Turmeric: Spicy route to weight loss
IT is a local spice commonly used for culinary. It resembles ginger with its near-yellow colour. It has been effectively used in pain, wounds, diabetes and heart disease. But recent United States study found that eating turmeric flavoured meals could be the best way to shedding excess kilos. CHUKWUMA MUANYA reports.
TURMERIC, an Asian spice cultivated in Nigeria and found in many curries, has a long history of use in reducing inflammation, healing wounds and relieving pain, preventing diabetes and heart failure, but can it induce weight loss?
The local spice, turmeric, has entered into herbal regimen for weight loss programme. A recent United States (U.S.) study suggests that turmeric may be a new way to spice up weight loss routine.
According to results from a new animal model study by U.S. Agricultural Research Service (ARS)-funded scientists and colleagues, a compound in turmeric stopped the spread of fat tissues in animal model.
The study was published in the May 2009 issue of the Journal of Nutrition. The researchers theorised that dietary curcumin could stall the spread of fat-tissue by inhibiting new blood vessel growth, called angiogenesis, which is necessary to build fat tissue.
Curcumin is a bioactive component in curry and turmeric that has been consumed daily in Asian countries for centuries without reported toxic effects.
In Nigeria, the craze is getting to feverish pitch. Many companies are now investing in growing and marketing turmeric in the country. Turmeric is now a common article of trade in most Nigeria market.
Eurobridge Industries Limited has one of the largest plantations in West Africa for turmeric. Their farm at Odogbulu in Ogun State is the only certified organic farm in Nigeria. Organic farm means no pesticides, no artificial fertilizers, no genetic modification, eco-friendly.
Turmeric is a spice that comes from the root of Curcuma longa, a member of the ginger family, Zingaberaceae. In traditional medicine, turmeric has been used for its medicinal properties for various indications and through different routes of administration, including topically, orally, and by inhalation.
In Nigeria, it is called atale pupa in Yoruba; gangamau in Hausa; nwandumo in Ebonyi; ohu boboch in Enugu (Nkanu East); gigir in Tiv; magina in Kaduna; turi in Niger State; onjonigho in Cross River (Meo tribe).
Turmeric, also known as curcuma, produces a root that is used to produce the vibrant yellow spice used as a culinary spice so often used in curry dishes.
Though native to India and parts of Asia, and is a relative of cardamom and ginger, turmeric has been domesticated in Nigeria.
The U.S. study was led by nutritionist Mohsen Meydani at the Jean Mayer United States Department of Agriculture (USDA) Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Massachusetts. Meydani is director of the HNRCA's Vascular Biology Laboratory.
Eighteen mice were assigned to three groups of six mice each. For 12 weeks, the mice were fed special diets. A "control" group's mix contained four percent fat, a "high fat" group's mix contained 22 per cent fat, and another group was fed the same "high fat" diet supplemented with curcumin. A mouse typically eats about 3,000 to 3,500 milligrams (the weight of about six or seven paper clips) daily, so the curcumin-supplemented mice would have consumed about 1.5 to 1.75 milligrams of curcumin daily - a relatively small amount.
The researchers recorded the body weight and food consumption of the mice twice each week. At the end of the 12-week period, their total body weight and fat distribution were measured.
The study found that supplementing the animals' high-fat diet with curcumin reduced body-weight gain and total body fat, even though food-intake was not affected, when compared to the non-supplemented high-fat-diet group.
The curcumin-treated group also had less blood vessel growth in fat tissue. Blood glucose, triglyceride, fatty acid, cholesterol and liver fat levels also were lower.
At this time, it is not known whether the amount of curcumin normally present in food dishes prepared with turmeric is sufficient to inhibit complex fat-tissue secretions that are involved in recruiting new blood vessel growth. The researchers' next step is to determine the effectiveness of dietary intake of curcumin in reducing weight in humans.
Today's herbalists and naturopaths consider turmeric to be one of nature's most potent anti-inflammatories and antioxidants. They say turmeric may help treat a variety of conditions related to inflammation and antioxidant damage, including cataracts, arthritis, cancer, and heart disease. It is also used to treatment of scabies and digestive disorders, promote wound healing, and strengthen the immune system.
Western medicine only recently began to study turmeric. However, this spice has long been used in Indian ayurvedic and traditional Chinese medicine to treat infection, gallbladder problems, dysentery, arthritis, and liver disorders.
Several studies performed by Nigerian scientists have supported many of turmeric's traditional use to fight inflammation, indigestion, and liver and heart disease.
