The nopal, or prickly-pear cactus, is one of the major national symbols of Mexico and appears on the Mexican flag.

This cactus has a long history of use as food and medicine. Its fleshy, leaf-like stems (cladodes), especially when young, are eaten as vegetables. The fruit is eaten raw, fermented into a beer, or turned into a cheese-like food. Medicinally, nopal fruit, stems, and flowers have been used to treat diabetes, stomach problems, fatigue, shortness of breath, easy bruising, prostate enlargement, and liver disease. Nopal is also a significant source of protein, vitamins, and minerals.

Although the results of animal studies and highly preliminary trials in humans are somewhat contradictory, taken together they suggest that nopal fruit and stems might have some benefit for diabetes.1-9 However, only properly designed and sufficiently large double-blind, placebo-controlled trials can tell us for sure whether nopal is effective, and none have been reported for this use of nopal. (For information on why such studies are essential, see Why Does This Database Rely on Double-blind Studies?)

The only properly designed study of nopal involved use of the cactus for treating hangover symptoms. In this double-blind, placebo-controlled study of 64 people, use of an extract made from the skin of nopal fruit significantly reduced hangover symptoms as compared to placebo.21 The greatest improvements were seen in symptoms of nausea, loss of appetite, and dry mouth. Overall, the rate of severe hangover symptoms was 50% lower in the treatment group as compared to the placebo group. The researchers involved in this study hypothesized that hangovers are caused by inflammation, and that the herb reduced inflammation.

There is weak evidence that nopal fruit, leaves, and/or stems might be helpful for improving cholesterolprofile.10-14,22Other studies suggest that nopal stems and fruit might have anti-inflammatory, pain-relieving, and stomach-protective effects.15 Finally, test tube studies suggest that the flower of the nopal cactus might be helpful for prostate enlargement ( BPH).16