All the food we eat - every grain of rice and kernel of corn - has been genetically modified. None of it was here before mankind learned to cultivate crops. The question isnt whether our food has been modified, but how.

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.

I think it is true that you can eat extremely healthy food at McDonald's, and you can eat amazingly badly at Chipotle.

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.

Flu is easily transmitted, so if you are working with sick people - who are most at risk for getting seriously ill - you ought to be vaccinated. I am not really equipped to say whether it should be the law or not.

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.

Daily vitamins are of no value.