Turmeric has a peppery, warm and bitter flavor and a mild fragrance slightly
reminiscent of orange and ginger, and while it is best known as one of the
ingredients used to make curry, it also gives ballpark mustard its bright yellow
color.
Turmeric comes from the root of the Curcuma longa plant and has a tough brown
skin and a deep orange flesh. Turmeric has long been used as a powerful
anti-inflammatory in both the Chinese and Indian systems of medicine. Turmeric
was traditionally called "Indian saffron" because of its deep yellow-orange
color and has been used throughout history as a condiment, healing remedy and
textile dye.
Turmeric (Curcuma longa), the bright yellow of the spice rainbow, is a
powerful medicine that has long been used in the Chinese and Indian systems of
medicine as an anti-inflammatory agent to treat a wide variety of conditions,
including flatulence, jaundice, menstrual difficulties, bloody urine,
hemorrhage, toothache, bruises, chest pain, and colic.
A Potent, Yet Safe Anti-Inflammatory
The volatile oil fraction of turmeric has demonstrated significant
anti-inflammatory activity in a variety of experimental models. Even more potent
than its volatile oil is the yellow or orange pigment of turmeric, which is
called curcumin. Curcumin is thought to be the primary pharmacological
agent in turmeric. In numerous studies, curcumin's anti-inflammatory effects
have been shown to be comparable to the potent drugs hydrocortisone and
phenylbutazone as well as over-the-counter anti-inflammatory agents such as
Motrin. Unlike the drugs, which are associated with significant toxic effects
(ulcer formation, decreased white blood cell count, intestinal bleeding),
curcumin produces no toxicity.
An Effective Treatment for Inflammatory Bowel Disease
Curcumin may provide an inexpensive, well-tolerated, and effective
treatment for inflammatory bowel disease (IBD) such as Crohn's and ulcerative
colitis, recent research suggests. In this study, mice given an inflammatory
agent that normally induces colitis were protected when curcumin was added to
their diet five days beforehand. The mice receiving curcumin not only lost much
less weight than the control animals, but when researchers checked their
intestinal cell function, all the signs typical of colitis (mucosal ulceration,
thickening of the intestinal wall, and the infiltration of inflammatory
cells)were all much reduced.
While the researchers are not yet sure exactly how
curcumin achieves its protective effects, they think its benefits are the result
of not only antioxidant activity, but also inhibition of a major cellular
inflammatory agent called NF kappa-B. Plus, an important part of the good news
reported in this study is the fact that although curcumin has been found to be
safe at very large doses, this component of turmeric was effective at a
concentration as low as 0.25 per cent-an amount easily supplied by simply
enjoying turmeric in flavorful curries.
Relief for Rheumatoid Arthritis
Clinical studies have substantiated that curcumin also exerts very powerful
antioxidant effects. As an antioxidant, curcumin is able to neutralize free
radicals, chemicals that can travel through the body and cause great amounts of
damage to healthy cells and cell membranes. This is important in many diseases,
such as arthritis, where free radicals are responsible for the painful joint
inflammation and eventual damage to the joints. Turmeric's combination of
antioxidant and anti-inflammatory effects explains why many people with joint
disease find relief when they use the spice regularly. In a recent study of
patients with rheumatoid arthritis, curcumin was compared to phenylbutazone and
produced comparable improvements in shortened duration of morning stiffness,
lengthened walking time, and reduced joint swelling.
Help for Cystic Fibrosis Sufferers
Curcumin, the major constituent of turmeric that gives the spice its yellow
color, can correct the most common expression of the genetic defect that is
responsible for cystic fibrosis, suggests an animal study published in the
Science (April 2004). Cystic fibrosis, a fatal disease that attacks the
lungs with a thick mucus, causing life-threatening infections, afflicts about
30,000 American children and young adults, who rarely survive beyond 30 years of
age. The mucus also damages the pancreas, thus interfering with the body-ability
to digest and absorb nutrients.
