Does Whey Protein Lower Neurofilament Light Chain (NfL) Levels?

Based on the available evidence, the answer is no — at least not based on current research.

What the Research Says

Pillser's database contains one randomized controlled trial (published in 2026, n=83) that specifically looked at this question¹.

The study investigated a combination of whey protein and vitamin D in patients with chronic obstructive pulmonary disease (COPD) for the purpose of reducing sarcopenia (muscle loss). As a secondary measure, the researchers assessed whether this intervention affected plasma neurofilament light chain (NfL) levels — a well-established biomarker of neuroaxonal damage.

The finding: The intervention did not alter plasma NfL levels. The effect was neutral, small, and not statistically significant¹.

Key Takeaways

Aspect	Finding
Number of studies	1 (RCT)
Effect on NfL	Neutral (no significant change)
Beneficial studies	0
Harmful studies	0

Context

In this study, while the whey protein + vitamin D combination was effective at reducing sarcopenia in COPD patients, it did not extend to lowering NfL or showing neuroprotective effects in the way one might hope. This doesn't mean whey protein is harmful to nerves — the study found no adverse effect — but it also found no evidence that it reduces circulating NfL levels.

That said, this is a single study with a specific population (COPD patients with sarcopenia), and NfL was not the primary outcome. More research in different populations would be needed to draw a firm conclusion.

Bottom line: Current evidence does not support whey protein as a means to lower neurofilament light chain levels.

Footnotes

1. Pillser research database, Whey Protein and Reduced Neurofilament Light Chain Level. ↩ ↩²