What is it: The mulberry fruit is a berry from trees in the Moraceae family, which are native to the warm, temperate and subtropical regions of Asia, Africa and America.
In China, it is found in places such as Yunnan, Sichuan, Xinjiang, Shanxi and Guangxi, said Ms Felicia Ng, a senior acupuncturist at the Complementary Integrative Medicine Clinic at Tan Tock Seng Hospital.
Known as sangshen in Chinese, the fruit consists of a cluster of soft drupelets arranged longitudinally around the central axis, much like a blackberry.
Ms Ng said the berries are purple when ripe, but can be green, white or red otherwise.
The fruit is plucked between April and June, then dried under shelter or in the sun.
She added that good quality mulberry fruit is purplish and has a glossy sheen.
The berries are very sweet, full of moisture and have thick flesh.
The mulberry fruit is sold at $1.20 for a tael (37.5g) at some traditional Chinese medicine (TCM) halls here.
How TCM uses it: The sweet and slightly sour mulberry fruit is considered cold in nature.
It is thought to move through the meridians of the liver and kidneys and it is prescribed when there is yin deficiency in both these organ systems.
Meridians are channels in the body through which qi (vital energy) travels.
A good flow of qi, as well as a balance of yin (the element responsible for cooling organs) and yang (the element linked to heat) in the body are needed for good health.
Yin deficiency is characterised by symptoms related to heat and dryness, such as dry eyes, dry throat, dry stools and hot flushes.
Ms Ng said drinking fluids may not alleviate the dryness in the throat.
In TCM, it is believed the health of the eyes is linked to that of the liver, while the health of the ears is based on that of the kidneys.
A person with liver-kidney yin deficiency will therefore have problems with the eyes and ears, and is likely to experience blurred vision and tinnitus (ringing in the ears).
The kidneys also promote growth and development of the body and play an important role in reproduction. Prematurely white hair and irregular periods are signs of deficiency in this area, Ms Ng said.
She said the mulberry fruit is also known to address water retention along with other herbs such as achyranthes root (niuxi) and doubleteeth pubescent angelica root (duhuo).
TCM practitioners believe that yin deficiency gives rise to a heaty body which has poor fluid circulation. The problem is then manifested as puffy-looking lower limbs that are characteristic of water retention.
Who is it for: Ms Ng said diabetics have a tendency to feel thirsty all the time, so they are more prone to liver-kidney yin deficiency.
People who sweat easily in the day or night, youngsters who spot grey hair and women with irregular periods are also likely to be suffering from this area of deficiency.
Ms Ng said the recommended dosage is 5 to 10g of the dry mulberry fruit per day.
Who should avoid it: The mulberry fruit is a cold herb, so it should not be consumed by those with "dampness" in the stomach, said Ms Ng.
This is easily recognised by the presence of loose and watery stool that marks diarrhoea.
What research has shown: In a 2010 article in the British Journal Of Nutrition, researchers reported that mulberry fruit extract significantly protected neurons (brain cells) from being destroyed in mice that had Parkinson's disease, a degenerative disease of the nervous system.
The study authors, from universities in South Korea, also reported that the mulberry fruit had a total phenolic content similar to that of the black bean and more than that of red or white beans.
Phenolic compounds are well known to have antioxidant effects. This means that they remove potentially damaging oxidising agents from within a living organism.
Get a copy of Mind Your Body, The Straits Times or go to straitstimes.com for more stories.