WHAT IT IS:
The sesame seed has one of the highest oil contents of any seed and adds a heady aroma to cooking.
It comes in colours of white, yellow, black and red.
Black sesame seeds can be eaten raw or cooked. Known as heizhima in Mandarin, they are tossed in salads, baked into cookies and bread and used to make sesame paste.
In traditional Chinese medicine (TCM), black sesame seeds are prized for their ability to combat ageing and fight illnesses associated with old age, said Dr Hong Hai, a TCM physician at Renhai Clinic and Public Free Clinic.
Found in places such as India, China, South America and Africa, the black sesame plant grows best in sandy, well-drained soil in a hot climate with moderate rainfall.
The sesame plant is an annual plant whose fruit takes about four months to ripen, at which point the seeds can be harvested, cleaned and dried.
According to the third edition of Chinese Herbal Medicine Materia Medica, good quality seeds are black, full and uniform in size, have an intense aroma and are not contaminated by foreign matter.
A 100g packet of black sesame seeds is sold for $1 at some provision shops here.
HOW TCM USES IT:
Black sesame seeds are thought to move through the liver, kidney and large intestine meridians, channels in the body through which qi (vital energy) travels. A good flow of qi in the body is required for good health.
The sweet-tasting seed is neutral in nature and regarded as a yin tonic. Yin is the element responsible for moistening and cooling the body.
When yin is deficient or depleted, it upsets the balance of yin and yang (the element linked to heat) in the body that is needed for good health, leading to symptoms of heat.
Yin deficiency in the kidneys is apparent through a sore throat, a red tongue without much coating and night sweats, while that in the liver is marked by dry and red eyes, a quick pulse and irritability, said Dr Hong.
Black sesame seeds are used to address yin deficiency in the liver and kidneys, which could result from working for consecutive late nights, emotional stress and serious illness, he added.
Black sesame seeds can also be used on their own or in combination with herbs such as processed rehmannia root and glossy privet fruit to nourish the blood and jing, said Dr Hong.
Jing (essence of nutrients) is the substance used for reproduction and regeneration in the body.
In TCM, it is believed that the kidneys store jing and generates blood-making bone marrow.
A deficiency in jing can eventually lead to blood deficiency.
The amount of jing declines with age and is depleted through excessive sexual activity and serious medical conditions, said Dr Hong.
A person deficient in jing in the kidneys would have symptoms such as premature grey hair, memory problems, backache and weakness in the knees.
Blood deficiency in the body is marked by symptoms such as dizziness, heart palpitations, insomnia and paleness, Dr Hong added.
The liver stores blood, which is regarded as an yin component of the body system.
Black sesame seeds are also known for their moistening effect on the large intestines to promote regular bowel movements. They can be used alongside herbs such as hemp seed and Chinese angelica for this purpose, said Dr Hong.
WHO IT IS FOR:
The high oil content of black sesame seeds makes them ideal for people with dry, large intestinal lining, a common problem among the elderly, said Dr Hong.
But one should not consume more than 10g of the seeds a day, he advised.
WHO SHOULD AVOID IT:
People with weak stomachs, who are thus prone to having loose stools and diarrhoea, should not take sesame seeds.
WHAT RESEARCH HAS SHOWN:
Sesame oil has been found to inhibit the growth of malignant melanoma in vitro and the proliferation of human colon cancer cells, reported a 2010 review article in the Agriculturae Conspectus Scientificus, a scientific journal in the field of agriculture.
It added that molecules of sesame seed oil maintain high-density lipoproteins, or "good" cholesterol, and lower low-density lipoproteins, commonly called "bad" cholesterol.
In an experiement at the Maharishi International College in Fairfield, Iowa, in the United States, students rinsed their mouths with sesame oil, resulting in an 85 per cent reduction in the bacteria which causes gingivitis, the review article noted.
Black sesame seed porridge (Serves four to five)
20g to 30g black sesame seeds
90g round-grained glutinous rice, washed and soaked
1 litre water
15g Chinese wolfberries, washed
Red sugar, as desired
1. Fry the black sesame seeds in a dry pan without oil till they become fragrant.
2. Grind the sesame seeds using a mortar and pestle, so that the nutrients can be more easily released from the seeds and absorbed by the body.
3. After soaking the glutinous rice for at least 30 minutes, cook it over low heat in 1 litre of water.
4. Stir regularly to prevent the rice from sticking to the pot.
5. Let the mixture simmer until the rice is cooked and becomes gooey.
6. Pour the ground sesame seeds and wolfberries into the pot. Stir for about 15 minutes until they are evenly mixed with the rice.
7. Add red sugar to taste. Serve warm.
Source: Dr Hong Hai, a traditional Chinese medicine physician at Renhai Clinic and Public Free Clinic