The study and its comparison
One hundred twenty healthy adults were randomized to 2.56 grams daily of aged garlic extract or placebo. Immune-cell proliferation was assessed at 45 days, and illness diaries covered 90 days. [1]
Selected immune-cell responses improved. Illness incidence, a secondary outcome, was not significantly different, although the active group reported fewer symptoms and fewer days of impaired functioning. [1]
What the finding establishes
Immune-cell activity, symptom severity and infection prevention are separate endpoints. Diary-based cold or flu reports do not necessarily identify a laboratory-confirmed infection, and an extract trial is not evidence that a garlic meal immediately clears congestion. Funding and conflicts were not established from the abstract. The findings do not supply a treatment for an acute respiratory illness. [1]
A hypothetical distinction
Imagine people have similar numbers of colds but report less disruption. That is different from preventing the colds.
| Detail | Interpretation |
|---|---|
| Measured outcome | Keep the endpoint specific |
| Study preparation | Not every retail product |
| Remaining uncertainty | Not resolved by a mechanism |
Sources for this article
- Supplementation with aged garlic extract improves both NK and γδ-T cell function and reduces the severity of cold and flu symptoms: a randomized, double-blind, placebo-controlled nutrition intervention.
Source consulted: 2026-09-19. This is a reference resource, not a claim that we conducted the studies or tested a product.