Dec. 16, 2008 -- Alternative medicines are used by 38 percent of American adults and nearly 12 percent of children, according to a large national survey done in 2007 that was released last week by the National Center for Complementary and Alternative Medicine (NCCAM).

Natural products were the most popular alternative treatment used by the nearly 24,000 adults and more than 9,400 children interviewed for the survey.

The survey included a general question asking participants whether they had used any herbs, supplements, and other natural products within the last 12 months. It also contained a specific question asking respondents to indicate which products, from a list of 45 possibilities, they had used within the last month.

Because the question was worded as usage within the last month, this could have influenced the final rankings of the top ten products. A remedy, such as echinacea has a seasonal usage, typically during the late fall and winter, and if you responded to the survey in the summer, you might not have used this cold-fighting product in the previous month.

Products, such as fish oil and glucosamine, have year-round uses -- factors that may have led to their respective number one and number two rankings.

Another NCCAM survey done in 2002 was equally large, but did not include children. A few natural remedies that appeared on the top ten list in 2002 but dropped off it in 2007 include St. John's wort, peppermint, ginger, and soy supplements.

A few products appeared on the 2007 top ten list for the first time. They included Coenzyme Q10, flaxseed, and combination herb pills.

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Here are the most popular natural products from the NCCAM survey (in order of popularlity), along with advice from some of the leading experts in the field about their use and the research on them.

#1 Fish oil

What it is: These oils, which come from cold water fish, such as sardines and salmon, supply omega-3 fatty acids. Fish oil capsules, suggested Dr. Roberta Lee, medical director for the Continuum Center for Health & Healing at Beth Israel Medical Center in New York City, offer a good way to get a nutritional oil without having to eat barrels of fish. "Omega-3 fats are notoriously under-represented in the diet because of our eating habits," she said.

What it's supposed to do: Fish oils are thought to help the heart and brain, as well as inflammatory conditions. The American Heart Association has recommended taking two to four grams of fish oil capsules a day to help bring down high triglyceride levels. One to three grams daily is the amount Lee advises for her patients with existing cardiovascular disease.

In her practice, she suggests fish oils to people with conditions that have an inflammatory component. This might include rheumatoid arthritis, inflammatory bowel disease, and lupus. Scientists are also experimenting with the use of fish oils for mental health concerns -- not as a replacement for drugs, but as an adjunct therapy.

What research suggests: "We're beginning to realize that fish oils are quite powerful," Lee pointed out. Fish oils are one of the many things that can help with high triglycerides and elevated lipid and cholesterol levels. Additional research is starting to look at the supplement's effect on asthma, ADHD, depression, atherosclerosis, and age-related macular degeneration.

Bottom line: There's a growing body of evidence suggesting that fish oils have positive effects on cardiovascular risk factors, but we still don't have data that it will affect cardiovascular mortality, said the NCCAM survey researchers. As Lee puts it, fish oils are inexpensive compared with other supplements, and they may be very effective for a broad range of conditions associated with inflammation.

#2 Glucosamine

What it is: Glucosamine is a compound that's found naturally in healthy cartilage, a connective tissue that covers the joints. But the supplement is derived from the shells of shrimp, crab, and other types of shellfish.

What it's supposed to do: It's been recommended for the treatment of osteoarthritis (OA), and in people at high risk for OA, or those who have already had a joint injury, it might be suggested to help prevent arthritis. Glucosamine might help build or rebuild damaged cartilage in people with OA.

What research suggests: The most convincing studies for glucosamine have examined its effectiveness in mild to moderate knee osteoarthritis, said Dr. Adam Rindfleisch, an assistant professor at the University of Wisconsin Family and Integrative Medicine Clinic in Madison. But he explained that there has been a lot of debate about how the studies have been carried out. The majority of them have used glucosamine hydrochloride, but some scientists suspect that glucosamine sulfate might be the form with the more powerful effect.

"My socks aren't knocked off by the most recent research, and it's not cheap to take," cautioned Rindfleisch.

Bottom line: Although some people might get some mild nausea as a side effect of glucosamine, Rindfleisch says he recommends the supplement (along with chondroitin) because he has seen it make a marked difference in some people with osteoarthritis.

"Give it a shot for at least six weeks or up to six months, and if you're not seeing a difference, then lay off," he advised. The typical daily dose is 1,500 milligrams of glucosamine, taken in divided doses of 500 milligrams three times a day.

