Cancer, Sarcopenia, and Nutrition: What Works After 65?

Older adults with cancer have good reason to care about muscle before treatment begins. Low skeletal muscle is associated with poorer outcomes in several cancer settings, while treatment can coincide with further loss. Yet the clinical question people actually need answered—what nutrition preserves muscle during cancer treatment?—has received remarkably little direct study.

The best current review found only nine eligible studies after screening 1,439 papers published from 2016 through 2024. Pattwell et al.'s 2026 systematic review focused specifically on adults aged 65 or older with cancer and confirmed or likely sarcopenia. It found preliminary signals that protein supplementation improved lean body mass and skeletal muscle index in some randomized trials. It did not identify enough comparable evidence to tell patients which protein dose, supplement, timing strategy, or cancer-treatment setting works best.

That is an unsatisfying answer, but it is an honest one. Muscle matters in oncology; the nutrition playbook is still under construction.

Why muscle loss deserves attention during cancer care

Sarcopenia means low muscle mass and function, often accompanied by weakness and reduced physical reserve. In cancer care, it can overlap with reduced appetite, swallowing problems, inflammation, inactivity, surgery, chemotherapy, radiotherapy, and hormonal treatment. Those forces do not arrive one at a time and politely wait their turn.

The prognostic evidence is strongest in head and neck cancer. A 2024 systematic review and meta-analysis pooled 37 studies with 11,181 participants and found that CT-defined sarcopenia was associated with poorer overall survival in people with head and neck cancer; the pooled adjusted hazard ratio was 2.11. This is an association, not evidence that restoring muscle will double survival or reverse the risk. It does establish that low muscle status identifies a group with substantially worse outcomes.

Other studies point in the same direction without proving the same mechanism. In a retrospective study of 174 patients with stage III–IVB oral squamous cell carcinoma treated with surgery and chemoradiotherapy, Lee et al. assessed skeletal muscle index on CT at the third cervical vertebra and systemic inflammation with the modified Glasgow prognostic score. Sarcopenia and systemic inflammation together predicted worse survival. The combination may identify patients with more severe disease burden or catabolism; it does not show that an anti-inflammatory diet changes survival.

CT-based measurement has practical appeal because cancer patients often already undergo imaging. A retrospective analysis of 283 patients treated with definitive radiotherapy for head and neck squamous cell carcinoma examined six C3-level CT body-composition measures before treatment. The study found prognostic value for skeletal muscle status. C3 muscle area is a useful surrogate for whole-body muscle status, but it is a measurement tool, not a treatment.

The direct nutrition evidence: encouraging, but too uneven to prescribe

Pattwell and colleagues used a systematic-review approach designed for a narrow clinical population: cancer, age 65 or older, confirmed or likely sarcopenia, and a nutritional intervention with quantifiable outcomes. The studies varied by cancer type, treatment regimen, intervention, and outcome measure, so the authors used narrative synthesis rather than forcing incompatible results into a pooled estimate.

The nine studies included protein supplementation, nutritional counseling, enteral feeding, and multimodal programs. Protein supplementation improved lean body mass and skeletal muscle index in some randomized controlled trials. Those are meaningful signals, particularly because lean mass loss is common during treatment. But the review does not supply a reliable cancer-specific dose comparison such as 1.0 versus 1.2 versus 1.5 grams of protein per kilogram per day. Nor does it establish whether supplementation works best before treatment, during treatment, or throughout recovery.

Lean body mass and skeletal muscle index are also surrogate outcomes. They may matter, but they do not automatically translate into better strength, fewer hospitalizations, greater treatment completion, better quality of life, or longer survival. A patient can retain a little more lean mass without gaining enough functional reserve to change day-to-day life. Oncology trials need validated functional outcomes alongside CT-based muscle measures.

The review also reported observational associations between higher fish intake, dietary fat intake, and lower sarcopenia risk. These findings fit a plausible interest in omega-3 fatty acids, but they do not justify an EPA or DHA dose recommendation for older people receiving cancer treatment. Dietary patterns can track with appetite, income, baseline health, and disease severity. Observational nutrition data are rarely a clean supplement trial wearing a trench coat.

