Is eating meat really as bad for you as smoking? According to the headlines, it is-but they miss out one vital fact. Protein becomes more and more important as you get older.
Eating protein, and especially meat and cheese, makes you four times more likely to develop cancer, a risk profile that is similar to smoking, a new study has claimed.
And the media was quick to jump on the findings with headlines that proclaimed that consuming animal protein every day is the same as smoking 20 cigarettes.
It sounds wrong, and it is wrong. It's all to do with how much protein you eat and your age, as the researchers from the University of Southern California were at pains to point out.
The risk exists only for people in their middle-age, but it flips over by the time you hit 65. Then, a high-protein diet is good for you, and helps protect you against a range of diseases.
It's all to do with the IGF-I protein, which helps our body grow, but can increase the risk of cancer. Our normal levels start to drop off by the time we reach 65, resulting in a loss of muscle mass.
And not all proteins are equal. Plant-based proteins, such as from beans, don't carry any health risk, whatever age you are when you eat them.
The study is also aimed at Americans, who eat more proteins than most everyone else. The researchers recommend that a middle-aged person should consume around 0.8 grams of animal protein per kilogram of body weight every day. That equates to around 50 grams of protein for a person weighing 130 pounds.
You should also be deriving just 20 per cent of your daily calories from protein, say the researchers who looked at the lifestyles and health of 6,318 adults over the age of 50.
(Source: cell Metabolism, 2014; 19 (3): 407-17