#3 Echinacea

What it is: Echinacea, also known as purple coneflower, is a member of the daisy family. People who have allergies to other daisy family members, including ragweed, marigolds, daisies, and chysanthemums, could also be sensitive to it.

What it's supposed to do: Echinacea is believed to help boost the immune system to fight off infection, most typically the common cold and other upper respiratory infections. It's been studied for its role in helping to shorten the duration and severity of a cold and for preventing it in the first place.

What research suggests: Even in the best data, echinacea never appeared to be a home run, noted Dr. Brent Bauer, director of the complementary and integrative medicine program at the Mayo Clinic in Rochester, Minn. "The overall enthusiasm for the herb has been appropriately dampened because we haven't seen many good studies coming up positive," he added.

In earlier studies it was hard to tell which of the three species of the plant were used, but more recently there have been larger trials with well-derived preparations of the herb, and they have been negative on shortening the length of a cold or staving it off.

Bottom line: More studies are leaning toward that echinacea is not all that effective for the common cold, said Bauer. "The studies are conflicting, but most look fairly negative."

#4 Flaxseed Oil, Pills

What it is: This tiny seed is an inexpensive plant-based source of omega-3 fats, but they are not the same exact omega-3s you would get by eating fish. Oils pressed from the seeds are either placed into capsules or sold as a liquid, yet, unlike consuming the food, they lack the beneficial dietary fiber as well as lignans, which are plant compounds that have estrogen-like activity and may protect against hormone-driven cancers.

What it's supposed to do: Grinding up the seeds and sprinkling them on cereals, salads, and cooked vegetables offers a good source of omega-3 fats in people who don't care to eat fish. "Flax might help keep you regular," explained Lee. And like fish oil, flax is believed to have anti-inflammatory activity. She often suggests ground flax to women with PMS and those with perimenopausal symptoms, and also to people with asthma.

What research suggests: There's less research on flax than there is on fish oil, even though they seemingly overlap in function, says Lee. Flax contains alpha-linolenic acid, a type of omega-3 found in plant foods, and its beneficial effects may not be as compelling as those from fish oils. In human trials, the evidence for any benefits to high cholesterol or triglyceride levels is mixed.

Bottom line: Lee endorses the use of buying whole flax seed, and grinding it up yourself. Ground flax is sensitive to light and heat, so she suggests keeping it refrigerated.

#5 Ginseng

What it is: A plant containing several different species and thought to be an overall tonic for well-being.

What it's supposed to do: Ginseng is considered an adaptogen, meaning that it's an herb believed to help you fight off the stresses in the environment. It's also purported to increase stamina to help you perform better -- physically, mentally, athletically, and perhaps, sexually. The herb is also believed to help boost immune function.

What research suggests: Panax ginseng (also known as Chinese or Korean) is the best studied form, explained Rindfleisch. (There is also an American ginseng and a Siberian form, known as Eleuthero.) He considers the evidence for ginseng as so-so with most of the findings coming from small trials. Rindfleisch said ginseng probably helps with overall thinking, yet he warned that, in some people, the herb might rev them up. He would not recommend that men try it for a sexual problem, such as erectile dysfunction. American ginseng has been studied to help with blood sugar control in people with type 2 diabetes.

Bottom line: Rindfleisch said ginseng might be worth a try in people with chronic fatigue at a dose of 100 milligrams twice a day.

#6 Combination Herb Pills

What they are: These natural products contain more than one herb or natural compound, explained Richard Nahin, one of the co-authors of the NCCAM surveys and the acting director of its division of extramural research. Two examples are a glucosamine/chondroitin blend for osteoarthritis or a combination of echinacea and goldenseal as an herbal remedy to help relieve a cold.

What they're supposed to do: Combination products are sold for a host of conditions, from the common cold and pain relief to anxiety and heart health, to name a few.

What research suggests: These days, most of the research on dietary supplements tends to focus on single ingredient herbs or supplements, to make it easier for scientists to pinpoint whether a natural product is having an influence on the condition or symptom being studied. "The question that comes up when combining things, is what's working?" pointed out Dr. Mimi Guarneri, medical director for the Scripps Center for Integrative Medicine in La Jolla, Calif. For example, it's harder to tease out which ingredient in a pain-relieving remedy is helping to ease inflammation and swelling when it contains many different herbs that might play a beneficial role.

Bottom line: According to Guarneri, she wouldn't necessarily shy away from suggesting that a patient use a combination product because sometimes she has found that they work better than one supplement alone, because the ingredients can have an additive effect. "Some combination products are really good. As a clinician, I would look at what the individual components are in a product and whether I know them to cause any benefit."

