Diet, fats and cholesterol

Part 5: Heart disease and high blood insulin

High blood glucose levels and consequent high blood insulin levels produce two effects that are responsible for cardiovascular diseases.

They are: increased thickening and stickiness of the blood which tends to clot and block the blood vessels, and the increased permeability of the capillary walls leading to the smaller blood vessels and capillaries leaking and rupturing.

Many studies have demonstrated that a breakdown of the endothelium , the inner lining of arteries and veins, occurs early in the insulin-resistant state and can predict future cardiovascular events. Similarly, insulin resistance has been associated with the metabolic syndrome, which also increases the risk of adverse cardiovascular outcomes.

But high insulin levels also:

• Increase risk of thrombosis
• Increase plaque formation
• Prevent plaque regression
• Stimulate connective tissue synthesis
• Stimulate insulin growth factor 1 (IGF-1)

All of which increase the risk of a heart attack .

Don't forget that long-term high insulin levels are caused only by eating a 'healthy', carbohydrate-rich diet.

References

1. Pyorala M, et al. Hyperinsulinemia and the risk of stroke in healthy middle-aged men: the 22 year follow-up results of the Helsinki Policemen Study. Stroke 1998; 29: 1860-1866.

2. Kamide K, et al. Insulin resistance is related to silent cerebral infarction in patients with essential hypertension. Am J Hypertens 1997; 10: 1245-1249.

3. Biessels GJ. Cerebral complications of diabetes: clinical findings and pathogenic mechanisms. Neth J Med 1999; 54: 35-45

4. Meigs JB, Mieeleman MA, Nathan DM, et al. Hyperinsulinemia, hyperglyceima, and impaired hemostasis. The Framingham offspring study. JAMA 2000; 283:221-229

5. DeFronzo RA, Eleuterio F. Insulin resistance: a multifaceted syndrome responsible for NIDDM, obesity, hypertension, dyslipidemia, and atherosclerotic cardiovascular disease. Diabetes Care 1991; 14: 173-91

for more on cholesterol and heart disease, see Cholesterol-and-Health.org.uk