'Natural' cold and flu remedies: what works? 2/11
(This article is adapted from ConsumerReportHealth.org.)
A "try everything" approach to fighting the flu seems to be common among nearly half of Americans, who said in a nationally representative poll that they plan to use nutritional supplements or homeopathic remedies to protect themselves from the flu this season or fend off its symptoms. But which supplements will really work against the flu and which help relieve a cold?
Two supplements that have been rated “possibly effective” against flu symptoms are elderberry and n-acetyl cysteine. The supplement ratings are based on the Natural Medicines Comprehensive Database (NMCD), a compendium from an independent research group that evaluates the evidence for safety and effectiveness of nutritional supplements. Both elderberry and n-acetyl cysteine are available as single ingredient supplements or as part of multi-ingredient formulations.
Clinical research suggests that some elderberry extracts might help relieve flu-like symptoms within 2 to 4 days of treatment for most patients. Supplements of n-acetyl cysteine, an amino acid derivative, might also help reduce flu symptoms. An Italian clinical trial published in 1997 of 262 mostly elderly people found that those who received the supplement during winter (the height of flu season) had significantly fewer flu infections and milder symptoms than those given the placebo.
For children, there is some evidence that vitamin D supplements can work against the flu. In a randomized clinical trial involving 334 Japanese school children, published in the May 2010 American Journal of Clinical Nutrition, children who took vitamin D supplements had a significantly decreased chance of contracting influenza A. Only 18 of the 167 children taking vitamin D3 supplements got influenza A, compared with 31 of 167 children in the placebo group.
However, in the study, there was no significant difference between the two groups in catching influenza B. In addition, children who had not previously taken vitamin D supplements showed the most benefit in this trial, suggesting that they might have been vitamin D deficient. The NMCD concluded that vitamin D supplements are "possibly effective" in reducing the chance of catching the flu, and "likely safe" when used appropriately.
Children and adults with severe flu symptoms—including severe diarrhea, vomiting, difficulty breathing, and high fevers—should seek medical attention and not just rely on supplements.
For safety, check with a doctor or pharmacist first
NMCD rates n-acetyl cysteine supplements as "likely safe," and elderberry extracts as "possibly safe" for short-term use, but it's important to first check with your doctor or pharmacist. Most supplements haven't been studied in pregnant or nursing women, who should avoid them.
Elderberry plants and fruit contain a cyanide-producing chemical. Consuming the plant's leaves, flowers, or unripened or uncooked fruit can result in nausea, vomiting, and diarrhea. Ingestion of large quantities may cause serious toxicity. People with allergies to grass pollen should also avoid elderberry extracts because of the potential for an allergic reaction.
Cold relief: vitamin C and zinc
There is no cure for the common cold,but you can get some relief. Supplements, such as vitamin C and zinc, have been found to be possibly effective in relieving symptoms of the common cold, according to the NMCD, but not against the flu.
While preliminary evidence published in 1997 suggested that zinc with selenium might fight flu infections in older, institutionalized patients, the evidence was weak, and the NMCD has rated zinc supplements as "possibly ineffective" against influenza.
Supplements plus flu shots
The Centers for Disease Control and Prevention recommends that all people 6 months and older get flu shots. The flu vaccine has proved to be safe over many decades, according to our medical advisers.
While estimates vary, overall the vaccine has been found to reduce flu episodes by about 70 to 90 percent in healthy adults. It's less effective in older people and those with compromised immune systems, but it can also lessen the severity of the flu, limiting the possibility of serious complications and deaths.
Also consider these other steps, which have been shown to reduce the risk of getting a cold or the flu:
• Wash your hands. Use disinfectant wipes on telephone and computer keyboards to prevent the transfer of viruses.
• Avoid close contact with sick people. And stay home if you have a cough and fever. Cover coughs and sneezes with tissues or the crook of your arm.
• Get plenty of sleep. Sleep-deprived volunteers in one study mustered half the immune response to a flu shot compared with those getting normal sleep. Eating well, exercising regularly, and reducing stress may also bolster immunity.
• If you smoke, quit. Smokers are vulnerable to the flu and its complications.
Related links
Common Cold: Essentials
Flu: Essentials
Fears about the flu shot linger 10/10
Inside this year’s flu vaccine 10/10
Colds and coughs: home remedies that work 6/08
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