(HealthDay News) — Obesity even in adolescence may raise the odds for colon and rectal cancers in adulthood, according to research published online July 24 in Cancer.
The new study was led by Zohar Levi, M.D., of the Rabin Medical Center in Petah Tikva, Israel. Levi’s team collected data on 1,087,358 Israeli men and 707,212 Israeli women. They had weight assessments at ages 16 to 19 between 1967 and 2002. Follow-up continued until 2012. The final sample included 1,794,570 participants.
Over an average follow-up of 23 years, 2,967 participants developed colorectal cancer, the researchers found. Among men, 1,403 had colon cancer, and 574 had rectal cancer. Among women, 764 had colon cancer, and 226 had rectal cancer. Overweight and obese teens in Israel had about a 53 percent higher risk for colon cancer as adults (for men: hazard ratio [HR] for overweight, 1.53; 95 percent confidence interval [CI], 1.28 to 1.84; HR for obesity, 1.54; 95 percent CI, 1.15 to 2.06; statistically significant from a body mass index [BMI] of 23.4 kg/m² [spline analysis]; for women: HR for overweight, 1.54; 95 percent CI, 1.22 to 1.93; HR for obesity, 1.51; 95 percent CI, 0.89 to 2.57; significant from a BMI of 23.6 kg/m²). For rectal cancer, obesity — but not overweight — was tied to more than double the risk for girls (HR, 2.03; 95 percent CI, 0.90 to 4.58; significant from a BMI of 30.6 kg/m²), and 71 percent higher odds for boys (HR, 1.71; 95 percent CI, 1.11 to 2.65; significant from a BMI of 29.6 kg/m²), compared to normal-weight teens.
“Notably, a high CDC healthy-range weight in adolescence might be associated with an increased risk of colon cancer in men; this observation needs further verification,” the authors write.