Scientists investigating a rise in cases of bowel cancer in young people have discovered a ‘surprising’ link: women who were breastfed appear to be at greater risk.
Researchers from Harvard and Washington University Schools of Medicine found that being breastfed as an infant was associated with an up to 40 percent higher chance of being diagnosed with the disease before age 55.
The longer someone breastfed, the more likely he or she was to be diagnosed with colon cancer, the study found.
Dr. Kimmie Ng, an oncologist at Harvard, said that while the team was still investigating the link, she believed the “Westernized lifestyle” was the cause.
Modern diets have long been linked to a host of cancers, and many of the harmful substances in junk food can pass through breast milk.
However, Dr. Ng stressed ‘this is just an association’ and urged women not to stop breastfeeding – which has been linked to incredible health benefits for babies.
Scientists investigating a rise in cases of bowel cancer in young people have discovered a ‘surprising’ link: people who were breastfed appear to be at greater risk
Data from JAMA Surgery shows colon cancer is expected to increase by 90 percent in people ages 20 to 34
The same data shows that rectal cancer will increase by 124 percent in the youngest age group
The scientists were interested in investigating possible environmental changes in relation to the emergence of colon cancer and looked at data from 158,696 women aged 27 to 93 years old from surveys and questionnaires as part of the Nurses’ Health Study and the Nurses’ Health Study II. .
The team also looked at diet, which required participants to complete the 160-question food frequency questionnaire. Although diet in adulthood is strongly linked to colon cancer, the association between breastfeeding and the cancer was not influenced by what the mothers ate.
To rule out other lifestyle factors that could have contributed to cases of colon cancer, researchers spoke to 40,000 of the people who took part in the study and collected detailed health information, including smoking and alcohol consumption during pregnancy, as well as comorbidities, weight and height.
After considering all variables, breastfeeding still appeared to have the greatest association with colon cancer.
Compared to women who were not breastfed, those who were breastfed for less than or equal to three months had a 14 percent higher risk.
Those who breastfed for four to eight months had a 17 percent increased risk, and those who breastfed for nine or more months had a 36 percent increased risk.
Particularly troubling was that a younger group of women within the cohort showed an approximately 40 percent increased risk of developing high-risk colorectal cancer before they turned 55.
A significant association was also observed between breastfeeding and an increased risk of adenomas before the age of 50.
An adenoma is a non-cancerous tumor in the lining of the colon. Although benign themselves, the formations are usually considered precancerous and can turn into malignant tumors.
The researchers were surprised by their results and wondered whether maternal health influenced colon cancer risk.
Ng said: “When you breastfeed, many health factors are obviously passed on from the mother to the child. So the natural question is, “Could it simply be that maternal health carries this increased risk?”
The researchers were interested in studying the relationship between breastfeeding and colon cancer because before the recent increase in cases, the incidence of the disease had decreased. Similarly, between the early 20th century and the 1960s, there was a decline in the number of women breastfeeding.
However, the number of women breastfeeding began to recover in the 1990s, in line with the increase in colorectal cancer rates.
The team cautioned that despite their findings, more research is needed, and that their analysis should not discourage people from breastfeeding their children, as this is the best source of nutrition for most babies.
The number of cases of colorectal cancer is increasing worldwide, creating an epidemic among young people.
Rates among young people are expected to double by 2030, and by the end of the decade, colorectal cancer is also expected to be the leading cause of cancer deaths in people under 50.
This is based on data from JAMA operationA study found that between 2010 and 2030, colon cancer in people aged 20 to 34 will increase by 90 percent. In the same age group, rectal cancer will have increased by 124 percent.
Cancers of the colon and rectum are the third most common type in the US and the third leading cause of death in both men and women.
The American Cancer Society (ACS) estimates that approximately 153,000 cases of colorectal cancer will be discovered this year, including 19,500 among those under 50 years of age.
About 52,550 people are expected to die from the disease.
The study was published in the journal Clinical Gastroenterology and Hepatology.