Authorised biography reveals how Apple founder planned to beat cancer – and his big rival

The hitherto secret world of Steve Jobs in which the Apple founder eschews conventional cancer treatment in favour of a vegan diet while bitterly feuding with Google over its rival smartphone is revealed in an authorised biography published next week.

The 630-page account of the technology pioneer's life reveals intimate details of his relationships, how he was influenced by LSD and railed against executives at Apple who, he believed, cared more about making money than good products.

Based on 40 interviews with Jobs, who died this month aged 56, the book paints a picture of a maverick whose single-minded world view – heavily influenced by the 1960s counterculture – at times brought him into conflict with friends, family and colleagues.

The publication of Steve Jobs by Walter Isaacson details Jobs' unconventional response to the news that he had a rare but treatable form of pancreatic cancer in October 2003. He pursued a diet of fruit and vegetables, fasted, underwent bowel cleansing and acupuncture, delaying surgery for nine months because he didn't want doctors to "open up my body". It was a decision he later came to regret, the book claims.

However Jobs went on to pay $100,000 to have all the genes of his tumour and his normal DNA sequenced, and oversaw every step of his subsequent care. He told his biographer he was undergoing cutting-edge treatment that would mean he would either be the first to "to outrun a cancer like this" or be among the last "to die from it".

In another revelation, Isaacson charts the depth of Jobs' fury at Apple's rival Google over its smartphone, declaring: "I'm going to destroy Android, because it's a stolen product." He said he was prepared to spend "every penny of Apple's $40bn in the bank to right this wrong".

Jobs also describes how taking LSD had "reinforced my sense of what was important: creating great things instead of making money, putting things back into the stream of history and of human consciousness as much as I could."

Jobs gave up on Christianity when he was aged 13 after seeing pictures of starving children on the cover of Time magazine. He later studied Zen Buddhism.

The book describes how Apple's first president Mike Scott was hired to keep an eye on Jobs, then aged just 22. Among his key tasks was persuading the company's founder to take a bath, with limited success.

Jobs' unusual love life is also laid bare. Isaacson recounts how in 1985 he fell in love with a computer consultant, Tina Redse.

He proposed to her four years later but she declined believing Jobs would "drive her crazy". His relationship with a former Goldman Sachs trader, Laurene Powell, also nearly foundered in 1990 when he proposed to her but failed to mention it again for several months until she moved out in despair. The couple eventually married.

The biographer: Who is he?

Publisher Simon & Schuster has brought forward the release of Walter Isaacson's biography to next week following Steve Jobs' death. Originally scheduled for early next year, pre-orders have already catapulted the book to the top of best-sellers. The chief executive of the Aspen Institute, an organisation dedicated to promoting leadership, was granted unprecedented access to Jobs, his family, friends, colleagues and doctors. He conducted his final interview with the Apple founder just weeks before his death. A former editor of Time magazine and ally of Barack Obama, Isaacson has also written biographies of Albert Einstein, Benjamin Franklin and Henry Kissinger.