Coauthor Lakshmi Prakash, Ph.D.
Human populations have been using spices to preserve and flavor their food all through recorded history. One of the earliest known spices is turmeric, which gives curry its yellow color. This distinctive color and taste come from a group of curcumin substances, often termed “curcumin complex.” These are also very ancient folk medicines. Spanning the spectrum from traditional foods to modern medicines, the curcumins are under intense research scrutiny for their exciting potential in many areas of human health.
These plant-derived chemicals (“phytochemicals”) are concentrated in the rhizome or underground stem of the turmeric plant. Quality curcumin dietary supplements contain mainly three compounds—curcumin (curcumin I, the major ingredient), demethoxy-curcumin (curcumin II), and bisdemethoxy-curcumin (curcumin III)—conveniently termed “curcumin complex.”
History and Traditional Usage
The turmeric plant (Curcuma longa) is a tall tropical shrub, a relative of ginger (Family Zingiberaceae) with an extensive branching rhizome system. When dried and cured for commercial use, these have a curcumins content of 2.5–5.0 percent. The turmeric powder is used as a dye for cloth and a coloring agent in foods and cosmetics, due to its bright yellow color.
Turmeric with its curcumins is a revered folk medicine across Asia. Over thousands of years it has been used as a digestive aid, for dental problems, for lung problems, liver disorders, blood sugar control, in wound healing, as an analgesic and antiseptic, to provide relief from cold and sore throat, for rheumatism and sprains, and for various eye, ear or skin problems. Many of these traditional uses are now validated by modern research.
Chemically, the curcumins are polyphenol substances endowed with highly potent antioxidant, antitoxic, and other properties beneficial to health. The first human clinical study on curcumins was published in 1937 in the prestigious English medical journal, The Lancet. The reported benefits of curcumins for gall bladder function were confirmed by a later double-blind trial. The past decade has seen greatly accelerated scientific interest in the curcumins, with more than 1,875 articles published between 1996 and 2005.
Potent Cell and Tissue Protection
The curcumins are versatile and powerful antioxidants. They protect against free radical attack from toxins in the food, water, air, and total daily living environment. They also block oxygen free radicals and others generated internally, including superoxide, hydroxyl radical, hydrogen peroxide, and nitric oxide. Pure curcumin I is a less potent antioxidant than the three curcumins in combination, suggesting a natural synergy within the complex.
The curcumins have important antioxidant effects in our tissues. They protect DNA against oxidative attack and also inhibit binding of toxins to DNA, thereby lowering the risk for mutations and other genetic damage. They scavenge excess nitric oxide and other free radical metabolites, to quench runaway oxidation that could destroy tissues. Through these and other potent antioxidant actions the curcumins help conserve the body’s natural antioxidant defenses.
After numerous animal experiments, the curcumins have proved to be versatile biological protectants. They protect the liver against solvent toxicity, protect the brain against alcohol, protect the heart and the kidney against damage from pharmaceutical drugs. Topically applied, they protect the skin against damage from experimental edema.
The curcumins provide another layer of biological protection through their molecular-specific binding with key proteins. Some of the categories they help regulate are (a) free radicalgenerating enzymes, (b) cytokine messengers, (c) cell adhesion mediators, (d) COX-2 (cyclo-oxygenase-2) and other highly oxidative enzymes, (e) receptors, and (f) growth factors. By interacting with such catalytic proteins, the curcumins help maintain gene integrity, facilitate detoxification, support hormonal regulation, and generally underpin the homeostatic processes that maintain life.
Benefits For The Digestive System
The curcumins’ digestive benefits have been recognized for millennia. They support healthy functioning of the stomach, intestines, gall bladder, liver, and pancreas. In recent clinical studies, people who consumed curcumin supplements experienced reductions in the numbers and sizes of colon polyps. The curcumin complex also lowered the levels of damaged DNA in their colon cells, thereby reducing mutation risk.
Support for Memory and Brain Adaptability (“Plasticity”).
The human brain is wonderfully adaptable by displaying great “neuroplasticity.” Its circuits are continually repatterned in response to incoming information; circuits that become damaged can be partly substituted by neighboring circuits; new circuits may be formed under the influence of growth factors. Curcumins support growth factor actions, and protect the brain against stress. They also protect the brain against attack from metabolic toxins such as homocysteine.
