Cholesterol linked to cancer risk
Some foods have also been found to have a healthy effect on blood cholesterol levels. Photo: PA
People with high levels of "good" cholesterol could be at lower risk of bowel cancer, according to new research.
Scientists believe increased levels of high-density lipoproteins (HDL) may have an impact on the way inflammation is handled in the body.
High levels of HDL have been shown to be good for health because they "collect" excess cholesterol in the blood and transport it to the liver where it is broken down.
Quitting smoking, losing excess weight and and taking frequent exercise have all been shown to boost levels of good cholesterol and reduce levels of bad cholesterol.
Some foods have also been found to have a healthy effect on blood cholesterol levels.
These include whole grains such as oatmeal, oat bran and whole-wheat products; nuts such as walnuts, almonds and brazil nuts; plant sterols and Omega 3 fatty acids, such as those found in fatty fish, flaxseeds and flaxseed oil.
In the latest study, published in the journal Gut, experts used data from more than 520,000 people taking part in the European Prospective Investigation into Cancer and Nutrition (EPIC), involving 10 countries.
Overall, more than 1,200 people developed bowel cancer during the course of the study.
They were compared with more than 1,200 people without bowel cancer to check for differences between the groups.
Blood tests were taken to check for markers of cholesterol and people were asked about their diets and lifestyles.
After adjusting for a wide range of factors, experts discovered that people with the highest levels of HDL cholesterol, and another blood fat called apolipoprotein A (a component of HDL cholesterol), had the lowest risk of developing bowel cancer.
Each rise of 16.6 milligrams per decilitre (mg/dl) in HDL and of 32 mg/dl in apoA reduced the risk of bowel cancer by 22pc and 18pc respectively.
The beneficial effect appeared to be confined to cancers of the colon rather than the rectum.
The experts, led by a team at the National Institute for Public Health and the Environment in the Netherlands, concluded: "These findings show that high concentrations of serum HDL are associated with a decreased risk of colon cancer.
"The mechanism behind this association needs further elucidation."
One suggestion for how HDL works is that it is linked to high levels of proteins that dampen down the body's inflammatory response.
In contrast, low levels of HDL have been linked to higher levels of proteins involved in inflammation.
Last week it was reported that experts at the University of Cincinnati in the US are investigating whether the cholesterol-reducing drugs, statins, could help prevent recurrence of bowel cancer in patients who have had a tumour removed.
Deborah Alsina, chief executive of Bowel Cancer UK, said: "We welcome this research and any further evidence that supports the benefits of a healthy diet.
"Through our health promotion activity we recognise that there is great thirst for information about diet and good bowel health amongst the general public.
"As further research emerges, we must be sure this is translated into clear and straightforward messages to enable the public to make healthy choices."
Press Association
