This year's flu season has hit the U.S. early and hard. Though the flu vaccine does offer some protection against the the predominant strain of the virus, it's not completely effective. And it can't protect you from the common cold or other illnesses circulating.
If you do become sick or if you want to avoid future illness, you'll probably find yourself in the aisle of your local pharmacy or supermarket, staring at rows of products. Some of those products make claims that are, at best, dubious.
Here are three treatments that aren't likely to help:
Oscillococcinum is a homeopathic rememedy developed and marketed by the French company Boiron. It is sold as temporary relief for flu-like symptoms, such as fatigue, headache, body aches, chills and fever. The company used to claim it could provide “fast relief of flu infection symptoms,” but changed its marketing language after the Food and Drug Administration sent the company a warning letter and it settled a class-action lawsuit in 2012 with California consumers.
The supposed active ingredient in Oscillococcinum is “Anas barbariae hepatis et cordis extractum,” which is Latin for “Barbary duck liver and heart extract.” As gross as that may sound, chances are there is not one particle of extract in the final product. The makers of Oscillococcinum begin with a solution containing 1 percent extract then repeatedly dilute it 200 more times. As Robert L. Park points out in his 2008 book, Superstition: Belief in the Age of Science, there would need to be at 10 to the 320nd power more universes-worth of atoms in the final solution for it to contain a single molecule of extract.
Homeopathy in general defies all scientific understanding of chemistry and physics. But the most important question is always: does it work? A 2012 Cochrane Review of the literature found only six randomized, placebo-controlled trials of Oscillococcinum's effect on flu-like illness. The authors noted that the overall trials were poorly reported, and concluded there was “insufficient good evidence to enable robust conclusions to be made about Oscillococcinum in the prevention or treatment of influenza and influenza-like illness.”
Many people take health products such as Airborne in the belief that its primary ingredient, Vitamin C, will help them stave off or decrease the duration of an illness. Airborne claims that scientific studies have shown its key ingredients “support the immune system.” However, the fine print on that statement points out that it has not been verified by the FDA, and that Airborne is not intended to “diagnose, treat, cure, or prevent any disease.”
The thing that confuses people about Vitamin C is that it is, in fact, essential to stay healthy. Deficiencies can lead to multiple health problems, including scurvy. A lack of Vitamin C can impair your ability to fight infection.
But most people get more than enough Vitamin C in their diets. The National Academy of Sciences’ recommended dietary allowance of 90 milligrams a day for males and 75 milligrams a day for females is easily satisfied by a normal diet. All fruits and vegetables contain some of the vitamin, and numerous other products are fortified with it.
Because Vitamin C is water soluble, excess amounts are excreted in urine and it is extremely difficult to overdose. So chances are taking supplements won’t hurt you. For the same reason, though, buying products to increase your Vitamin C will do little beyond making your pee more expensive.
Zinc is the most likely candidate among popular “natural” remedies to actually have some beneficial effect. Zinc is directly involved in the production of the white blood cells that are a major weapon in the body's fight against infection. Zinc has indirect impacts on the immune system in other ways as well. It's the main ingredient in popular over-the-counter products like Zicam.
Scientific studies of zinc's effect on the common cold have been mixed. A 2006 systematic review in Clinical Infectious Diseases found severe methodological flaws in most clinical trials. The ones that did meet the review's criteria had mixed results. A 2011 Cochrane analysis of the medical literature found some evidence to suggest that zinc supplementation might reduce the duration and frequency of colds, but could not find enough consistency to recommend dosage, length of treatment, or other details. There has been little research into whether zinc works for the flu.
On the other hand, there can be serious dangers to zinc supplementation. Zicam was forced to pull products administered nasally because of complaints that the products caused anosmia, a sometimes permanent loss of sense of smell. The National Center for Complementary and Alternative Medicine says zinc can cause gastrointestinal problems when taken orally. It interacts with penicillin and other drugs. And too much zinc (or zinc taken for too long) can lead to copper deficiency and actually impair immune function.
The trick is to think of zinc (and any other supposed remedy, for that matter) as a drug. As with other drugs, you have to weigh the potential benefits against the potential risks. Right now, the evidence of benefit from zinc for colds or flu is pretty weak. Given all the known dangers, you're probably better off spending your money elsewhere.
There are natural ways, of course, to battle colds and flu. Wash your hands regularly with soap and warm water. Avoid contact with sick individuals. If you've already caught an illness, keeping yourself hydrated and getting plenty of rest will allow your body to fight the infection faster. These tactics aren't perfect, either. But at least they're free.