Indo-Mediterranean diet better than low-fat for CAD

Moradabad, India - A Mediterranean-style diet rich in alphalinolenic acid seems to be more effective in primary and secondary prevention of coronary artery disease than a conventional "low-fat" diet, according to a new study in the Lancet this week.

Dr Ram B Singh (Medical Hospital and Research Centre, Moradabad, India) and colleagues found that the group of patients randomized to an "Indo-Mediterranean" dietrich in whole grains, fruits, vegetables, and nutshad approximately half the risk of sudden cardiac death and nonfatal heart attacks as the second group, given a local diet similar to the National Cholesterol Education Program (NCEP) step-1 diet.

Singh et al note that people of South Asian origin are more susceptible to CAD but that this is not explained by conventional risk factors, such as cholesterol and obesity, alone. They hypothesized that if the benefits of the Mediterranean dietas shown by the Lyon Heart Study and other trialsextend to non-Mediterranean populations, this might provide "an economically feasible and realistic method to reduce CAD" in other regions of the world.

They recruited participants through advertisements in newspapers and local service clubs, who had to be older than 25 and have 1 or more of the major risk factors for CADhypertension, hypercholesterolemia, or diabetes mellitusor angina or a previous MI in the absence or presence of other risk factors. Most respondents had sedentary occupations, and two thirds of patients were vegetarian. Baseline risk factors were similar in the 2 groups, including the fact that roughly half of the patients in each group smoked and they had similar patterns of therapeutic drug use.

The researchers met with the participants every week for 3 weeks, and both groups were advised to eat foods that would provide a dietary intake similar to the NCEP step-1 diet. In addition, patients in the Mediterranean-style diet group were advised to eat at least 400 g to 500 g of fruits, vegetables, and nuts and 400 g to 500 g of whole grains, legumes, rice, maize, and wheat each day, as well as mustard or soy bean oil. Patients from both groups were also advised to walk briskly for a minimum of 3 km to 4 km or to jog intermittently for 10 to 15 minutes a day.

Food intake and physical activity were recorded for the first 3 weeks, then at weeks 4, 8, 12, and 24, then at 12-week intervals out to 2 years to assess dietary adherence and exercise activity. The principal end points of the study were fatal or nonfatal MIs, sudden cardiac deaths, and the combined total of these events.

"The aim of these dietary recommendations was to provide people in the intervention group with plenty of phytochemicals, antioxidants, and alphalinolenic acid (the major n-3 fatty acid in these foods)," Singh et al state.

After 2 years of follow-up, the intervention group had a significant reduction in risk of nonfatal MI, sudden cardiac death, and total cardiac end points compared with controls (see table). There were also fewer fatal MIs among the intervention group, although the difference was not significant.

One of the co-authors, Dr Elliot M Berry (Hebrew University Hadassah Medical School, Jerusalem), told heartwire that the population studied is already consuming a diet considered healthy by the American Heart Association. But urban dwellers in India and immigrant Indians living in other nations have much higher rates of CAD than those living in rural India. The latter consume 300 g to 500 g per day of whole grains and mustard oil, which is rich in n-3 fatty acids.

"Urban dwellers and immigrants...have yet to learn the messages for prevention of heart disease," Berry commented.

"Baseline diets contained large amounts of total and saturated fats and cholesterol...[and they] substitute potato and refined carbohydrates for grains and use proatherogenic vegetable ghee and clarified butter in place of oils," the researchers note.

In addition, Indian studies "show inadequate fruit and vegetable consumption."

The Indo-Mediterranean diet used in this study provided results "comparable to drug medicationbut at a cost of about $1US per day. That makes tremendous health and economic sense," Berry commented. The whole grains, fruits, vegetables, and oils used in the study were seasonal, traditional, and produced by farmers at this low cost. "The Mediterranean diet is applicablewith variationsto everybody," he added.

"Our trial in a non-Western population has shown that...a [Mediterranean-style] diet is associated with a pronounced decline in CAD morbidity and mortality, without an increase in noncardiac deaths and in the presence of improved metabolic profiles. The long-term benefits may be even more substantial," the authors conclude.

Heartwire from Medscape © 2002 

Cite this: Indo-Mediterranean diet better than low-fat for CAD - Medscape - Nov 07, 2002.