Too much meat — particularly red meat — has been shown to be bad for the health, but protein from plants may actually offset the negative effects, a new study has revealed.

In fact, people who eat more plant protein and less animal protein may have longer lives even when they have unhealthy habits such as smoking or heavy drinking, the new report said.

When it comes to protein intake, where the protein comes from is just as important as how much of it people eat, researchers explained.

Plant Protein Is Better Than Animal Protein

Led by Harvard University researcher Mingyang Song, the team of experts followed more than 130,000 health professionals over several years.

Half of the participants receive 14 percent of their calories from animal protein sources such as eggs, dairy and meat, while 4 percent is from plant protein sources such as grains, pasta, nuts, legumes and beans.

At the beginning of the study, most of the participants were 49 years old and were women. By the end, approximately 36,000 of the participants have died — 13,000 died of cancer and 8,850 died of cardiovascular disease.

Researchers took into account several lifestyle factors such as obesity, drinking, smoking and physical inactivity. They found that each 3 percent surge in calories from plant protein was linked to a 10 percent decreased risk of death during the duration of the study.

On the other hand, each 10 percent increase in the intake of calories from meat was linked to 2 percent higher risk of mortality from any cause and an 8 percent risk of death from cardiovascular disease, scientists found.

Eating Meat Is Deadlier For Obese/Overweight Participants

Song and colleagues discovered that the link between animal protein and death was stronger for participants who were overweight or obese.

Nutrition researcher Pagona Lagiou, who was not involved in the study, says obese individuals and those with unhealthy lifestyle habits possibly have underlying inflammatory or metabolic disorders that enhance the effects of high intake of animal protein.

Furthermore, Song and the team found that those who eat meat and have a healthy lifestyle tend to eat more poultry and fish, while those who have an unhealthy lifestyle and have higher mortality risks tend to eat more eggs, red meat and high-fat dairy.

"[W]e suspect the different sources of animal protein between the two groups may contribute to the stronger results in the unhealthy lifestyle group," says Song.

Erasing The Link

Eating animal protein did not appear to be associated with higher risk of premature death for people with a healthy lifestyle. Eating more plant protein also did not seem to be linked to a longer life for them.

One of the limits of the new study is that it is observational and cannot prove that the type of protein we consume directly influences how long people live. It was also possible that lifestyle and eating habits of healthcare professionals in the research might not represent a broader range of adults.

Details of the new study are published in the journal JAMA Internal Medicine.

Photo: Winfried Mosler | Flickr