Buckwheat Leaves: Edible or Poisonous?
While buckwheat leaves and buckwheat microgreens (sprouts) are indeed edible, these nutrient-dense leaves contain a poisonous substance, fagopyrin, which can make you sick when consumed in large amounts. Keep reading to get the full scoop.
Buckwheat Greens: Culinary and Medicinal Uses
Young leaves, stems and blossoms of both the common buckwheat plant (Fagopyrum esculentum moench) and the tartary buckwheat plant (Fagopyrum tataricum) have been used both for medicinal and culinary purposes in Europe and Asia. When used as a food, the leaves and stems are cooked and consumed as a vegetable, or they are ground into fine green flour which is then used in breads, pancakes, and noodles. Buckwheat seedlings or sprouts are also consumed as microgreens. When used medicinally, dried buckwheat leaves are typically infused to make tisane (herbal tea) or processed into supplements.
Buckwheat Leaves Contain Health-Boosting Compounds...
According to an article published in The European Journal of Plant Science and Biotechnology in 2010, buckwheat leaf flour is rich in proteins and minerals such as magnesium, calcium, potassium, copper, manganese, and iron. In addition, several studies have shown buckwheat leaves to contain high amounts of rutin (also known as rutoside). In fact, the rutin content of buckwheat leaves (and blossoms) has been reported to be much higher than that of buckwheat groats.
Rutin, a powerful antioxidant, is thought to be largely responsible for the extraordinary health benefits of buckwheat groats, including the ability of buckwheat to fight leg edema (leg swelling caused by fluid retention), varicose veins, poor circulation, and atherosclerosis (hardening of the arteries).
...But They Also Contain a Toxic Substance
Now, that all sounds great, but there's one problem with eating buckwheat leaves: these innocent looking green leaves contain high levels of fagopyrin, a somewhat poisonous fluorescent pigment of the helianthrone family. When ingested in significant amounts, fagopyrin is known to cause phototoxicity (also known as photoirritation) in humans and animals, causing their skin to become hypersensitive to sunlight. A person suffering from fagopyrism, a condition caused by phototoxicity triggered by the consumption of fagopyrin-containing food, typically develops red skin which is accompanied by a burning sensation. After the initial burning sensation, they may also feel their skin become sensitive to hot water, cold water, or friction.
Buckwheat microgreens (or sprouts) and mature buckwheat greens seem to be equally toxic. A Slovenian study published in Planta Med in 2011 found that 14-day old buckwheat sprouts grown in a sprouter contained nearly as much fagopyrin as mature plants. Based on their findings, the researchers estimated the safe daily intake of buckwheat sprouts to be at least 40 grams.
Another Slovenian study (published in the October 2008 issue of the journal Food Chemistry) compared the fagopyrin content of buckwheat leaves versus stems, and found that the leaves contained much more of this toxic substance than the stems. By contrast, buckwheat greats and tea made from buckwheat groats have not been shown to contain high levels of fagopyrin.