Equating bitter orange extract with ephedra just 'an old wives tale,' researcher says

19-Jun-2018 - Last updated on 19-Jun-2018 at 16:22 GMT

A researcher with long experience in p-synephrine, the active ingredient in bitter orange extract, says he’s frustrated with the intransigence of certain authorities who deem the ingredient unsafe because of a superficial chemical resemblance to the banned substance ephedra.

Sidney Stohs, PhD, has had a long career at Creighton University followed by a decade or so as an industry consultant. In recent years he has worked with Novel Ingredients (now part of Innophos), manufacturers of the bitter orange extract branded as AdvantraZ (the company markets a similar product under the brand name Kinetiq). The ingredient has long been marketed for its thermogenic properties as a weight loss ingredient.

Ephedra was marketed as a weight loss thermogenic, too. But as far as Stohs is concerned that, and the idea that both ingredients can be extracted from botanicals, is where the similarities end.

Ephedra shadow

“What is really bothersome to me is the fact that we see well known websites, including governmental sources, that make this extrapolation to ephedrine when in fact there have been more than 30 scientific papers that lay out the structural differences between these two that impact both the bioavailability as well as their receptor binding properties,” Stohs told NutraIngredients-USA.

While both ingredients boost the metabolism, they work on very different principles, Stohs said. Ephedra boosted heart rate and blood pressure and was implicated in several high profile deaths, including that of Minnesota Vikings football player Corey Stringer, who collapsed after a training session during a time when he was using an ephedra product in an effort to quickly get down to playing weight.

Thermogenesis without stimulation

“What the studies show is that synephrine is a very poor binder to these receptors that boost heart rate and blood pressure,” Stohs said. “It enhances lipid mobilization and the use of fats for energy. And it enhances the uptake of glucose into the liver and ultimately into the mitochondria in the cells.”

Stohs recently released a summary paper on p-synephrine research. One randomized, double-blinded study, funded by Novel Ingredients, gave 98 mg of AdvantraZ in two daily doses to subjects over a 60 day period. Stohs said no adverse effects were observed with respect to heart rate, blood pressures, blood chemistries, or blood cell counts with differentials.

No additive effect with caffeine

The paper also laid out subsequent research that paired p-synephrine with caffeine, another popular ingredient in weight loss formulations. No adverse effects were observed, and the changes in heart rate, etc., were what would be expected with the caffeine alone, and those effects were only observed when the caffeine dose in the combination study material was boosted above 300 mg.

Stohs said much of this information was combined into a dossier that Novel Ingredients used to self affirm AdvantraZ as GRAS. In his view, the issue ought to be put to rest.

“The key point is that it is a thermogenic and not a stimulant. My biggest concern is that these authorities just ignore the science. I wish they would stop spreading what in effect are old wives tales,” he said.