Lotus seed

The sacred lotus is an aquatic perennial with large round leaves held above the water and big pink or white flowers. After the petals fall, a flat-topped seed pod shaped like a showerhead forms, holding 10 to 30 oval seeds, each about the size of a small olive. Fresh seeds are green with a thin skin and crisp, sweet, slightly starchy flesh. Dried seeds are hard and creamy white or tan, and are sold shelled and often with the green germ (lian xin) removed. The germ tastes very bitter. Cooked seeds become soft, floury and delicately sweet, like a mild chestnut. They are also sold roasted, candied and as paste, and puffed lotus seeds are a snack.

The sacred lotus is native to a broad region from India and southern Asia through China, Japan and Southeast Asia to northern Australia, and it has been cultivated for food in ponds and paddy-like fields for thousands of years. The plant's name Nelumbo comes from the Sinhalese word nelum, while lotus is the Greek name for various plants, later applied to this species. The seed's Chinese name lian zi echoes lian, which sounds like the word for continuous or connected, so the seed carries a symbolism of unbroken descendants and good fortune in weddings.

Lotus seeds were gathered long before the plant was grown deliberately, and archaeological finds in China and India confirm the use of lotus as a food and sacred plant. In Hinduism and Buddhism the lotus represents purity, rising spotless from muddy water, and the seed pod and flower appear in temple art and offerings. In Chinese medicine, lian zi has been recorded for more than two thousand years, where it is used in tonics for the spleen, kidney and heart.

Lotus seeds have a remarkable reputation for longevity. Seeds recovered from dry lake beds in Manchuria and elsewhere have been reported to germinate after hundreds or even over a thousand years, and some of these have been radiocarbon dated, which has made the lotus a famous example of seed dormancy.

In East Asia, sweetened lotus seed paste became the classic filling for mooncakes at the Mid-Autumn Festival, as well as for pastries in Japan and Vietnam. In India, roasted or popped lotus seeds are eaten during fasts, and they are sold in markets under the name kamal gatta. The seeds are confused with makhana, or fox nut, which comes from a different water plant, Euryale ferox, though both are puffed and used in similar ways.

Fresh lotus seeds are eaten raw as a seasonal snack, while dried seeds are simmered in sweet soups (tong sui), congee, herbal chicken soup and braised dishes. They are ground to a paste for mooncakes, buns, and Japanese and Vietnamese sweets, and candied for New Year trays. In Indian cooking the seeds are fried, roasted or added to curries and kheer. The bitter green germ is removed for cooking but is steeped as a tea in Chinese folk practice. Leaves, rhizomes and stamens of the lotus are also used in food and drinks, but the seeds are the most widely sold part.

Dried lotus seeds provide plant protein, fibre, magnesium, potassium and phosphorus with very little fat. Traditional medicine uses them for calming and digestion, and laboratory studies report antioxidant flavonoids and alkaloids, but human clinical trials are scarce and no health claim is firmly established. The bitter germ contains alkaloids such as liensinine that have been studied for effects on heart rhythm in animals. Lotus seed paste is often heavily sweetened, which counts toward sugar intake.