Researchers found that tooth loss is linked to slower walking speed and poorer memory function in older people.The research team from University College London (UCL) in the UK analyzed data from over 3,100 adults aged 60 and over living in England. The study was published in the American Geriatrics Society.

The data came from the English Longitudinal Study of Aging (ELSA) and allowed the researchers to compare performance in tests of memory and walking speed of participants who had none of their own teeth with equivalents who had some natural teeth.

The analysis showed that subjects who had lost all their natural teeth performed around 10% worse in both memory and walking than counterparts with natural teeth.

Lead author Dr. Georgios Tsakos, of UCL's Department of Epidemiology and Public Health, says the findings suggest: "Tooth loss could be used as an early marker of mental and physical decline in older age, particularly among 60-74 year-olds."

The link between total tooth loss and poorer memory performance became insignificant when researchers took into account a wide range of factors, such as age, gender, smoking, drinking,depression, physical health, and – in particular – socioeconomic status 

However, the link between total tooth loss and slower walking speed remained significant when all these influencers were taken into account; people with none of their natural teeth still walked slightly more slowly than peers who had some of their teeth.

The researchers also looked at the link between losing all natural teeth and having poorer memory and slower walking speed 10 years later. This was noticeably stronger in the adults aged 60-74 years than in those aged 75 and over.

"There are many factors likely to influence this decline," he suggests, "such as lifestyle and psychosocial factors, which are amenable to change." Total tooth loss is a rare condition in high-income households in the US nowadays; it has contracted geographically to states with disproportionately high poverty, note the authors.

Periodontal or gum disease is the most common cause of tooth loss among adults. A 2012 study by the Centers for Disease Control and Prevention (CDC) estimates that around half of the adult population in the US has periodontal disease, with cases ranging from mild to severe.

The prevalence is much higher in those living below the poverty line (over 65%), those with less than a high school education (nearly 67%), and among older Americans (around 70%), note the CDC. They add that among older Americans aged 65 and over, the prevalence rate is around 70%.