High levels of 'good' cholesterol may cut bowel cancer risk
Study finds high concentrations of HDL are associated with a decreased risk of colon cancer
8th March 2011 - High levels of "good" HDL (high density lipoprotein) cholesterol seem to cut the risk of colon cancer (bowel cancer), suggests research published online in the journal Gut.
The researchers base their findings on participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. It’s tracking the long term impact of diet on the development of cancer in more than half a million people in 10 European countries, including the UK.
Bowel cancer is the third most common cancer in the UK and approximately 80% of cases develop in people who are 60 or over. Bowel cancer may affect the colon (the last part of the large intestine before the rectum) or the rectum.
Bowel cancer and cholesterol: The research
More than 1,200 people who developed colon and rectal cancers - 779 colon and 459 rectal - were matched with other participants of the same age, gender, and nationality who were free of cancer.
Blood samples taken when they joined the study, and the dietary questionnaires these participants had completed, were compared to see if there were any discernible differences between the two groups.
The analysis showed that those who had the highest levels of HDL "good" cholesterol, and another blood fat, apolipoprotein A, or apoA - a component of HDL cholesterol - had the lowest risk of developing colon cancer.
Each rise of 16.6 mg/dl in HDL and of 32 mg/dl in apoA reduced the risk of colon cancer by 22% and 18%, respectively, after taking account of diet, lifestyle, and weight.
However, HDL and apoA levels had no impact on the risk of rectal cancer.
After excluding those who had only been monitored for two years, as they may have already been undergoing cancerous changes when they joined the study, only levels of HDL were associated with a reduction in colon cancer risk.
The authors say their findings show that high concentrations of HDL cholesterol are associated with a decreased risk of colon cancer but say the mechanism behind this needs to be looked at further.
However, if their findings are confirmed, they say that cholesterol levels may be used, in addition to other modifiable risk factors already applied in clinical practice, to advise patients about changing their lifestyle to reduce bowel cancer risk.
In an emailed statement, Yinka Ebo, senior health information officer at Cancer Research UK, says: "We know that bowel cancer is more common in people who carry excess weight. Altered blood cholesterol levels often go hand-in-hand with obesity and this study aimed to find out if this may be behind the cancer link.
"The researchers found that high levels of HDL 'good' cholesterol could protect against colon cancer, but not bowel cancer overall, and they couldn't explain why this might be. The next step will be to carry out a larger, longer- running trial to see if these findings are seen again and to discover how HDL cholesterol might lower the risk of the disease.
"Keeping a healthy body weight is one of the best ways to cut your risk of many cancers including bowel cancer."