The answer? A balanced diet

However, another cause may be diets. Japan largely banned meat for 1,200 years, and still consumes relatively little meat and dairy. Too much of these can be damaging, since they contain saturated fatty acids, which correlate to heart disease. Studies have also tied eating lots of processed red meat to a greater risk of stroke. But too little may be unwise as well, because they provide cholesterol that may be needed for blood-vessel walls.