Listener Jenny, who enjoys a 90% cocoa bar from time to time, got in touch to ask if some of the reports that dark chocolate can have a positive effect on things like circulation and mood - have any truth behind them? 

But Jenny also told Sliced Bread that since she read reports that heavy metals such as lead and cadmium could be in dark chocolate - she's been unable to enjoy her regular bar, until she knows it's safe to eat!

Each episode Greg investigates the latest ad-hyped products and trending fads promising to make us healthier, happier and greener. Are they really 'the best thing since sliced bread' and should you spend your money on them? If you’ve seen an ad, trend or wonder product promising to make you happier, healthier or greener, email us at sliced.bread@bbc.co.uk or send a voice note to our WhatsApp number, 07543 306807.

RESEARCHER: PHIL SANSOM  PRODUCERS: KATE HOLDSWORTH & GREG FOOT