Low cholesterol increases stroke risk

Part 3: Low cholesterol also increases ischaemic stroke risk

There is no doubt the risk of haemorrhagic stroke is increased by low cholesterol levels, but that still leaves ischaemic strokes. Although the effect is similar to a haemorrhagic stroke, the cause is different. Instead of a blood vessel leaking in the skull, in this case, an artery is blocked by a clot.

For the same reason that heart attacks are blamed on cholesterol blocking coronary arteries, so are ischaemic strokes blamed on a fatty diet. But the theory that eating too much saturated fat increases the risk of a stroke, also seems to have no foundation. In 1997, we got a Christmas present from the long-running Framingham study when it published findings that for every 3% more calories from fat, ischaemic stroke risk went down by 15%.[1]

Confirmation came 6 years later in yet another study. This time, scientists at the Department of Nutrition, Harvard School of Public Health, studied 43,732 men aged 40-75 years who were free from cardiovascular diseases and diabetes in 1986 and followed them for 14 years.[2]

During that period they studied intakes of every conceivable type of fat: animal fat, fish oil, vegetable oil, saturated, mono-unsaturated, polyunsaturated, trans fat, as well as the amounts of each that were consumed. They found that none of them made any difference whatever and conclude:

'These findings do not support associations between intake of total fat, cholesterol, or specific types of fat and risk of stroke in men.'

References