I’ve read that peanut butter causes cancer and roasting doesn’t remove lectins
Lectin Quantitation in Peanut and Soybean Seeds - E. M. Ahmed (1986)
“Lectins were inactivated by heat; moist heat was more effective than dry heat. Roasted peanuts seeds (177 C for 30 min) and boiled peanuts (5% saline solution for 1 hr) were devoid of active lectin.”
Table 4 from that paper shows that commercially available products have substantially reduced lectin but not zero.
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There are various papers showing an association between peanut lectin (and aflatoxin) and cancer, but there are also papers suggesting reduced risk of cancers from eating peanuts…