Excessive consumption of tigernut can cause abdominal bloating, diarrhea, and constipation due to the high fibre content. People with Crohn's disease and other digestive issues may also experience issues with eating a lot of the nuts. Contamination of the nut by certain fungi can release toxic mycotoxins, which are injurious to the body. The nut also contains some anti-nutrients, such as phytate, oxalates. The anti-nutrients can reduce the vitamins and minerals available to the gut.