I'm starting to work with a group of food writers that focuses on locally-grown, organic, etc. One of them has a new book that's sold as many in two weeks as mine has in two years, and is selling two per day now. I just got the sample chapter and it has a whopper of a factual error in the central point that it's making.

I can't recommend it to my audience, I know that. Now I'm trying to figure out if I should offer to fact check it for her, because it clearly needs it.

Oh, her target market for it? It's a nutrition textbook for homeschoolers.

You know how carrots are good for your eyes?

Except you know how that's wartime propaganda? http://www.snopes.co...dient/carrots.asp

That's the lead example in a book about how real food is good for us, while recommendations from the government are more about corporate interests than our health.

Oops.

http://kidshealth.or...itamin_chart.html

Good sources of vitamin A are milk, eggs, liver, fortified cereals, darkly colored orange or green vegetables (such as carrots, sweet potatoes, pumpkin, and kale), and orange fruits such as cantaloupe, apricots, peaches, papayas, and mangos.

We "all know" carrots are good for vision. But no more so than lots of other foods are, many of which are more appetizing.

So why do we all know about carrots? Because of a government propaganda effort.

No, they didn't make up something out of whole cloth. The best propaganda is always close enough to the truth that people of good faith can at least take it seriously.

In this case, the point she was making was that scientists tried to isolate the nutrient in carrots that was good for vision, and they focused on beta carotene. And of course they were wrong, ha ha! It was the whole food that was effective.

Except that's not it either. Even the whole food isn't exceptionally good for vision. At best it can alleviate a deficiency that might cause problems. No study has suggested that vitamin A, or beta carotene, or whole carrots, actually improves vision for people who don't have any problems.

So if someone does have vitamin A deficiency, eating carrots can help. That fact doesn't make carrots the poster child for eating whole foods instead of the supplements the government would have you take instead.

The switch from butter to margarine ... cholesterol causes heart disease ... red meat will make you fat ... eat less meat and more grains ... Any one of these would be a better example.