# 7 Ginkgo Biloba

What it is: The claim to fame for this extract made from the leaves of an ancient tree is its antioxidant activity, as well as its potential to improve blood flow to the brain.

What it's supposed to do: Ginkgo is best known for its possible brain-boosting powers. The herb has been studied for its ability to prevent and treat dementia, and has also been looked at for improving cognitive function, such as memory, in healthy adults.

In Germany, the remedy has been used to treat vascular claudication, a type of pain that occurs while walking because the leg doesn't get enough blood. The Mayo Clinic is currently analyzing data from a more than three-year trial on the use of ginkgo in cancer patients experiencing "chemobrain," a type of mental fogginess that occurs in some people following chemotherapy and radiation.

What research suggests: Although studies done 10 or 15 years ago on gingko seemed initially promising, research done in the last year or two suggests that the herb may not work as a preventive for dementia, said Bauer. "The needle is pushing more in the direction that we're not seeing a strong protective effect on dementia."

He cautioned that the jury is still out because ginkgo can cross the blood-brain barrier and has antioxidant properties, meaning it can squelch free radicals.

Bottom line: Ginkgo is a vasodilator, so it might do something to increase blood flow, noted Bauer. He said small studies suggest some ability to improve cognitive function in healthy people, but not enough to say you'll think better.

#8 Chondroitin

What it is: A chemical compound derived from cartilage, typically from the windpipe of a cow.

What it's supposed to do: It's typically used in conjunction with glucosamine, primarily to help treat pain and swelling in people with osteoarthritis. It may replace a different material in cartilage than glucosamine does, but whether this is truly happening is subject to debate, according to Rindfleisch. Because the supplement is sometimes made from parts of a cow, some people were worried that taking the supplement might theoretically increase their risk for mad cow disease.

What research suggests: Right now, the research on chondroitin for osteoarthritis is even less convincing than it is for glucosamine, suggested Rindfleisch.

Bottom line: The typical daily dose of chondroitin sulfate is 1,000 to 1,200 milligrams, often taken as 400 milligrams three times a day. If you decide to try it, use it together with the supplement, glucosamine sulfate.

#9 Garlic (Allium sativum) Supplements

What it is: Allicin, a component of whole garlic and believed to be the medically active ingredient in the clove, is placed into supplement form.

What it's supposed to do: From a cardiac standpoint, garlic has been thought to help lower total cholesterol, and LDL cholesterol, in particular, said Guarneri, who is a cardiologist. People who consume more garlic in their diet may reduce their risk for stomach and colorectal cancers. Supplements of the fragrant bulb have also been suggested for reducing high blood pressure and for treating infections.

What research suggests: There's no research that it can improve cardiovascular outcomes or decrease cholesterol, noted Guarneri. "As a matter of fact, there are negative studies." The evidence for some cholesterol-lowering benefit seems to come from short-term studies of 4 to 12 weeks in length. Data on the herb's ability to reduce blood pressure suggests only a modest reduction.

Bottom line: "Garlic may be something that people can use for other reasons, such as an infection or a sore throat, but I've not seen a benefit from it for cholesterol," concluded Guarneri. She said garlic is not her first choice of supplements to help lower cholesterol; she prefers, instead, to recommend red yeast rice.

#10 Coenzyme Q-10

What it is: Also known as CoQ10 or ubiquinone, this substance is normally produced by the body and is a necessary cofactor in the production of energy by cells.

What it's supposed to do: Low levels of CoQ10 have been reported in patients with Parkinson's disease, congestive heart failure, and those taking statin drugs to reduce cholesterol. Guarneri believes that "it's a necessary agent in protecting against statin-induced myopathy, a type of muscle ache and weakness that can be a side effect of taking the drug in some people. She also thinks 1,200 milligrams of it a day can be beneficial in people who have symptoms of Parkinson's disease, and it could be helpful for people who have muscle weakness.

What research suggests: "There's strong research that CoQ10 is an independent predictor of mortality in chronic heart failure," pointed out Guarneri. CoQ10 works on the mitochondria in cells, where energy is produced. There's good evidence that if levels are deficient, supplementation can be effective.

Bottom line: "It's an excellent cofactor for supporting the energy of the cell," advised Guarneri, who recommends it to all of her patients on statin drug therapy and those who have congestive heart failure.

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