Swapping animal for plant protein in your diet can lead to a longer life, research has shown.
A large study found that every 3% increase in calories from plant protein reduced the risk of death from all causes by 10%. It was also associated with a 12% lower risk of death from heart disease.
In contrast, raising the animal protein share of calories by 10% led to a 2% higher risk of all-cause death and an 8% greater chance of dying from a heart problem.
Animal protein foods include all types of meat, fish, eggs and dairy products such as milk and cheese. Plant sources of protein include cereals, beans, nuts, legumes, soya and bread.
The greater risk of dying linked to eating animal protein was more pronounced among people who were obese, had a history of smoking, drank heavily, and who did little exercise.
Among the healthiest participants, the association disappeared – possibly because health-conscious people tended to eat more fish and poultry rather than red and processed meat, said the researchers.
Lead scientist Dr Mingyang Song, from Massachusetts General Hospital, US, said: “Overall, our findings support the importance of the sources of dietary protein for long-term health outcomes.
“While previous studies have primarily focused on the overall amount of protein intake – which is important – from a broad dietary perspective, the particular foods that people consume to get protein are equally important.
“Our findings suggest that people should consider eating more plant proteins than animal proteins, and when they do choose among sources of animal protein, fish and chicken are probably better choices.”
The researchers analysed data from two large US studies focusing on diet and health, the Nurses’ Health Study and the Health Professionals Follow-up Study.
Together, they recruited a total of 131,342 participants with an average age of 49 whose progress was followed for up to 32 years. Each participant filled out food questionnaires detailing his or her diet.
During the follow-up period more than 36,000 deaths were recorded. Almost 9,000 of these were due to cardiovascular disease, 13,000 to cancer and about 14,000 to other causes.
The scientists concluded: “Substitution of plant protein for animal protein, especially from processed red meat, may confer substantial health benefit. Therefore, public health recommendations should focus on improvement of protein sources.”