Exercise and diet raised levels of klotho, an anti-aging protein

Klotho has one of the most arresting back stories in aging biology: turning the gene down produces aging-like changes, while overexpression can extend lifespan. The protein comes in several forms, including a membrane-bound version concentrated in the kidney and brain and a secreted version that circulates in blood, urine and cerebrospinal fluid, where it helps regulate phosphate metabolism and hormone-like growth factors. One interaction, between β-klotho and FGF21 in muscle, is thought to be critical in the development of sarcopenic obesity, the combination of excess fat and shrinking muscle. That raises a practical question: do klotho levels actually track with obesity and muscle loss in people, and can lifestyle shift them?

The authors ran a systematic review, registered in advance on PROSPERO and conducted following PRISMA guidelines, asking how klotho levels behave in adults with obesity or sarcopenic obesity. They screened 713 articles and selected 20 studies for inclusion. The included work spanned observational, cross-sectional and cohort studies as well as clinical trials. Participants were overweight, obese or sarcopenic obese adults, compared against people with a normal body mass index, with circulating klotho levels as the common thread across the evidence.

Across the included studies, significant associations emerged between klotho levels and obesity, metabolic syndrome and cardiovascular risk. Exercise and dietary interventions positively influenced klotho levels. Higher levels, in turn, were linked to improved muscle strength and a slower decline. On that basis the authors position klotho as a potential biomarker for obesity, metabolic syndrome and sarcopenic obesity, while stressing that its mechanisms and any therapeutic potential still need to be worked out.

Most of what made klotho famous came from genetic work, where dialling the gene up or down changed how organisms aged. This review gathers the human evidence and finds the protein behaving much as that story would predict, tracking metabolic health and responding to lifestyle change. What it cannot settle is direction. Because most included studies followed people rather than manipulating klotho directly, nobody yet knows whether low klotho helps cause metabolic trouble or simply reflects it, and whether deliberately raising it would change outcomes.

Klotho is not something you can order on a routine blood panel, and this review does not turn it into one. What it offers is a reason to think the familiar habits, regular training and a careful diet, reach deeper into aging biology than the scale or the mirror shows. It also adds a candidate explanation for why active people tend to hold on to muscle strength for longer. For now this is knowledge rather than a protocol: there is no klotho pill, and no proof that raising the protein directly would help.