Being overweight and not exercising are known risk factors for causing inflammation and cancer
And the risk is even higher among overweight or obese men and lean women, as well as men and women who DON’T drink alcohol, according to the study.
Only women have less risk of getting rectal cancer through the western diet.
Researchers explained that what people eat can influence inflammation in the body as measured by inflammatory biomarkers.
The inflammation plays a role in cancer development including bowel cancer, the umbrella term for colon or rectal cancer.
Bowel cancer is the fourth most common type of cancer in the UK, with 41,000 diagnosed each year
Intervention studies have shown that diet modulates inflammation, therefore, dietary patterns with higher inflammatory potential may influence colorectal cancer risk
Diet and lifestyle such as being overweight or obese and not exercising are known clear risk factors for causing inflammation and cancers.
Several studies found anti-inflammatory drugs, such as aspirin, can reduce bowel cancer development.
But rather than prescribing aspirin because of its side effects, experts said a safer option was to chose foods with anti-inflammatory properties.
These include green leafy vegetables, dark and yellow vegetables, coffee and tea and low amounts of red and processed meats, refined grains and sugary drinks.
Bowel cancer is the second biggest cancer killer in the UK, with nearly 16,000 deaths a year
Bowel cancer is the fourth most common types of cancer diagnosed in the UK with over 41,000 Britons diagnosed with it each year.
It is also the second biggest cancer killer with nearly 16,000 dying each year.
Research Associate Fred Tabung, of the Harvard T.H. Chan School of Public Health in the US, said: “Inflammation plays an important role in cancer development, including colorectal cancer.
“Intervention studies have shown that diet modulates inflammation, therefore, dietary patterns with higher inflammatory potential may influence colorectal cancer risk.“
Professor Charles Fuchs of Yale Cancer Centre in Connecticut added: “In parallel to the growing understanding that inflammation contributes to colorectal cancer risk, the past several decade have documented the fact that diet and lifestyle factors are clear risk factors for developing colorectal cancer, with a number of foods being associated with risk including red meat, western pattern diet as well as what’s often referred to energy excess including obesity and sedentary lifestyles.
“So recognising a number of factors that drive the risk of colorectal cancer, we believe is important in the US and western countries.
“More over, many of these dietary and lifestyle factors, beyond being independent risk factors for colorectal cancer, have been associated with being pro-inflammatory state.
“So, one may then ask is a diet that potential promotes inflammation, is that another risk factor indication for colorectal cancer.”
The study followed 121,050 adults for 26 years and their diet.
In particular it used an empirical dietary inflammatory pattern (EDIP) score based on a weighted sum of 18 food groups that characterises dietary inflammatory potential based on circulating levels of inflammation biomarkers.
Processed meat, red meat, offal, white fish, vegetables other than green leafy vegetables and dark yellow vegetables, refined grains, high-energy sugary drinks, diet drinks and tomatoes were positively related to circulatory markers of inflammation.
Beer, wine, tea, coffee, dark yellow vegetables comprising carrots, yellow squash, and sweet potatoes, green leafy vegetables, snacks, fruit juice, and pizza were inversely related to concentrations of the inflammatory markers.
A diet rich in sugary drinks, red meat and unrefined grains increases the risk of bowel cancer
It found those who ate the most pro-inflammatory diets reported lower physical activity, higher BMI, and were more likely to have diabetes.
They were also less likely to be using multivitamins and reported lower intakes of dietary fibre, dietary calcium, and whole grains, than those consuming the most anti-inflammatory diets.
It found that men who ate the most pro-inflammatory diets had a 44 per cent higher risk of bowel cancer than men with the least, and women’s cancer risk was 22 per cent higher.
Overall it was 32 per cent higher for both men and women.
Dr Tabung added: “The study conveys two important findings.
“First, higher dietary inflammatory potential was associated with higher risk of developing colorectal cancer in men and women.
“In both men and women, associations were observed in all anatomic sites, except for the rectum in women.
“Second, risk of developing colorectal cancer was even higher among overweight or obese men and lean women and among men and women not consuming alcohol.
“The differences by body weight category may partly underlie the differences by sex observed for rectal cancer risk; whereas the differences by alcohol intake category may indicate that the influence of alcohol on colorectal cancer risk through mechanisms other than inflammation, may be stronger than that of its effects on the EDIP.”
The study was published in the journal JAMA Oncology.