Extra niacin could help prevent treatment-related cancers, study finds
People undergoing chemotherapy may be able to reduce the risk of
developing treatment-related cancers by taking supplements of the B
vitamin niacin, research by a University of Guelph scientist reveals.
In a study published in the journal Mutation Research, James Kirkland,
a human biology and nutritional sciences professor, changed the niacin
status of rats receiving cancer treatments. He found that DNA damage is
more severe in bone marrow with low niacin levels and that development
of other cancers is enhanced. “There were 47 per cent more cancer
treatment-related malignancies in niacin-deficient rats,” said Kirkland,
who has been examining the nutritional effects of niacin for nearly a
In chemotherapy, drugs damage the DNA of cancer cells that are dividing
rapidly within the body. But that DNA destruction also applies to the
formation of blood cells in the bone marrow, where cells also divide
quickly. “That brings on new treatment-related cancers such as leukemia
and cancer of the bone marrow,” Kirkland said. In fact, people
undergoing chemotherapy are 10 to 100 times more likely to develop such
cancers than the general public, and three to 10 times more likely than
cancer patients undergoing radiation.
Kirkland’s research shows how niacin deficiency plays a role. In the
study, niacin-deficient rats were found to have 80 per cent less of the
oxidized co-enzyme nicotinamide adenine dinucleotide (NAD+) in their
bone marrow and 65 per cent less in their blood. This is a crucial
finding because NAD+ is involved in the repair process for DNA. It is
used in the synthesis of poly(ADP-ribose) -- a large molecule made at
the site of DNA damage that sends signals notifying cells that damage
has taken place. “Niacin deficiency influences this repair process by
inhibiting the rejoining of broken DNA strands,” Kirkland said.
Meanwhile, NAD+ concentrations were three times higher in the bone
marrow of rats that received niacin supplements, according to the study.
“We have found that bone marrow is extremely sensitive to changes in
dietary niacin levels, and that niacin status causes dramatic
differences in bone marrow poly (ADP-ribose) levels,” Kirkland said.
Cancer patients are already more susceptible to niacin deficiency because
of side effects such as nausea and vomiting, he said. Additionally, bone
marrow is more sensitive to niacin deficiency than are organs such as
the lungs and liver. “Pharmacological supplementation of niacin
may represent a rapid and safe way to help protect the bone marrow
cells of cancer patients,” he said.
An earlier study conducted by Kirkland, published by the the American
Society for Nutritional Sciences in The Journal of Nutrition, also shows
that niacin-deficient rats who have undergone chemotherapy have lower
long-term survival rates than rats with adequate or supplemented levels
of the vitamin. “This could represent many extra years of disease-free
life in human populations,” he said.
Prof. James Kirkland
Department of Human Biology and Nutritional Sciences
(519) 824-4120, Ext. 56693
For media questions, contact Communications and Public Affairs: Lori Bona Hunt, (519) 824-4120, Ext. 53338, or Rachelle Cooper, (519) 824-4120, Ext. 56982.