A reader recently wrote to me, "my brother in law has lung cancer and I have read a diet high in vitamin C and beta-carotene is NOT recommended where lung cancer is involved as it seems to aid the cancer to metastasize".

I get messages like this every once in a while from people wondering about lowering vitamin intakes after reading studies that have found correlations between vitamin supplements and certain disease states. I believe the scientific study this reader was referring to (American Journal of Epidemiology. 2009;169) was an epidemiological look at the correlation between supplementing with vitamin C and beta-carotene and lung cancer.

It's important to note that this study was not looking at dietary sources of these vitamins; it was looking at supplements. This brings up all sorts of questions about what sort of supplements the subjects were using, whether or not they were synthetic or natural vitamins, what the source of the nutrients were and what other sorts of ingredients were present. It may bring into question the methods vitamin companies use for extracting or creating their vitamin supplements and what sort of additives are included.

However, this study was not conclusive in finding the mechanism involved in increasing lung cancer risk. It is highly unlikely that vitamin C and beta-carotene, nutrients vital for the proper operation of the human organism, are responsible for causing cancer. As such, avoiding food sources of these nutrients is not advisable, regardless of your current state of health.

Vitamin C and beta-carotene are vital components of the diet that your body needs in order to carry out all its necessary functions. The idea of actually attempting to lower your exposure to these nutrients is akin to starving yourself because a study found that certain foods cause cancer. Dietary sources of nutrients should never be feared. This is what makes our bodies function properly and avoiding them could lead to serious nutrient deficiency, further disease and death.

Incidentally, another study published a few months after the one that found vitamin C and beta-carotene increased risk of lung cancer, found that supplementing with a multivitamin, which contained both vitamin C and beta-carotene, was helpful in reducing lung cancer risk in current and former smokers. There is obviously some contradictory information here and the issue is far from settled.

In the meantime, take health studies with a grain of salt, but don't scrimp on the nutrient-dense foods!

The Healthy Foodie is Doug DiPasquale, Holistic Nutritionist and trained chef, living in Toronto. Doug specializes in private in-home holistic cooking lessons. You can email him with inquiries or questions for the blog at dugdeep@gmail.com.