Obesity Linked to 10 Common Cancers

Being overweight and obese puts people at greater risk of developing
10 of the most common cancers, according to research in the Lancet
medical journal.

Scientists calculated individuals carrying this extra weight could
contribute to more than 12,000 cases of cancer in the UK population
every year.

They warn if obesity levels continue to rise there may be an
additional 3,700 cancers diagnosed annually.

The study of five million people is the largest to date to confirm the link.

This variation tells us BMI must affect cancer risk through a number
of different processes, depending on cancer type"

Doctors often warn being overweight can increase the risk of
developing cancer, but this study highlights those forms of the
disease where the risk is greatest.

Led by scientists from the London School of Hygiene and Tropical
Medicine researchers gathered data on five million people living in
the UK, monitoring changes to their health over a period of seven
years.

They found each 13-16kg (2-2.5 stone) of extra weight an average adult
gained was linked firmly and linearly to a greater risk of six
cancers.
How big this risk was varied depending on tumour type.

People who had a high body mass index (calculated using weight and
height) were also more likely to develop cancer of the liver, colon,
ovaries, and post-menopausal breast cancer.

But the effects for these cancers were less clear-cut and were
influenced by individual factors such as the menopause.

Researchers say though obesity was associated with the development of
the most common cancers - which represent 90 per cent of the cancers
diagnosed in the UK, some showed no link at all.

And there is some evidence to suggest a higher BMI is associated with
a lower chance of getting prostate cancer.

Dr. Krishnan Bhaskaran, who led the research, said: "There was a lot
of variation in the effect of BMI on different cancers.

"For example, risk of cancer of the uterus increased substantially at
higher body mass index, for other cancer we saw a more modest increase
in risk or no effect at all.

"This variation tells us BMI must affect cancer risk through a number
of different processes, depending on cancer type"

Tom Stansfeld, at Cancer Research UK, said: "Although the relationship
between cancer and obesity is complex, it is clear carrying excess
weight increases your risk of developing cancer.

"Keeping a healthy weight reduces cancer risk and the best way to do
this is through eating a healthy, balanced diet and exercising
regularly."