Shelling out

Eggshells are a great source of calcium, but think again if you're contemplating adding them to your diet.

- BY JENNIFER BOWDEN

We're encouraged to eat what we would normally discard to combat food waste. An example is orange skin - high in vitamin C and fibre - which I cut finely and add to anything. But what about egg shells: with their high calcium content could they see the end of osteoporosis?

Many readers are getting creative about using parts of foods that once went straight into the bin. Orange peel in baking, eating kiwifruit with skin on, broccoli stems grated into slaws, carrot-top pesto - they're all great ideas. But eggshells?

It’s true that eggshells are packed with calcium. In fact, they are made of about 95% calcium carbonate, the same form used in many commercial calcium supplements.

But chewing or swallowing pieces of hard, sharp eggshell is not safe. They can scratch or damage the mouth, throat or digestive tract.