Researchers now know that cystic fibrosis is caused by mutations in the gene
that encodes for a protein (the transmembrane conductance regulator or CFTR).
The CTFR protein is responsible for traveling to the cell-surface and creating
channels through which chloride ions can leave the cell. When the protein is
abnormally shaped because of a faulty gene, this cannot happen, so chloride
builds up in the cells, which in turn, leads to mucus production.
The most common mutation, which is called DeltaF508, results in the
production of a misfolded protein. When mice with this DeltaF508 defect were
given curcumin in doses that, on a weight-per-weight basis, would be
well-tolerated by humans, curcumin corrected this defect, resulting in a
DeltaF508 protein with normal appearance and function. In addition, the Yale
scientists studying curcumin have shown that it can inhibit the release of
calcium, thus allowing mutated CTFR to exit cells via the calcium channels,
which also helps stop the chloride-driven build up of mucus. Specialists in the
treatment of cystic fibrosis caution, however, that patients should not
self-medicate with dietary supplements containing curcumin, until the correct
doses are known and any adverse interactions identified with the numerous
prescription drugs taken by cystic fibrosis sufferers.
Cancer Prevention
Curcumin's antioxidant actions enable it to protect the colon cells from free
radicals that can damage cellular DNA—a significant benefit particularly in the
colon where cell turnover is quite rapid, occuring approximately every three
days. Because of their frequent replication, mutations in the DNA of colon cells
can result in the formation of cancerous cells much more quickly. Curcumin also
helps the body to destroy mutated cancer cells, so they cannot spread through
the body and cause more harm. A primary way in which curcumin does so is by
enhancing liver function. Additionally, other suggested mechanisms by which it
may protect against cancer development include inhibiting the synthesis of a
protein thought to be instrumental in tumor formation and preventing the
development of additional blood supply necessary for cancer cell growth.
Inhibits Cancer Cell Growth and Metastases
Epidemiological studies have linked the frequent use of turmeric to lower
rates of breast, prostate, lung and colon cancer; laboratory experiments have
shown curcumin can prevent tumors from forming; and research conducted at the
University of Texas suggests that even when breast cancer is already present,
curcumin can help slow the spread of breast cancer cells to the lungs in mice.
In this study, published in Biochemical Pharmacology (September 2005),
human breast cancer cells were injected into mice, and the resulting tumors
removed to simulate a mastectomy.
The mice were then divided into four groups. One group received no further
treatment and served as a control. A second group was given the cancer drug
paclitaxel (Taxol); the third got curcumin, and the fourth was given both Taxol
and curcumin.
After five weeks, only half the mice in the curcumin-only group and just 22%
of those in the curcumin plus Taxol group had evidence of breast cancer that had
spread to the lungs.
But 75% of the mice that got Taxol alone and 95% of the control group
developed lung tumours.
How did curcumin help? "Curcumin acts against transcription factors, which
are like a master switch," said lead researcher, Bharat Aggarwal. "Transcription
factors regulate all the genes needed for tumors to form. When we turn them off,
we shut down some genes that are involved in the growth and invasion of cancer
cells."
In another laboratory study of human non-Hodgkin's lymphoma cells published
in Biochemical Pharmacology (September 2005), University of Texas
researchers showed that curcumin inhibits the activation of NF-kappaB, a
regulatory molecule that signals genes to produce a slew of inflammatory
molecules (including TNF, COX-2 and IL-6) that promote cancer cell growth. In
addition, curcumin was found to suppress cancer cell proliferation and to induce
cell cycle arrest and apoptosis (cell suicide) in the lung cancer cells. Early
phase I clinical trials at the University of Texas are now also looking into
curcumin's chemopreventive and therapeutic properties against multiple myeloma
and pancreatic cancer, and other research groups are investigating curcumin's
ability to prevent oral cancer.
Turmeric and Onions May Help Prevent Colon Cancer
Curcumin, a phytonutrient found in the curry spice turmeric, and quercitin,
an antioxidant in onions, reduce both the size and number of precancerous
lesions in the human intestinal tract, shows research published in the August
2006 issue of Clinical Gasteroenterology and Hepatology.
