I started to write about science and medicine at the Washington Post, in the early days of the AIDS epidemic.

Be sceptical, ask questions, demand proof. Demand evidence. Don't take anything for granted. But here's the thing: When you get proof, you need to accept the proof. And we're not that good at doing that.

Daily vitamins are of no value.

Benjamin Franklin refused to have one of his children vaccinated against smallpox. The four-year-old boy died, and Franklin wrote later of how mistaken he was to expose him to the needless risk.

I think it's too soon to say that, and I think, basically - most of the people that I ran across and most of the studies that I saw suggest people don't go to McDonald's to eat healthy food. They go to eat fries and cheeseburgers.

I understand the horrors of having no insurance, but, believe me, eight hours of sleep and good meals are NOT going to prevent you from getting sick. Don't gamble with your life; it's a stupid bet.

Vaccination is a public health issue because influenza is a highly contagious disease. If you don't vaccinate your child, his or her schoolmates are much more likely to become ill. That is why some places (New York, for example) are making the vaccine mandatory for school children.