Office Hours: Cholesterol and Heart Disease — What I’ve Changed My Mind About

What It Covers

Dr. Mark Hyman explains why he changed his approach to cholesterol and heart disease based on new research. He argues that insulin resistance and inflammation, not cholesterol levels alone, drive heart disease risk. He details which lab tests actually predict heart attacks and how metabolic dysfunction affects 93% of Americans.

Key Questions Answered

• •ApoB Testing: Apolipoprotein B measures the actual number of harmful cholesterol particles in blood, not just their weight. Only 1% of cholesterol tests ordered by doctors include this marker, yet cardiology guidelines now recognize it as a causal factor for heart disease. Function Health includes ApoB in their standard panel for tracking metabolic health.
• •Heart Attack Paradox: In a study of 136,000 people who arrived at emergency rooms with heart attacks, 75% had normal LDL cholesterol levels. Nearly all had abnormal triglyceride to HDL ratios. This ratio should be one to one or less. A ratio of five to one indicates extremely high heart attack risk regardless of normal LDL numbers.
• •Skinny Fat Syndrome: Twenty percent of normal weight people have insulin resistance and face the same heart disease risk as obese individuals. This explains why 93% of Americans show metabolic dysfunction despite only 75% being overweight. Body composition matters more than body mass index. Visceral belly fat drives inflammation and cholesterol oxidation that damages arteries.
• •Lipoprotein Little A: One in five people have elevated LP(a), a genetic cholesterol marker that independently increases heart disease risk. No current treatments directly lower it effectively, though medications are in development. People with high LP(a) must optimize all other risk factors including blood sugar, blood pressure, exercise, and eliminate refined carbohydrates to compensate for genetic vulnerability.
• •Sugar Drives Inflammation: Americans consume approximately one pound of sugar and flour daily, totaling 152 pounds of sugar and 132 pounds of flour annually per person. This drives insulin resistance, which creates small dense LDL particles that penetrate artery walls. High sensitivity C-reactive protein predicts heart disease better than LDL cholesterol according to Harvard and Cleveland Clinic data.