Five patients with an inherited form of precancerous polyps in the lower
bowel known as familial adenomatous polyposis (FAP) were treated with regular
doses of curcumin and quercetin over an average of six months. The average
number of polyps dropped 60.4%, and the average size of the polyps that did
develop dropped by 50.9%.
FAP runs in families and is characterized by the development of hundreds of
polyps (colorectal adenomas) and, eventually, colon cancer. Recently,
nonsteroidal anti-inflammatory drugs (NSAIDs such as aspirin, ibuprofen) have
been used to treat some patients with this condition, but these drugs often
produce significant side effects, including gastrointestinal ulcerations and
bleeding, according to lead researcher Francis M. Giardiello, M.D., at the
Division of Gastroenterology, Johns Hopkins University.
Previous observational studies in populations that consume large amounts of
curry, as well as animal research, have strongly suggested that curcumin, one of
the main ingredients in Asian curries, might be effective in preventing and/or
treating cancer in the lower intestine. Similarly, quercetin, an anti-oxidant
flavonoid found in a variety of foods including onions, green tea and red wine,
has been shown to inhibit growth of colon cancer cell lines in humans and
abnormal colorectal cells in animals.
In this study, a decrease in polyp number was observed in four of five
patients at three months and four of four patients at six months.
Each patient received curcumin (480 mg) and quercetin (20 mg) orally 3 times
a day for 6 months. Although the amount of quercetin was similar to what many
people consume daily, the curcumin consumed was more than would be provided in a
typical diet because turmeric only contains on average 3-5 % curcumin by weight.
Turmeric Teams Up with Cauliflower to Halt Prostate
Cancer
Prostate cancer—the second leading cause of cancer death in American men with
500,000 new cases appearing each year—is a rare occurrence among men in India,
whose low risk is attributed to a diet rich in brassica family vegetables and
the curry spice, turmeric.
Scientists tested turmeric, a concentrated source of the phytonutrient
curcumin, along with phenethyl isothiocyanates, a phytochemical abundant in
cruciferous vegetables including cauliflower, cabbage, broccoli, Brussels
sprouts, kale, kohlrabi and turnips.
When tested singly, both phenethyl isothiocyanate and curcumin greatly
retarded the growth of human prostate cancer cells implanted in immune-deficient
mice. In mice with well-established prostate cancer tumors, neither phenethyl
isothiocyanate nor curcumin by itself had a protective effect, but when
combined, they significantly reduced both tumor growth and the ability of the
prostate cancer cells to spread (metastasize) in the test animals.
Reduce Risk of Childhood Leukemia
Research presented at a recent conference on childhood leukemia, held in
London, provides evidence that eating foods spiced with turmeric could reduce
the risk of developing childhood leukemia. The incidence of this cancer has
risen dramatically during the 20th century, mainly in children under age five,
among whom the risk has increased by more than 50% cent since 1950 alone. Modern
environmental and lifestyle factors are thought to play a major role in this
increase.
Childhood leukemia is much lower in Asia than Western countries, which may be
due to differences in diet, one of which, the frequent use of turmeric, has been
investigated in a series of studies over the last 20 years by Prof. Moolky
Nagabhushan from the Loyola University Medical Centre, Chicago, IL.
"Some of the known risk factors that contribute to the high incidence of
childhood leukemia are the interaction of many lifestyle and environmental
factors. These include prenatal or postnatal exposure to radiation, benzene,
environmental pollutants and alkylating chemotherapeutic drugs. Our studies show
that turmeric-and its colouring principle, curcumin-in the diet mitigate the
effects of some of these risk factors."
