Despite the worst U.S. recession in decades, sales of organic and sustainable products have continued to grow, experts say, with shoppers willing to spend a few more dollars in a bid to become more green.

U.S. supermarket sales of environmentally sustainable or "ethical" products - from energy-efficient light bulbs to organic produce - will rise about 8.7 per cent in 2009 to nearly $38 billion, according to a recent study by Packaged Facts, a market research provider.

President Barack Obama's commitment to tackle climate change, a string of scandals over tainted food and effective marketing of sustainable products have helped convince more Americans to buy green.

"I've been reading about carbon footprints," said Lindsey Hoffman, 24, as she selected organic lettuce at a Whole Foods Market in Manhattan, "and though I'd prefer to go to a farmer's market, this is better than anything else."

"When I walked in I saw gorgeous asparagus, but as it's $4 a bunch and flown in from Peru, I stayed away," she said.

While sustainable and organic goods have traditionally occupied the premium shelves of supermarkets, an increasing number of retailers such as Wal-Mart Stores Inc. and Safeway Inc. have expanded their offerings and some prices now rival conventional products.

Sales of goods specifically labeled organic rose 17 per cent to $24.6 billion in 2008, according to the Organic Trade Association.