Every day, our DNA receives thousands of tiny, individual stresses. These “hits” can be caused by many different factors: tobacco, alcohol, the sun’s UV rays, certain viruses and even diets that lack important nutrients, like folate. Folate refers both to the natural form of this B vitamin (found in dark green leafy vegetables, beans, asparagus, strawberries and orange juice) and the man-made form called folic acid (found in vitamin supplements and “enriched” breakfast cereals, breads, rice and pasta).

Over many years, these hits can so damage our DNA that its instructions to cells in our body become garbled. The normal process of cell reproduction and growth can be disrupted. Cancer occurs when abnormal cells arise and grow uncontrollably.

Folate plays two vital roles in keeping our DNA functioning normally. First, folate is directly involved with making basic building blocks of DNA. A long-term lack of folate in the diet makes it harder for the body to build DNA in the normal way. Similar, but abnormal, building blocks are substituted, but they can become unstable and break.

Second, folate is important to a basic biological process called methylation. In methylation, a single atom of carbon is added to other molecules that permit hundreds of the body’s vital chemical reactions to proceed. Adequate amounts of folate help provide a steady supply of carbon atoms and enable these reactions to occur smoothly.

Normal methylation appears particularly important to our DNA. If carbon atoms attach themselves haphazardly to our DNA, instructions for normal cell growth can be jumbled. For example, the appropriate time for cell reproduction could be distorted. These incorrect instructions could then be passed to other cells through cell division.

As the research continues, our knowledge of how folate fights cancer will deepen. In the meantime, make sure you eat folate-rich vegetables and grains every day to shore up your natural defenses that protect you from cancer.

Although a mostly plant-based diet should meet your daily needs, supplementation is recommended for women who may become pregnant, are pregnant or breastfeeding. Other individuals may benefit. Consult your doctor to see whether you should take a supplement. Keep in mind that more than the Recommended Daily Allowance of folate can have health risks. Excessive use of supplements can mask a vitamin B12 deficiency and may interfere with certain drugs, like methotrexate, that are used to treat cancer.