You need to identify the steps at which contamination can occur - those are the critical control points. You take steps to make sure that that doesn't happen. And you monitor and evaluate and test to make sure that your system is working properly. And if it's done diligently and done faithfully and monitored carefully, then they're producing safe food. And no astronaut of which I'm aware has ever gotten food poisoning in outer space.

We don't have a farm-to-table food safety system. I keep saying this. It came as a big surprise to the FDA that tomatoes were being grown in the United States, sent to Mexico for packing, and then sent back. I mean, they had no idea that our food chain worked like this.

One way in which we can encourage the Chinese government to take more vigorous action to control food safety in their country is by just saying we're not going to buy Chinese foods until they get their system cleaned up. Admittedly it's a difficult system to get under control because an astonishing percentage - maybe 80 percent - of the foods in China are produced in small backyard operations.

The problem with nutrient-by-nutrient nutrition science is that it takes the nutrient out the context of the food, the food out of the context of the diet, and the diet out of the context of the lifestyle.

These days the biggest issue is how many calories you consume. So all of this stuff distracts people from thinking about calories.

What we know about diets hasn't changed. It still makes sense to eat lots of fruits and vegetables, balance calories from other foods, and keep calories under control. That, however, does not make front-page news.

If we have a food supply that we can't trust, that has enormous implications for the way we view government, for the way we trust business, and for our international trade relations.