Each day as I travel through downtown Tucson, I am amazed at how quickly the most ancient of human behaviors have changed. For as long as there have been Homo sapiens - roughly 200,000 years - people have filled their lives principally with two activities: talking directly with other people, and doing physical things.

I know of no culture in the world at present or any time in the past that has not been heavily involved with one or more psychoactive substances.

The bottom line is that the human body is complex and subtle, and oversimplifying - as common sense sometimes impels us to do - can be hazardous to your health.

American businesses are struggling to pay outrageous, exploitive insurance bills for their employees, hampering our ability to compete globally.

The most common objection that I hear to walking as exercise is that it's too easy, that only sweaty, strenuous activity offers real benefits. But there is abundant evidence that regular, brisk walking is associated with better health, including lower blood pressure, better moods and improved cholesterol ratios.

As any doctor can tell you, the most crucial step toward healing is having the right diagnosis. If the disease is precisely identified, a good resolution is far more likely. Conversely, a bad diagnosis usually means a bad outcome, no matter how skilled the physician.

The best way to detoxify is to stop putting toxic things into the body and depend upon it's own mechanisms.