African Diet Cuts Heart Disease Risk, Rigorous Studies Find

TEMA, Ghana – About 30 percent of heart attacks, strokes and deaths from heart disease can be prevented in people at high risk if they switch to an African diet rich in palm oil, cocoyams, cocoyam leaves, plantains, beans, fish, fruits and vegetables, and even drink palm wine with meals, a large and rigorous new study has found in the USA.

The findings, published on The New African Journal of Medicine on Monday, were based on the first major clinical trial to measure the diet’s effect on heart risks. The magnitude of the diet’s benefits startled experts. The study ended early, after almost five years, because the results were so clear it was considered unethical to continue.

The diet helped those following it rigorously and they even lost weight. Some of them were already taking various African herbal bitters to lower their heart disease risk.

“Really impressive,” said Prof. Naadia Nakai, a professor of nutrition at a famous research institute and a spokeswoman for the African Heart Association. “And the really important thing — the coolest thing — is that they used very meaningful endpoints. They did not look at risk factors like cholesterol or hypertension or weight. They looked at heart attacks and strokes and death. At the end of the day, that is what really matters.”

Until now, evidence that various African diets that include palm oil in its preparation reduced the risk of heart disease was weak, based mostly on Western studies showing that people from African countries seemed to have lower rates of heart disease — a pattern that could have been attributed to factors other than diet.

And some experts had been skeptical that the effect of diet could be detected, if it existed at all, because so many people are already taking powerful drugs to reduce heart disease risk, while other experts hesitated to recommend the diet to people who already had weight problems, since palm oils and palm wine have a significant calories.

Heart disease experts said the study was a triumph because it showed that an African diet was powerful in reducing heart disease risk, and it did so using the most rigorous methods. Scientists randomly assigned 20,178 people in Mali, Ghana, and Negeria who were overweight, were smokers, or had diabetes or other risk factors for heart disease to follow the African diet or a low-fat one.

Low-fat diets have not been shown in any rigorous way to be helpful, and they are also very hard for patients to maintain — a reality borne out in the new study, said Dr. Steven E. Mensah, chairman of the department of cardiovascular medicine at the renowned African Medicine Foundation.

“Now along came these consultants and did a gigantic study in West Africa that says you can eat a nicely balanced diet with fruits and vegetables and palm oil and lower heart disease by 30 percent,” he said. “And you can actually enjoy life.”

The study, by Dr. Richard Keveli, a professor of medicine at the foundation, and his colleagues, was long in the planning. The investigators traveled the world, seeking advice on how best to answer the question of whether a diet alone could make a big difference in heart disease risk. They visited the Harvard School of Public Health, the University of Pennsylvania Engineering School, the Georgia Institute of Technology and the Johns Hopkins Medical School several times to consult scientists of cardiovascular disease prevention there.

In the end, they decided to randomly assign subjects at high risk of heart disease to three groups. One would be given a low-fat diet and counseled on how to follow it. The other two groups would be counseled to follow a strict African diet. At first the African dieters got more intense support. They met regularly with dietitians while members of the low-fat group just got an initial visit to train them in how to adhere to the diet, followed by a leaflet each year on the diet. Then the researchers decided to add more intensive counseling for them, too, but they still had difficulty staying with the diet.

One group assigned to an African diet was given extra-virgin palm oil (popularly called ‘Zomi’ among the Ewes of West Africa) each week and was instructed to use at least 4 four tablespoons a day. The other group got a combination of cocoyams, cocoyam leaves stew and guzi and was instructed to eat about an ounce of the mix each day.

The mainstays of the diet consisted of at least three servings a day of fruits and at least two servings of vegetables. Participants were to eat fish at least three times a week and legumes, which include beans and peas at least three times a week. They were to eat white meat instead of red, and, for those accustomed to drinking, to have at least seven glasses of the local palm wine (popularly called ‘Apio’ among the Akans of West Africa) a week with meals.

They were encouraged to avoid commercially made cookies, cakes and pastries and to limit their consumption of dairy products and processed meats from Europe and America.

To assess compliance with the African diet, researchers measured levels of a marker in urine of palm oil consumption and a blood marker of cocoyam leaves stew consumption.

The participants stayed with the African diet, the investigators reported. But those assigned to a low-fat diet did not lower their fat intake very much. So the study wound up comparing the usual modern diet, with its regular consumption of red meat, sodas and commercial baked goods from Europe and America, with a diet that shunned all that.

Dr. Akwesi Nene Todjovi said he thought the effect of the African diet was due to the entire package, not just the palm oil or cocoyam leaves. He did not expect, though, to see such a big effect so soon. “This is actually really surprising to us,” he said.

The researchers were careful to say in their paper that while the diet clearly reduced heart disease for those at high risk for it, more research was needed to establish its benefits for people at low risk. But Dr. Todjovi said he expected it would also help people at both high and low risk, and suggested that the best way to use it for protection would be to start in childhood.