Protein and Creatine Supplement Use Expands Beyond Niche Demographics

Protein and creatine supplements, historically associated with bodybuilding and elite sports, have seen a significant expansion in their user base. This shift is driven by increased public awareness of their purported benefits for muscle synthesis, strength, and cognitive function, extending to general fitness enthusiasts, older adults, and individuals seeking general wellness. This widespread adoption necessitates that healthcare providers possess a foundational understanding of these compounds.

Physiological Mechanisms and Clinical Relevance

Dietary protein, comprising amino acids, is fundamental for muscle protein synthesis, tissue repair, and various metabolic processes. While adequate protein intake can typically be achieved through diet, protein supplements, such as whey, casein, and plant-based options, offer a convenient method to increase daily protein consumption. This can be particularly relevant for individuals with higher protein requirements, such as athletes, or those with inadequate dietary intake, including some older adults at risk of sarcopenia. For instance, a systematic review published in 2015 indicated that protein supplementation, when combined with resistance training, can enhance muscle mass and strength in both younger and older adults.¹

Creatine, a naturally occurring guanidino compound, is primarily stored in skeletal muscle as phosphocreatine. It plays a critical role in the rapid regeneration of adenosine triphosphate (ATP), the primary energy currency of cells, particularly during short, intense bursts of activity. Supplementation with creatine monohydrate has been extensively studied. A meta-analysis from 2003, encompassing 100 studies, demonstrated that creatine supplementation typically increases muscle creatine and phosphocreatine stores by 10% to 40%.² This elevation in intramuscular creatine has been consistently shown to improve high-intensity exercise performance, increase lean body mass, and enhance strength.^2,3 Beyond athletic performance, emerging research is exploring creatine's potential neuroprotective effects and its role in cognitive function, particularly in conditions involving energy metabolism deficits.⁴

The safety profile of both protein and creatine supplements is generally favourable when used appropriately. Protein supplements are typically well-tolerated, with gastrointestinal discomfort being the most common reported side effect, often linked to lactose intolerance in whey protein users. Creatine monohydrate is also considered safe for healthy individuals. Concerns regarding renal dysfunction with creatine use have largely been unsubstantiated by clinical research in individuals with normal kidney function. A 2019 position statement by the International Society of Sports Nutrition concluded that creatine monohydrate is safe and effective for increasing muscle mass and strength, with no evidence of adverse effects on kidney or liver function in healthy individuals.⁵ However, caution is advised for individuals with pre-existing renal conditions, where creatine supplementation could potentially exacerbate kidney stress.⁶

Clinicians should be prepared to discuss the appropriate use, potential benefits, and any contraindications with patients. This includes assessing dietary intake, activity levels, and underlying health conditions. For example, patients with chronic kidney disease should avoid creatine supplementation due to the theoretical risk of accelerating disease progression.⁶ Furthermore, the quality and purity of supplements vary widely, underscoring the importance of advising patients to select products from reputable manufacturers that undergo third-party testing.