Editor—Yet again, a potential relation between low cholesterol concentrations and haemorrhagic stroke is dismissed.1 Yet again, a causal relation between high cholesterol concentrations, ischaemic stroke, and coronary heart disease is (apparently) confirmed.
Yet data from Japan directly contradicts Ebrahim et al's conclusions. From 1958 to 1995 fat consumption increased from 5% to 20% of the total daily energy consumption, and cholesterol concentrations rose from 3.9 mmol/l to 5.0 mmol/l.2 During this period the rate of stroke (combined) fell from 1344/100 000/year to 205/100 000/year in those aged 60-69. This is a 6.5-fold reduction in the rate of stroke.3 (There was also a decrease in death rate from coronary heart disease.)
The possibility that increased fat consumption was the causal factor in reducing the rate of stroke is strongly supported by a study in Stroke, which concluded that: “A high consumption of animal fat and cholesterol was associated with a reduced risk of cerebral infarction death.”4
A low cholesterol concentration has been found to be associated with an increased risk of haemorrhagic stroke in many different studies. And when cholesterol concentrations rose dramatically in Japan the rate of stroke plummeted.
A low cholesterol concentration may well be a “causal” risk factor for haemorrhagic stroke, and the connection cannot be dismissed by this study.
Competing interests: MEK is a member of the international network of cholesterol sceptics (THINCS).
References
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