Do Any Foods Cause or Prevent Cancer?

Discussions of food and cancer prevention in the media have long suffered from the whiplash effect. One week a study comes out saying that a specific food or beverage doubles cancer risk. Two weeks later, another states the complete opposite, asserting it’s a superfood that cuts your cancer risk in half! The result? Confused public and patients, who start losing faith in nutritional science and feel like they might as well eat whatever they want, since they can’t find consensus about what to eat and what to avoid.

Earlier this month, on August 11, the New York Times published an article on this problem, highlighting a 2013 study by researchers from Harvard and Stanford. The Times article both sheds light on this issue and aggravates it.

These researchers wanted to determine if there was consistency among studies about specific foods that might cause or prevent cancer in large populations. To do so, they randomly selected recipes from the Boston Cooking-School Cookbook, and from those recipes focused on 50 different ingredients that are popularly eaten in the United States. Next step, the team searched the scientific literature for epidemiological studies indicating whether those food items were linked to the cause or prevention of cancer in different populations. The list included ingredients as diverse as veal, wine, tomatoes, salt, sugar, carrots, lemons, thyme, vanilla and hickory nuts. 40 of the 50 ingredients had studies on the foods’ cancer preventive properties.

The authors provide a graph that shows the increased and decreased risk for each food. Potato is one food with a wide spread of studies showing both increased and decreased risk. So do milk, lemon, corn, tea, coffee and eggs. On the other hand, studies of pork and bacon consistently show just significant increases in risk of certain cancers, while onion and carrot only decreased risk. All studies of sugar they analyzed suggest increased risk with just a single exception.

These are important conclusions from data the authors reviewed and should help inform nutritionists. Their study does have certain limitations however: For example, different cancers were studied as if a single disease, whereas cancer actually comprises over a hundred separate diseases, with different nutritional risks for different cancers. Also, the research analyses did not include a number of foods that are widely acknowledged to have cancer-preventive properties, such as vegetables in the cabbage family.

The Times, on the other hand, quotes authorities who say that there’s no link found between diet and cancer, or that lifestyle studies in general are so confusing that we might as well not even bother with them – a discouraging message both for people trying to stay healthy and for cancer patients.

We beg to differ. The scientific paper, and much of the “whiplash literature” in nutrition, suffer from an excessive focus on one food or one lifestyle factor at a time. Studies evaluating whole dietary patterns, such as the Western diet, the Asian diet and the Mediterranean diet, are much more useful and much more realistic assessments of the complex effects of the combination of foods we put on our plates every day.

And, as Dr Block’s book Life Over Cancer emphasizes, diet alone is neither the sole cause of nor the sole answer to cancer. A sound, plant-based diet is one of the foundations of cancer prevention and treatment. But it’s not the single solution. Instead, the combined impact — of exercise, ways that you cope with the stresses in life, how much alcohol you consume, and even that streetlight that shines into your window at night disrupting your sleep — is what contributes to cancer, not to mention genetics and environmental pollution! And the many factors that go into promoting cancer growth also might fuel growth once a cancer is established.

Unfortunately, just piling up on superfoods or cutting out sugar – even though truly helpful — won’t be an absolute guarantee against cancer. The multi-dimensional, multi-targeted program at the Block Center is designed to counteract the known factors that could be causing or fueling cancer, in addition to providing comprehensive and innovative conventional treatment. If that’s your interest, we suggest that you call us today for an appointment with our team.