Many of us have our own theories about sleep. Perhaps it's avoiding coffee after lunch, drinking chamomile tea before bed, or having a warm glass of milk. But what does the science actually say?

In this episode of The Food Chain, Ruth Alexander explores the relationship between food and sleep, asking whether changing what we eat and drink can help us get a better night's rest.

Professor Marie-Pierre St-Onge, Director of the Center of Excellence for Sleep & Circadian Research at Columbia University, explains what decades of research have revealed about the links between diet and sleep quality. She discusses why poor sleep can change our food choices, how certain dietary patterns are associated with better sleep, and why scientists are increasingly interested in nutrients such as fibre and tryptophan.

Sleep physician Dr Allie Hare, President of the British Sleep Society, brings the perspective of the clinic. She explains the questions patients ask most often, from caffeine and alcohol to herbal remedies and sleep supplements, and discusses some of the biggest misconceptions people have about improving their sleep.

Together, they discuss whether there really are "sleep foods", what role meal timing might play, and how social media trends and expensive supplements can distract us from the basics.

Along the way, they answer listeners' questions and share practical, evidence-based advice on the changes you can make today to improve your chance of a good night's sleep tonight.

The history of smoking foods stretches back many years, but when did what began purely for preservation become a highly sought-after flavour? In this episode of The Food Chain, Ruth Alexander explores the origins of smoked foods and finds out why their flavours are so appealing to so many people around the world. She visits a smokehouse run by Michael Price in the port city of Lancaster in north-west England, where he explains the techniques used to flavour a variety of fish, as well as some of the more unusual demands he’s received from chefs. We learn about the science behind smoked flavours from Professor Heather Smyth, a flavour chemist and sensory scientist at the University of Queensland in Brisbane, Australia. And food historian, Professor Ken Albala, walks us through thousands of years of history via a meal prepared using his own home smoker in Stockton, California. We also investigate the impact of EU legislation with the European Food Safety Authority, following a European ban on several smoke flavour additives, and ask what this might mean for the future of smoked foods.

Music is part of the backdrop to millions of meals every day. But what if it is doing more than simply creating atmosphere?

In this episode of The Food Chain, Rumella Dasgupta explores the growing evidence that sound can shape the way we experience food and drink. From scientists studying how the brain combines hearing and taste, to chefs designing dishes around playlists, we ask whether music has become an ingredient in its own right.

Chef Gaggan Anand explains why music sits at the centre of his restaurant in Bangkok, where sound, lighting and food are carefully choreographed into a single experience. Cognitive neuroscientist Ophelia Deroy shares research showing how music can influence our perception of sweetness, bitterness and texture, and explains why flavour is far more than what happens on the tongue.

We also hear from Ola Sars, founder of the business music platform Soundtrack, whose company helps restaurants, cafés and hotels tailor the music they play. He shares research suggesting that the right soundtrack can influence customer behaviour and even affect sales.

But not everyone is convinced. Dan Keeling, co-owner of London's Noble Rot restaurants and a former music industry executive who signed artists including Coldplay and Lily Allen, explains why he has chosen not to play music in his dining rooms at all.

From silent restaurants to carefully curated playlists, from neuroscience labs to commercial dining rooms, we explore the increasingly important role sound plays in the way we eat.