The Kitchen’s Gold
People call it the golden spice because, not only of its yellowish golden color but also of its numerous uses such as medicinal, culinary, cultural and religious. Turmeric has been interwoven with the daily life of Sri Lankans from time immemorial. A pinch of turmeric powder is a must in each and every curry prepared in a Sri Lankan kitchen. Turmeric dissolved water is the earliest known purifier used in religious ceremonies. Its subtle flavor, distinct yellowish color and powerful aroma are highly respected in both Sinhalese and Tamil cultures.
Historical Uses
Turmeric, a plant belongs to ginger family (Curcuma longa) native to South Asia, which has been commercially cultivated in the region for a very long time. Known as Kaha in Sinhalese and Manjal in Tamil, turmeric’s rhizome or the underground rootstalk, is used for many purposes in South East Asian countries. The use of turmeric dates back nearly 4000 years to the Vedic culture in India, where it was originally used as a culinary spice and in religious ceremonies. It has also been used as a household disinfectant in both India and in Sri Lanka.
According to Sanskrit medical treatises of Ayurvedic and Unani systems, turmeric has a long history of medicinal use. Susruta’s Ayurvedic Compendium, dating back to 250 bc, recommends an ointment containing turmeric to relieve the effects of poisoned food. Currently it is used in Ayurvedic medicine for many ailments including abdominal pain, anorexia, biliary disorders, catarrh, cough, diabetes and diabetes wounds, hepatic disorders, jaundice, rheumatic disorders, sinusitis, sprains and swellings. Due to its bright yellow or orange color, turmeric had been traditionally used as a dye in the past. The uses include the coloring of robes of Buddhist monks. Use of turmeric as a dye is not practiced much at present due to unstable nature of the color. However, even at present, it is used for drawing religious art such as letter Om and also to adorn the statues of gods. In culinary art also it is used to give both color and flavor to the food.
Modern Scientific Research on Turmeric
Composition
More than 100 components have been isolated and identified from turmeric. The main components are called as curcuminoids which comprises of several compounds accounting to 5 – 6.5% of the dry weight. Curcumin is the major curcuminoid found in turmeric. Volatile oils are also an important components which gives the typical aroma of turmeric. Volatile oil contain phellandrene, sabinene, cinol, borneol, zingiberene and sesquiterpenes.
Beneficial Effects
Modern scientific research had found that turmeric can be used for both prevention and therapy of diseases. In vitro studies (carried in a test tube or outside the human or animal body) reveal many beneficial properties including antioxidant, anti-inflammatory, antimutagenic, antimicrobial, and anticancer activity.
Antioxidant Activity
Reactive oxygen species (ROS) and free radicals (FR) are highly reactive molecules that have the potential to damage other molecules in the human body. These could be naturally generated in the body and could also enter the body through inhalation of polluted air, smoking and contaminated food. Presence of excessive amounts of ROS and FR is called as ‘oxidative stress’. Prolonged oxidative stress has been found to be one of the key factors in the development of non-communicable diseases such as heart disease, stroke, cancer, diabetes and neurodegenerative diseases. Human body has protective mechanisms against oxidative stress through antioxidant enzymes and antioxidant molecules. In addition, antioxidant molecules derived from the diet also play an important role in the protective mechanism against oxidative stress.
Review of eight human clinical trials on the effect of curcumin revealed that the major bioactive compound in turmeric has antioxidant activity in humans. This demonstrates that consumption of turmeric may reduce the risk of the development of non-communicable diseases such as heart disease, stroke, cancer, diabetes and neurodegenerative diseases.
