I read book saying that plant based diet helps reduce the risk of various deceases. are there more recent large scale studies about this?

No: Most scientists reject the china study's conclusions. Campbell did a historical review of mao-era (no animal food available) death certificates, which he accepted uncritically.; he promised peer-reviewable studies that never appeared. And his near-vegan patients died much younger than we do. He then wrote a paper praising eating fish. Yet many vegans feel much better, and i admire commitment.