If you want to increase your chances of living longer, dump the red meat and eat more chicken - and fish and nuts and legumes, too.

New research conducted at the Harvard School of Public Health shows that eating red meat is linked to not only an increased risk of death from cardiovascular disease and cancer, but to overall mortality. The study also concluded that substituting other forms of protein was associated with a lower risk of dying.

Researchers studied over 20 years worth of data from nearly 38,000 men in the Health Professionals Follow-up Study and nearly 84,000 women in the Nurses' Health Study who were free of cancer and cardiovascular disease at the beginning of each study. Their diets were assessed through food frequency questionnaires every four years.

Bacon and hot dogs tended to be associated with a higher risk of dying than other red meats, whether unprocessed or processed.

A combined 23,926 deaths were documented from the two studies. Cardiovascular disease was the cause of 5,910 deaths and 9,464 deaths were attributed to cancer. The study showed that eating red meat, particularly processed red meat, on a regular basis was associated with an increased risk of dying. Eating one serving of unprocessed red meat per day increased the risk of dying by 13 percent while a daily serving of processed red meat (one hot dog or two slices of bacon) raised the risk by 20 percent.

Lead researcher An Pan, a research fellow in the Department of Nutrition at the Harvard School of Public Health, said that this study adds to the evidence that eating high amounts of red meat increases the risk of type 2 diabetes, heart disease, stroke, and some types of cancer. The analysis of data took into consideration chronic risk factors such as age, body mass index, physical activity, and family history of heart disease or cancer.

Higher intakes of red meat were associated with a greater calorie intake and a lower intake of whole grains, fruits, and vegetables. Bacon and hot dogs tended to be associated with a higher risk of dying than other red meats, whether unprocessed or processed.

Saturated fat and cholesterol found in red meat may partially explain the associations found in this study. Both unprocessed and processed meats contain a similar content of saturated fat; however, processed meat also contains both sodium and nitrates which may explain their additional harm.

The research provides clear evidence that the regular consumption of red meat, and particularly processed meat, plays a significant role in premature death, according to Frank Hu, senior author of the study.

The researchers believe cutting red meat consumption in half could have prevented 9.3 percent of deaths in men and 7.6 percent of deaths in women in the study. Replacing one serving of red meat with an equivalent amount of fish reduced the risk of dying by 7 percent while poultry doubled the protection. Consuming legumes and low-fat dairy instead of a serving of red meat lowered risk by 10 percent, whole grains by 14 percent, and nuts by 19 percent.

What was not taken into consideration in this study is whether the red meat consumed was lean or fatty so whether that would have made a difference is not known. Red meat provides significant sources of zinc, iron, selenium, B vitamins, and vitamin D, but it is not the only source of these essential nutrients. If a person chooses to eat red meat, lean cuts should be chosen, and it should be eaten in moderation and balanced with a diet including other protein sources, such as fish, poultry, nuts, low-fat dairy, and legumes. A serving of meat is about the size of a deck of cards.

In a commentary on the study, Dr. Dean Ornish points out that reducing red meat consumption has a beneficial effect on more than just health. It also impacts global warming and energy consumption. The study is published online in the Archives of Internal Medicine.