Folate and Cancer

Tuesday, January 9, 2007 - 4:17pm

By Dena McDowell, MS, RD

Eating a well balanced plant based diet may reduce your risk of developing certain forms of cancer. Research has shown eating fruits and vegetables which are rich in folate is associated with reducing your cancer risk. Folate and folic acid have been linked with potentially reducing risk of breast, colon, rectal, and pancreatic cancer.

Folate defined
Folate is a naturally present B vitamin that is water soluble. Folic acid is the man made form of folate and makes up a large part of the United State’s dietary intake due to food fortification. The body is two times more efficient in absorbing and utilizing folic acid as compared to the food sources of folate. Folate and folic acid are responsible for producing and maintaining red blood cells because they play an integral part in making DNA and RNA. Proper red blood cell production prevents anemia. Folate is also responsible for producing homocysteine levels.

Food sources of folate
The best food sources of folate are green leafy vegetable such as spinach. Fruits such as oranges and strawberries are also excellent sources of folate. Other foods that are rich in folate are legumes (dried peas and beans). Folic acid was added to the U.S. food supply in the mid 1990’s as a way to reduce the amount of neural tube defects seen in U.S. infants. These folic acid enriched foods include dried cereal, white rice, and pasta and as mentioned above foods fortified with folic acid are easier to absorb compared to foods that have folic acid naturally present in them.

Daily requirements of folate
To prevent deficiencies in folate Recommended Daily Allowances for children and adults have been established. Children between ages one and three need 150 micrograms a day of folate. From ages four through eight, 200 micrograms of folate is needed. Teens ages nine through thirteen need 300 micrograms a day whereas those fourteen and older need 400 micrograms a day. Women who are pregnant need 600 micrograms a day and if nursing need 500 micrograms a day. If diet is lacking in folate or folic acid the following may occur: increased risk of neural tube defects in infants, anemia induced by folate deficiency which can occur as weakness, sore tongue, headaches, irritability, memory problems, and behavioral issues. A lack of folate in the blood stream can also cause an increase in homocysteine which increased the risk of developing heart disease.

People who are pregnant, abuse alcohol, have malabsorption problems, kidney or liver disease have an increased need for folate through diet or supplementation. Taking certain medications may also impair folate absorption causing an increased need. These medications include: dilatin, primidone, metformin, sulfasalazine, triamtrene, methotrexate, and some barbiturates.

Taking large doses of folate or folic acid is not recommended as it may cause a lack of vitamin B 12. The upper limit for folate in adults is 1000 micrograms a day unless instructed differently by your physician. A lack of vitamin B12 can show as another form of anemia and if not treated may result in permanent nerve damage.

Reducing cancer risk with increased folate intake
Research has shown that a diet lacking in folate appears to increase risk of developing breast, colon and pancreatic cancer. The most confounding evidence of this was seen in the Nurse’s health study when researchers followed 88,000 women’s dietary habits over a 14 year period. Researchers found that older women (ages 55-69) who took in adequate amounts of folate through diet and a multivitamin had a lower risk of developing colon cancer. Another study found that Chinese women who consumed diets highest in folate or folic acid had a lower risk of breast cancer compared to their counterparts who consumed low amounts of folate. Alcohol negates the effect of positive effect of folate in the diet therefore if large amounts of alcohol are consumed along with folate or folic acid the positive effects will not been seen. Researchers state that although these studies show promising results more research needs to be done in order to establish a causal relationship.

Eating a healthy diet rich in fruits and vegetables is an important way to reduce the risk of many disease states such as cancer, heart disease and stroke. Research has shown early promising results in regards to reducing risk of cancer and folate however more research needs to be done. It is recommended to eat between five and nine servings of colorful fruits and vegetables every day. Doing so will help meet your daily needs for folate. If eating large of amounts of fruits and vegetables is unlikely then supplementing with a daily multivitamin which contains 100 percent of the daily value of folic acid will be sufficient.