Life expectancy under Mao increased from 39 years (yes, true) to around 66 years in the mid-seventies. China was more or less the poorest country in the world when Mao and the CCP took over, and the poverty one sees from his time in office is a reflection of the disaster that was inherited -- a country ridden with drugs, gangs, and widespread disease and ignorance.
Since Deng's reforms, China's life expectancy has not matched the increases seen in the rest of the world. All this is information readily attainable from the UN website. As Chinese capitalism has grown richer, a large segment of its population has grown poorer. Sounds almost Marxian.
If there ever was a major Leftist leader in need of a second look, it is Mao.