What HMB and resistance training can—and cannot—add

HMB, or beta-hydroxy-beta-methylbutyrate, is a metabolite of leucine often marketed for muscle preservation. The evidence is more mature outside oncology. A 2021 systematic review and meta-analysis of HMB in older adults found positive effects on lean body mass, but it did not study older adults undergoing cancer treatment. Active cancer treatment brings inflammation, toxicity, altered intake, and treatment-specific catabolism that make direct extrapolation unsafe.

A 2022 study of older sarcopenic adults after hip replacement examined resistance training combined with HMB. It supports the feasibility of pairing nutrition with exercise in a post-surgical catabolic setting, not an oncology-specific protocol. Postoperative recovery and chemotherapy are not interchangeable physiologic states.

Resistance training has the strongest general evidence base for sarcopenia. In a 2024 meta-analysis of 22 randomized trials involving 959 sarcopenic older adults, resistance training produced small improvements in relative muscle mass (standardized mean difference 0.25, 95% confidence interval 0.06 to 0.45) and absolute muscle mass (0.28, 0.06 to 0.50). It produced larger improvements in handgrip strength (0.83, 0.43 to 1.23) and knee-extension strength (0.90, 0.50 to 1.30). These participants were not defined as older adults receiving active cancer treatment, so the effect sizes are a benchmark, not a promise.

A 2026 review of resistance training plus amino acid-based supplements reaches the same broad non-cancer question: combined approaches may help older adults with sarcopenia. Cancer-specific trials must still determine whether people can tolerate the training, whether the nutrition changes outcomes, and which patients benefit.

Treatment and medication can complicate the picture

Muscle loss has been documented alongside cancer therapies, but association should not be confused with proof of a single cause. In high-risk prostate cancer, a study of 125 patients receiving radiotherapy and androgen-deprivation therapy measured CT-derived body composition at baseline and within a year. Patients lost an average 5.5% of skeletal muscle index over 180 days (95% confidence interval −7.0% to −4.0%; p<0.001), and muscle loss was associated with higher non-cancer mortality. That study cannot show that a supplement would prevent either muscle loss or mortality.

Observational research has also linked skeletal muscle loss during neoadjuvant chemotherapy with breast-cancer treatment response, but it does not prove chemotherapy directly caused the loss or that nutrition would prevent it. Meanwhile, GLP-1 receptor agonists deserve a medication review in patients already vulnerable to muscle loss. A 2025 network meta-analysis of 22 randomized trials with 2,258 adults with diabetes, overweight, or obesity found that GLP-1 receptor agonists reduced lean mass by a mean 0.86 kg versus comparators (95% confidence interval −1.30 to −0.42 kg). This was not a cancer population, but it is relevant when clinicians weigh metabolic benefits against muscle reserve.

What patients can reasonably do now

Older patients with cancer should not self-prescribe a high-dose protein, HMB, or omega-3 regimen based on the current evidence. Kidney disease, swallowing difficulty, gastrointestinal toxicity, drug interactions, weight trajectory, and the planned treatment all change what is safe and feasible. The useful next step is early assessment: ask the oncology team, oncology dietitian, or rehabilitation clinician about unintentional weight loss, intake, strength, physical function, and whether existing CT imaging can help assess muscle status.

For people medically cleared to exercise, resistance training and adequate nutrition are sensible components of supportive care because the non-cancer sarcopenia evidence supports both muscle and strength gains. That general principle should not be mistaken for a proven cancer-treatment protocol. The direct evidence supports cautious optimism about protein supplementation, not a precise prescription.

The science has identified the problem more clearly than the solution: low muscle is linked to worse cancer outcomes, while adequately powered trials have yet to show which nutritional strategy preserves function during treatment in adults over 65.

The next useful studies should compare clearly defined interventions, use CT-measured skeletal muscle and validated functional outcomes, and follow patients through treatment rather than stopping at a laboratory measure. Until then, the strongest claim is also the least glamorous: screen early, individualize care, and do not confuse biological plausibility with proof.