What Is Turmeric?
Ancient writings of the explorer Marco Polo mention this spice as far back as 1290 AD. Its description and benefits have been documented in various writings through history, but during the rule of the British in India, between 1858 to 1947, turmeric became known as a component of curry powder, which was shared across the west.
Turmeric is actually a yellow-gold coloured spice, with its distinct colour supplied by the compound curcumin. It became a topic of investigation regarding its health benefits when it was found that its addition into food helped to preserve the foods freshness and palatability.
Curcumin molecules and derivatives (globally labelled curcuminoids) are generally 2-5% of the spices structure but are a key active ingredient (2).
Some varieties of turmeric can contain up to 9% curcumin, however, alongside these compounds, turmeric also contains essential oils and omega 3 fatty acids, as well as proteins and carbohydrates (1). There are also a variety of plant-based naturally occurring compounds (phytochemicals) which include the water soluble antioxidant, turmerol (3).
What Is Curcumin?
Curcuminoid molecules are polyphenols, meaning they are chemically structured with a number of carbolic acid molecules. Depending on their structure, they are labelled curcumin I, II or III; and despite confusion as to whether one analogue is able to be more active than the others, it is universally agreed that curcumin is the most potent component of turmeric (4-5).
In fact, this molecule is said to exhibit benefits in a variety of areas of health and physiology. These benefits vary from being an anti-inflammatory and anti-oxidant agent, to a protective agent of organ health (particularly the liver).
The strong anti-oxidant and anti-inflammatory effects are suggested to assist with various areas of cellular development and chemical signalling in our bodies, alongside modulating levels of key proteins and growth factors.
We will elaborate on these miraculous abilities further…
Amazingly, curcumin has a natural anti-inflammatory potency equal to nonsteroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone (24), and is more potent than the commonly taken Ibuprofen (25)! It also does not come with the potential side effects which other anti-inflammatory agents have.
Its mechanism of anti-inflammatory action appears to be through various pathways including:
? Inhibition of induction of COX-2 (an enzyme responsible for inflammation and pain) (26-27)
? Inhibition of LOX-2 (another pro-inflammatory enzyme) (28-30)
? Inhibition of cytokines (31-36) and transcription factors (37-41) involved with the inflammatory reaction
? Inhibition of nitric oxide synthase (an enzyme which stimulates nitric oxide production which is a signalling molecule involved in inflammation) (42)
Additionally, there is evidence that the anti-inflammatory effect of curcumin is due to its anti-oxidant potency (43-46).
It is well established that peroxidation of lipid cell membranes and oxidative damage by free radical molecules to DNA and cellular proteins is associated with various diseases and even the aging process. Curcumin is suggested to have a role in fighting against such oxidative stress.
? Health against oxidative damage is modulated through control of the reduction-oxidation reaction (redox status). Simply put, the reduction is the gain of an electron (leading to a decrease in oxidation state by a molecule); whilst oxidation is the opposite, the loss of an electron (increase in oxidation state).
Through a few different means, curcumin has been found to modulate redox status of cells and provide oxidative protection.
For example, curcumin assists to suppress lipid peroxidation and protect our cell membranes (47-51).
? Additionally, curcumin increases the expression of glutathione in our cells (52-56), which is one of the body’s main protectors against free radicals by scavenging these radicals and reducing oxidative stress.
? Finally, curcumin may also have a further role against oxidation through its ability to bind to iron (57).
It is not a surprise then that curcumin (and turmeric) have been found to have an effect on disease processes characterised by oxidative stress. In fact, water and fat soluble turmeric extracts show as strong an antioxidant effect as both vitamin C and vitamin E (58).
Turmeric & Curcumin | Clinical Benefits
#1 Wound Healing
One of the most prescribed uses in folklore and clinical use of curcumin is for the healing of wounds (60). The antioxidant benefits of this compound it seems can assist rate of healing both in laboratory studies and animal model trials (61-63). The antioxidant effects of curcumin help to inhibit against oxidative damage from free radicals such as hydrogen peroxide to protect skin and collagen cells during healing.
Another interesting area of benefit is in the management of arthritis, which has been examined using human trials. For example, one study (64) randomised a group of patients with rheumatoid arthritis to receive either curcumin (1200mg per day) or the non-steroidal anti-inflammatory phenylbutazone (300mg per day) for a period of 2 weeks.
Amazingly, the results of this study found that those provided with curcumin showed the same amount of symptom improvement than the anti-inflammatory group, and had no side effects! These symptom benefits included significant reduction of morning joint stiffness, increased walking time and decrease in joint swelling.
Such benefits are also supported by other arthritis studies both on cartilage cells (65-67) and in animal studies (68).
One of the most incredible therapeutic benefits of curcumin is in its anti-carcinogenic effects, as both the antioxidant and anti-inflammatory roles of this compound can influence the reactions responsible for malignant cell transformation (69).
For example, a 10% reduction in oral cancer lesion size has been demonstrated with the use of turmeric as a topical agent applied to the tongue (70).
Curcumin also demonstrates anti-cancer benefits through the facilitation of reactions which lead to cancer cell apoptosis (death). This has been seen in various types of cancer including:
? Head and neck (71)
? Lung (72)
? Pancreatic (73)
? Ovarian (74)
? Breast (75)
Due to this amazing ability, it is no wonder that curcumin is being examined as a possible universal cancer preventative agent!
A fantastic bit of research looked at the use of applying curcumin topically to skin suffering from psoriasis lesions (81). During this experiment, the researchers applied a 1% curcumin alcohol gel firstly to a group of 10 people with psoriasis. 5 of these individuals has 90% resolution of their skin lesions between 2-6 weeks, and the other 5 had 50-85% resolution after 8 weeks!
They then compared the curcumin gel to the standard alcohol gel base. After 1 month the entire curcumin group had improved by between 25% and 75%, whilst the control group had either shown no benefit (33%) or had even worsened (66%)!
#5 Other Benefits of Turmeric/Curcumin?
For expediency, I should state for the record that curcumin’s therapeutic benefits far exceed that which can be encapsulated into this article!
Instead, I shall list some of the other areas which curcumin has been shown to demonstrate its anti-oxidant and anti-inflammatory effects.
This would include:
? Reduction in induction and severity of acute pancreatitis (76)
? Reduction in anti-inflammatory response in irritable bowel disease (77)
? Improvement in histological signs of colonic inflammation (colitis) (78)
? Protection against gastric ulcers (79)
? Reduction in mast cell activation from allergies (80-81)
? Inhibition of virus replication in HIV (82)
? Increases in serotonin and reduction in depressive behaviors in mice (83)
? Inhibition of the hyaluronidase enzyme in snake bite venom, reduction in tissue damage and increased survival time (84)
Based upon the wide body of evidence, doses of 500-8,000mg of turmeric per day have been used in human studies, however standard extracts are typically used in lower amounts (approximately the 250-2,000mg range).
Periods of 3-4 months are well established to be suitable for turmeric/curcumin usage!
Take Home Message
The benefits of turmeric (and its main active ingredient, curcumin) are vast!
The antioxidant and anti-inflammatory effects seen in therapeutic and laboratory studies indicate to us that the usage of this spice throughout history is based upon very real molecular mechanisms.
As such, it behooves us to consider increasing our intake of turmeric to ensure we take advantage of its effects. Go on, spice up your life!