Prevention

5.3.1 Supplements and nutraceuticals

Supplements and nutraceuticals have emerged as accessible adjuncts in the pursuit of healthy ageing, yet their impact on healthspan and lifespan remains comparatively modest, ranging from adding months to a couple of years, and, in many cases, insufficiently quantified in human populations to date.

Vitamin D: supplementation, particularly in older adults, has been associated with improved bone health and reduced risk of fractures: a meta-analysis found that vitamin D supplementation significantly reduced the risk of falls and fractures among elderly populations, contributing to better mobility and independence later in life (Bolland et al., 2014).

Vitamin B12: is essential for neurological function and red blood cell formation; supplementation is especially beneficial in older adults and those following plant-based diets, with research showing that correcting B12 deficiency can help to prevent cognitive decline and anaemia (O’Leary & Samman, 2010).

Other supplements: with emerging evidence include omega-3 fatty acids, which have been linked to reduced cardiovascular risk and improved cognitive function in older adults (Kromhout et al., 2010), and antioxidants such as coenzyme Q10, which may support mitochondrial function and reduce oxidative stress.

NAD+ boosters: including nicotinamide riboside (NR) and nicotinamide mononucleotide (NMN) are designed to replenish cellular NAD+ levels which decline with age, affecting mitochondrial function and cellular repair mechanisms. Preclinical studies in mice have demonstrated that NR supplementation can enhance mitochondrial function, improve insulin sensitivity, and increase endurance (Yoshino et al., 2011), while some studies suggest up to a 5–10% increase in mean lifespan in rodent models (Zhang et al., 2016). In humans, however, Martens et al. (2018) found that 1000 mg/day NR supplementation raised NAD+ levels and reduced systolic blood pressure (~10 mmHg) in older adults over 6 weeks, but did not produce statistically significant improvements in physical performance or metabolic health over this short time frame. No human studies to date have demonstrated an increase in lifespan attributable to NAD+ boosters.

Resveratrol: a polyphenolic compound found in grapes used to make red wine has been extensively investigated for its putative role as a caloric restriction mimetic and activator of sirtuin pathways. In animal models, resveratrol supplementation has increased mean lifespan by approximately 20–30% in lower organisms (Howitz et al., 2003; Wood et al., 2004), but in mammals, results are less dramatic and depend on genetic background and diet (Baur et al., 2006). In human trials, resveratrol has improved some surrogate endpoints—such as insulin sensitivity (Timmers et al., 2011)—but meta-analyses confirm a lack of robust, long-term data on healthspan or lifespan gains in humans (Sahebkar et al., 2015). At present, the estimated benefit in humans is unlikely to exceed a few months of improved healthspan, and no clinical trial has demonstrated a statistically significant increase in human lifespan with resveratrol supplementation.

However, it is important to note that while some supplements show clear benefits in specific populations or conditions, indiscriminate use is not universally recommended and may even carry risks. The efficacy of these interventions often depends on individual health status, genetic factors, and baseline nutrient levels, underlining the need for personalised approaches and further clinical research to clarify optimal use for healthspan and lifespan extension.