A recent population study of more than 1,000 elderly Asians found that those who consumed curry “occasionally” and “often or very often” scored significantly better on a recognized test of memory function, compared against those who “never or rarely” consumed curry. A clinical trial is in progress that tests curcumin complex for memory support in healthy people.
Toxins that enter the body or are produced in the body can trigger lipid peroxidation and other “free-radical” processes that damage our vessel walls and sometimes also our circulating blood cells. In animal and human studies, curcumin complex reduced lipid peroxide levels in the blood. In two human studies LDL cholesterol was lowered and HDL cholesterol was elevated.
In a preliminary clinical trial that lasted just two weeks, there were indications curcumin complex could improve joint flexibility and walking time. Curcumin complex also can down-regulate troublesome COX-2 overactivity, and without adverse effects. A longer-term human trial would clarify the value of the curcumins for joint health.
Turmeric powder has been used as a cosmetic for over 2000 years. It is used in poultices to dress wounds, to treat bites, burns and other skin problems, ease itching, even to soothe the perineal area during childbirth. Experimentally, the curcumin complex protects skin cells against radiation and other types of free radical attack, therefore may help slow skin aging.
Support for Immunity
Curcumin complex supports immunity by inhibiting inappropriate cell proliferation. Substances that damage DNA, cause mutations, modify cell growth programs, or stimulate unneeded cell division all can trigger uncontrolled cell proliferation. In animals the curcumins blocked these unwanted effects. In related experiments with cultured human cells, the curcumins down-regulated the telomerase enzyme linked to loss of cell growth control.
In other animal experiments, the curcumins boosted macrophage activity and antibody responses. Also curcumin III partially corrected defective function in macrophages cultured from human blood.
The Curcumins Are Versatile Gene Regulators
Curcumin complex has a dimension of activity beyond classical metabolism, that is, regulating the activity of vital human genes. “Nutrigenomic” research using cutting-edge gene probe techniques has established that the curcumins contribute to healthy functioning of many genes. The curcumins favorably influence genes involved with:
- Regulation of cyclo-oxygenase-2 ( COX-2) enzyme activity
- Control over apoptosis (programmed cell death)
- Triggering the cell cycle into and out of division mode
- Management of cell proliferation
- Growth factor balance for new blood vessel formation.
Bioperine Dramatically Improves Curcumin Absorption The curcumins are relatively poorly absorbed when taken by mouth. Piperine, extracted from black pepper fruit, is proven via multiple double-blind trials to enhance nutrient absorption. In one human study, the administration of 2000 mg of curcumin complex together with 20 mg of piperine boosted bioavailability by 20 times (2000 percent).
When consumed with a small amount of Bioperine (95 percent standardized piperine), a 1,000 to 1,500 mg daily intake of curcumin complex can access the blood and circulate to the tissues. Although their bioavailability is low, when consumed daily by mouth the curcumins eventually may benefit all the body’s organs.
Curcumin Complex-Has A Brilliant Future
Currently more than 16 clinical trials are underway on curcumin complex, and many more are planned. Bioavailability continues to be an issue, but when suitably potentized (as with bioperine) the curcumins do get into human tissues. Using the colon as an example, just a minimal level of curcumins in the tissue was linked to polyp reduction and a reduction of mutated DNA.
One factor contributing to the bioavailability problem is the wide variation in potency of commercial curcumin sources. This makes standardized preparations most desirable (preferably a minimum 95 percent in curcumins I, II, and III). Also curcumin dietary supplements should be free of iron and copper, which could cause free radical problems. For curcumin complex, as with all dietary supplements, the consumer is well advised to deal only with reputable and proven suppliers.
Curcumin complex has moved beyond traditional human staple to being the focus of rapt attention in both the nutritional and the medical fields. Its huge range of traditional applications and its many potentially beneficial actions are systematically becoming validated by modern basic and clinical research. Curcumin complex has emerged as a breakthrough for whole-body health, healing, and quality of life into old age.
Lakshmi Prakash Ph.D. is Vice President of Innovation and Business Development at Sabinsa. Dr. Lakshmi Prakash received a BSc degree in chemistry, and BSc and MSc degrees in food technology from the University of Mumbai, India. Her Ph.D. degree is in food science from Rutgers University, New Jersey. Dr. Prakash has over 25 years of combined research and management experience.