A diet rich in animal protein and meat, in particular, is not good for your health, a new study from the University of Eastern Finland finds.
Men whose primary sources of protein were animal-based had a 23% higher risk of death during the follow-up than men who had the most balanced ratio of animal and plant-based protein in their diet.
The researchers found a high intake of meat, in particular, seemed to associate with adverse effects: men eating a diet rich in meat, i.e. more than 200 grams per day, had a 23% greater risk of death during the follow-up than men whose intake of meat was less than 100 grams per day.
The men who participated in the study mainly ate red meat. The mean age of the men participating in the study was 53 years at the onset, and diets clearly lacking in protein were not typical among the study population.
How Was The Study Conducted?
The study is based on the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) that analyzed the dietary habits of approximately 2,600 Finnish men aged between 42 and 60 at the onset of the study in 1984-1989.
The researchers studied the mortality of this study population in an average follow-up of 20 years by analyzing registers provided by Statistics Finland.
The analyses focused on the associations of dietary protein and protein sources with mortality during the follow-up, and other lifestyle factors and dietary habits were extensively controlled for, including the fact that those eating plenty of plant-based protein followed a healthier diet.
Most nutrition recommendations nowadays limit the intake of red and processed meats. In Finland, for example, the recommended maximum intake is 500 grams per week.
The study also found that a high overall intake of dietary protein was associated with a greater risk of death in men who had been diagnosed with Type 2 diabetes, cardiovascular disease or cancer at the onset of the study.
A similar association was not found in men without these diseases.
“These findings should not be generalized to older people who are at a greater risk of malnutrition and whose intake of protein often remains below the recommended amount,” Heli Virtanen from the University of Eastern Finland points out.
The researchers say the findings highlight the need to investigate the health effects of protein intake especially in people who have a pre-existing chronic medical condition.
Earlier studies have suggested that a high intake of animal protein, and especially the consumption of processed meats such as sausages and cold cuts, is associated with an increased risk of death. However, the big picture relating to the health effects of protein and different protein sources remains unclear.