Diet, fats and cholesterol

Part 6: High cholesterol protects against cardiovascular diseases

The diet that agencies like Diabetes UK and the American Diabetes Association recommend are supposed to reduce your cholesterol and so reduce your risk principally of heart disease. The evidenc is wholly against this.

In fact, findings suggest that high cholesterol levels actually protect against atherosclerosis and heart disease.

This would also explain why, although most cardiovascular diseases are seen after the age of 60, studies of the elderly find that those with high cholesterol have fewer heart attacks than those with low cholesterol.

Two studies which considered total blood cholesterol levels and mortality in the elderly were published in the Lancet almost simultaneously in 1997. In the first, scientists working at Leiden University's Medical Centre found that 'each 1 mmol/L increase in total cholesterol corresponded to a 15% decrease in mortality'.[1]

Similarly, doctors at Reykjavik Hospital and Heart Preventive Clinic in Iceland also studied total mortality and blood cholesterol in men over eighty to show that those with blood cholesterol levels over 6.5 mmol/L had less than half the death rate (48%) of those whose cholesterol level was a 'healthy' 5.2 mmol/L.[2]

This relationship between low cholesterol and higher mortality was strengthened by a further study published six years later. The UCLA School of Medicine, Los Angeles, studied the association between blood cholesterol levels and 7-year all-cause mortality.[3] What they found was that people whose cholesterol levels were below 4.4 mmol/L (169 mg/dL) had nearly double the death rate over the period of those with higher levels. While some of this increase was attributed to inflammation and poor diet, the low cholesterol link was still apparent even after these factors had been allowed for.

Not surprisingly,

"In general, study has demonstrated that multiple risk factors for coronary heart disease are worsened for diabetics who consume the low-fat, high-carbohydrate diet so often recommended to reduce these risks."[4]

Low cholesterol, diabetes and obesity

Because of a heightened interest in people with very low cholesterol levels, several studies have looked at other possible effects. One unexpected finding was that diabetics tended to have lower cholesterol levels than non-diabetics. Those with the lowest cholesterol levels were also more likely to be obese.[4]

Low cholesterol and other conditions

Low cholesterol has also been shown to increase a wide range of other conditions from cancers to Alzheimer's to suicides and aggressive behaviour.

In view of the evidence against lowering your cholesterol levels, you might like to consider why on earth anyone would want to lower their cholesterol.

References

1. Weverling-Rijnsburger AWE, et al. Total cholesterol and risk of mortality in the oldest old. Lancet 1997; 350: 1119-23.

2. Jonsson A, Sigvaldason H, Sigfusson N. Total cholesterol and mortality after age 80 years. Lancet 1997; 350: 1778-9.

3. Hu P, Seeman TE, Harris TB, Reuben DB. Does inflammation or undernutrition explain the low cholesterol-mortality association in high-functioning older persons? MacArthur studies of successful aging. J Am Geriatr Soc 2003; 51: 80-4.

4. Chen YD, et al. Why do low-fat, high-carbohydrate diets accentuate postprandial lipemia in patients with NIDDM? Diabetes Care 1995; 18: 10-16

4. Franzblau A, Criqui MH. Characteristics of persons with marked hypocholesterolemia. A population-based study. J Chronic Dis 1984; 37: 387-95.

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