In Taiwan, vegetables don’t get much more humble than sweet potato greens. Until quite recently, they were regarded as food for pigs, and many among Taiwan’s older generation have memories of resorting to sweet potato leaves has a last bastion against hunger in the day’s before the island’s economic miracle.
After years of media reports about the excessive use (and harmful residues) of pesticides, herbicides and chemical fertilizers of more upmarket vegetables, the health-conscious are beginning to rediscover sweet potato greens as a relatively uncontaminated vegetable. And the very reason for its new appeal is the fact that this low cost vegetable is robust enough to survive the pestilential Taiwan summers with little aid for modern agricultural science, and is much too cheap to warrant the use of expensive chemical aids.
In fact, sweet potato greens often don’t even warrant display space in the larger stalls of traditional markets, and are sold by old ladies with a small harvest of vegetables from their own plots on the fringes of the more established grocers.
According to a study by the University of Arkansas, “sweet potato leaves are comparable to spinach in nutrient content,” with “levels of iron, calcium, and carotene rank[ing] among the top as compared to other major vegetables.” (www.uaex.edu/publications/PDF/FSA-6135.pdf) There is also considerable literature on the antioxidant and chronic disease prevention benefits of the vegetable.