Turmeric, Blood Sugar and Diabetes
Diabetes is becoming an epidemic in the United States – the National Institute of Diabetes and Digestive and Kidney Diseases reports that 23.6 million American (nearly 8 percent of the population) had diabetes in 2007. Animal studies suggest that turmeric may be helpful for diabetes and related complications, although clinical studies have yet to confirm the findings.
The September 2008 issue of Molecular Nutrition & Food Research reported a study on the effects of curcumin on blood glucose and insulin in mice. Korean researchers fed diabetic and non-diabetic mice curcumin for six weeks (mice in the control group received no curcumin). Curcumin significantly lowered blood glucose levels in the diabetic mice, but not in the non-diabetic mice. These findings suggest that curcumin may play a role in glucose control for type 2 diabetes.
In 2007, researchers at Wayne State University in Michigan found that curcimin may help prevent diabetic retinopathy, a common complication in diabetics and a leading cause of blindness in the United States. In a placebo-controlled study, the researchers fed diabetic rats curcumin for six weeks and then examined the rat’s retinas for signs of inflammation and oxidative stress. They found that curcumin protected the rats’ eyes by preventing diabetes from reducing the antioxidant capacity of the retinas.
Curcumin may also protect against other complications associated with diabetes. In 1995, Indian researchers reported that curcumin improved metabolic health in diabetic rats. In 1998, the same researchers found that eight weeks of curcumin supplementation improved symptoms of diabetes-related kidney damage in rats.
Turmeric and Cardiovascular Health
In 1992, researchers at the Amala Cancer Research Center in India conducted a small clinical trial to evaluate the effects of curcumin on cholesterol levels and lipid peroxides (oxidized fatty acids). Ten volunteers received 500 milligrams of curcumin per day for seven days. At the end of the study, the volunteers showed decreased levels of lipid peroxides and cholesterol, and increased levels of HDL (“good”) cholesterol. Based on these findings, the researchers recommended further research on the potential use of curcumin to prevent arterial disease.
In 2005, Hossam Arafa, a researcher in Egypt, studied the effects of curcumin on blood lipid levels in rats. Arafa fed rats a high-cholesterol diet for seven days, raising their blood lipid and LDL (“bad”) cholesterol levels while lowering their HDL cholesterol levels. Arafa then introduced curcumin to the rats’ diets, which reversed many of the damaging effects of the high-cholesterol diet, lowering blood lipid and LDL levels while raising HDL levels. Arafa concluded that curcumin has obvious cholesterol lowering effects unrelated to its antioxidant activity.
Turmeric and the Mind
Alzheimer’s disease is a degenerative brain disease that affects memory and other cognitive functions. Though it is associated with age, Alzheimer’s disease is not a normal part of aging. Researchers have identified several risk factors for Alzheimer’s disease, including genetics, environmental toxins, oxidation and inflammation.
Because of its antioxidant and anti-inflammatory properties, some researchers hypothesize that turmeric may reduce the risk of Alzheimer’s disease. This hypothesis is supported by the low rates of Alzheimer’s disease in India, where turmeric is a common spice and Alzheimer’s disease affects as little as one percent of the elderly populations in some villages.
Research on animals explains how turmeric protects against Alzheimer’s disease. A team of researchers at the University of California, Los Angeles, conducted one such study in 2001, testing the effects of curcumin on inflammation, oxidation and plaque buildup in mice with symptoms of Alzheimer’s. Curcumin decreased all three, leading the researchers to conclude that curcumin shows promise as a preventive treatment for Alzheimer’s disease.