Small quantities of processed meat such as bacon, sausages or salami can increase the likelihood of dying early by a fifth, researchers from Harvard School of Medicine found. Eating steak increases the risk of early death by 12%.

The study found that cutting the amount of red meat in peoples’ diets to 1.5 ounces (42 grams) a day, equivalent to one large steak a week, could prevent almost one in 10 early deaths in men and one in 13 in women.

The scientists said that the government’s current advice that people should eat no more than 2.5 ounces (70 grams) a day, around the level the average Briton already consumes, was “generous”.

Dr Frank Hu, co-author of the study, said: “Given the growing evidence that even modest amounts of red meat is associated with increased risk of chronic disease and premature death, 2.5 ounces (70 grams) per day seems generous. The bottom line is that we should make red meat only an occassional rather than regular part of our diet.”

Red meat often contains high amounts of saturated fat, while bacon and salami contain large amounts of salt. Replacing red meat with poultry, fish or vegetables, whole grains and other healthy foods cut the risk of dying by up to one fifth, the study found.

The study published in the Archives of Internal Medicine followed more than 100,000 people for around 28 years asking them periodically about their diet and lifestyle.

It was found that for every serving of red meat – equivalent to 3 ounces (85 grams) – eaten each day there was an 18 per cent increased risk of dying from heart disease and a 10 per cent increased risk of dying from cancer.

For each serving of processed meat, equivalent to two slices of bacon or one hot dog, the risk of dying from heart disease rose by a 21 per cent and from cancer by 16 per cent.

Lead author Dr An Pan from the Department of Nutrition at Harvard, wrote in the journal: “We found that greater consumption of unprocessed and processed red meats is associated with higher mortality risk.

“Compared with red meat, other dietary components, such as fish, poultry, nuts, legumes, low-fat dairy products, and whole grains, were associated with lower risk.

“These results indicate that replacement of red meat with alternative healthy dietary components may lower the mortality risk.”

Scientists added that people who eat a diet high in red meat were also likely to be generally unhealthier because they were more likely to smoke, be overweight and not exercise.

In an accompanying editorial Dr Dean Ornish, of the University of California, San Francisco, said that eating less red meat could also help tackle climate change.

He said: “In addition to their health benefits, the food choices we make each day affect other important areas as well. What is personally sustainable is globally sustainable. What is good for you is good for our planet.”

A landmark study by the World Cancer Research Fund published in 2005 recommended that people should not eat more than 1.1lb (499 grams) of red meat a week, and that children should not be given processed meat like sausages at all.

Dr Rachel Thompson, Deputy Head of Science at the World Cancer Research Fund, said:

“This study strengthens the body of evidence which shows a link between red meat and chronic diseases such as cancer and heart disease. The research itself seems solid and is based on two large scale cohort studies monitored over a long period of time.”

Dr Carrie Ruxton, from the Meat Advisory Panel (MAP), a British group of doctors and scientists funded by the industry, cast doubt on the findings and said the conclusions were based on a “theoretical” model”

She said that red meat is a valuable source of iron, zine and vitamin D which is vital for health, especially in pregnant women and infants.

A Department of Health spokesperson said: “Red meat can be part of a balanced diet. But people who eat a lot of red and processed meat should consider cutting down as regularly eating a lot could increase your risk of bowel cancer.”