WEDNESDAY, April 10 (HealthDay News) -- Consuming higher amounts
of calcium may lower the likelihood of precancerous colon and
rectal lesions in people who are at increased risk due to
variations in two genes, a new study suggests.
High calcium intake did not affect risk in people without the
The findings may help explain inconsistent results in previous
research about the link between calcium intake and the risk for
these lesions, called colorectal adenomas, the researchers
They also said the findings may help identify patients who would
benefit from calcium supplements or higher levels of calcium in
The study of nearly 6,000 people in Tennessee found that
patients with the highest calcium intake had no reduced risk for
colorectal adenomas if they had no variations in two genes -- KCNJ1
and SLC12A1 -- that are essential in calcium reabsorption in the
Fifty-two percent of the study participants had variations in at
least one of the genes and 13 percent had variations in both genes.
There was a strong association between high calcium intake and a 39
percent reduced risk of colorectal adenomas in those with a
variation in one gene. High calcium intake was linked to a 69
percent reduced risk in those with variations in both genes.
The risk of advanced or multiple adenomas was 89 percent for
people who had a high calcium intake and had variations in both
genes, according to the study, which is scheduled for Wednesday
presentation at the annual meeting of the American Association for
Cancer Research, in Washington, D.C.
The findings suggest that a person with variations in one or
both of the genes will have an increased risk for colorectal
adenomas if they consume less than 1,000 milligrams of calcium a
day, said study author Dr. Xiangzhu Zhu, a staff scientist with the
epidemiology division in the department of medicine at
Vanderbilt-Ingram Cancer Center in Nashville, Tenn.
"These patients should increase their calcium intake to reduce
the risks," Zhu said in an association news release.
The findings could lead to genetic tests to identify people who
would benefit from higher calcium intake, the researchers said.
Although the research showed an association between increased
calcium intake and lowered risk of adenomas, it did not prove a
Because this study was presented at a medical meeting, the data
and conclusions should be viewed as preliminary until published in
a peer-reviewed journal.
The American Cancer Society has more about