Ephedra, what is this herb?
Franda Vaughan, Natures-Herbs dot Com
Weight loss aid
Ephedra preparations may be useful as a weight loss aid. Although ephedrine does suppress appetite, its main mechanism for promoting weight loss appears to be by increasing the metabolic rate of adipose tissue. Its weight reducing effects are greatest in those individuals with a low basal metabolic rate and/or decreased diet-induced thermogenesis.
Many people are predisposed to being overweight because their bodies lay down fat efficiently; other people go the other way--they burn fat efficiently. The reason for the difference has to do with how our bodies process the food we eat. A certain amount of the food we eat is converted immediately to heat. This effect is known as diet-induced thermogenesis (heat production). The degree of diet-induced thermogenesis is what determines whether an individual is likely to be obese. In lean individuals a meal may stimulate an up to 40 percent increase in heat production. In contrast, obese individuals often display only a 10 percent (or less) increase in heat production. In these people the food energy is stored instead of being converted to heat.
The degree of heat production--whether it be high or low--is determined by the sympathetic nervous system. This portion of the nervous system controls many body functions, including metabolism. In other words, the reason why many obese individuals have a "slow metabolism" is because of a lack of stimulation by the sympathetic nervous system. Ephedrine can activate the sympathetic nervous system, thereby increasing the metabolic rate and thermogenesis. This results in weight loss by addressing the underlying defect in metabolism.
The thermogenic effects of ephedrine can be enhanced by methylxanthines and salicylates. Herbs rich in these active ingredients can be used just like the isolated principles. Good methylxanthine sources include coffee (Coflea arabica), tea (Camellia sinensis), cola nut (Cola nitida), and guarana (Paullinea cupana). Natural salicylates can be found in members of the mint and oak families. The optimum dosage of the crude plant preparation or extract depends on the content of active ingredient. Standardized preparations may produce more dependable results.
In one animal study, ephedrine when used alone resulted in a loss of 14 percent in body weight and 42 percent in body fat; however, ephedrine used in combination with caffeine or theophylline resulted in a loss of 25 percent in body weight and 75 percent in body fat. TM In contrast, when either caffeine or theophylline was used alone there was no significant loss in body weight. The animals in this study lost weight owing to the increased metabolic rate and fat cell breakdown promoted by ephedrine and enhanced by caffeine and theophylline. Let's review some of the studies on ephedrine and weight loss.
Ephedrine as the sole weight loss agent has been the subject of several clinical studies. The results have been inconsistent. For example, in one study, overweight individuals were given, three times daily, either a placebo (group I), 25 milligrams of ephedrine (group II), or 150 milligrams of ephedrine (group III) for 3 months. Dietary treatment consisted of 1,000 calories per day for females and 1,200 calories per day for males. Weight loss was similar in all groups. Patients in group III (ephedrine, 150 milligrams per day) showed significantly more side effects than the placebo group.
In another study, ten obese women were treated with diet therapy (1,000-1,400 calories per day) and either ephedrine (50 milligrams three times per day) or placebo for 2 months and then crossed over. Weight loss was significantly greater during the ephedrine period (5.3 pounds) than during the placebo period (1.4 pounds). The reason for these differences appears to be that ephedrine is effective primarily in those people with defects in diet-induced thermogenesis, and is ineffective in those without this defect. Overall the results seem to indicate that ephedrine alone is not as effective in promoting weight loss compared to combination products, even when ephedrine is given at a high daily dosage (e.g., 150 milligrams per day).
Ephedrine with methylxanthines
As mentioned earlier, the effectiveness of ephedrine in weight loss is greatly enhanced when it is combined with caffeine and/or theophylline. Most of the recent studies have used a combination providing 20 milligrams of ephedrine and 200 milligrams of caffeine three times daily. Long-term studies have shown good safety and efficacy.
In one of the largest studies, 180 overweight patients were treated by diet and either an ephedrine-caffeine combination (20 milligrams/200 milligrams), ephedrine alone (20 milligrams), caffeine alone (200 milligrams) or placebo three times a day for 24 weeks. The mean weight loss was significantly greater in the group given the ephedrine-caffeine combination. Each member of the ephedrine-caffeine group lost, on average, 36 pounds in 24 weeks compared to 29 pounds for those in the placebo group. In the groups receiving ephedrine or caffeine ~ weight loss was similar to that of the placebo group. Side effects (tremor, insomnia, and dizziness) were transient, and after 8 weeks of treatment there was no difference in side effects between the group receiving the ephedrine-caffeine combination and the placebo group. Both systolic and diastolic blood pressure fell similarly in all four groups, indicating the weight loss promoted by ephedrine and caffeine counteracts any increase in blood pressure these substances may promote.
Although more recent studies have used a daily dose of 60 milligrams of ephedrine and 600 milligrams of caffeine, these high doses may not be necessary. In one study, a daily dose of 22 milligrams ephedrine, 30 milligrams caffeine, and 50 milligrams theophylline was shown to greatly increase the basal metabolic rate and diet-induced thermogenesis.
Ephedrine and aspirin
The thermogenic effects of ephedrine are further enhanced by aspirin. In one study, the effect of ephedrine (30 milligrams) and aspirin (300 milligrams) on the acute thermogenic response to a liquid meal (250 kilocalories) was investigated in lean and obese women. The resting metabolic rate was measured prior to each of the following treatments: meal only, meal plus ephedrine, or meal plus ephedrine and aspirin. Following the meal-only treatment, the mean increase in metabolic rate was 0.17 and 0.13 kilocalories per minute in the lean and obese groups, respectively. With the meal-plus-ephedrine treatment, the corresponding rises were 0.21 and 0.19 kilocalories per minute. And, following the meal plus ephedrine and aspirin the rise was 0.23 kilocalories per minute in both groups.
Another study looked at the safety and efficacy of a mixture of ephedrine (75-150 milligrams), caffeine (150 milligrams), and aspirin (330 milligrams), in divided premeal doses, compared to a placebo in twenty-four obese humans. Dietary intake was not restricted. Overall weight loss in 8 weeks was 4.84 pounds for the combination group versus 1.5 pounds for the placebo group. Eight of thirteen placebo subjects returned 5 months later and received the combination treatment. After 8 weeks, mean weight loss with the combination treatment was 7 pounds versus 2.86 pounds for the period of time when they were on the placebo. Six subjects continued on the formula for 7 to 26 months. After 5 months on ephedrine-caffeine-aspirin, average weight loss in five of these subjects was 11.44 pounds. The sixth subject lost 145 pounds in 13 months by self-imposed caloric restriction in combination with taking the ephedrine-caffeine-aspirin combination. In all studies, no significant changes in heart rate, blood pressure, blood glucose, insulin, and cholesterol levels, and no differences in the frequency of side effects, were found between groups.
The appropriate dose of ephedra depends on the alkaloid content. The average total alkaloid content of Ephedra sinica is 1 to 3 percent. For asthma and as a weight loss aid the dose of ephedra should contain an ephedrine content of 12.5-25.0 milligrams and be taken two to three times daily. For the crude herb this would require a dose of 500 to 1,000 milligrams three times per day. Standardized preparations are preferred as they are more dependable in terms of therapeutic activity. For example, Ephedra sinica extracts are available that have a standardized alkaloid content of 10 percent. The dosage of a 10 percent alkaloid content extract would be 125 to 250 milligrams three times daily.
ToxicityEphedra can produce the same side effects that ephedrine produces, that is, increased blood pressure, increased heart rate, insomnia, and anxiety. The Food and Drug Administration (FDA) advisory review panel on nonprescription drugs recommended that ephedrine not be taken by patients with heart disease, high blood pressure, thyroid disease, diabetes, or difficulty in urination due to enlargement of the prostate. In addition, ephedrine should not be used by patients taking antihypertensives or antidepressants.