What Are Meta-Analyses and Why Do They Matter?

A meta-analysis is a statistical method that combines the results of multiple independent studies on the same topic to arrive at a more reliable overall conclusion. Because individual studies can produce conflicting results due to differences in methodology, sample size, or population studied, meta-analyses help researchers identify patterns that might not be apparent from any single study alone. They are generally considered one of the highest levels of scientific evidence.

Meta-analyses often appear in the studies Zynava links to because they provide a more comprehensive picture than individual studies. However, not all meta-analyses are equal — their quality depends on the quality and consistency of the underlying studies included. A meta-analysis of ten well-designed randomized controlled trials is far more informative than one combining a handful of small observational studies. Keep these distinctions in mind when reading supplement research.