A new study has found that a high protein diet is as dangerous as smoking.
Research from the University of Southern California shows that high levels of animal protein in those under 65 were associated with a fourfold increase in their risk of death from cancer compared to those on a low protein diet.
A “high-protein” diet was defined as deriving at least 20% of daily calories from protein. The researchers recommend a middle-aged person consume around 0.8g of protein per kilogram of body weight, per day.
So if you weigh 70 kilos – that’s 11 stone – that’s 56 grams of protein a day.
Protein levels controls the growth hormone IGF-I, which help bodies grow but high levels of which have been linked to cancer.
Levels of IGF-I drop off dramatically after age 65, leading to potential frailty and muscle loss. The study shows that while high protein intake during middle age is very harmful, it is protective for those over 65 who ate a moderate or high-protein diet.
Animal-based proteins such as red meat, milk, and cheese were most harmful. ‘Some proteins are better for you than others, for example plant-based proteins like beans. Vegans seem to do better in studies than those who eat animal based proteins.’ said Dr Longo
“But the good news is that there is no evidence that fish is bad for you. So fish plus vegetables is really the best group of proteins,”
Dr Longo, who skips lunch, recommends a diet high in complex carbohydrates and low in protein.
“I follow a fish and vegetable based diet which is high in complex carbohydrates. This is a diet that has been found in the most long-lived populations of the world,” he said.