Patients searching for options
“It’s important to understand that the desire to seek out alternatives for feeling better is initiated from the patient side,” affirms Cathy M. Goeddeke-Merickel, MS, RD, LD, managing editor of the Renal Nutrition Forum of the Renal Dietitians Dietetic Practice Group. “The chronically ill population is looking for options to feel better or lessen the side effects of the long list of prescribed medications.”
By Goeddeke-Merickel’s estimates, awareness and acknowledgment of nutraceutical and botanical use has soared over the years, especially in the past five years, a trend that has been addressed by the National Kidney Foundation (NKF) and the American Dietetic Association (ADA).
For example, “the NKF has recognized the increased utilization of these products in its patient population and is providing more patient-education materials. This area is a significant topic of interest at the national NKF meetings.”
Meanwhile, nutraceuticals meet with widespread skepticism among physicians, who believe, perhaps, that the use of nutrient-based supplements is not supported by strong evidence. This skepticism is not new. Consider this comment on medicinal foods that appeared in The Journal of the American Medical Association 101 years ago:
The facts in regard to so-called medicinal foods—their failure to measure up fully to what has been and is claimed for them, their great relative cost, their dangerous alcohol content, and the likelihood that some physician following blindly the optimistic suggestions of those commercially interested will do his patients harm—these facts are now public, and every intelligent physician who becomes familiar with these facts may be counted on to take the necessary steps to guard himself and his patients against placing more confidence in these articles than they deserve (JAMA. 1907;48:1681).
The seeds of doubt may be planted as early as medical school, where the topic of nutraceuticals rarely is on the curriculum. Some practitioners are put off simply by the unfamiliar term, which was coined in 1989 by Stephen L. DeFelice, MD, founder of the nonprofit Foundation for Innovation in Medicine (www.fimdefelice.org) in Cranford, N.J.
He shared his definition with Renal & Urology News: “A nutraceutical is a food or part of a food that has a medical or health benefit, including the prevention and treatment of disease. It can be a whole natural food, a processed food, a pill, or a liquid.”
Other experts and organizations have put their own spin on what the field of nutraceuticals encompasses, but generally speaking, a nutraceutical is a bioactive chemical or compound with medicinal or health benefits that is isolated from a food source and concentrated in a supplement form, to be used at higher concentrations than could be obtained solely from dietary sources.
Do they work?
For many clinicians, the biggest problem lies in whether the scientific evidence supports the use of these compounds in CKD. “The question of when nutrients or even drugs are beneficial is very difficult to answer,” notes Joel Kopple, MD, professor of medicine and public health at the David Geffen School of Medicine at the University of California in Los Angeles.
As a nephrologist with a long-standing interest in nutrition, Dr. Kopple has published hundreds of papers addressing nutrition in renal disease and has served as president of the American Society for Parenteral and Enteral Nutrition and Metabolism as well as the International Society for Renal Nutrition.
“Nephrologists as a group tend to be rather skeptical of therapeutic nutritional management,” he said, “but since the 1990s it has become very apparent that protein-wasting malnutrition is associated with very poor outcomes, increased morbidity, increased mortality, and decreased quality of life.”
One obstacle to nutraceutical acceptance is the gray area between a nutrient and a real drug, but some nutraceuticals are available only by prescription. Coenzyme Q10, which can be deficient in people with diabetes, is a registered pharmaceutical in some countries outside the United States.
Another ingredient straddling the nutrient/pharmaceutical line is calcitriol, which is commonly prescribed to prevent or treat low calcium levels, hyperparathyroidism, and bone disease in people with impaired kidney function. Calcitriol is the most active naturally occurring form of vitamin D, but the FDA defines it as a drug.
Dr. Kopple agrees with imposing careful regulation on a substance that can so easily be ingested at toxic levels. In fact, he would not classify calcitriol as a nutraceutical because it has been chemically modified, but he points out that calcitriol “is simply a compound that has been only slightly modified from what you eat in food. The difference between 1,25-dihydroxycholecalciferol (calcitriol) and the vitamin D you’ll eat or make from sunlight is just two hydroxyl groups added at different parts of the compound.
“When it comes to compounds like vitamin D or some of the newer modifications that I use in kidney disease,” he adds, “I don’t think there’s a nephrologist alive who wouldn’t agree that these can be very, very valuable agents for people to take.”