Anti-inflammatory Activity
The immune system is the body’s defense against infectious organisms and other toxic invaders. Through a series of steps referred to as “immune response”, the immune system attacks the organisms and other toxic substances that invade the body and cause disease. Some of these reactions result in inflammation. Signs of inflammation are heat (rise in body temperature), redness, swelling and pain. Excessive or prolonged inflammation could damage the human body and increase the risk of non-communicable diseases such as heart disease, stroke and diabetes. Therefore, it is important that inflammation is controlled quickly once the causing agent is eliminated. Further, exposure to environmental toxins and toxicants such as smoke, dust particles, pesticides, mycotoxins, polychlorinated biphenyls (PCBs) and toxic metals could also trigger inflammation. As exposure to such agents are common in the present day environment, anti-inflammatory compounds derived from the diet could play an important role in mitigating the adverse effects of inflammation.
Curcumin has been demonstrated to possess anti-inflammatory activity in human clinical trials and safety of consumption of curcumin. It was revealed that consumption of 8 g of curcumin per day was safe. Further it demonstrated that consumption of curcumin reduce the risk of non-communicable diseases such as heart disease, stroke, and diabetes.
Effect on Lipids in Blood
One of the main risk factors for heart disease is high lipid levels in blood. Human clinical trials had shown that curcuminoids could reduce blood lipid levels. Therefore, it could be concluded that turmeric consumption can reduce the risk of heart disease.
Effect on High Blood Pressure
High blood pressure is a major risk factor for both heart disease and stroke. Long term consumption of turmeric or curcumin proved to improve blood pressure, thus decreasing the risk of heart disease and stroke.
Diabetes
Review of human clinical trials had shown that turmeric powder has a significant effect on controlling blood sugar levels implying that consumption of turmeric may reduce the risk of diabetes.
Heart Disease
Oxidative stress, inflammation, high blood lipids, high blood pressure and diabetes are all risk factors for heart disease. As human clinical trials have shown that turmeric could alleviate all these factors, long term consumption of turmeric may reduce the risk of heart disease.
Skin Health
Turmeric has been extensively used in traditional medicine for skin disorders and improvement of skin health. Recently human clinical trials showed that both ingestion and topical application of turmeric has therapeutic benefits on skin health including reduction of hyperpigmentation of the skin. Hyperpigmentation is a common, usually harmless condition in which patches of skin become darker in color than the normal surrounding skin. This darkening occurs when an excess of melanin, the brown pigment that produces normal skin color, forms deposits in the skin.
Effect on the Diseases of the Digestive Tract
Turmeric has been extensively used in traditional medicine for stomach aches and indigestion. Recent research has focused attention on the effect of turmeric on ulcerative colitis and Crohn’s disease. Ulcerative colitis is a long-term condition that results in inflammation and ulcers of the colon and rectum. Crohn’s disease is a type of inflammatory bowel disease. It causes inflammation of the digestive tract, which can lead to abdominal pain, severe diarrhoea, fatigue, weight loss and malnutrition. Human clinical trials has shown that turmeric could reduce the effect of these diseases.
Arthritis
Limited number of human clinical trials have shown that turmeric may give relief from pain in arthritis patients. This improves the function in these patients.
Highlights
Turmeric is a spice that has received much interest from both the medical/scientific worlds as well as from the culinary world. It received worldwide attention for its multiple health benefits, which appear to act primarily through its anti-oxidant and anti-inflammatory mechanisms. Phytochemical analysis of turmeric has revealed a large number of compounds, including curcumin, volatile oil, and curcuminoids, which have been found to have potent pharmacological properties. Wisdom in traditional medicine and also modern scientific research has shown that consumption and topical use of turmeric may be beneficial in reducing the risk and alleviating the symptoms of many common diseases
Processing
Before turmeric can be used, the rhizomes must be processed. Rhizomes are generally boiled or steamed to remove the raw odour, gelatinize the starch, and produce a more uniformly coloured product. The rhizomes are removed from the heat and dried in the sun to final moisture content between 8% and 10%. The dried rhizomes are polished to remove the rough surface and ground to a powder.
Dr M T Kumudini Gunasekare (BSc Agric. Hons. Sri Lanka; PhD, UK)
Agribusiness Specialist – Agriculture Sector Modernisation Project
