This meta-analysis included 10 trials for analysis of oat bran.
There was found to be a statistically significant decrease in total cholesterol with oat bran in the combined trials. There was an average reduction of 5.1 mg/dL (0.13mmol/L) in cholesterol.
Larger reduction in cholesterol with oat soluble fiber was found to occur if the initial cholesterol level was higher than 229 mg/dL, particularly when the dose of oat soluble fiber was 3g or more.
The authors' conclusions were that "This analysis supports the hypothesis that incorporating oat products into the diet causes a modest reduction in blood cholesterol level."