Updated on 4/4/2005
It is a myth that the peel of vegetables is the most nutritious part. In fact, the peel is there to protect the more nutritious part of the vegetable (or fruit) underneath. And I agree with the idea that raw vegetables (and those you plan to cook) should be peeled if you don't know where they came from and, therefore, don't know what pesticide residues they may contain.
If you are a regular reader, you know that I recommend buying organic produce whenever possible in order to avoid the pesticides used on fruits and vegetables. However, if organic produce isn't available to you I recommend buying locally grown fruits and vegetables when available. You're more likely to find fresh, ripe produce at farmers' markets or farm stands than in supermarkets, and the fruits and vegetables are less likely to be waxed and sprayed with pesticides. Better yet, if possible, grow your own vegetables in your backyard.
When you do buy commercially grown vegetables, be sure to peel such vegetables as carrots, potatoes, cucumbers and acorn squash. To reduce your exposure to pesticides, I also recommend washing green beans and leafy vegetables in a solution of one teaspoon of dishwashing detergent to a gallon of water. Swirl the fruits and vegetables in the solution and then rinse them well with warm water.
Andrew Weil, M.D.