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. 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.
There is also weak evidence that nopal fruit and stems might be helpful for reducing cholesterol levels.
Other studies suggest that nopal stems and fruit might have anti-inflammatory, pain-relieving, and stomach-protective effects. In addition, test tube studies suggest that the flower of the nopal cactus might be helpful for prostate enlargement (BPH).
The optimum dosage, or the most active species of nopal cactus, has not been established. Two studies found benefit with 500 g daily of Opuntia streptacantha stems.Two other studies used dried Opuntia ficus indica.
As a widely eaten food, nopal is presumed safe. However, safety in young children, pregnant or nursing women, or individuals with severe liver or kidney disease has not been established.