Nagabhushan has shown that the curcumin in turmeric can:
- inhibit the mutagenicity of polycyclic aromatic hydrocarbons (PAHs)
(carcinogenic chemicals created by the burning of carbon based fuels including
cigarette smoke)
- inhibit radiation-induced chromosome damage
- prevent the formation of harmful heterocyclic amines and nitroso
compounds, which may result in the body when certain processed foods, such as
processed meat products that contain nitrosamines, are eaten
- irreversibly inhibit the multiplication of leukemia cells in a cell
culture
Improved Liver Function
In a recent rat study conducted to evaluate the effects of turmeric on the
liver's ability to detoxify xenobiotic (toxic) chemicals, levels of two very
important liver detoxification enzymes (UDP glucuronyl transferase and
glutathione-S-transferase) were significantly elevated in rats fed turmeric as
compared to controls. The researchers commented, "The results suggest that
turmeric may increase detoxification systems in addition to its anti-oxidant
properties...Turmeric used widely as a spice would probably mitigate the effects
of several dietary carcinogens."
Curcumin has been shown to prevent colon cancer in rodent studies. When
researchers set up a study to analyze how curcumin works, they found that it
inhibits free radical damage of fats (such as those found in cell membranes and
cholesterol), prevents the formation of the inflammatory chemical
cyclooxygenase-2 (COX-2), and induces the formation of a primary liver
detoxification enzyme, glutathione S-transferase (GST) enzymes.
When the rats
were given curcumin for 14 days, their livers' production of GST increased by
16%, and a marker of free radical damage called malondialdehyde decreased by 36%
when compared with controls. During this two week period, the researchers gave
the rats a cancer-causing chemical called carbon tetrachloride. In the rats not
fed curcumin, markers of free radical damage to colon cells went up, but in the
rats given turmeric, this increase was prevented by dietary curcumin. Lastly,
the researchers compared giving turmeric in the diet versus injecting curcumin
into the rats' colons. They found injecting curcumin resulted in more curcumin
in the blood, but much less in the colon mucosa. They concluded, "The results
show that curcumin mixed with the diet achieves drug levels in the colon and
liver sufficient to explain the pharmacological activities observed and suggest
that this mode of administration may be preferable for the chemoprevention of
colon cancer."
Cardiovascular Protection
Curcumin may be able to prevent the oxidation of cholesterol in the body.
Since oxidized cholesterol is what damages blood vessels and builds up in the
plaques that can lead to heart attack or stroke, preventing the oxidation of new
cholesterol may help to reduce the progression of atherosclerosis and diabetic
heart disease. In addition, turmeric is a good source of vitamin B6, which is
needed to keep homocysteine levels from getting too high. Homocysteine, an
intermediate product of an important cellular process called methylation, is
directly damaging to blood vessel walls. High levels of homocysteine are
considered a significant risk factor for blood vessel damage, atherosclerotic
plaque build-up, and heart disease; while a high intake of vitamin B6 is
associated with a reduced risk of heart disease.
In research published in the Indian Journal of
Physiology and Pharmacology, when 10 healthy volunteers consumed 500 mg of
curcumin per day for 7 days, not only did their blood levels of oxidized
cholesterol drop by 33%, but their total cholesterol droped 11.63% , and their
HDL (good cholesterol) increased by 29%! (Soni KB, Kuttan R).
How Turmeric Lowers Cholesterol
Tumeric's cholesterol-lowering effects are the result of the curry spice's
active constituent, curcumin, which research reveals is a messaging molecule
that communicates with genes in liver cells, directing them to increase the
production of mRNA (messenger proteins) that direct the creation of receptors
for LDL (bad) cholesterol. With more LDL-receptors, liver cells are able to
clear more LDL-cholesterol from the body.
LDL-receptor mRNA increased sevenfold in liver cells treated with curcumin at
a concentration of 10 microM, compared to untreated cells. (Liver cells were
found to tolerate curcumin at levels of up to 12. microM for 24 hours). (Peschel
D, Koerting R, et al. J Nutr Biochem)
Protection against Alzheimer's Disease
Growing evidence suggests that turmeric may afford protection against
neurodegenerative diseases. Epidemiological studies show that in elderly Indian
populations, among whose diet turmeric is a common spice, levels of neurological
diseases such as Alzheimer's are very low. Concurrently, experimental research
conducted recently found that curcumin does appear to slow the progression of
Alzheimer's in mice. Preliminary studies in mice also suggest that curcumin may
block the progression of multiple sclerosis. While it is still unclear how it
may afford protection against this degenerative condition, one theory is that it
may interrupt the production of IL-2, a protein that can play a key role in the
destruction of myelin, the sheath that serves to protect most nerves in the
body.
