A global study led by researchers in Canada found that compared to a prudent diet high in fruit and vegetables, a Western style diet that is high in meat, eggs, fried foods and salty snacks, raises the risk of having a heart attack by 30 per cent, regardless of which part of the world you live in. An Oriental diet, characterized by regular intakes of tofu and soy sauce, appeared to have no effect on heart attack risk.

The study was the work of Dr Salim Yusuf, a professor of medicine at McMaster University in Hamilton, Ontario, and colleagues from other research centres in Canada and other countries, and was published online on 20 October in Circulation. Yusuf is also director of the Population Health Research Institute at Hamilton Health Sciences in Ontario.

For their research, Yusuf and colleagues used data from 5,761 heart attack patients and 10,646 healthy controls taking part in the INTERHEART study, a standardized case-control investigation involving participants from 52 countries. The participants were mostly aged between 53 and 57 years.

The participants filled in questionnaires and were interviewed about the foods they ate. The results were classified into 19 food categories, for instance leafy greens would be one category, dairy foods another, and so on.

Using a statistical method called factor analysis the researchers found that the eating habits of the participants as characterized by their intake across the 19 food categories, fell into three main types: Oriental (high intake of tofu, plus soy and other sauces); Western (high intake of fried foods, salty snacks, eggs and meat); and prudent (high intake of fruit and vegetables).

After adjusting for potential influencers like age, sex, physical activity, smoking, body mass index (BMI), and geographical region, further analysis based on the three dietary patterns revealed that the more that a diet resembled the prudent diet, the lower the risk of heart attack, and the more it resembled a Western diet (higher regular intake of fried and salty foods, meat and eggs) the higher the risk.

The risk of having a heart attack was 30 per cent higher when the diet was closer to the Western style compared to the prudent style.

The Oriental diet appeared to have no effect on heart attack risk. The researchers suggested that the beneficial impact of tofu was cancelled out by the salt in the soy and other sauces.

Yusuf and colleagues concluded that:

"An unhealthy dietary intake, assessed by a simple dietary risk score, increases the risk of AMI [Acute Myocardial Infarction or heart attack] globally and accounts for {approx}30% of the population-attributable risk."

According to a press statement from the American Heart Association, Yusuf said that the purpose of the study was to:

"Understand the modifiable risk factors of heart attacks at a global level."

"This study indicates that the same relationships that are observed in Western countries exist in different regions of the world," he added.

"Dietary Patterns and the Risk of Acute Myocardial Infarction in 52 Countries. Results of the INTERHEART Study."
Romaina Iqbal, Sonia Anand, Stephanie Ounpuu, Shofiqul Islam, Xiaohe Zhang, Sumathy Rangarajan, Jephat Chifamba, Ali Al-Hinai, Matyas Keltai, Salim Yusuf on behalf of the INTERHEART Study Investigators.
Circulation, Published Online October 20, 2008.
doi:10.1161/CIRCULATIONAHA.107.738716

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Source: Journal Abstract, American Heart Association.

: Catharine Paddock, PhD.