This is a very expansive query. Let me briefly answer this. Garlic is an important plant extensively used in Chinese medicine while turmeric is popular in Ayurveda. Increasingly though turmeric properties are being understood and appreciated by people across the globe.
Medicinal properties of garlic
There is extensive reference to its medicinal properties in both the Charaka Samhita and the Sushruta Samhita, ancient Indian medical texts. Both Indians and Chinese regard garlic as an aphrodisiac. It aids digestion, improves respiration, and was used to get rid of intestinal worm infestation (Woodward, 1996). It helps in improving qi—life energy. Charaka Samhita recommends the use of garlic to treat heart disease and arthritis too. Garlic’s effect is also said to be diuretic.
The Ebers Papyrus (c. 1550 BC) prescribes the use of garlic in cases of high blood pressure and clogged arteries. Garlic was also prescribed to alleviate general malaise, and combat infestations of insects, worms, and parasites.
Hippocrates recommended the use of garlic in respiratory ailments, as a cleansing agent, and to treat abdominal growths. Dioscorides recommended the use of garlic to keep arteries clean. Pliny’s Historica Naturalis mentions the use of garlic to improve digestion and to treat insect bites, arthritis, and convulsions.
Before the discovery of antibiotics, garlic was consumed in large quantities, especially during disease epidemics. Its anti-microbial properties were thought to provide protection. In 2002-2003, the SARS epidemic in China killed hundreds of people; garlic was consumed widely, hoping for protection against the virus.
Garlic bulbs Photo: Sudhir Ahluwalia copyright Asian Herbs
It is a widely-researched species and is a popular herbal supplement cleared for use in the US, Europe, and across the globe. The plant is known to be effective in reducing high blood pressure, showing promise in reducing cardiovascular risk (Ackermann et al., 2001).
Garlic is useful in alleviating atherosclerosis (Berthold et al., 1998). It also tested positive for efficacy against Type 2 diabetes (Ashraf et al., 2005).
The antioxidant properties of aged garlic extract were observed by Dillon et al. (2003). Dorant et al. (1996) observed the spice’s ability to moderate the impact of colorectal cancer. A similar correlation was made in Durak et al. (2003) in prostate cancer patients. Heron et al. (1999) observed that garlic supplements can be used to treat parasitic infections.
Borelli et al. (2007) performed a study that reveals adverse interactions of garlic with certain drugs. Isoniazid used to treat tuberculosis and in birth control pills, the cyclosporine is given after organ transplant, and blood-thinning medications could all be made less effective when garlic supplements are taken by patients.
Medicinal properties of turmeric
Traditionally, it has been used to treat skin, gastrointestinal, autoimmune, liver, eye, and other disorders. Turmeric is said to provide relief in allergies, gall bladder ailments, edema, tumors, and cataract. Its anti-inflammatory and antibacterial properties are used to treat inflammations and infections.
Curcumin is the yellow pigment in turmeric and has been in use as medicine for centuries. Curcuminoids have been extracted from turmeric (Kulkarni et al., 2012) Pharmacological reviews undertaken by Ammon et al. (1991), Jurenka (2009), and others validate curcumin’s anti-inflammatory property. Curcumin, the active compound in the spice, exhibits anti-spasmodic activity. It was seen to stimulate bile secretion in animals and help treat liver disorders.
Turmeric plant with rhizome – Photo: Sudhir Ahluwalia copyright for Asian Herbs
Araujo et al. (2001) and Aggarwal et al. (2007 and 2009) have noted the anti-cancer, antiviral, antibacterial, anti-fungal, and gastrointestinal actions of curcumin. It is also helpful in treating liver and other ailments. Curcumin is said to prevent Alzheimer’s disease (Balasubramanian, 2006; Yanagisawa et al., 2010; Yang et al., 2004; Lee 2002; and Tomiyama, 2010).
The action of turmeric oil molecule ar-turmerone was studied by Jankasem et al. (2013), and its anti-fungal property on the skin was validated. The anti-microbial property of turmeric was observed in experiments conducted by Khan et al. in 2009.
Curcuma longa is a lesser-known drug in homeopathy. Even then, its traditionally accepted medicinal properties were subjected to a multicentric clinical trial. Turmeric was found to be useful in treating anxiety, dementia, dysmenorrhea, gingivitis, toothache, lumbago, pharyngitis, etc. (Chakraborty et al., 2011).
A study conducted by Kim et al. (2009) validated the impact of turmeric in checking the replication of the hepatitis B virus. The hepatoprotective effect of the species was observed in rats induced with liver cirrhosis (Salama et al., 2013). The antioxidant activity of the species was observed in experiments by Yadav et al. (2013).
There is a lot more to these two plants. For more read here.