From the Guidelines
Consuming 25 grams of whey protein daily is generally safe and potentially beneficial for a 55-year-old male, as it falls within the recommended protein intake guidelines for older adults and can help maintain muscle mass, which naturally declines with age. According to the most recent and highest quality study, older individuals exhibit a blunted post-prandial muscle protein synthesis (MPS) response to amino acid/protein intake when compared with younger individuals 1. This suggests that older adults may require more dietary protein to stimulate MPS, with approximately 0.4 g/kg/meal required to maximally stimulate MPS, compared to 0.24 g/kg/meal for younger individuals.
For a 55-year-old man, 25 grams of whey protein daily can contribute to overall daily protein needs and support recovery from exercise, helping to preserve lean body mass. Whey protein is a complete protein containing all essential amino acids and is particularly rich in leucine, which stimulates muscle protein synthesis. However, individuals with kidney disease should consult their healthcare provider before adding protein supplements, as they may need to limit protein intake 1. Those with dairy allergies or lactose intolerance should choose lactose-free or hydrolyzed whey options.
To maximize benefits, it is recommended to distribute protein intake throughout the day rather than consuming it all at once, and combine supplementation with regular resistance exercise. Staying well-hydrated when using protein supplements and being aware that some products may contain added sugars or artificial ingredients is also important. The estimated average requirement (EAR) for protein in men aged 19 to 50 years is 0.66 g/kg/d, but daily protein requirements differ across individuals, and older adults may require more protein to maintain muscle mass and overall health 1.
Some studies have investigated the effects of protein supplementation on lean body mass in older adults, with mixed results. For example, a study by Mitchell et al. (2017) found that protein intake at 1.6 g/kg/d increased lean body mass compared to 0.8 g/kg/d, while another study by Mertz et al. (2021) found no significant increase in lean body mass with protein supplementation 1. However, the most recent and highest quality study suggests that older adults require more dietary protein to stimulate MPS, supporting the recommendation for 25 grams of whey protein daily.
Key considerations for protein supplementation in older adults include:
- Distributing protein intake throughout the day
- Combining supplementation with regular resistance exercise
- Staying well-hydrated
- Choosing lactose-free or hydrolyzed whey options for those with dairy allergies or lactose intolerance
- Consulting with a healthcare provider for individuals with kidney disease
- Being aware of potential added sugars or artificial ingredients in protein supplements.
From the Research
Health Impact of 25g/day Whey Protein in 55-year-old Male
- The daily consumption of 25g of whey protein by a 55-year-old male may have potential health implications, particularly on kidney function, as suggested by several studies 2, 3, 4, 5, 6.
- High-protein intake, including whey protein, may lead to increased intraglomerular pressure and glomerular hyperfiltration, potentially causing damage to the kidneys and exacerbating chronic kidney disease (CKD) 3, 4.
- A study on rats found that high-whey-protein intake led to a significant increase in kidney weight, urinary volume, and acidity, as well as a reduction in urinary citrate excretion 5.
- However, it is essential to note that the majority of the studies associated the damaging effects with chronic and abusive use of whey protein, and the kidneys and liver were the main organs affected 2.
- The quality of dietary protein may also play a role in kidney health, with animal protein, including whey protein, potentially increasing the risk of end-stage kidney disease (ESKD) compared to plant-based protein sources 4.
- Resistance training may have a protective effect against alterations in renal health status and some metabolic parameters induced by high-protein diets, including whey protein 5.
- The current evidence suggests that high-protein diets, including those with whey protein, may accelerate renal disease progression, and the renal impact of high-protein weight-loss regimens and the implications of dietary protein quantity and type across the stages of chronic kidney disease require further exploration 3, 4, 6.