Soy lowers cardiovascular disease risk factors in diabetics with kidney disease

An article published online on January 9, 2008 in the journal Diabetes Care reported that long-term soy intake can reduce cardiovascular disease risk factors among diabetic patients with kidney disease (nephropathy). Injury to the kidney is a not uncommon complication of diabetes, necessitating the switch to a low protein diet consisting of 70 percent animal protein. However, this type of diet may have adverse effects on blood cholesterol, contributing to the development of atherosclerosis, which may already be a concern for diabetic patients.

Leila Azadbakht, PhD, of Isfahan University of Medical Sciences in Iran and her colleagues enrolled 18 men and 23 women with diabetic nephropathy in a four year trial which compared the effect of diets containing 35 percent soy protein in addition to 35 percent animal and 30 percent vegetable protein, with diets containing the standard 70 percent animal protein and 30 percent vegetable protein. Blood samples were analyzed for fasting plasma glucose, total cholesterol, low density lipoprotein (LDL) cholesterol, C-reactive protein, triglycerides, creatinine and urea nitrogen, and urine samples for creatinine and protein, at the beginning of the study and every six months for four years.

At the study's conclusion, the group that received soy protein had experienced a significant decline in plasma fasting glucose, cholesterol, LDL cholesterol, and triglycerides, as well as in proteinuria and urinary creatinine. Serum CRP levels were also significantly lower in the group that received soy compared with the control group, demonstrating a reduction in inflammation.

To the authors knowledge, this is the first long-term study to assess the effect of soy on kidney-related biomarkers and cardiovascular risk factors. The findings suggest that soy protein may be a beneficial substitute for some of the animal protein in the standard diet recommended to kidney disease patients.

—D Dye


February 01, 2008

Popular fruits may protect against neurodegeneration

An article published online on January 24, 2008 in the Journal of Food Science reported that the fruits most commonly consumed by Westerners and Asians, in addition to providing us with fiber, vitamins and minerals, may have a protective effect against the neurodegeneration that occurs in Alzheimer's disease.

Free radical formation induced by amyloid beta, a substance that forms in the brains of Alzheimer's patients, results in neurotoxicity that is believed to be responsible for the neuronal degeneration that takes place in the disease. Antioxidants from fruits and vegetables may help prevent some of this free radical activity, thereby helping to protect the brain.

C. Y. Lee of Cornell University and his Korean colleagues pretreated cultured neuron-like cells derived from rats with four concentrations of phenolics extracted from apples, bananas, and oranges. The cell cultures were then exposed to hydrogen peroxide, a well known inducer of oxidative stress.

Cell viability tests showed that all of the fruit extracts dose-dependently reduced neurotoxicity compared with cells that were treated with hydrogen peroxide alone. Apples showed the greatest benefits, with the highest concentration associated with the greatest increase in viability. Although the lowest concentration of banana showed less benefit than the lowest orange concentration, the highest concentration of banana demonstrated a greater effect than the highest concentration of orange.

"Our study demonstrated that antioxidants in the major fresh fruits consumed in the United States and Korea protected neuronal cells from oxidative stress," the authors conclude. "In addition, it has been reported that apple juice with antioxidative phytochemicals protected brain tissue against oxidative damage, and improved cognitive performance in genetically induced Alzheimer's disease mice. Therefore, additional consumption of fresh fruits such as apple, banana, and orange may be beneficial to improve effects in neurodegenerative diseases such as Alzheimer’s.”

—D Dye