Protein from nuts and seeds is beneficial for the heart, but consuming large amounts of meat protein can cause a sharp increase in the risk of cardiovascular diseases, a study has found.
Researchers from Loma Linda University in the US and Institut National de la Recherche Agronomique in France studied data from more than 81,000 participants.
The study, published in the International Journal of Epidemiology, found that people who consumed large amounts of meat protein experienced a 60 per cent increase in cardiovascular disease, while people who consumed large amounts of protein from nuts and seeds experienced a 40-percent reduction in cardiovascular disease.
"While dietary fats are part of the story in affecting risk of cardiovascular disease, proteins may also have important and largely overlooked independent effects on risk," Fraser said.
Researchers have long suspected that including nuts and seeds in the diet protects against heart and vascular disease, while red meats increase risk.
Nutritionists have traditionally looked toward what he termed "bad fats" in meats and "helpful fats" in nuts and seeds as causal agents.
"This new evidence suggests that the full picture probably also involves the biological effects of proteins in these foods," said Gary Fraser, from Loma Linda University in the US.
The team's research differed in another significant way from previous investigations.
While prior studies have examined differences between animal and plant proteins, this study did not stop at just two categories, but chose to specify meat protein and proteins from nuts and seeds along with other major dietary sources.
"This research is suggesting there is more heterogeneity than just the binary categorisation of plant protein or animal protein," Fraser said.