Experts Lack Proof On Health Benefits Of Herbal Fen-Phen
Losing pounds and keeping them off is difficult, though you wouldn’t know it from visiting most local health food and vitamin stores.
The diet aisles are crammed with products and promises, most notably herbal capsules marketed as replacements for “fen-phen” (fenfluramine-phentermine), the prescription drugs pulled off the market last September by the Food and Drug Administration because of such side effects as leaky coronary valves and weakened heart muscles.
Now herbal products are advertised as safe substitutes for the forbidden combination. They typically combine St. John’s wort, an herb highly regarded as a depression remedy, and ephedra, a natural stimulant.
Nutritionists aren’t convinced these herbal remedies are safe or effective as diet aids. They fret that Americans regard herbs as harmless, no matter what the dose. And relying on the FDA to weed out worthless or dangerous substances is shortsighted, especially with supplements, which avoid the review that drugs go through. The FDA tends to act only after problems become apparent.
“Ephedra is also known as ma huang,” said Janet Walberg Rankin, a professor in the department of human nutrition, foods and exercise at Virginia Tech University in Blacksburg. “It is a stimulant that can work to lessen appetite, but people have actually died from taking too much. The FDA is collecting data and it is expected to either ban ma huang or require a warning label.”
There are no significant studies to prove the success rate of herbal fen-phen products, Rankin said. She recommends asking for documentation from any company claiming scientific results.
“The FDA can’t keep up with dietary supplements,” she said. “Consumers are the guinea pigs in many cases, and the FDA has limited resources.”
Weight-conscious individuals are especially vulnerable to manufacturers’ come-ons. Herbal fen-phen is just one example.
Chromium supplements promise to “increase your metabolism so it works more efficiently.” (By biological standards, an efficient metabolism works more slowly and allows a person to survive on fewer calories, but that doesn’t bother advertising copywriters).
Rankin said chromium-based supplements are basically harmless to your health but “not your budget.”
A recent position paper about chromium from the American College of Sports Medicine criticized the scientific method behind some studies of weight-loss supplements. College researchers acknowledged that some studies show chromium users reported greater fat loss than control groups. But those experiments did not regulate how much exercise participants engaged in, a key variable; five chromium-eating distance runners are likely to burn more fat than five remote-clicking sedentary individuals who use the supplement.
Most manufacturers cover themselves. The fine print says that the supplements are formulated to work with proper diet and exercise.
The newest weight-loss supplements put amino acids in a bottle. These primary elements of protein, especially phenylalanine and L-carnitine, are touted as craving-busters (you are supposed to desire less sugar) and brain-balancers (said to regulate serotonin, a brain chemical linked to mood).
But evidence is thin. None of these weight-loss supplements has been thoroughly tested, said Wahida Karmally, director of nutrition at the Irving Center for Clinical Research at Columbia University in New York.
“There are certainly no long-term studies,” Karmally said. “We see people all the time who come here saying, ‘I spent lots of money on these supplements. They didn’t work. What can you do for me?”’ Karmally doesn’t blame the dieters, but her recommendations are simple and familiar: proper eating and exercise for people looking to shed a few extra pounds, and medical guidance for anyone with a more significant amount to lose.
“The ads are everywhere,” she said. “It is important to realize there are no shortcuts to losing weight and keeping it off, despite what you might hear from the advertising community or even friends. No one should be trying supplements without supervision.”