A number of studies have suggested that curcumin, the biologically active
constituent in turmeric, protects against Alzheimer's disease by turning on a
gene that codes for the production of antioxidant proteins. A study published in
the Italian Journal of Biochemistry (December 2003) discussed curcumin's
role in the induction of the the heme oxygenase pathway, a protective system
that, when triggered in brain tissue, causes the production of the potent
antioxidant bilirubin, which protects the brain against oxidative (free radical)
injury. Such oxidation is thought to be a major factor in aging and to be
responsible for neurodegenerative disorders including dementias like Alzheimer's
disease. Another study conducted jointly by an Italian and U.S. team and
presented at the American Physiological Society's 2004 annual conference in
Washington, DC, confirmed that curcumin strongly induces expression of the gene,
called hemeoxygenase-1 (HO-1) in astrocytes from the hippocampal region of the
brain.
Curcumin Crosses Blood-Brain Barrier, May Help Prevent
Alzheimer's Disease
Research conducted at UCLA and published in the Journal of Biological
Chemistry (December 2004), which has been confirmed by further research
published in the Journal of Agricultural and Food Chemistry (April 2006),
provides insight into the mechanisms behind curcumin's protective effects
against Alzheimer's disease.
Alzheimer's disease results when a protein fragment called amyloid¦Â
accumulates in brain cells, producing oxidative stress and inflammation, and
forming plaques between nerve cells (neurons) in the brain that disrupt brain
function.
Amyloid is a general term for protein fragments that the body produces
normally. Amyloid¦Â is a protein fragment snipped from another protein called
amyloid precursor protein (APP). In a healthy brain, these protein fragments are
broken down and eliminated. In Alzheimer's disease, the fragments accumulate,
forming hard, insoluble plaques between brain cells.
The UCLA researchers first conducted test tube studies in which curcumin was
shown to inhibit amyloid¦Â aggregation and to dissolve amyloid fibrils more
effectively than the anti-inflammatory drugs ibuprofen and naproxen. Then, using
live mice, the researchers found that curcumin crosses the blood brain barrier
and binds to small amyloid-Â species. Once bound to curcumin, the amyloid-Â
protein fragments can no longer clump together to form plaques. Curcumin not
only binds to amyloid-Â, but also has anti-inflammatory and antioxidant
properties, supplying additional protection to brain cells.
Turmeric Boosts Amyloid Plaque Clearance in Human
Alzheimer's Patients
The most active ingredient in turmeric root, bisdemethoxycurcumin, boosts the
activity of the immune system in Alzheimer's patients, helping them to clear the
amyloid beta plaques characteristic of the disease.
In healthy patients, immune cells called macrophages, which engulf and
destroy abnormal cells and suspected pathogens, efficiently clear amyloid beta,
but macrophage activity is suppressed in Alzheimer's patients.
Using blood samples from Alzheimer's patients, Drs. Milan Fiala and John
Cashman have shown that bisdemethoxycurcumin boosts macrophage activity to
normal levels, helping to clear amyloid beta. Fiala and Cashman also observed
that bisdemethoxycurcumin was more effective in promoting the clearance of
amyloid beta in some patients' blood than others, hinting at a genetic element.
Further study revealed the genes involved are MGAT III and Toll-like receptors,
which are also responsible for a number of other key immune functions.
Bisdemethoxycurcumin enhances the transcription of these genes, correcting the
immune defects seen in Alzheimer's patients. Proc
Natl Acad Sci U S A. 2007 Jul 31;104(31):12849-54.