Researchers from the Lovelace Respiratory Research Institute, in Albuquerque, have discovered that a diet rich in leafy green vegetables and some types of multi-vitamins can protect against lung cancer.
This is particularly important, because even if you have stopped smoking, you are still at increased risk of developing lung cancer, compared with someone who has never smoked.
The study surveyed 1,100 current and former smokers who submitted spit samples and completed detailed questionnaires about their dietary habits. Scientists analyzed the spit samples for eight different genes associated with an increased risk of cancer. They then explored whether intaking 21 varieties of vegetables had any positive or negative impact on the formation of these genes.
Gene methylation occurs every time the DNA replicates. It is one of the modifications that occur after each replication. It is implicated in several biological functions and is even a tumor suppressor. If this process of replication deviates from the normal, it can result in the abnormal cells seen in cancer.
Researchers found there was less aberrant gene methylation in smokers who took supplements containing vitamin C, carotenoids, lutein, folic acid, and vitamins A and K. All of these are also naturally present in leafy green vegetables. High folic acid intake has also been shown in previous studies to have a protective effect against the spread of colon cancer.
Authors of the study say that dietary influences on cancer should be taken into consideration when developing cancer prevention programs.
"Additional research is needed to independently validate the current observations, and also to help resolve contradictions between varying studies," said Dr. Sudhir Srivastava Chief of the Cancer Biomarkers Research Group at the National Cancer Institute.
"This particular study used a well-planned design and can serve as a basis for future identification of the mechanistic targets of these dietary factors. Such studies are important steps for the future success of chemopreventive strategies"