Sarcopenia & Muscle Preservation

Older adults have anabolic resistance — the same protein dose that maximally stimulates muscle protein synthesis in young adults (20 g) is sub-threshold in older adults. Trial evidence and the PROT-AGE position paper both recommend 30-40 g of high-quality protein per meal, hitting at least 1.2 g/kg/day total. Whey delivers the highest leucine content per gram, which is the primary trigger for muscle protein synthesis. If appetite is limited, an essential amino acid (EAA) blend at 10-15 g is more efficient per gram than whole protein.^{[1, 2, 3]}

The Candow 2019 review summarized multiple trials showing creatine combined with resistance training in older adults produces substantial gains in muscle mass, strength, and physical function — larger than either intervention alone. Creatine also has emerging evidence for bone density and falls prevention in this group. No loading phase needed; daily consistency over 3-4 weeks saturates muscle stores. Monohydrate is the gold-standard form; expensive variants offer no advantage.^{[4, 5, 6]}

Leucine is the primary amino acid trigger for muscle protein synthesis. Katsanos 2006 demonstrated that older adults need a higher proportion of leucine in an amino acid mix than young adults to maximally stimulate MPS — additional leucine alongside meals can overcome anabolic resistance when total protein intake is borderline. HMB (beta-hydroxy-beta-methylbutyrate) is a downstream leucine metabolite with strong evidence in older adults, particularly during illness, hospitalization, or unintended weight loss. The Wu 2015 meta-analysis showed HMB preserved muscle mass in older adults across seven RCTs. Choose leucine if protein intake is adequate; choose HMB if dealing with illness, immobility, or sarcopenia confirmed by DEXA.^{[7, 8, 9]}

Vitamin D deficiency correlates strongly with sarcopenia and weakness in older adults. The Bischoff-Ferrari 2009 BMJ meta-analysis showed supplemental vitamin D at 700-1000 IU/day reduced fall risk in older adults by roughly 19%. Falls are the bridge between sarcopenia and fracture, so the falls-prevention benefit compounds with the muscle benefit. Get a 25(OH)D blood test and aim for the 30-50 ng/mL range. Most older adults living at higher latitudes or with limited sun exposure need 1000-2000 IU/day to reach that range.^{[10, 11, 12]}

Smith 2011 showed that 4 g/day of omega-3 fish oil for 8 weeks enhanced the muscle protein synthesis response to amino acids and insulin in older adults — a direct mechanistic answer to anabolic resistance. Smith 2015 followed up with a 6-month trial showing fish oil increased thigh muscle volume and grip strength in healthy older adults. The signal is consistent but the evidence base is smaller than for the foundational interventions, so this stays in the experimental tier. The benefit likely runs through dampening chronic inflammation and modulating muscle membrane composition.^{[13, 14, 15]}