Introduction
Sarcopenia — derived from the Greek words sarx (flesh) and penia (loss) — is the progressive, age-related loss of skeletal muscle mass, strength, and function. First formally defined by Rosenberg in 1989, sarcopenia is now recognised as a major geriatric syndrome and an independent risk factor for disability, falls, fractures, hospitalisation, and premature mortality.
Muscle mass peaks in the third to fourth decade of life and begins to decline at approximately 1% per year from the age of 40. After 60, this rate accelerates to 1.5–2% per year, with muscle strength declining even more rapidly — at approximately 2–3% per year. By the age of 80, individuals may have lost up to 50% of their peak muscle mass.
Pathophysiology of Sarcopenia
Sarcopenia is multifactorial in aetiology, involving complex interactions between hormonal, neurological, nutritional, and inflammatory mechanisms:
Hormonal Changes
- Testosterone: Declines progressively in men from the fourth decade; testosterone is anabolic and directly stimulates muscle protein synthesis (MPS) and satellite cell activation.
- Oestrogen: Post-menopausal decline in women is associated with accelerated muscle loss and increased adipose infiltration of muscle tissue.
- Growth Hormone (GH) and IGF-1: GH secretion declines with age (somatopause), reducing IGF-1 levels and impairing MPS and satellite cell proliferation.
- Insulin resistance: Age-related insulin resistance impairs the anabolic response of muscle to both insulin and amino acids — a phenomenon termed "anabolic resistance."
Neurological Factors
Age-related loss of alpha motor neurons leads to denervation of fast-twitch (Type II) muscle fibres, which are preferentially lost in sarcopenia. Reinnervation by slow-twitch motor units partially compensates but results in reduced power and speed of contraction.
Chronic Low-Grade Inflammation
Inflammageing — the chronic, low-grade inflammatory state associated with ageing — is characterised by elevated circulating levels of pro-inflammatory cytokines including IL-6, TNF-α, and CRP. These cytokines activate the ubiquitin-proteasome pathway, accelerating muscle protein degradation and inhibiting MPS.
Anabolic Resistance
Older muscle demonstrates a blunted MPS response to both protein ingestion and resistance exercise compared to younger muscle. This anabolic resistance means older adults require higher protein intakes and greater exercise stimulus to achieve equivalent rates of MPS.
Clinical Consequences
- Falls and fractures: Reduced muscle strength and power impair balance and gait stability, significantly increasing fall risk.
- Functional decline: Loss of lower limb strength impairs activities of daily living — rising from a chair, climbing stairs, and walking — leading to loss of independence.
- Metabolic consequences: Skeletal muscle is the primary site of postprandial glucose disposal. Sarcopenia contributes to insulin resistance, type 2 diabetes, and metabolic syndrome.
- Increased surgical risk: Sarcopenic patients have poorer surgical outcomes, longer hospital stays, and higher complication rates.
- Mortality: Multiple prospective studies demonstrate that low muscle mass and grip strength are independent predictors of all-cause mortality in older adults.
Diagnosis
The European Working Group on Sarcopenia in Older People (EWGSOP2) defines sarcopenia by the presence of low muscle strength (primary criterion) plus either low muscle quantity/quality or low physical performance. Assessment tools include grip strength dynamometry, the chair stand test, gait speed measurement, DXA scanning, and bioelectrical impedance analysis (BIA).
Nutritional Strategies
Protein Intake
Adequate dietary protein is the cornerstone of sarcopenia prevention and management. Current evidence supports 1.2–1.6 g of protein per kg of body weight per day for older adults, with 25–40 g of high-quality protein per meal to maximally stimulate MPS. Leucine — the primary trigger for MPS via mTORC1 activation — should be prioritised.
Whey Protein Isolate
Whey protein isolate (WPI) is rapidly digested and has the highest leucine content of any protein source (~10–11% leucine by weight), making it particularly effective at stimulating MPS in older adults. Multiple RCTs demonstrate that whey protein supplementation, combined with resistance exercise, significantly increases muscle mass and strength in sarcopenic older adults.
We recommend:
- PURE Whey Protein — a clean, high-quality whey protein for daily muscle support
- True WPI 90 Rich Chocolate — a premium 90% whey protein isolate with superior amino acid profile
- True WPI 90 Strawberry & Cream — high-quality isolate in a great-tasting flavour
- True WPI 90 Natural — unflavoured, minimally processed isolate for versatile use
Creatine Monohydrate
Creatine is one of the most extensively researched ergogenic supplements. In older adults, creatine supplementation (3–5 g/day) combined with resistance training has been shown to increase muscle mass, strength, and functional performance.
We stock:
- Designs For Health Creatine Monohydrate — practitioner-grade, ultra-pure creatine monohydrate
- RN Labs Creatine Monohydrate Powder — a high-quality NZ-available option
- NOW Creatine Monohydrate Micronised Powder — micronised for better mixability and absorption
- My Way Up Pure Creatine — a clean, no-filler creatine monohydrate option
Vitamin D
Vitamin D receptors are expressed in skeletal muscle, and Vitamin D plays a direct role in muscle protein synthesis, fibre size, and neuromuscular function. Deficiency is associated with muscle weakness, impaired balance, and increased fall risk. Supplementation in deficient older adults improves muscle strength and reduces fall incidence.
Omega-3 Fatty Acids
EPA and DHA have demonstrated anti-inflammatory and anabolic properties in skeletal muscle. Omega-3 supplementation (2–4 g/day) has been shown to enhance the MPS response to amino acids and insulin in older adults, partially overcoming anabolic resistance.
- Bepure Three Fish Oil — a concentrated omega-3 formulation for daily use
- About Health Lester's Oil — a premium omega-3 blend supporting muscle and joint health
Magnesium
Magnesium is required for over 300 enzymatic reactions, including those involved in ATP synthesis and muscle contraction. Low magnesium status is associated with reduced muscle strength and physical performance in older adults.
- RN Labs Magnesium Glycinate — a highly bioavailable form ideal for muscle function and sleep
- RN Labs Magnesium Citrate — well-absorbed and gentle on digestion
- UltraMag Magnesium — a multi-form magnesium complex for comprehensive support
Exercise
Progressive resistance training (PRT) is the most effective intervention for sarcopenia. Recommendations include 2–3 sessions per week targeting major muscle groups, with progressive overload and compound movements (squats, deadlifts, rows, presses) for maximal muscle recruitment.
Conclusion
Sarcopenia is not an inevitable consequence of ageing — it is a modifiable condition. Early identification and intervention through optimised protein nutrition, targeted supplementation, and progressive resistance training can significantly attenuate muscle loss, preserve functional independence, and improve quality of life in older adults. At The Wellness Store, our team can guide you toward evidence-based nutritional strategies and practitioner-quality supplements to support healthy muscle ageing.
This article is for educational purposes only and does not constitute medical advice. Please consult your healthcare provider before commencing any new supplement or exercise programme.