Linoleic acid, a fatty acid found in vegetable oils, appears to protect against various kinds of stroke.
Researchers in Japan measured linoleic acid levels in blood samples from a group of 7,450 men and women aged 40 to 85. The study was part of a larger survey of cardiovascular risk done between 1984 and 1993. There were 197 strokes in the group during this time - 122 were ischaemic (caused by a blood clot) and 75 haemorrhagic (caused by bleeding).

There was a clear link between linoleic acid levels and stroke risk. Each five per cent increase in linoleic acid was associated with a 28 per cent reduction in total stroke risk. There was a 34 per cent reduction in ischaemic stroke, 37 per cent reduction in lacunar infarction (a stroke involving small arteries in the centre of the brain) and 19 per cent reduction in haemorrhagic stroke.

It's thought the linoleic acid improves the circulation to the brain and helps lower blood pressure. More research is needed to explore the role of linoleic acid in stroke prevention, however. Good sources of this valuable fatty acid are corn oil, sunflower oil, safflower oil and soy beans.