Q: Do energy-boosting foods and beverages work? Are they safe?
A: A multitude of herbs, supplements, soft drinks and so-called energy drinks claim to boost energy. Here's a look at some of these substances -- and whether the evidence supports their claims:
• Chromium picolinate is a mineral marketed to build muscle, burn fat and increase energy and athletic performance. Research does not support these claims.
• Coenzyme Q10. Studies have shown coenzyme Q10 supplements to improve exercise capacity in people with heart disease. Their effects in people without heart disease are not clear.
• Creatine. There is some evidence that creatine can build muscle mass and improve athletic performance requiring short bursts of muscle activity, at least in younger adults. But it does not appear to build muscle in older adults or reduce fatigue in people of any age.
• DHEA is touted to boost energy and also prevent cancer, heart disease and infectious disease, among other things. But this hormone has no proven benefits, and it may pose serious health risks.
• Ephedra was banned by the FDA in 2004 because of major safety concerns, but it remains available for sale on the Internet. Ephedra is not safe in any amount. One night years ago I got a call from the emergency room. A patient of mine had fainted, and when she arrived at the ER it became clear that she was having dangerous heart rhythms. Shortly after arriving, she started having a very dangerous rhythm, ventricular tachycardia. If she had not been in a medical setting where we could treat her, she could have died. She had no underlying heart disease -- but she admitted that she had been taking ephedra to boost energy.
• Ginkgo biloba does not appear to improve cognition (thinking) in people with Alzheimer's disease. Regarding memory in people without dementia, the evidence is mixed.
• Ginseng. This relatively safe and popular herb may reduce fatigue and enhance stamina and endurance. It can boost energy without causing a crash, unlike sugar.
• Guarana. This herb induces a feeling of energy because it's a natural source of caffeine. Taken with other caffeinated beverages, however, it could ultimately lower your energy by interfering with sleep.
• Vitamin B12. Some doctors give injections of vitamin B12 as energy boosters. But unless you have true B12 deficiency, vitamin B12 treatments are unlikely to boost your energy. Instead of looking to supplements for energy, switch to a healthful diet loaded with vegetables, fruits, whole grains, nuts, lean protein and unsaturated fats. And exercise more.
That's a much better way to beat an energy shortage. I know that some of you may say: "There he goes again: Exercise and a healthy diet are the solution for everything." But they really do improve well-being.
I've had many patients who told me, in so many words, "I don't have enough energy to exercise." But I pushed them, they started regular exercise, and two to three months later had more energy than they'd had for years.
• Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com.