I think some of his claims are wild – he doesn't mention how nutrition affects the mind. However I am convinced that belief plays a crucial role – placebo shows this.
(below from Amazon)Through the research of Dr Lipton and other leading-edge scientists, stunning new discoveries have been made about the interaction between your mind and body and the processes by which cells receive information. It shows that genes and DNA do not control our biology, that instead DNA is controlled by signals from outside the cell, including the energetic messages emanating from our thoughts. Using simple language, illustrations, humour, and everyday examples, he demonstrates how the new science of Epigenetics is revolutionising our understanding of the link between mind and matter and the profound effects it has on our personal lives and the collective life of our species. This paperback edition of The Biology of Belief fully updates and revises the material from the bestselling original edition, and adds material in the light of the seismic effect the book has had.