Women who take a daily multivitamin before and during pregnancy sharply reduce the likelihood that their children will develop leukemia, brain tumours and other forms of childhood cancer, according to new Canadian research.
The startling finding that a cheap supplement purchased at the drug store can prevent cancer as well as a range of birth defects adds weight to the theory that micronutrients have lifelong health benefits for the developing fetus. It also bolsters the case for having all women of childbearing age take multivitamins, particularly those rich in folic acid.
"This is almost too simple an idea for people to take seriously, but they should take it seriously," said Gideon Koren, director of the Motherisk program at the Hospital for Sick Children in Toronto.
"Proper nutrition -- and that includes a daily prenatal multivitamin -- can prevent a large proportion of childhood cancer."
The new research, published in today's edition of the medical journal Clinical Pharmacology & Therapeutics, found that children born of mothers who took a daily multivitamin containing folic acid had a 47-per-cent lower risk for neuroblastoma (the most deadly form of childhood cancer), a 39-per-cent lower risk for leukemia (the most common form of pediatric cancer) and a 27-per-cent lower risk for brain tumours.
The study is a meta-analysis, a compilation and analysis of previously published studies. Dr. Koren said research has shown, in bits and pieces, the possible benefits of prenatal multivitamins, but this paper is the first to pull together the data related to childhood cancers.
"This is the real deal," said Ronald Barr, head of the division of hematology-oncology at McMaster Children's Hospital in Hamilton.
Dr. Barr was not involved in the research.
He said the effects of multivitamins are dramatic but the findings should prompt parents and parents-to-be to ponder a larger message beyond taking a daily pill.
"This research should really get you thinking about the importance of good nutritional habits early in life -- even before birth," Dr. Barr said. "You really can't stress too much how important this is to good health."
A prenatal multivitamin is specially designed to foster normal fetal development.
It contains more folic acid, more iron, and less vitamin A than a regular multivitamin.
Earlier research has shown dramatic benefits of taking prenatal multivitamins.
These include sharply lower rates of neural tube defects such as spina bifida, cardiovascular defects, limb deformities, cleft palate, urinary-tract defects and hydrocephalus.
Evidence of the importance of micronutrients -- and folic acid in particular -- has been growing for years. But, still, only about half of Canadian women of childbearing age consume the recommended 400 micrograms daily of folic acid. (Folic acid is a synthetic form of folate, a B vitamin. In addition to prenatal vitamins, folic acid is added to flour-based foods such as pasta and white bread in Canada. Folate is found naturally in leafy green vegetables, including spinach, in citrus fruits and in dried beans.)
Dan Mornar, the parent support co-ordinator at B.C. Children's Hospital in Vancouver and the father of two children who developed cancer, said he hopes the new findings will spark renewed attention in the issue and prompt all women to take a daily prenatal multivitamin.
"Anything that comes along by way of prevention, we have to embrace it," he said.
"I can tell you from experience that no parent wants to walk down that dark road of having a child with cancer."
Mr. Mornar's son Jonathan died of neuroblastoma in 1993, at age 12. His daughter, Kahtrina was also treated for a malignant brain tumour six years ago, but she is now doing well.
Mr. Mornar said the new research should not be seen as the last word on childhood cancer, but it offers some hope.
"This isn't a magic bullet -- multivitamins won't prevent 100-per-cent of cancer -- but it does offer some much needed hope," he said.
Dr. Koren said that while his research focuses on pregnant women and their offspring, there could be larger, broader implications.
For example, there is research showing that getting adequate levels of folic acid can reduce the risk of colorectal cancer and heart disease.
That means taking a multivitamin may be important for women and men alike, regardless of age.
"The reality is that a large segment of our population does not eat properly. They lack essential micronutrients and that has many health implications that we are only beginning to understand," Dr. Koren said.