Purslane is a plant source of omega-3 fatty acids and melatonin, and it has the highest content of alpha linolenic acid (ALA) of any wild plant that can be eaten. Each 100 gms. of purslane contains 300-400 mg. of ALA, 12.2 mg. alpha tocopherol from of vitamin E, 26.6 mg. of ascorbic acid, 1.9 mg. beta carotene, and 14.9 mg. glutathione.
There is more melatonin in purslane than in other fruits or vegetables and melatonin has anti-oxidant effects and is anti-inflammatory. In previous studies chickens and rats had higher melatonin blood levels when they were fed foods that contained melatonin. The authors believe that purslane eaten by humans would result in increased melatonin levels on blood testing.
Melatonin slows cancer growth similar to how omega-3 fatty acids, by inhibiting the uptake and metabolism of omega-6 linoleic acid (LA). LA is a growth factor that increases tumor growth. Cancer and heart disease are of low incidence in parts of the Mediterranean where large amounts of purslane are consumed.
CONCLUSION: Purslane is a plant that contains the highest levels of omega-3 fatty acid and high levels of melatonin. This may be associated with reduced occurrence of cancer and heart disease.
NOTE: A study by Simopoulos, AP, the Journal of the American College of Nutrition (1992), showed high levels of antioxidants in purslane.