According to a pharmacognocist at the College of Medicine University of Lagos (CMUL), Idi-Araba, dr. Olukemi A. Odukoya, "Turmeric helps detoxify the body, and protects the liver from the damaging effects of alcohol, toxic chemicals, and even some pharmaceutical drugs. Turmeric stimulates the production of bile, which is needed to digest fat. Turmeric also guards the stomach by killing salmonella bacteria and protozoa that can cause diarrhoea."
Chief Executive of Eurobridge Industries, Richard Farrant, said: "Nature has blessed them with a very high curcumin content turmeric which shows in the rich golden style of their turmeric powder. The convenient packaging in 100gm sealed bags is available at N0 3, Balogun Street, Oregun industrial Estate, Ikeja. It makes it useful as a seasoning, as a spice, as a colourant and as a herbal supplement for health and healing. Their hygienic processing and packaging make them live up to their motto 'Quality is our strength'."
Earlier study found curcumin, the major polyphenol found in turmeric, appears to reduce weight gain in mice and suppress the growth of fat tissue in mice and cell models.
The researchers led by Meydani studied mice fed high fat diets supplemented with curcumin and cell cultures incubated with curcumin.
"Weight gain is the result of the growth and expansion of fat tissue, which cannot happen unless new blood vessels form, a process known as angiogenesis." said Meydani.
"Based on our data, curcumin appears to suppress angiogenic activity in the fat tissue of mice fed high fat diets."
Meydani continued, "It is important to note, we don't know whether these results can be replicated in humans because, to our knowledge, no studies have been done."
Turmeric is known for providing flavor to curry. One of its components is curcumin, a type of phytochemical known as a polyphenol. Research findings suggest that phytochemicals, which are the chemicals found in plants, appear to help prevent disease. As the bioactive component of turmeric, curcumin is readily absorbed for use by the body.
Meydani and colleagues studied mice fed high fat diets for 12 weeks. The high fat diet of one group was supplemented with 500 mg of curcumin/ kg diet; the other group consumed no curcumin. Both groups ate the same amount of food, indicating curcumin did not affect appetite, but mice fed the curcumin supplemented diet did not gain as much weight as mice that were not fed curcumin.
"Curcumin appeared to be responsible for total lower body fat in the group that received supplementation," said Meydani, who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts. "In those mice, we observed a suppression of microvessel density in fat tissue, a sign of less blood vessel growth and thus less expansion of fat. We also found lower blood cholesterol levels and fat in the liver of those mice. In general, angiogenesis and an accumulation of lipids in fat cells contribute to fat tissue growth."
Writing in the May 2009 issue of the Journal of Nutrition, the authors note similar results in cell cultures. Additionally, curcumin appeared to interfere with expression of two genes, which contributed to angiogenesis progression in both cell and rodent models.
"Again, based on this data, we have no way of telling whether curcumin could prevent fat tissue growth in humans." Meydani said. "The mechanism or mechanisms by which curcumin appears to affect fat tissue must be investigated in a randomized, clinical trial involving humans."
This study was funded by a grant from the United States Department of Agriculture. Asma Ejaz, a graduate student who worked on this project received a scholarship grant from the Higher Education Commission of Pakistan.
Since inflammation plays a big role in many diseases and is believed to be involved in onset of both obesity and Type 2 diabetes, Dr. Drew Tortoriello, an endocrinologist and research scientist at the Naomi Berrie Diabetes Center at Columbia University Medical Centre U.S., and his colleagues were curious what effect the herb might have on diabetic mice.
Tortoriello, working with pediatric resident Dr. Stuart Weisberg and Dr. Rudolph Leibel, fellow endocrinologist and the co-director of the Naomi Berrie Diabetes Centre, discovered that turmeric-treated mice were less susceptible to developing Type 2 diabetes, based on their blood glucose levels, and glucose and insulin tolerance tests.
They also discovered that turmeric-fed obese mice showed significantly reduced inflammation in fat tissue and liver compared to controls. They speculate that curcumin, the anti-inflammatory, anti-oxidant ingredient in turmeric, lessens insulin resistance and prevents Type 2 diabetes in these mouse models by dampening the inflammatory response provoked by obesity.
Their findings were published in Endocrinology and were presented at ENDO 2008, the Endocrine Society's annual meeting in San Francisco, United States.
Turmeric (Curcuma longa) has no known dose-limiting toxicities in doses of up to at least 12 grams daily in humans. The researchers tested high-doses of a dietary curcumin in two distinct mouse models of obesity and Type 2 diabetes: high-fat-diet-fed male mice and leptin-deficient obese female mice, with lean wild-type mice that were fed low-fat diets used as controls.
