Can Organic Food Prevent Cancer?

Exercising, applying sunscreen, getting health screenings—you know the drill to help prevent cancer. Now a French study suggests adding another step to the list—eating organic. But is this a real validation of the health benefits of going organic or just another headline grabber?

The study: Researchers from respected institutions across France followed nearly 70,000 adults, mostly women with the average age of 44, for five years. Participants filled out questionnaires detailing how often—”never,” “occasionally” or “most of the time”—they chose organic versions of 16 categories of foods, from fruits and veggies to dairy, meat, fish, eggs, coffee, tea, wine, chocolate and sugar. They also provided yearly health updates, including any cancer diagnoses, but were not asked about any other behaviors that could raise or lower cancer risk.

The results: Participants whose diet included the highest proportion of organic foods had 25% fewer cases of cancer compared with those who never ate organic foods. The most significant reductions were seen with lymphoma (76% overall and 86% for non-Hodgkin lymphoma) and postmenopausal breast cancer (34%).

The limitations: The study didn’t pinpoint which foods in particular offered the most cancer protection. (Chances are it wasn’t the sugar!) The theory is that cancer reduction comes from an overall reduction in pesticide ingestion. After all, three such chemicals—glyphosate (the notorious ingredient in the weed killer RoundUp), malathion and diazinon—have been rated “probably carcinogenic to humans” by the International Agency for Research on Cancer.

This is the second study to find a link between eating organic and a reduced risk for non-Hodgkin lymphoma. However, the first one, done four years earlier in the UK and involving 623,000 middle-aged women, showed little or no decrease for any other types of cancer.

How might you put these findings into action? Here’s advice from registered dietitian Sharon Palmer…

Prioritize your produce. We already know that eating lots of fruits and veggies in general is a big part of a cancer-prevention diet. If you can’t afford to buy all organic produce, buy organic versions of foods known to have high levels of pesticide residues, notably strawberries, spinach, nectarines, cherries, apples, tomatoes, peppers and potatoes. Each year, the nonprofit Environmental Working Group puts out the “Dirty Dozen,” a list of produce with the highest levels of pesticides, and the “Clean 15” with the lowest levels of pesticides. Use these lists as shopping guides. Where can you skip organic? In general, foods that have a tough or thick outer peeling such as melons, avocado, pineapple and citrus fruits have lower pesticide residues—but do wash them well before you cut them to avoid contaminating the fruit inside. Cruciferous vegetables such as cabbage, broccoli and cauliflower often require less pesticide so can also be bought “conventionally grown.”

Shop farmer’s markets. Ask local growers how they cultivate their crops. Although they may not be certified organic, they could be forgoing synthetic pesticides and farming in a way that’s more protective of the soil and local ecosystem and more cost-effective for you.

Grow your own food. This is the least costly way to eat organic. If you grow your own tomatoes and lettuce and herbs and other crops without spraying them with pesticides or using synthetic fertilizers, these are essentially home-grown “organic.”

Reallocate dollars within your overall food budget. Move the dollars you spend on sugary, nutrient-poor foods to the organic foods column. Consider other expensive items you can cut back on, such as meat, and spend that money on organic grains (including flours), beans, fruits, vegetables and eggs.

For more of Sharon’s tips, check out “Is It Really More Healthful to Shop Organic?“