Can soy isoflavones lower cholesterol?

Although soy protein appears to reduce LDL cholesterol by 4.3% on average,^[1] the contribution to this effect from the soy isoflavones is unknown.^[2][3] A meta-analysis did find that soy isoflavones reduced LDL cholesterol and total cholesterol in people with high cholesterol. However, soy protein had a similar effect.^[4] A 2008 meta-analysis of randomized controlled trials found that soy isoflavones did not improve LDL cholesterol levels in women with normal cholesterol.^[5] The evidence remains uncertain, and more research is needed before soy isoflavones can be recommended as a cholesterol-lowering agent.