The Science Media CentreWednesday 30 June 2010, 3:17PM
Media release from Science Media Centre
Research published in The Lancet Oncology today shows a
strong causal link between obesity in Asia-Pacific people, and an
increased risk of dying from cancer.
While an increased risk of death from cancer has been linked with
obesity in Western populations, little research until now has
looked at any effects in Asia-Pacific populations.
Now, a study of Asia-Pacific people, including 10,400 New
Zealanders, has found that overweight and obese people are 6% and
21% (respectively) more likely to die from cancer when compared
with their normal-weight counterparts.
The Lancet paper can be accessed by registered
journalists in the SMC Resource Library. The SMC rounded up
comment on the paper from obesity and nutrition experts:
Dr Elaine Rush, Professor of Nutrition, Faculty
of Health and Environmental Science, Auckland University of
"The Asia Pacific Cohort Studies collaboration of almost half a
million people in the Asia Pacific region included 10,400 New
Zealand people first measured in 1992. The important message to
take from this study is that in general an increase in body weight
(forget BMI - adults do not change in height) is associated with
increased risk of cancer (in general).
"The use of BMI cut-offs is a tool to look at patterns of
association - it does not mean for an individual that if BMI is
normal that there is necessarily less personal risk of cancer. We
do not know! The increase in body weight of populations is driven
by changes in the environment from the start of life.
"For many, increased body weight is a form of malnutrition -
excess energy supplying nutrients (protein, fat, carbohydrate and
alcohol) and often not enough of all the other vitamins, minerals
and myriad of other nutrients we can only get in the right
combination from whole fruit and vegetables and other foods.
"On top of that regular physical activity keeps the functions of
the body tuned and efficient. Particularly for children their
growth is changed by their nutrition and physical activity
patterns; these patterns imprint onto human function; effects that
are not reversible but often only seen in later life - increased
risk for cardiovascular disease, type 2 diabetes, stroke and
cancer. This paper adds to the evidence that maintaining healthy
function across the life course is essential. Action is needed at a
population level to improve the food supply and promote a healthier
"Note - the authors conclusions are based on the data being
adjusted for age and smoking status - age we cannot control but
smoking has profound ill effects on health - stopping smoking may
cause weight gain but overall risk for an individual will be
Angela Berrill, Director of ABC Nutrition,
"While many of us in New Zealand may be aware of the positive link
between obesity and health conditions such as type 2 diabetes and
heart disease, there has been limited local research about any
associations with cancer - until now. A recent study investigated
this relationship in Asia-Pacific populations and included
participants from New Zealand.
" Research findings indicate that overweight and obesity are
positively correlated to an increased risk of all cancer mortality,
with a 21% higher risk for obese individuals compared to normal
weight individuals. While Body Mass Index (BMI) was not adjusted
for ethnic variations to cut off points, this still provides us
with an indication of an association. However, more research is
needed to gain a clearer picture; especially in relation to
ethnicity and at which BMI values the associated cancer risk
started to increase.
"Overweight and obesity rates in New Zealand continue to rise.
Results from this study suggest there now may be an additional
reason to maintain a healthy weight - reducing the risk of cancer.
Key strategies to maintain a healthy weight include eating a
balanced diet with a variety of fruit and vegetables, portion
control and taking part in at least 30 minutes of physical activity
Jan Pearson, Health Promotion Manager at the
Cancer Society of New Zealand, comments:
"With the rapid growth of Asian populations in New Zealand these
results highlight the need for comprehensive policies and
programmes, and the provision of appropriate health services to
address the needs of these communities."