Scientists are only beginning to understand the peculiar relationship music has with our memories. Peter J. Thompson/National Post Scientists are only beginning to understand the peculiar relationship music has with our memories.

As a trigger for memories, music is a uniquely powerful medium. There is hardly a person alive who cannot be cast back to a childhood joy, or a teenage heartache, by hearing a familiar song.

Other senses, such as smell, can do the same thing. Wine enthusiasts, for example, are forever conjuring the past through their tasting notes, and the French author Marcel Proust is widely cited in memory studies because he based an entire memoir, Remembrance of Things Past, on the smell of tea biscuits.

But music is different.

Washington - Drugmaker MedImmune is recalling nearly 5 million doses of swine flu vaccine because the nasal spray appears to lose strength over time, federal health officials announced Tuesday.

The vaccine recall is the second this month caused by declining potency and comes as public health officials urge millions of Americans to get vaccinated against swine flu.

The action affects more than 4.6 million doses, but the vast majority have already been used, according to the Food and Drug Administration. Agency officials said the vaccine was strong enough when it was distributed in October and November.

The 35-year-old federal law regulating tap water is so out of date that the water Americans drink can pose what scientists say are serious health risks - and still be legal.

Only 91 contaminants are regulated by the Safe Drinking Water Act, yet more than 60,000 chemicals are used within the United States, according to Environmental Protection Agency estimates. Government and independent scientists have scrutinized thousands of those chemicals in recent decades, and identified hundreds associated with a risk of cancer and other diseases at small concentrations in drinking water, according to an analysis of government records by The New York Times.

But not one chemical has been added to the list of those regulated by the Safe Drinking Water Act since 2000.

Autism disorders increased by 57% in just four years, the CDC today reported.

By the end of 2006, one in 110 U.S. kids had an autism disorder diagnosed by age 8: one in 70 boys and one in 315 girls, reflecting a nearly fivefold higher risk for males.

The new CDC estimate of autism prevalence, obtained from analysis of child evaluation records in 11 states, is virtually identical to autism numbers reported for 2007 from a huge telephone survey reported last October.

Are today's kids really more likely to have autism, or are doctors and parents just getting better at recognizing this family of developmental disorders?

Noted British psychiatric researcher Malcolm Peet conducted a provocative cross-cultural analysis of the relationship between diet and mental illness. His primary finding was a strong link between high sugar consumption and the risk of both depression and schizophrenia.

There are at least two potential mechanisms through which refined sugar intake could exert a toxic effect on mental health. First, sugar actually suppresses activity of a key growth hormone in the brain called BDNF. BDNF levels are critically low in both depression and schizophrenia.

Second, sugar consumption triggers a cascade of chemical reactions in your body that promote chronic inflammation. In the long term, inflammation disrupts the normal functioning of your immune system, and wreaks havoc on your brain. Once again, it's linked to a greater risk of depression and schizophrenia.

Decide for yourself. Bis-Phenol A is an additive in clear, hard plastics. It is used in water bottles, baby bottles, soda can liners, etc. and is known to leach into the foods and liquids which are stored in it. It is in recycling category 7 (on the bottom of the bottle, in the triangle). Independent academic studies suggest it presents a variety of risks to humans. The government, relying on industry studies, claims the facts are unclear. By Bill Moyers and Expose.

Visit the PBS archives to see the complete show and more of Bill Moyers.

New horizons in biomonitoring are identifying environmental exposures that may play a role in health problems, including cancer, neurological disorders and diabetes. At their fingertips, researchers already have precise measurements of nearly 150 chemicals in several thousand American adults and children. Now the Centers for Disease Control and Prevention is preparing to release even more extensive data, and expand its reach by testing 500 umbilical cords, which will allow scientists to determine which chemicals babies are exposed to in the womb. Biomonitoring "is a game changer in environmental health," said Thomas Burke of Johns Hopkins University. Nevertheless, actual use of the information hasn't yet fulfilled its potential.

Perhaps the most derided of alternative medicines is my own favorite - homeopathy. Over the past few years, detractors have focused their efforts in the United Kingdom and have succeeded in crippling homeopathic hospitals and clinics funded by the National Health Service, as well as the practices of many homeopaths.

A few well-placed editorials in prominent newspapers have done the trick, despite the fact that Prince Charles and the rest of the royal family are ardent supporters of homeopathy.

It now seems that some of these folks are taking their show on the road. Two key UK players, Michael Baum and Edzard Ernst have published a commentary in the November 2009 issue of the American Journal of Medicine [1] in which they state, "a belief in homeopathy exceeds the tolerance of an open mind. We should start from the premise that homeopathy cannot work and that positive evidence reflects publication bias or design flaws until proved otherwise."

Not surprisingly, their commentary also reflects a complete ignorance of homeopathy and the range of studies that support its effectiveness. For example, their article incorrectly uses the term "potentation" instead of "potentization" for the method used to create homeopathic remedies (more on this later). The authors also insist on citing a single negative meta-analysis study that has already been shown to be methodologically flawed [2], while ignoring many positive studies in respected publications, including two other meta-analyses that showed positive results [3 - 8].

So why do the skeptics love to hate homeopathy? Perhaps because it is one of the most threatening alternative modalities - financially, philosophically, and therapeutically. Actually, homeopathy has been a threat to allopathy ever since the 1800s, when German physician Samuel Hahnemann developed the homeopathic system.

A new study at the University of Wisconsin-Madison suggests that depressed patients are unable to sustain activity in brain areas related to positive emotion.

The study challenges previous notions that individuals with depression show less brain activity in areas associated with positive emotion. Instead, the new data suggest similar initial levels of activity, but an inability to sustain them over time. The new work was reported online the week of Dec. 21 in the Proceedings of the National Academy of Sciences.

"Anhedonia, the inability to experience pleasure in things normally rewarding, is a cardinal symptom of depression," explains UW-Madison graduate student Aaron Heller, who led the project. "Scientists have generally thought that anhedonia is associated with a general reduction of activity in brain areas thought to be important for positive emotion and reward. In fact, we found that depressed patients showed normal levels of activity early on in the experiment. However, towards the end of the experiment, those levels of activity dropped off precipitously.

A report published in the new journal Science Translational Medicine has made an interesting discovery concerning the relationship between sugar intake and the balance of intestinal flora. Researchers have discovered that a diet high in sugar and fat substantially alters the bacterial composition in the gut, making it difficult to maintain a healthy weight.

Dr. Jeffrey Gordon of Washington University in St. Louis has been accumulating research for years that highlights the role intestinal bacteria plays in regulating bodily weight. Intestinal flora, sometimes called "good" bacteria, is vital for the proper digestion of food and assimilation of nutrients into the blood. When digestive bacteria is out of balance or otherwise altered, the body is unable to convert otherwise indigestible foods into digestible form.

The research, conducted on mice, experimented with implanting various strains of bacteria into mice in order to observe their effects. The two primary divisions of bacteria, Firmicutes and Bacteroidetes, compose approximately 90 percent of all bacteria. Studies by Dr. Gordon have revealed that Firmicutes bacteria are more efficient at digesting food that the body is unable to digest on its own.