Thus, we were also asked to review the evidence for the effectiveness and safety of supplements that combine ephedra and caffeine as well as ephedrine and caffeine-containing products. To assess the evidence for the effectiveness of ephedra and ephedrine in weight loss and athletic performance, we performed an exhaustive search and review of the medical research "literature" using the well-accepted procedures of evidence-based medicine.
The literature review was conducted by our staff with the assistance of several clinical experts. Only controlled clinical trials and randomized controlled trials of effectiveness—that is, studies that satisfied a strict set of quality criteria—were included in our analysis. Randomized controlled trials RCT are clinical trials in which participants are assigned randomly to one of two or more treatment groups.
Controlled clinical trials are those in which participants are assigned to a treatment group using a semi-random procedure such as a participant's date of birth, a patient identification number, or the order of enrollment.
In all, we reviewed the results of 52 clinical trials that measured the effects of ephedra or ephedrine on weight loss and athletic performance.
Most of these studies included one group of participants who were randomly chosen to receive only a placebo an inactive dummy pill. This type of study maximizes the likelihood that any differences found between the groups taking the test supplement and those taking the placebo are real, not due to chance or bias. Studies of weight loss usually measure the weight lost over the course of the study, the weight lost per month, or the proportion of an individual's original weight that was lost.
For each group of studies that made the same comparisons for example, all studies that compared the effects of ephedra and herbal caffeine on weight loss with the effects of a placebo , we combined the results of all studies in that group, using a statistical technique called meta-analysis, and calculated the average total weight lost as well as the average lost per month. Over the short term four to six months , ephedrine, ephedrine plus caffeine, and supplements containing ephedra or ephedra plus caffeine promoted modest increases in weight loss, about two pounds per month more than the weight loss of persons taking the placebo.
Products containing caffeine seemed to promote slightly more weight loss than those containing only ephedrine. However, none of the studies lasted longer than six months, far less than the twelve months researchers consider the minimum necessary to establish the value of a weight loss product studies that lasted less than two months were excluded from our analysis because two months is simply too short a time to assess a meaningful change in weight.
We found no studies that assessed the effects of ephedra-containing dietary supplements on athletic performance. Thus we analyzed only studies of products containing ephedrine or ephedrine plus caffeine, seven studies in all. No two studies were judged similar enough in design to combine their results: Measures of athletic performance varied widely from one study to another.
As a result, our conclusions regarding the effects of ephedrine on athletic performance are based on a nonquantitative synthesis of the research rather than on meta-analysis. In addition, no study looked at long-term changes in performance. Our analysis found that one-time use of ephedrinecontaining products seems to enhance immediate physical performance, but only when taken in combination with caffeine.
These results, too, must be interpreted with caution. The studies assessed performance immediately after a single dose; none of the studies examined the type of chronic, long-term use typical of consumers of these products. What's more, the study participants,all young, fit males,may not be typical of the average consumer.
To assess the safety of ephedra- and ephedrine-containing products, we reviewed four sources for reports of adverse events. After the ban, there was one death in and There were none in and in the years after Leikin said.
He speculated that the initial declines seen just before the ban went into effect could have been the result of natural fluctuations in the number of poisonings and major effects. Unfortunately, said Dr. Barrett, who operates the Quackwatch. Over 12 weeks, ingesting a combination of ephedra and caffeine 3 times per day led to a reduction of 7. Another 6-month study in overweight and obese people compared a supplement containing ephedrine and caffeine to a placebo during a weight loss program The group taking ephedrine lost 9.
The ephedrine group also decreased body weight and LDL bad cholesterol more than the placebo group. Overall, the available evidence indicates that ephedrine-containing products — particularly when paired with caffeine — may increase weight and fat loss.
Ephedrine plus caffeine may increase metabolic rate and fat loss more than either ingredient alone. Studies show the combination of ephedrine and caffeine produces greater weight and fat loss than a placebo. Doses of ephedrine used in research vary, with intakes of less than 20 mg per day considered low, 40—90 mg daily considered moderate, and doses of — mg per day considered high.
Although some positive effects on metabolism and body weight have been seen across a variety of doses, many have questioned the safety of ephedrine.
Individual studies have shown mixed results regarding the safety and side effects of this substance across a variety of doses. Some have reported no significant side effects, while others indicate a variety of side effects that even caused participants to withdraw from the studies 10 , 17 , In-depth reports have combined the results of multiple studies to better understand concerns associated with ephedrine consumption.
One analysis of 52 different clinical trials found no serious adverse events such as death or heart attack in studies on ephedrine — with or without caffeine Yet, the same analysis found these products were associated with a two- to threefold increased risk of nausea , vomiting, heart palpitations, and psychiatric problems.
Additionally, when individual cases were examined, several deaths, heart attacks, and psychiatric episodes were potentially linked to ephedra Based on the evidence, potential safety concerns were significant enough to prompt legal action in the United States and elsewhere 1.
While some individual studies did not demonstrate serious side effects of ephedra or ephedrine consumption, mild to highly concerning side effects became apparent upon examination of all available research. While the ephedra herb and products like ma huang tea are available for purchase, dietary supplements containing ephedrine alkaloids are not.
Some ephedrine-containing medications are still available over the counter, though regulations on the purchase of these products can vary by state. For this reason, some dietary supplement manufacturers will market weight loss products that contain other compounds found in ephedra, but not ephedrine alkaloids. Other alternative weight loss supplements include green tea extract EGCG and glucomannan.
These supplements typically carry more mild side effects, such as bloating or diarrhea. Although ECA stacks may be a quick way to drop a few pounds or feel alert, they can wreak havoc on your overall health. ECA stacks provide stimulation, or fake energy. They can mask the real underlying reasons for low energy. Healthy eating and regular exercise remain the safest way to successfully lose weight and keep it off.
Ephedra gained popularity as a weight loss supplement in the s, but safety concerns arose. A novel interface could help our brains communicate using radio waves. Tea contains several stimulant substances, including caffeine, theobromine, theophylline and L-theanine.
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