Health Warnings

Some brands of hand sanitizers, including gels and wipes, contain levels of alcohol that can potentially cause alcohol poisoning if ingested.

This warning is especially relevant for parents and teachers at day cares, preschools, and elementary schools, as young children who don't know better than to lick curious-smelling substances from their hands can experience alcohol poisoning from accidental ingestion of common hand sanitizers like Germ-X and Purell.

While nations around the world are either banning or limiting cell phone use by children, and some by those under the age of 12 years-old, Health Canada has remained mum on the subject.

France is nearing the point where it will make it illegal to market cell phones to children.

In late 2008, the Vitamin D Council issued a warning on ingesting cod liver oil due to concerns about high levels of vitamin A in many brands of cod liver oil.

What follows are my answers to the most common queries that I received on the Vitamin D Council's paper.

According to two studies out of the U.K., wearing daily disposable contact lenses or contact lenses that are supposed to allow more oxygen into the eyes does not lead to a lowered risk of developing dangerous eye infections.

Regardless of what type of contact lenses are used, the biggest risk factor for developing a painful infection of the cornea called microbial keratitis is sleeping with contact lenses on.

Melamine is a synthetic compound that is traditionally used to make plastics and laminates.

In 2007, melamine was suspected by the U.S. FDA to have tainted pet food, and in September 2008, almost 54,000 infants in China became ill after ingesting melamine that was found in baby formula and milk products; four infant deaths have also been reported.

A 20/20 investigation suggests that fatal car accidents are regularly caused by old rubber tires spontaneously disintegrating on the road. This report focuses on the alarming reality that some new tires that are sold in stores like Wal-mart and Sears may actually be several years old. 20/20's investigation actually found some "new" tires on sale at Wal-mart and Sears stores in the States that were up to 12 years old.

View the complete 20/20 report here:

The headline is correct - brain tumors now claim more children's lives than any other type of cancer. There aren't any published studies in the medical literature that all epidemiologists can point to and offer as proof that regular use of a cell phone can increase a child's risk of developing a brain tumor. And there never will be such a study, as definitive proof in the research world requires a double-blind, randomized control trial; how can you conduct a trial in which you ask a group of children to use a cell phone for 'x' number of hours per week?

Female night shift workers have a higher risk of developing breast cancer than the rest of the female population. An interesting study in the December 1, 2005 issue of Cancer Research provides new information that might partly explain why this is.

Researchers found that sleeping for several hours in nighttime darkness promotes a healthy blood level of a hormone called melatonin, which can significantly suppress the growth and proliferation of breast tumours.

According to a study published in the August 1, 2007 issue of the journal Sleep, rotating shift workers have significantly lower levels of serotonin (precursor to melatonin) than people who work regular day shifts. A total of 683 men of European ancestry were evaluated for this study; 437 were day workers, and 246 were rotating shift workers.

Serotonin is a hormone that circulates throughout your body. It is also a neurotransmitter in your central nervous system (brain and spinal cord). A chronically low level of serotonin is associated with many health challenges, the most common of which are:

Since 1997, I've evaluated and worked with about two dozen people who have had knee or hip replacement surgeries. A few have reported having better quality of life following joint replacement surgery, while the majority have reported experiencing more difficulties than they did before having surgery.

If you have a severely deteriorated joint that prevents or significantly hinders basic activities of daily living, I think that joint replacement surgery is an option worth considering. But I think it's critical to do two things before undergoing surgery: