Sweet and savoury excesses linked to poor heart health

CARDIOVASCULAR diseases (CVDs) are the number one cause of death globally, according to the World Health Organisation (WHO). An estimated 17.3 million people died from CVD in 2008, representing 30% of all global deaths; of these deaths, an estimated 7.3 million were due to coronary heart disease and 6.2 million were due to stroke. By 2030, WHO estimates that almost 23.6 million people will die from CVDs, mainly from heart disease and stroke, which are projected to remain the leading causes of death.

One of the most important behavioural risk factors of heart disease and stroke is an unhealthy diet. The effects of excessive salt and trans-fatty acids, for instance, have been well established clinically, and are linked to increased blood pressure, raised blood glucose and blood lipids. An unhealthy diet is also directly related to overweight and obesity, which are called ‘intermediate risk factors' or metabolic risk factors.

More recently, two large epidemiological studies have linked consumption of red meat and sugar-sweetened drinks to an increased risk of heart disease.

Red light for red meat

Eating red meat, particularly processed red meat, increases risk for premature death, says a new study1 from Harvard School of Public Health (HSPH). Red meat contains substances that have been linked to increased risk of chronic diseases, such as cardiovascular disease and cancer. These include heme iron, saturated fat, sodium, nitrites, and certain carcinogens that are formed during cooking.

HSPH researchers observed 37,698 men from the Health Professionals Follow-up Study for up to 22 years, and 83,644 women in the Nurses' Health Study for up to 28 years, who were free of CVD and cancer at baseline. Diets were assessed through questionnaires every four years.

One daily serving of unprocessed red meat (about the size of a deck of cards) was associated with a 13% increased risk of mortality, and one daily serving of processed red meat (one hot dog or two slices of bacon) was associated with a 20% increased risk.

Amongst specific causes, the corresponding increases in risk were 18% and 21% for cardiovascular mortality, and 10% and 16% for cancer mortality. These analyses took into account chronic disease risk factors such as age, body mass index, physical activity, family history of heart disease, or major cancers.

"Our study adds more evidence to the health risks of eating high amounts of red meat, which has been associated with type 2 diabetes, coronary heart disease, stroke, and certain cancers in other studies," said lead author An Pan, research fellow in the Department of Nutrition at HSPH.

The study also found, however, that substituting other healthy protein sources, such as fish, poultry, nuts, and legumes, was associated with a lower risk of mortality.

Replacing one serving of total red meat with one serving of a healthy protein source was associated with a lower mortality risk: 7% for fish, 14% for poultry, 19% for nuts, 10% for legumes, 10% for low-fat dairy products, and 14% for whole grains. The researchers estimated that 9.3% of deaths in men and 7.6% in women could have been prevented at the end of the follow-up if all the participants had consumed less than 0.5 servings per day of red meat.

"This study provides clear evidence that regular consumption of red meat, especially processed meat, contributes substantially to premature death," said senior author Frank Hu, professor of nutrition and epidemiology at HSPH. "On the other hand, choosing more healthful sources of protein in place of red meatZapatillas Trail Running