The claim: dust mites make allergies worse
Facts: Most people with allergies or asthma know well the hazards of dust mites, the microscopic household critters long said to be one of the most common triggers of allergic symptoms.
But that is not what studies show. Scientists have repeatedly found that various physical and chemical methods recommended for controlling dust mites, such as sprays and impermeable bed covers, do little by themselves to prevent allergies. If they do work, it is usually as one of several steps taken to reduce household allergens. A meta-analysis published in 2008, for example, looked at 54 randomized studies that compared various mite-control measures with placebo interventions, or none at all, in people with asthma. It found that the control measures made no significant difference. A 2007 study followed 126 asthma patients, some of whom were trained to use control measures such as impermeable bed covers and others who used placebo interventions. After two years, the scientists found that the groups showed no difference in their use of inhalers or reductions in symptoms such as wheezing and coughing.
These and other studies suggest that people with allergies and asthma would do well to rely on a broad programme of interventions, such as frequently washing clothes and blankets, using air conditioning instead of humidifiers and strictly limiting exposure to allergens such as smoke and strong odours.
The bottom line: Research suggests that controlling dust mites alone may not prevent allergies.
The claim:drinking flat soda can ease an upset stomach
The facts: It is not often that a soft drink is seen as medicinal. But when it comes to stomach distress, many people view a cup of flat soda as just what the doctor ordered.
The quick and popular remedy—usually in the form of cola, ginger ale or clear sodas—is said to help settle the stomach with its slight fizz and replenish fluids and glucose lost by vomiting and diarrhoea. Parents also find that children who are verging on dehydration but reluctant to consume any liquids are more amenable to soda. But research shows that may not be a great idea. British researchers conducted a review of the medical literature going back to the 1950s in search of scientific evidence supporting the claim. They found none. Then, after a biochemical analysis, they compared the contents of colas and other sodas with over-the-counter oral-rehydration solutions containing electrolytes and small amounts of sugar. The soft drinks, the authors found, not only contained very low amounts of potassium, sodium and other electrolytes, but also in some cases as much as seven times the glucose recommended for rehydration by the World Health Organization. “Carbonated drinks, flat or otherwise, including cola, provide inadequate fluid and electrolyte replacement and cannot be recommended,” they said.
The bottom line: Flat soda, a popular remedy for upset stomach, may do more harm than good.
ANAHAD O’CONNOR/©2008/The New York Times