National Institutes of Health • National Center for Complementary and Alternative Medicine
Weight Loss and Complementary Health Practices:
What the Science Says
Scientific evidence has demonstrated that there is no magic pill for weight-loss. When you talk to your patients about weight loss, be sure to explain that most dietary supplements marketed for weight loss haven’t been proven effective and some have been proven to be dangerous.
Acai berry products have become popular in the United States, where they have been marketed as folk or traditional remedies for weight-loss and anti-aging purposes, but there is no definitive scientific evidence to support these claims.
Strength of Evidence
- No independent studies have been published in peer-reviewed journals that substantiate claims that acai supplements alone promote rapid weight loss.
- There is no definitive scientific evidence based on studies in humans to support the use of acai berry for any health-related purpose.
- Researchers who investigated the safety profile of an acai-fortified juice in animals observed that there were no body weight changes in rats given the juice compared with controls.
- There is little reliable information about the safety of acai as a supplement. It is widely consumed as an edible fruit or as a juice.
- People who are allergic to acai or to plants in the Arecaceae (palm) family should not consume acai.
Bitter orange has been used in traditional Chinese medicine and by indigenous people of the Amazon rainforest for nausea, indigestion, and constipation. Current folk or traditional uses of bitter orange are for heartburn, loss of appetite, nasal congestion, and weight loss. It is also applied to the skin for fungal infections such as ringworm and athlete's foot.
Strength of Evidence
- Overall, only a few small studies of bitter orange have been published. The evidence is insufficient to support the use of bitter orange for any health purpose.
- Many herbal weight-loss products now use concentrated extracts of bitter orange peel in place of ephedra. However, bitter orange contains the chemical synephrine, which is similar to the main chemical in ephedra. The U.S. Food and Drug Administration banned ephedra because it raises blood pressure and is linked to heart attacks and strokes; it is unclear whether bitter orange has similar effects. There is currently little evidence that bitter orange is safer to use than ephedra.
- Because bitter orange contains chemicals that may speed up the heart rate and raise blood pressure, it may not be safe to use as a dietary supplement. There have been reports of fainting, heart attack, and stroke in healthy people after taking bitter orange supplements alone or combined with caffeine. People should avoid taking bitter orange supplements if they have a heart condition or high blood pressure, or if they are taking medications (such as MAO inhibitors), caffeine, or other herbs/supplements that speed up the heart rate.
- Due to lack of safety evidence, pregnant women or nursing mothers should avoid products that contain bitter orange.
- Bitter orange oil used on the skin may increase the risk of sunburn, particularly in light-skinned people.
Ephedra’s principal active ingredient, ephedrine, is a compound that can powerfully stimulate the nervous system and heart. Ephedra has been used for more than 5,000 years in China and India to treat conditions such as colds, fever, flu, headaches, asthma, wheezing, and nasal congestion. More recently, ephedra was used as an ingredient in dietary supplements for weight loss, increased energy, and enhanced athletic performance.
Strength of Evidence
- Much research has been conducted on the safety and efficacy of ephedra.
- According to the U.S. Food and Drug Administration (FDA), there is little evidence of ephedra’s effectiveness, except for short-term weight loss. However, the increased risk of heart problems and stroke far outweighs any benefits.
- An NCCAM-funded study that analyzed phone calls to poison control centers found a higher rate of side effects from ephedra, compared with other herbal products.
- Other studies and systematic reviews have found an increased risk of heart, psychiatric, and gastrointestinal problems, as well as high blood pressure and stroke, with ephedra use.
- In 2004, the FDA banned the U.S. sale of dietary supplements containing ephedra. The FDA found that these supplements had an unreasonable risk of injury or illness—particularly cardiovascular complications—and a risk of death. The ban does not apply to traditional Chinese herbal remedies or to products like herbal teas regulated as conventional foods.1
- Between 1995 and 1997, the FDA received more than 900 reports of possible ephedra toxicity. Serious adverse events such as stroke, heart attack, and sudden death were reported in 37 cases.
- Using ephedra may worsen many health conditions such as cardiovascular disease, kidney disease, and diabetes.
- Ephedra may cause seizures in otherwise healthy people as well as in people with seizure disorders.
- Taking ephedra can also result in anxiety, difficulty urinating, dry mouth, headache, heart damage, high blood pressure, irregular heart rhythms, irritation of the stomach, kidney stones, nausea, psychosis, restlessness, sleep problems, and tremors.
- Women who are pregnant or breastfeeding and children should avoid taking ephedra.
- Ephedra use may lead to serious health problems when used with other dietary supplements or medicines.
- Combining ephedra with caffeine increases the risk of potentially serious side effects.
Green tea and green tea extracts, such as its component EGCG, have traditionally been used to prevent and treat a variety of cancers, including breast, stomach, and skin cancers, and for mental alertness, weight loss, lowering cholesterol levels, and protecting skin from sun damage.
Strength of Evidence
- Much research has been conducted on the effects of various green tea preparations on weight loss and weight maintenance.
- A 2012 Cochrane review of 18 studies in overweight or obese adults found that the loss in weight in adults who had taken a green tea preparation was very small, statistically not significant, and not likely to be clinically important.
- Green tea is safe for most adults when used in moderate amounts.
