and 1983: A systematic review and meta-analysis (Doctoral dissertation, University of the West of Scotland).

🔎 #HeartHealth #LDL #CholesterolMyths #NutritionScience #FollowTheScience