Higher levels of heart disease risk factors may explain why people native to South Asia tend to have heart attacks at a younger age, a Canadian-led international study on cardiovascular disease found.

The South Asian countries of India, Pakistan, Bangladesh, Sri Lanka, and Nepal account for about a quarter of the world's population and contribute the highest proportion of cardiovascular diseases compared with any other region worldwide.

Protective factors such as exercise were less common among South Asians than controls from other countries, the team said.
(CBC)

For South Asians, the average age for a heart attack is about 53 compared with 58 in other parts of the world.

"The reason why South Asians get heart disease at an earlier age is because they have a higher proportion of people with bad cholesterol and less good cholesterol," said the study's author, Dr. Salim Yusuf of McMaster University in Hamilton, Ont.

For the study in Wednesday's Journal of the American Medical Association, Yusuf and his colleagues looked at almost 30,000 people from many countries.

South Asians who had heart attacks were compared with those who didn't and to people of other ethnicities who did or did not have heart attacks.

A history of diabetes was also more common among the South Asians, the researchers found.

Risk factors for immigrants, too

Other risk factors for cardiovascular disease, such as smoking, lack of exercise and poor diet were generally the same for people of all ethnicities.

"The earlier age of acute myocardial infarction in South Asians can be largely explained by higher risk factor levels at younger ages," the study's authors concluded.

The cholesterol differences are probably biological, but poor diet doesn't help. In dishes such as curries, vegetables may be cooked so long that they lose their health benefits, and the cooking habits follow South Asians when they emigrate, Yusuf said.

"I think South Asian immigrants who have come to North America are at even greater risk of heart disease compared to those living in their home countries," said Yusuf. "The reason for this is that they're even more urbanized."

Everyone should eat healthy food, get enough exercise, not smoke and get checked out by a doctor, but the advice may matter more for South Asians, he added.