Why Organic Foods Might Reduce Cancer Risk


By Dr. Nasha Winters, ND, FABNO

Eating organic foods might reduce your risk of cancer. This was the headline that hit news channels on October 22, 2018. The news may not surprise many of my followers, but it is at least affirming. The information came from a large, well-designed study of French adults that was published by the esteemed Journal of the American Medical Association (JAMA) online. the study surveyed 68,946 men and women to determine how often they ate organic foods. Researchers followed up with participants for about four and a half years to assess cancer risk. During that time, 1,340 participants developed cancer.

Results of the study showed that higher consumption of organic foods reduced the overall risk of cancer by 25%. Organic foods were most strongly associated with a reduced risk of non-Hodgkin’s lymphoma and postmenopausal breast cancer. The results were consistent with a similar study, conducted in the United Kingdom (UK) a few years ago. That study followed 623,080 middle-aged women for about nine years and found that eating more organic food was associated with a 21% reduced risk of non-Hodgkin lymphoma.

Previous studies have shown that people who eat more organic foods have lower levels of pesticide residues in their urine, and a study published just this year found that the urinary concentration of pesticides directly increased in association with intake of pesticide-laden fruits and vegetables. The studies of men and women in France and the UK, however, did not measure any markers in blood or urine. Because of this, the studies do not tell us WHY organic foods reduced cancer risk.

Below we take a look at what it means to say a food is “organic” and why these foods might pose a lower cancer risk than their conventional counterparts.

5 Requirements for Organic Foods

The United States Department of Agriculture (USDA) sets strict guidelines for organic food production and labeling. Here are five highlights from those guidelines:

1. Organic foods must be produced without genetic engineering (GMOs)

Genetic engineering is the process of transferring genetic information from one species to another in order to achieve a certain trait. For example, soy has been genetically engineered to tolerate the herbicide glyphosate, and corn has been engineered to produce its own insecticide. One concern about GMOs is that they have led to a dramatic spike in the use of herbicides like glyphosate. Glyphosate is classified by the International Association of Cancer Research (IARC) as a probable human carcinogen. Safety research on GMO crops is limited, and experts worry that might pose health hazards that have not yet been explored.

2. Organic foods must be produced without ionizing radiation

Ionizing radiation is used on conventional spices, meats, and fresh fruits and vegetables to preserve them and increase their shelf life. The process does not make the foods radioactive, and the US Food and Drug Administration (FDA) claims that irradiated food is safe. But the Center for Food Safety published a report highlighting research to the contrary. They suggest that ionizing radiation compromises food quality.

3. Organic foods must be produced without sewage sludge

That’s not a typo. Conventional practices allow farmers to apply sewage sludge to their fields. The problem is that sewage can introduce contaminants to the soil. A study of barley and sorghum fields where sewage sludge had been applied for four years found that the sludge had introduced heavy metals, like cadmium and lead, into the soil.

4. Organic foods must be produced with allowed substances

The USDA has a long list of substances that are permitted for growing organic crops and raising animals to produce organic dairy or meat. The idea is only to use substances that will not harm the environment or interfere with the nutritional value of the food. Synthetic herbicides, pesticides, and ash from burning manure are examples of substances that are not permitted in organic agriculture.

5. Organic foods must include only allowed ingredients

Processed foods that are labeled as organic (like cookies, crackers, and flavored yogurt) are allowed to have some ingredients that are not organic. But this is not a free-for-all. Only certain added ingredients are allowed. Artificial colors, flavors, and preservatives are examples of food additives that are not allowed in organic foods.

Conventional Foods and Cancer

When we look at the requirements for organic foods and organic labeling, we begin to see why foods that do not meet these requirements might pose a risk. Foods that are not grown organically have higher residues of pesticides and herbicides. This is not only true for GMO crops but even for conventionally-grown non-GMO crops. A recent report from the Environmental Working Group (EWG) found that all samples of cereals they tested, including Quaker Oats and Cheerios, contained alarming levels of glyphosate.

Non-organic animal products are more likely to contain growth hormones, antibiotics, and heavy metals. Arsenical medications are given to conventionally-raised chickens, and studies have shown that people who consume more chicken have higher urinary levels of arsenic. Milk from cows treated with recombinant bovine growth hormone (rBGH) has higher levels of IGF-1, which is a growth factor shown to promote breast, prostate, colorectal, or other cancers.

Research is piling up in support of organic over conventional foods. As agricultural practices have changed over the years, whole and healthy foods (like meat, milk, and oats) have become toxins. The takeaway message is summed up in a magnet on my refrigerator—a quote that I like to repeat to my clients:

“Eat organic food. Or as your grandmother called it, FOOD.”