London - The “Delia effect” is a well-established phenomenon. If cookery writer Delia Smith recommends an ingredient in her cookery programmes, it causes a nationwide shortage.

Supermarkets famously ran out of cranberries in 1995 when Delia used them in a recipe.

Now, shops have spotted a new trend: The Nigella effect.

During Nigella Lawson’s Italian-inspired TV series Nigellissima, Marks & Spencer saw sales of Italian ingredients soar.

Oregano, which features in many of her dishes, was up 79 percent, while Parmesan sales increased by ten percent.

Italian olive oil sales soared by 67 percent and spaghetti by 20 percent.

The term “Delia Effect” became so common it got in the Collins English Dictionary in 2001. Will Nigellissima help Nigella make it into the 2013 edition? - Daily Mail