Women who are obese have a much greater risk of developing colorectal cancer before the age of 50 than women of normal weight. Until the age of 50, the disease is rare, but according to the latest research, ladies with the highest BMI are twice as likely to be at risk than with the correct ratio. Colorectal cancer is one of the most deadly cancers.
According to researchers from the Washington University School of Medicine in St. Louis, together with researchers from other centers, in the United States, the number of deaths from colorectal cancer began to decline after the introduction in the 80s of the recommendation to undergo colonoscopy in people in the age of 50. However, for reasons still unknown, the number of deaths from cancer of the colon and rectum (part of the large intestine) is increasing in people between the ages of 20 and 49.
An epidemiological analysis carried out by researchers published in the journal JAMA Oncology shows that BMI at 18 years of age, current BMI and the scale of weight gain from early adulthood are associated with an appropriate risk of developing the disease before the age of 50.
The authors of the publication took into account data on over 85 women aged 25 to 44 participating in the Nurses’ Health Study II project, which started in 1989. The analysis included information such as weight change over the course of life, family history, endoscopies and lifestyle. In the period under consideration, doctors diagnosed 114 cases of colorectal cancer in the study group. The weight was of great importance here.
– Our results emphasize the need to maintain a healthy body weight, starting in early adulthood, to prevent early colon cancer – says one of the lead authors of the study, Prof. Yin Cao from Washington University. – We hypothesized that the obesity epidemic could affect the incidence of early colorectal cancer, but we were surprised by the strength of the relationship observed and the impact of obesity and weight change from early adulthood – adds the scientist.
Compared to women with the lowest BMI (18,5 – 22,9), participants with the highest BMI had more than twice the risk of developing cancer. Normal BMI ranges from 18,5 to 24,9 kg per square meter. BMI in the range of 25 – 29,9 is considered overweight, and over 30 – obesity.
The researchers emphasize that the higher risk of cancer associated with obesity also occurred in women without a family history of the disease.
Early appearance of colon and rectal cancer is relatively rare, with an average of eight cases per 100. people.
According to the calculations of scientists, approx. 22 percent could be avoided. diagnosed in the study with this type of cancer, if all participants had a normal BMI. On a population scale, this translates into thousands of cases.
Unfortunately, since routine screening is not carried out at this age, the disease is often detected in an advanced state. Recently, however, the American Cancer Society in its recommendations lowered the age of starting colonoscopy to 45 years.
The scientists emphasize that their research was observational. That is, it has not shown that obesity alone poses a greater risk of cancer. It is possible that a higher weight is due to other factors that also affect the risk of cancer, such as diabetes or metabolic syndrome. However, the discovered dependencies are another reason why obese people become interested in their health.