Abstract
Context
Whey protein (WP), a high-biological-value protein contained in milk, may have anti-inflammatory properties and can reduce proinflammatory cytokines; however, the current evidence is inconclusive.

Objective
The aim of this study was to further investigate the effects of whey protein supplementation on inflammatory factors and oxidative stress in adults.

Data Sources
We conducted a comprehensive search up to March 2022 using relevant key words in databases such as PubMed, Scopus, Embase, and the Cochrane Central Register of Controlled Trials, focusing on randomized controlled trials (RCTs).

Data Extraction
RCTs that examined the impact of WP on C-reactive protein, tumor necrosis factor alpha, interleukin-6, glutathione, malondialdehyde, and total antioxidant capacity were selected independently by 2 authors. Results were pooled using a random-effects model as weighted mean differences and 95% CIs.

Data Analysis
The results of the present study demonstrated that WP supplementation had no significant effect on the modulation of inflammation and oxidative stress compared with the control. None of the predefined subgroup analyses explained the differences in the effects of WP supplementation on inflammatory factors and oxidative stress.

Conclusion
This research suggests that WP supplementation had no significant effect on inflammatory factors and oxidative stress.