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.
The China Study. There is a current national bestseller which presents a comprehensive study of nutrition, called the china syndrome - startling implications for diet, weight loss and long-term health, written by t. Colin campbell, phd and thomas m. Dambell ii. Change your diet and dramatically reduce your risk of cancer, heart disease, diabetes and obesity, declares the inside cover liner. Published 2005. $25.