Can jug or under sink filters, promising to soften tap water and improve taste, really take out what they claim?

Greg Foot gathers the experts live at Cheltenham Science Festival, dives into the data and crunches the numbers to get answers for listener Elaine.

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?

All of our episodes start with YOUR suggestions. 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 AND GREG FOOT