Did you know that shelled nuts are more vulnerable to rancidity? That's because the protective casing of the shell has been removed. So be careful where you buy your shelled nuts (if you do); make sure there's a high turnover, and that they are organic if possible.

You would think shelled nuts were a fairly pure food product right? Well maybe not. Often the factories that shell nuts use chemicals in the process. Ethylene gas is often used to help release walnuts from the shell, they are protected from spoilage with methylbromide (a nervous system depressant), then blanched with a dip in hot dye (for a  pleasing colour) or a mixture of glycerine and sodium carbonate. For pretty coloured walnuts they are often bleached with a mixture of chloride of lime, and sodium carbonate. When you buy non organic grocery store nuts you're probably getting more than you bargained for.

The above is from a fabulous new book called "Unsafe at any Meal: How to Avoid Hidden Toxins in Your Food" by Dr Earl Mindell's.