WAYNE, N.J., Sep 08, 2005 (BUSINESS WIRE) -- Two recent scientific studies - conducted at McGill Nutrition and Food Science Centre and University of California, San Francisco (UCSF) - have shown Advantra Z(R), Nutratech's proprietary Citrus aurantium (bitter orange) extract for weight-loss and sports nutrition markets, increases resting metabolic rate and has no impact on blood pressure, respectively.
In "Synephrine Pharmacokinetics and Cardiovascular Changes after Ingestion of Citrus Aurantium Dietary Supplements," Christine Haller, M.D., a fellow in medical toxicology at UCSF, conducted a randomized, double-blind, placebo-controlled study utilizing Advantra Z as the synephrine source. Researchers noted that while they believe "ephedra-free weight loss dietary supplements have significant cardiovascular stimulant actions ... these pressor effects are not likely caused by Citrus aurantium." The study says even in eight-fold higher dosages, Advantra Z had no effect on blood pressure. Dr. Haller's study was presented at the annual meeting of International Journal of Clinical Pharmacology and Therapeutics and published in September's American Journal of Medicine.
Dr. Haller's findings echo results from independent laboratory Chromadex, which recently found Advantra Z contains the stable p-isomer of synephrine, not m-synephrine, which has the potential for raising blood pressure.
"Some weight-loss and sports nutrition supplements have been associated with adverse cardiovascular effects, but the popular bitter orange ingredient Advantra Z tested in the Haller study used dosages that were equivalent to those found in supplements sold on the market and did not have any adverse effect on blood pressure," said Mark Blumenthal, founder and executive director of the American Botanical Council.
Bob Green, president of Nutratech, noted the study also confirms that Advantra Z produces only a negligible increase in heart rate: 11 beats per minute. Using calculations from the National Center for Chronic Disease Prevention and Health Promotion, for most people this is less than heart-rate increases generated by light-intensity exercise, like walking or gardening.
"We also wholeheartedly concur with Dr. Haller's recommendation that consumers - particularly those with hypertension, heart disease or other pre-existing conditions - consult with their health care providers before embarking on a dietary supplement regimen," said Green.
Another report, "Increase in the Thermic Effect of Food in Women by Adrenergic Amines Extracted from Citrus Aurantium," looked at the efficacy of Citrus aurantium with Advantra Z as the source. Results of the study, conducted by Rejeanne Gougeon at McGill Nutrition and Food Science Centre were published in the July issue of Obesity Research.
The study determined that thermic response to Citrus aurantium was higher in men when taken alone and more efficacious for women when added to a meal. The report notes, "Citrus aurantium had no effect on blood pressure and pulse rate...."
Based in Wayne, N.J., Nutratech, Inc., provides innovative, proprietary and patented nutraceutical ingredients to the dietary supplement, weight management, sports nutrition, beverage and food industries.