"Few Smiths lived beyond the age of 55," says James, whose family has been decimated by a congenital problem disposing them to heart disease, he says.

At 40, James started jogging, five miles three times a week, to prevent the arterial disease which had left his father an invalid. But at 65, having paid no attention to his diet, James found he would get exhausted after only a quarter mile. James was diagnosed with heart disease and received an angioplasty.