Frailty & Ageing (Anti-ageing)

Summary — Frailty is an ageing-related field in which stem cell research has reached randomised, double-blind, placebo-controlled studies. A University of Miami team followed a phase I study of 15 frail older adults with a randomised, double-blind phase II study of 30 people (2017), reporting improved six-minute walk distance and reduced inflammatory markers in one dose group. These studies measured specific physical function and blood markers; they did not show people 'becoming younger' or ageing being 'reversed'.

What is frailty?

Frailty is a state in which muscle strength, activity, walking speed, weight and vitality decline together with age, so that health collapses easily under minor stresses such as a cold, a fall or a hospital stay. It is different from simply being old: among people of the same age, some are frail and some are not. Frail older adults face higher risks of falls, long-term care, hospitalisation and death. In Japan the term フレイル is widely used, and community programmes to detect and manage frailty early are active.

Frailty arises from a combination of muscle loss (sarcopenia), chronic low-grade inflammation, poor nutrition, multiple chronic diseases and medications, and social isolation. In particular, the persistent low-grade inflammation that develops with age is known to be closely linked to frailty.

Current standard management

Exercise — especially strength and balance training — is the foundation of frailty management, together with adequate protein and energy intake, nutrients such as vitamin D, review of unnecessary medicines, management of chronic diseases and social participation. Many studies show that such management can improve frailty or slow its progression. Stem cell research aims to test whether, alongside this basic management, it is possible to act directly on the biological background of frailty: chronic inflammation and reduced tissue resilience.

Why stem cells are studied

With age, the number and function of the body's stem cells decline and tissues recover less well from damage. Researchers hypothesised that intravenous mesenchymal stem cells from young donors might, through the factors they secrete, reduce chronic inflammation and support vascular function and tissue repair, improving physical function.

Reported research findings

① Phase I study (University of Miami, US, 2017) — an open-label study in which 15 older adults meeting frailty criteria received a single intravenous infusion of allogeneic mesenchymal stem cells from young donors. The main aim was safety, and no serious infusion-related adverse events were reported. Improvements in six-minute walk distance, physical function measures and blood inflammatory markers (such as TNF-α) were reported after infusion.

② Randomised, double-blind, placebo-controlled phase II study (University of Miami, US, 2017) — 30 people were randomised to two cell doses (100 million and 200 million) or placebo. At six months, six-minute walk distance improved significantly more in the 100-million group than with placebo, and blood inflammatory markers decreased. Interestingly, the same degree of difference was not seen in the 200-million group, which received more cells. Both studies were published in a gerontology journal. The investigators acknowledged the small size and said larger studies were needed.

The gap to 'anti-ageing'

These studies measured specific outcomes such as walking distance, physical function scores and blood inflammatory markers. They did not show younger-looking skin, longer life or reversal of ageing itself. Information about stem cell interventions promoting skin beauty, general vitality or 'rejuvenation' should be checked against the population and measures of the underlying studies.

Safety and points to note

In clinical trial settings, intravenous allogeneic mesenchymal stem cells were generally well tolerated, but older adults often have multiple conditions and medications, so risk must be assessed individually. The ISSCR warns about stem cell interventions sold without evidence, and the U.S. Food and Drug Administration (FDA) provides information on the risks of unapproved stem cell interventions.

Open questions

Tasks in this field include confirming efficacy in larger randomised studies and determining the right dose, dosing interval and duration of effect. It also needs to be established what added benefit there is compared with, or in combination with, exercise and nutritional management.

How frailty is diagnosed and measured

The best-known criteria for frailty are the frailty phenotype proposed by Fried: unintentional weight loss, self-reported exhaustion, low physical activity, slow walking speed and weak grip strength. Meeting three or more indicates frailty, and one or two indicates pre-frailty. In Japan, the J-CHS criteria, adapted for the Japanese population, are widely used.

Treatment studies use outcomes such as the six-minute walk test, which measures distance walked in six minutes; the Short Physical Performance Battery (SPPB, scored out of 12), combining balance, gait speed and rising from a chair; grip strength; and questionnaires on daily activities and quality of life. The University of Miami studies measured blood inflammatory markers such as TNF-α along with six-minute walk distance. Six-minute walk distance is known to reflect older adults' mobility and prognosis well, but it varies with condition and motivation, so comparison with a placebo group is important.

The above summarises results reported in published papers and public-agency materials. University and institute names are given to identify research sources, not to introduce or recommend any medical institution. Reported results do not mean the same effect for everyone, and the suitability of any treatment is decided by the medical team.

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