This study explored the association between lutein and zeaxanthin status and the incidence of frailty among community-dwelling adults aged ≥50 years in the Irish Longitudinal Study on Ageing (TILDA).
Musculoskeletal health declines with age, including a decrease in skeletal muscle mass and function, a reduction in bone mineral density, and a deterioration of bone microstructure. The adverse changes in bone and muscle that occur with ageing can lead to sarcopenia and osteoporosis.
This can result in impaired physical performance, mobility problems, falls, fractures, and compromised quality of life.
Nutrition, along with other healthy lifestyle factors (such as a physical activity), is well established as an important factor in preventing musculoskeletal decline and frailty in the elderly.
According to observational studies, consuming more fruit and vegetables is associated with improved musculoskeletal health and a lower incidence of deficiency in older adults.
Methods & Results
As part of Wave 1, plasma concentrations of lutein and zeaxanthin, as well as grip strength, typical gait speed, timed up-and-go (TUG), probable sarcopenia, and bone mass was measured (calcaneal broadband ultrasound stiffness index).
A longitudinal analysis determined the changes in usual gait speed, grip strength (at Wave 4), TUG (at Wave 5), probable sarcopenia (at Wave 4), and frailty (Fried’s phenotype, Frailty Index, FRAIL Scale, Clinical Frailty Scale-classification tree, at Wave 5). This study analyzed data using linear and ordinal logistic regression adjusted for confounders.
According to Fried’s phenotype, FRAIL scale, Clinical Frailty Scale, and Frailty Index, participants who were non-frail at Wave 1 had lower odds of progressing to higher frailty categories by Wave 5, based on plasma lutein and zeaxanthin concentrations.
After eight years of follow-up, higher plasma lutein and zeaxanthin concentrations were associated with a lower likelihood of incident frailty. In addition, several musculoskeletal health indices were positively associated with baseline plasma lutein and zeaxanthin concentrations cross-sectionally, but they were not predictive of longitudinal changes in these outcomes.
“Our observation that plasma lutein and zeaxanthin concentrations were modestly associated with several indices of physical performance (usual gait speed, TUG) cross-sectionally, but were not associated with changes in these outcomes over time, suggests that plasma lutein and zeaxanthin concentrations may be markers but not predictors of physical performance in older adults,” – the researchers concluded.
It has been proposed that oxidative stress contributes to frailty onset by damaging cellular macromolecules (carbohydrates, lipids, proteins, and DNA), causing cellular senescence, and upregulating proinflammatory cytokines, leading to the dysfunction of several tissues and organs.
As ageing decreases endogenous antioxidant defences, increasing exogenous antioxidant intake, such as carotenoids, through the diet may help restore redox balance and reduce oxidative damage.