*The following is excerpted from an online article posted on U.S. News & World Report.
Obesity even in adolescence may raise the odds for colon cancer in adulthood, a large new study finds.
Overweight and obese teens in Israel had about a 53 percent higher risk for colon cancer as adults, researchers found.
And for rectal cancer, obesity -- but not overweight --was tied to more than double the risk for girls, and 71 percent higher odds for boys, compared to normal-weight teens.
"This study is additional evidence that risk factors for colon cancer operate through the life course," said Dr. Andrew Chan, an associate professor of medicine at Harvard Medical School.
The findings "highlight the importance of maintaining a healthy body weight even in childhood," added Chan, who wasn't involved in the study.
According to the American Cancer Society, colon cancer is the third most common cancer diagnosis in U.S. men and women, excluding skin cancer.
With so many young Americans overweight or obese, concerns have been growing about the effect of excess weight on chronic disease, including cancer, later in life.
"When you are young, obesity is a disease that puts you at risk for many medical problems," said Dr. David Bernstein, chief of hepatology at Northwell Health's Center for Liver Diseases in Manhasset, N.Y.
"We know about diabetes, we know about arthritis, and now we know about colon cancer," said Bernstein, who had no role in the research.
"There is a well-documented link between obesity and colon cancer in adults," said Bernstein. "It makes sense that if you are obese when you are young, then you are going to have more problems when you are older."
Bernstein said it takes years to develop cancers, so it's not surprising that the effects of obesity in adolescents are seen in adulthood.
The new study was led by Dr. Zohar Levi, of Rabin Medical Center in Petah Tikva, Israel. Levi's team collected data on nearly 1.1 million Israeli men and more than 707,000 Israeli women. They had weight assessments at ages 16 to 19 between 1967 and 2002. Follow-up continued until 2012.
The final sample included almost 1.8 million participants, according to the study. The results were published online in the journal Cancer.
Over an average follow-up of 23 years, nearly 3,000 participants developed colon cancer, the researchers found.
While the study found a link between teenage obesity and adult colon cancer, it doesn't show a direct causal relationship.
Source: U.S. News & World Report