Healthy kidney function is essential for normal blood pressure and water balance. The kidneys produce hormones to regulate constriction of arteries so they get enough blood supply to perform their filtering function. The volume of blood and tissue fluid is kept in range by excretion of water and salts.
Excess water weight was traditionally called “dropsy”, a condition of fluid retention which can be caused by either kidney failure or congestive heart failure.
Antioxidants are vital for many aspects of our health. To choose the top ten for kidney health, I first checked the web site for Vitamin Research Products, a leading dietary supplement company. I then searched the medical literature to see which antioxidants have been tested for kidney support. Here are the results:
Resveratrol. Found in grapes and red wine, this supplement is popular for heart health. It has also been found to protect kidneys against ischemia/reperfusion damage.
Bilberry. The fruit extract is known for its support of eye health. In animal experiments, it protected kidneys against damage by the oxidative food additive KBrO3.
Green tea. Both the tea and its extracts are popular for antioxidant benefits throughout the body. Diabetic mice demonstrated better kidney function and reduced blood glucose with green tea dietary supplements.
Grape seed. Similar to resveratrol, the proanthocyanidins in grape seeds have been found to protect the body from a variety of oxidative stresses.
N-acetyl cysteine. This has been used for protection from the toxic effects of smoking. It was also found to protect the kidneys from diabetic damage in animal experiments.
L-carnosine. This naturally occurring dipeptide was found to protect kidneys against ischemia/reperfusion damage in animals.
Silymarin. This herb is known primarily for its role in liver health. It was also found to protect the kidneys against ischemic damage in animals.
Vitamins A, C, and E. The “ACE” vitamins all improved kidney function in an animal model of renal artery stenosis, which is a narrowing of the artery to the kidney caused by atherosclerosis.
A few other antioxidants deserve mention. A research team at Georgetown University found that alpha-lipoic acid improves kidney function in diabetes, but produced the opposite result in nondiabetic kidneys. Other popular antioxidant dietary supplements include coenzyme Q10, rosemary, and turmeric. For these, I found no references showing specific benefits for the kidneys, but the medical literature has numerous reports of other healthy antioxidant effects.
by Linda Fugate, Ph.D.
For a complete list of medical journal references, see http://siderealobserver.wordpress.com/2009/10/02/antioxidants/
For consumer information on antioxidants, see the Vitamin Research Products library at http://vrp.com/