The inflammation associated with obesity was shown several years ago by researchers in the Naomi Berrie Diabetes Centre to be due in part to the presence of immune cells called macrophages in fat tissues throughout the body. These cells produce "cytokine" molecules that can cause inflammation in organs such as the heart, and islets of the pancreas, while also increasing insulin resistance in muscle and liver. Researchers hypothesized that by suppressing the number and activity of these cells, with turmeric or a drug with similar actions, it may be possible to reduce some of the adverse consequences of obesity.
Curcumin administration was also associated with a small but significant decline in body weight and fat content, despite level or higher calorie consumption, suggesting that curcumin beneficially influences body composition.
"It's too early to tell whether increasing dietary curcumin (through turmeric) intake in obese people with diabetes will show a similar benefit," Tortoriello said. "Although the daily intake of curcumin one might have to consume as a primary diabetes treatment is likely impractical, it is entirely possible that lower dosages of curcumin could nicely complement our traditional therapies as a natural and safe treatment."
For now, the conclusion that Tortoriello and his colleagues have reached is that turmeric - and its active anti-oxidant ingredient, curcumin - reverses many of the inflammatory and metabolic problems associated with obesity and improves blood-sugar control in mouse models of Type 2 diabetes.
In addition to exploring novel methods of curcumin administration to increase its absorption, they are also interested in identifying novel anti-inflammatory processes invoked by curcumin and in adapting those processes in the development of more potent curcumin analogues.
Also, researchers at the Peter Munk Cardiac Centre of the Toronto General Hospital, Canada have discovered that eating curcumin, a natural ingredient in the spice turmeric, may dramatically reduce the chance of developing heart failure.
In a study entitled, "Curcumin prevents and reverses murine cardiac hypertrophy," published in the February edition of the Journal of Clinical Investigation, researchers found when the herb is given orally to a variety of mouse models with enlarged hearts (hypertrophy), it can prevent and reverse hypertrophy, restore heart function and reduce scar formation.
The healing properties of turmeric have been well known in eastern cultures for some time. The herb has been used in traditional Indian and Chinese medicine to reduce scar formation. For example, when there is a cut or a bruise, the home remedy is to reach for turmeric powder because it can help to heal without leaving a bad scar.
Unlike most natural compounds whose effects are minimal, curcumin works directly in the cell nucleus by preventing abnormal unraveling of the chromosome under stress, and preventing excessive abnormal protein production.
"Curcumin's ability to shut off one of the major switches right at the chromosome source where the enlargement and scarring genes are being turned on is impressive," says Dr. Peter Liu, cardiologist in the Peter Munk Cardiac Centre and Scientific Director at the Canadian Institutes of Health Research - Institute of Circulatory and Respiratory Health. However Dr. Liu cautions that moderation is important, "the beneficial effects of curcumin are not strengthened by eating more of it."
Liu, who holds the Heart and Stroke Foundation's Polo Chair Professor in Medicine and Physiology at the University of Toronto, says that since curcumin is a naturally occurring compound that is readily available at a low cost, it might be a safe and effective means of preventing heart failure in the future.
"Whether you are young or old; male or female; the larger your heart is, the higher your risk is for developing heart attacks or heart failure in the future. However, until clinical trials are done, we don't recommend patients to take curcumin routinely. You are better off to take action today by lowering blood pressure, reducing cholesterol, exercising and healthy eating," says Liu.
If clinical trials of curcumin support initial findings of heart enlargement prevention, it may offer hope for millions of patients with heart enlargement in a relatively safe and inexpensive manner. Curcumin-based treatments are currently in clinical trials for pancreatic and colorectal cancer patients with promising results.
Also, scientists in Michigan are reporting discovery of the secret behind the fabled healing power of the main ingredient in turmeric - a spice revered in India as "holy powder."
In the study, Ayyalusamy Ramamoorthy and colleagues point out that turmeric has been used for centuries in folk medicine to treat wounds, infections, and other health problems. Although modern scientific research on the spice has burgeoned in recent years, scientists until now did not know exactly how curcumin works inside the body.
Using a high-tech instrument termed solid-state NMR spectroscopy, the scientists discovered that molecules of curcumin act like a biochemical disciplinarian. They insert themselves into cell membranes and make the membranes more stable and orderly in a way that increases cells' resistance to infection by disease-causing microbes.