- There have been some case reports of liver problems in people taking concentrated green tea extracts. The problems do not seem to be connected with green tea infusions or beverages. Although these cases are very rare and the evidence is not definitive, experts suggest that concentrated green tea extracts be taken with food, and that people discontinue use and consult a health care practitioner if they have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice.
- Green tea and green tea extracts contain caffeine. Caffeine can cause insomnia, anxiety, irritability, upset stomach, nausea, diarrhea, or frequent urination in some people.
- Green tea extract contains small amounts of vitamin K, which can make anticoagulant drugs, such as warfarin, less effective.
Mind and Body Approaches
There is considerable interest and growing scientific evidence that meditation and yoga may be useful complementary interventions in supporting behavior change and healthier lifestyles, including weight-loss and weight management programs.
Mindfulness meditation is a type of meditation that uses various approaches such as attention on breathing to develop increased awareness of the present. The physiological effects include reduced stress and develop better skills in control of emotions and craving.
- To date there are only a few studies on the effects of mindfulness as a component of weight-loss programs, but the evidence is intriguing and research is ongoing.
- A 2013 systematic review and meta-analysis of the effect of food intake memory and awareness on eating indicates that attentive eating is likely to influence food intake, and incorporating attentive- or mindful-eating principles into other interventions may aid in weight loss and maintenance.
- Meditation is considered to be safe for healthy people.
- There is a theoretical concern, and there have been rare reports that meditation could cause or worsen symptoms in people who have certain psychiatric problems, but this question has not been fully researched.
- Individuals with existing mental or physical health conditions should speak with their health care providers prior to starting a meditative practice and make their meditation instructor aware of their condition.
Yoga is a mind and body practice with origins in ancient Indian philosophy. The various styles of yoga typically combine physical postures, breathing techniques, and meditation or relaxation. There are numerous schools of yoga. Hatha yoga, the most commonly practiced in the United States and Europe, emphasizes postures (asanas) and breathing exercises (pranayama). Some of the major styles of hatha yoga are Iyengar, Ashtanga, Vini, Kundalini, and Bikram yoga.
Strength of Evidence
- Research on the effectiveness of yoga as an intervention for weight loss is limited and varies in quality.
- According to a 2013 review of the current evidence base of yoga for weight loss, overall, therapeutic yoga programs can be frequently effective in promoting weight loss and are a potentially successful intervention for weight maintenance and prevention of obesity.
- A pilot study of a 3-month yoga program for adults at high risk for developing type 2 diabetes suggests that yoga would be a possible risk reduction option for this population, and that yoga holds promise as an approach to reducing cardiometabolic risk factors and increasing self-efficacy for this group.
- Yoga is generally low-impact and safe for healthy people when practiced appropriately under the guidance of a well-trained instructor.
- Overall, those who practice yoga have a low rate of side effects, and the risk of serious injury from yoga is quite low. However, certain types of stroke as well as pain from nerve damage are among the rare possible side effects of practicing yoga.
- Women who are pregnant and people with certain medical conditions, such as high blood pressure, glaucoma (a condition in which fluid pressure within the eye slowly increases and can damage the eye’s optic nerve), and sciatica (pain, weakness, numbing, or tingling that can extend from the lower back to the calf, foot, or even the toes), should modify or avoid some yoga poses.
The term "acupuncture" describes a family of procedures involving the stimulation of points on the body using a variety of techniques. The acupuncture technique that has been most often studied scientifically involves penetrating the skin with thin, solid, metallic needles that are manipulated by the hands or by electrical stimulation.
- Not much research has been conducted on the effects of acupuncture for weight loss.
- A 2012 study in obese adults, who had just completed a behavioral weight-loss program, compared an acupressure technique with a control intervention comprised of social-support group meetings for weight maintenance. The primary analysis of the study showed no significant difference in weight regain between the acupressure and control groups.
- In another study, researchers examined the effect of auricular acupuncture on obese women compared with placebo (sham acupuncture). Researchers found no statistical difference in body weight, body mass index, and waist circumference between the acupuncture group and placebo.
- Relatively few complications have been reported from the use of acupuncture. However, acupuncture can cause potentially serious side effects if not delivered properly by a qualified practitioner.
Talking With Your Patients About Weight-Loss
NIH has many resources and tips to help you talk with your patients about healthy eating, physical activity recommendations, and weight management. Remember to ask your patients about their use of dietary supplements so you can educate them about the potential side effects and risks. Also, keep in mind that cultural differences can impact weight, favorite foods, social norms and practices, and related issues.
NCCAM Clinical Digest is a service of the National Center for Complementary and Alternative Medicine, NIH, DHHS. NCCAM Clinical Digest, a monthly e-newsletter, offers evidence-based information on CAM, including scientific literature searches, summaries of NCCAM-funded research, fact sheets for patients, and more.
The National Center for Complementary and Alternative Medicine is dedicated to exploring complementary and alternative healing practices in the context of rigorous science, training CAM researchers, and disseminating authoritative information to the public and professionals. For additional information, call NCCAM's Clearinghouse toll-free at 1-888-644-6226, or visit the NCCAM Web site at nccam.nih.gov. NCCAM is 1 of 27 institutes and centers at the National Institutes of Health, the Federal focal point for medical research in the United States.
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