A New Peanut Butter Scare



If the peanut butter in your cabinet comes from peanuts that were grown or stored in hot, humid conditions, it could be contaminated with aflatoxin, a mold directly linked to liver cancer by the National Institute of Environmental Health Sciences (NIEHS) and the Massachusetts Institute of Technology. Peanuts’ soft, porous shells make them especially vulnerable to the mold, which the International Agency for Research on Cancer has classified as a Group 1 carcinogen to humans.

Virtually all sources of commercial peanut butter in the U.S. contain minute quantities of aflatoxin, but it is usually far below the U.S. Food and Drug Administration’s (FDA) recommended safe level. The FDA requires all commercial, pre-packaged organic and non-organic peanut butters to contain aflatoxin levels of no more than 20 parts per billion (ppb). Distributors like Whole Foods Market claim their peanut butters are aflatoxin-free or far below the FDA recommended levels.

Those who grind their own peanut butter fresh in the supermarket may be the most at risk of ingesting aflatoxin. This is because the peanuts that sit in the grinding machine case are stored for much longer than peanuts processed for commercial peanut butters, increasing the potential for mold and fungus growth. These grinding machines are also not tested by the FDA for aflatoxin contamination. Buying only pre-packaged, commercial peanut butters may put anxious consumers at ease; however there are added sugars and trans fats to consider in some of these choices, as well as high pesticide levels in non-organic brands.

If you’re considering buying a healthy, organic peanut butter, you’d be wise to pick up some celery sticks to dip in it. Researchers at Johns Hopkins University found that eating vegetables such as celery, carrots, parsnips and parsley can decrease the carcinogenic effects of aflatoxin. They also found success with chlorophyllin, which is abundant in green, leafy vegetables, in reducing the risk of liver cancer in aflatoxin-exposed individuals. Consumption of chlorophyllin at each meal resulted in a 55% reduction of aflatoxin in urine. It’s believed that chlorophyllin reduces aflatoxin levels by blocking the absorption of the toxin in the gastrointestinal tract.

Refrigerating peanut butter after purchase is also a smart step in preventing the hot, moist environment that favors aflatoxin growth.

While you may feel apt to make use of some of these precautions, the risk of contamination to healthy Americans is very low. According to the U.S. Department of Agriculture (USDA), no cases of aflatoxicosis have been reported in the U.S, and exposure to aflatoxin contamination exists mainly in developing countries like Kenya.

The prevalence of hepatitis B in developing nations also puts their populations at a higher risk of developing liver cancer. Kenya’s Medical Research Institute and Centers for Disease Control and Prevention reports 56-98% of the adult population in Sub-Saharan Africa to have or have had Hepatitis B. Johns Hopkins University researchers found those who tested positive for the Hepatitis B virus and were also exposed to aflatoxin in their diet had about 60 times the risk of developing liver cancer than that of unexposed individuals.

Global warming-related temperature spikes and droughts could increase the existence of aflatoxin in crops, which could lead to more contamination-related illness and death in developing countries. More aflatoxin contamination could also pose significant economic impacts. The Food and Agriculture Organization (FAO) estimates that 25% of the world’s food crops are affected by aflatoxins, and losses incurred from rejected shipments due to aflatoxin contamination can substantially affect export markets. Aflatoxin’s economic impact and its dangers to human health are driving manufacturers, regulatory agencies and researchers to find measures for control and rapid detection of the toxic substance in foods.