Overall diet plays bigger role than individual nutrients in heart health?

Several of these foods have individually been held up as strong protective agents against heart disease - with the individual heart health components such as fibre or omega-3 fatty acids, subject to health claims or health claim applications in some countries.

But Teresa Fung, the study's lead author and assistant professor of nutrition at Simmons College School for Health Studies in Boston, says that "because nutrients and food are consumed in combination, their cumulative effect on disease risk may be best investigated by considering the entire eating pattern."​

She added: "Overall dietary patterns are easier to recommend to the public than individual foods."​

While her approach needs to be confirmed by further studies, it could be an important strategy for marketers of health and functional foods.

In Europe there are around 650,000 stroke deaths each year. Smoking, obesity, high cholesterol and physical inactivity are all controllable risk factors for the event, and are driving a rapidly growing heart health foods market. In the UK this category is to grow 7.6 per cent to reach sales of £145 million by 2007, according to Datamonitor. This is second only to gut health in terms of purpose categories.

For the new study, published in this week's rapid access issue of Stroke​, researchers gathered dietary information on 71,768 female nurses, aged 38-63, who had no history of heart disease or diabetes. Starting in 1984 and following them until 1998, researchers identified two dietary patterns: 'prudent' and 'Western', consisting of red and processed meats, refined grains, and sugary desserts.

During 14 years of follow-up, the nurses were scored on how closely their diet resembled both the prudent dietary pattern and again on closeness to the 'Western' pattern. A higher score indicated closer adherence to the dietary pattern. The women were ranked according to the scores, then divided into five groups (quintiles), with one group of quintiles for each type of diet.

After controlling for lifestyle and risk factors for stroke, the risk for any type of stroke among women with the highest Western diet scores was 58 per cent greater than the risk for women in the lowest quintile. The increased risk for ischaemic stroke was about 56 per cent greater.

While the results show that risk of any stroke for women with the highest prudent diet score was 22 per cent lower than women with the lowest prudent diet score, these results were not statistically significant.

Women with Western eating habits were more likely to smoke, less likely to take vitamins and less active, the study also found.

Women who ate the Western diet and also had hypertension had more than three times the risk of strokes caused by blockages compared with Western dieters without hypertension.

More diet studies using food patterns may determine if this is the most effective way to identify disease risk, said the researchers.