Revealed: The factors that put you at risk of cancer – as the number of preventable cases in Britain reaches 184,000 this year

More than 375,000 Britons are diagnosed with cancer every year.

Although the cause of the disease is unknown in the majority of patients, four in ten cases are preventable, research shows.

These are caused by lifestyle factors such as smoking, alcohol consumption, diet and exposure to the sun’s ultraviolet rays.

It means that 184,000 patients could have avoided cancer this year if they had lived healthier lives, experts think.

Here, MailOnline explains how these factors cause cancer and what you can do to reduce your risk.

Smoking

Smoking is the biggest cause of cancer, not just in the UK, but worldwide.

There is no safe level of smoking and quitting completely is the best thing you can do for your health, says Cancer Research UK.

Smokers are at risk of developing 15 types of cancer, including lung, colon and bladder cancer.

This is because tobacco smoke releases more than 5,000 chemicals – including toxic metals and toxic gases – known to cause cancer.

These damage parts of the DNA that protect cells against cancer.

In addition, some chemicals make it harder for the body to repair DNA damage, which can cause cancer in cells, according to Cancer Research UK.

Experts warn that even occasional and social smoking increases the risk of cancer. They suggest quitting by reducing the number of cigarettes you smoke per day.

Smoking is the biggest cause of cancer in the world and being smoke-free can prevent 15 types of cancer

Alcohol Change UK says drinking 14 units a week or less will keep the risk of cancer low

Alcohol

Drinking alcohol can increase the risk of seven types of cancer, including breast, colon and oral cancer.

Although any amount of alcohol can increase the risk of cancer, Alcohol Change UK says drinking 14 units a week or less will keep the risk low.

But whatever your drinking habits, according to Cancer Research UK, cutting back will reduce your risk of cancer.

Alcohol alone causes around 11,900 cases of cancer every year in Britain, says Alcohol Change UK.

There is evidence that acetaldehyde – a chemical produced when the body breaks down alcohol – is toxic and damages the DNA in our cells, which can then cause cancer.

As with smoking, experts say the only way to reduce this risk is to reduce the amount of alcohol you drink.

Eating pattern

A healthier diet could prevent up to a third of cancer cases in Britain.

Although the risk between diet and cancer is complicated, experts say eating foods like red and processed meat can increase the risk of colon cancer.

According to Cancer Research UK, having a BMI of 25 or higher also increases the risk of 13 types of cancer.

The charity says excess fat can send signals to the rest of the body, causing cells to divide more often, which can then lead to cancer.

Experts say losing weight, belly fat and eating more fruits and vegetables and less processed meat can help reduce the risk of cancer.

Having a BMI of 25 or higher increases the risk of 13 types of cancer. Eating too much red meat and processed meat can also increase your risk of colon cancer

The more often you sunburn, the greater the risk of melanoma skin cancer, experts warn

sun exposure

Burning just once every two years is enough to triple your risk of melanoma skin cancer, compared to never burning.

Ultraviolet radiation (UV) is an energy source released naturally by the sun. But too much of this, either from the sun or tanning beds, can damage the DNA in the skin, according to Cancer Research UK.

Experts at the charity say that if enough DNA damage builds up over time, it can cause cells to grow out of control, leading to skin cancer.

Staying out of the sun between March and October in the UK between 11am and 3pm when the UV rays are strongest, and wearing sunscreen, can help protect your skin from sun damage.

Experts also warn people to avoid using tanning beds and sunbathing.