Almost half (45 per cent) of all cancers in men and 40 per cent in women could be prevented, according to a major study.

One in 25 cancers is linked to a person’s job

The Cancer Research UK report found more than 100,000 cancers each year in the UK are caused by four lifestyle factors – smoking, unhealthy diets, alcohol and people being too fat.

This rises to around 134,000 cases a year when 14 lifestyle and environmental factors are taken into account.

Smoking is by far the biggest lifestyle contributor to a person’s risk of developing cancer, accounting for 23 per cent of all cancers in men and 15.6 per cent in women.

As well as lung cancer, it is implicated in other forms of the disease including bladder, kidney, pancreatic and cervical cancer. The charity said the review, which is published in the British Journal of Cancer, is the most comprehensive to date.

One in 25 cancers is linked to a person’s job, such as being exposed to chemicals or asbestos, while one in 33 is linked to infections, such as the human papillomavirus, which causes most cases of cervical cancer.

Overall, 34 per cent of cancers in 2010 (106,845) were linked to smoking, diet, drinking alcohol and excess weight.

In men, 6.1 per cent (9,600) of cancer cases were linked to a lack of fruit and vegetables, 4.9 per cent (7,800) to occupation, 4.6 per cent (7,300) to alcohol, 4.1 per cent (6,500) to overweight and obesity and 3.5 per cent (5,500) to excessive sun exposure and sunbeds. In women, 6.9 per cent (10,800) were linked to overweight and obesity, 3.7 per cent (5,800) to infections such as HPV, 3.6 per cent (5,600) to excessive sun exposure and sunbeds, 3.4 per cent (5,300) to lack of fruit and vegetables and 3.3 per cent (5,100) to alcohol.

In April 2010, researchers in the Journal of the National Cancer Institute found that eating fruit and vegetables to ward off cancer has a “modest” effect at best.

Their research on almost 500,000 people found eating five portions of fruit and vegetables a day (about 400g) had very little effect on cancer risk, as did eating more or fewer portions. The study includes estimates of all the cancers that could have been prevented in 2010. The report included examination of dietary factors, such as people’s consumption of fibre-rich foods, red meat and processed meats such as ham, bacon and sausages.

A high-fibre diet is known to reduce the risk of bowel cancer, while red and processed meat is thought to increase the risk. Drinking alcohol is linked to a range of cancers, including breast cancer, liver cancer and cancer of the oesophagus.

Some nine per cent of lung cancers in the latest study were also linked to a lack of fruit consumption.