Study Shows Heart Attack Risk Increases by Western Diet

People who consumed the Western diet had a 35 percent greater risk of having a heart attack compared to people who consumed little or no fried foods and meat.

22/10/08 The typical Western diet — fried foods, salty snacks and meat — accounts for about 30 percent of heart attack risk across the world, according to a study of dietary patterns in 52 countries reported in Circulation: Journal of the American Heart Association.

Researchers identified three dietary patterns in the world:

* Oriental: higher intake of tofu, soy and other sauces;
* Prudent: higher intake of fruits and vegetables; and
* Western: higher intake of fried foods, salty snacks, eggs and meat.

The Prudent diet was associated with a lower heart attack risk than the Oriental, researchers said. “The objective of this study was to understand the modifiable risk factors of heart attacks at a global level,” said Salim Yusuf, D.Phil., the study’s senior author.

Previous studies have reached similar conclusions about the Prudent and Western diet in the United States and Europe. This study broadens those findings and identifies a unique dietary pattern that researchers labeled “Oriental” (because of a higher content of food items typical of an Oriental diet.) The dietary pattern recommended by the American Heart Association is similar to the Prudent diet described in this study.

“This study indicates that the same relationships that are observed in Western countries exist in different regions of the world,” said Yusuf, professor of medicine at McMaster University and director of the Population Health Research Institute at Hamilton Health Sciences in Ontario, Canada.

Researchers analyzed the INTERHEART study, which documents the association of various risk factors and the risk of heart attack in about 16,000 participants in 52 countries. Here, they analyzed 5,761 heart attack cases and compared them to 10,646 people without known heart disease (controls).

The researchers created a dietary risk score questionnaire for heart attacks patients, based on 19 food groups and adjusted it for dietary preferences for each country. Trained medical personnel interviewed the heart attack patients and the control group. The questionnaires included healthy food items (such as fruits and vegetables) and unhealthy food items (such as fried foods and salty snacks).

“A simple dietary score, which included both good and bad foods with the higher score indicating a worse diet, showed that 30 percent of the risk of heart disease in a population could be related to poor diet,” said Romania Iqbal, Ph.D., lead author of the study.

After adjusting for known risk factors, researchers found:

* People who consumed the Prudent diet of more fruits and vegetables had a 30 percent lower risk of heart attack compared to people who ate little or no fruits and vegetables.
* People who consumed the Western diet had a 35 percent greater risk of having a heart attack compared to people who consumed little or no fried foods and meat.
* The Oriental pattern showed no relationship with heart attack risk.

Researchers said that while some components of the Oriental pattern may be protective, others such as the higher sodium content of soy sauces, may increase cardiovascular risk, neutralizing any relationship.

It’s expensive and time-consuming to establish a large and long-term study examining the relationship of diet and heart attack in every region of the world. So the approach of this study is the only feasible way to examine the relationship to diet and heart disease from multiple populations in a relatively short time at an affordable cost, Yusuf said.

Data from this study helped confirm that changes in dietary intake, including the consumption of more fruits and vegetables, can help reduce the risk of having a heart attack in populations worldwide, he said. “At the same time, an unhealthy dietary intake, assessed by a simple dietary risk score, accounts for nearly one-third of the world population’s attributable risk,” Yusuf said.

Other co-authors are: Sonia Anand, M.D.; Stephanie Ounpuu, Ph.D.; Shofiqul Islam, M.Sc.; Xiaohe Zhang, M.Sc.; Sumathy Rangarajan, M.Sc.; Jephat Chifamba, MD.; Ali Al-Hinai, M.D.; and Matyas Keltai. Individual author disclosures can be found on the manuscript.

The INTERHEART study was funded by the Canadian Institutes of Health Research; the Heart and Stroke Foundation of Ontario; the International Clinical Epidemiology Network; and through unrestricted grants from several pharmaceutical companies (with major contributions from Astra Zeneca, Novartis, Hoechst Marion Roussel [now Aventis], Knoll Pharmaceuticals [now Abbott], Bristol-Myers Squibb and Sanofi-Sythelabo); and by various national bodies and pharmaceutical firms in different countries. In the United States, King Pharma provided funding.