You’ve probably heard that peanuts should be avoided because they contain carcinogens – cancer causing substance. What this is referring to is aflatoxins – a natural toxin produced by certain strains of the mold Aspergillus flavus and A. parasiticus that grow on peanuts when they are grown in warm, humid soils. Peanuts aren’t the only affected crops. Aflatoxins have been found in pecans, walnuts and pistachios, as well as grains, soybeans and spices.

In lab animals, when given large amounts aflatoxins have been shown to be a potent carcinogen known to cause liver cancer, which may be a link to liver cancer in Africa where peanuts are a dietary staple.

Consumers Union looked into this concern and found that detectable amounts of aflatoxins in peanut butter varied from brand to brand. The lowest amounts were found in the  well known brands peanut butter brands such as Peter Pan, Jif and Skippy. The highest levels were found in peanut butter ground fresh in health food stores.

Another thing to note is that there hasn’t been an outbreak or rise in liver cancer among children, and as we know, and children eat a lot of peanut butter.

Should you stop eating peanut butter?

If you love peanuts or peanut butter there’s no reason why you have to avoid them. But because we don’t know the long-term effects of low levels of aflatoxins, just like anything else I recommend only eating peanuts in moderation. Peanuts are composed to healthy monounsaturated fats, but I still recommend almonds (almond butter, anyone?) and walnuts over peanuts because of their superior fatty-acid profile, particularly walnuts because of their Omega 3 content which reduce inflammation and support a healthy heart.

When shopping for peanut butter, check the ingredients list for only peanuts and salt & avoid raw or minimally processed (when do I ever say that?! Ha!).  Avoid other ingredients such as hydrogenated oils (trans fats), sugar and other additives.

Bottom line: Enjoy your peanuts, just in moderation – meaning 1-2x / week.