Being overweight or obese 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.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.
Cancer of the uterus had the highest increased risk
gallbladder,kidney,cervix,thyroid,leukaemia had the lowest rise in
risk.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% 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.”
BBC
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