Sugar and heart disease: insulin resistance vs cholesterol

Dr. Anthony Jay, a researcher who spent five years on heart disease research at Boston University, argues that sugar, not cholesterol, is the main culprit behind arterial plaque. Here are his arguments, with the caveat that they challenge mainstream cardiology, so use them as a starting point for questions to ask your doctor.

The heart prefers fat, until insulin resistance

Your body runs on two fuels, sugar and fat. Protein is a structural material, like the metal framework of a car. Most cells prefer sugar if given a choice, but the heart prefers fat. When people become insulin resistant and eat carbs at every meal, the heart can become addicted to sugar and then lacks fuel. Jay says the coronary arteries starve too, so artery walls absorb lipids, and doctors blame the fats because they are present in the plaque.

During exercise the heart stays about 85% to 95% on fat oxidation, which makes it a marathon runner. Jay cites an ultrarunner who ran 118 miles with zero calories after five years of low-carb eating.

The hazard ratio gap

He points to a study of 28,000 people looking at early onset heart attacks:

• Insulin resistance: hazard ratio 6.4
• Hypertension: 2.3
• Triglycerides: 2.1
• LDL: 1.38, a 38% higher risk

Insulin resistance is a 640% increase, yet the medical system emphasizes LDL. Jay believes this reflects drug sales: statins brought in billions and, as patents expire, attention is shifting to PCSK9 drugs and Lp(a) therapies.

What Lp(a) and LDL really are

Jay says Lp(a) is LDL with a tail that binds oxidized byproducts, like a street sweeper cleaning up after a parade. It rises during infection and was higher in people who survived COVID. Blaming the sweeper rather than the garbage, he says, misses the point. To reach a 1.5 hazard ratio, he says, Lp(a) must hit about 193 for heart disease and higher for stroke. LDL, in his view, is a fat transporter that can rise on low-carb diets and also tracks with bad habits such as smoking, poor sleep, trans fats and high ferritin.

He questions PCSK9 inhibitors such as Repatha, citing a re-adjudication of the FOURIER trial that reported more cardiac deaths in the drug group, and says a newly approved oral drug lowered LDL about 36% without measuring plaque or heart disease.

The Randle cycle

When fats and carbs arrive together, insulin shuts the gate for fats to enter cells and the cells burn sugar. For an insulin-resistant person, the combination leaves both sugar and fats circulating, causing advanced glycation and advanced lipoxidation end products. A healthy, active person handles it better, because exercising muscle absorbs glucose without insulin.

Testing: CAC versus CCTA

• CAC scan: low radiation, cheap ($40 in South Dakota, about $150 in Minnesota), takes 15 seconds and returns a number. Scores run from 0 to about 5,000, not 0 to 100, so a score of 20 does not mean 20% blockage.
• CCTA with AI: about five times more radiation, near $1,000, and subject to plus or minus 20% variation. In a study of three expert readers, agreement scored 2.3 out of 10. Jay argues this feeds fear and overtreatment.

He also says hard plaque has never been safe: a 2016 analysis showed risk climbs with CAC score, and hard plaque rose 12% to 14% per year on statins in one study.

Aging, stress and athletes

Metabolism slows with age, so the same diet becomes harder on your insulin sensitivity. Jay says people can get away with carbs at 20, especially while exercising, but the margin shrinks later, and plaque is rare before age 50 in the arteries he examined. He also links stress and inflammation to heart disease through insulin resistance, since cortisol responses worsen it, and he questions endurance athletes who keep glucose at 160 to 210 during events. Even if that helps performance, he says, it may not be optimal for health. On fasting, he criticizes a headline claiming a 91% higher heart disease risk based on a phone questionnaire, released the same month as a positive umbrella review.

What to do

1. Test your insulin along with fasting glucose. Jay wants insulin below 5, and one cardiologist suggests below 8. Normal lab ranges, he says, are too broad.
2. Get a CAC scan after age 50.
3. Exercise, consider intermittent fasting and limit carbohydrates your body cannot burn. An umbrella review of intermittent fasting found benefits for waist, insulin resistance and triglycerides.
4. Treat HDL as a marker of good habits, not a target to raise with drugs.

Conclusion

Jay urges people to measure what matters, especially insulin, and to prevent plaque over decades. A fasting insulin below 5 signals you are doing well, and rising values predict more plaque over the years, since it takes about 30 years to build up and about as long to prevent. Share these ideas with your doctor before changing any medication.