Under the watchful gaze of Old Father Time, Martin Keown takes another step around the famous Lord’s turf as he reflects on how much we can lose as the clock ticks away.

Daily Mail Sport joined the former Arsenal and England defender as they and nearly 100 others walked a century of laps around the outfield – the equivalent of more than 31 miles – to bring up their own century at Lord’s and raise money for Alzheimer’s Society.

Keown’s mother Angela has lived with Alzheimer’s for more than 20 years, and now resides in a care home. Before then, he passed up the chance to work with Arsene Wenger after his playing career to help his dad care for her.

The former Arsenal and England defender also talks as we walk, his wife Nicola alongside him, about how a career playing the sport he loves has likely robbed him of precious time with his loved ones later in life, so close is the link between dementia and heading the ball.

Keown has admitted in the past his worries about a 21-year career heading a football. Towards the end of his playing days, he got dizziness and double vision when heading one travelling at speed.

‘The game you love has kind of taken away vital time ahead of me to spend with my loved ones,’ he says. ‘It’s like a paradox, isn’t it? But I made those choices. I didn’t know the outcome that playing football would be so problematic. But I don’t regret it.’

Only, as Keown is keen to point out, it is far from just footballers who are at serious risk. That is not the reason he’s here, walking lap after lap. One in three of us born in the UK will develop dementia in our lifetime and yet one in three people living with the condition do so without being diagnosed.

‘We need to create an awareness of what’s happening with dementia and Alzheimer’s,’ says Keown. ‘How poorly it’s funded and how, if you have a loved one in this terrible plight, how you get some help on this journey. Because it's a very difficult journey.’

Alzheimer’s disease and dementia remain the biggest killers in the UK, accounting for nearly 77,000 deaths a year. There remains no cure.

’It’s not just something you get when you’re old, let’s be clear about that,’ he adds. ‘When I go to visit my mum, I see quite young people. I wonder is it a carer or a patient and, invariably, it’s a patient.’

As always with dementia, it’s as much about the toll it takes on those close to the sufferer. ‘Who is caring for the carer? My father said “Look, we supported you for 22 years as a player”. I had a real dilemma but I needed to commit to my family. The most amount of care is coming from a loved one and you cannot put a price on that.

‘My dad said it was the biggest fight of his life to keep my mum at home. It really was. He learned to cook. He learned to sew. This was a guy that was in management and he just completely retrained himself. It was unbelievable.

‘My mum, believe it or not, could still iron. She was one of the quickest ironers. She could still remember. She didn’t want that taken away but then she’d leave the iron on and would burn herself. It was becoming dangerous but she could still remember. You hear of people with dementia still being able to play piano.’

‘When you’ve got a loved one, you just get drowned in it all. It becomes so solemn and you wonder what’s life for, what you’re battling for. You see someone work their whole life for their retirement and the minute they get there, they’re just looking out of the window like a mannequin.

It can demotivate you but we need to make sure that doesn’t happen to other people. That’s where the motivation has to be, doesn’t it? All of this walking takes us a step closer to finding a cure.’