We all want to live as long as is possible, and for many years scientists have been exploring the subject of longevity to unlock its secrets with varying degrees of success, and so to explore ageing and metabolism I'm joined physiologist Prof Joseph Baur.

We ask exactly what causes ageing and why there is no consensus on this question.

We hear about calorie restriction and how it has been shown to increase the life of animals by up to 40%.

Dr Baur busts the myth of antioxidants' ability to stave off ageing.

Expect to hear about the molecule NAD, how it declines as we get older which seems to have an influence on the ageing process and we discover NAD's relationship with an enzyme called CD34. Dr Baur also tells us of the groundbreaking work he has done to discover an important NAD transporter that carries NAD from the cell cytoplasm into the mitochondria.

We also ask how do we boost NAD levels and what significance does NMN have?

Plus we hear about the market for anti-ageing NAD supplementation and why one needs to take anti-ageing assertions made by certain companies with a pinch of salt given the lack of clinical trials.