It is traditional to begin an article about Lynne Franks, the woman once heralded as a PR guru and, perhaps less flatteringly, as the inspiration for Jennifer Saunders’s character Edina in Absolutely Fabulous, by questioning her sanity. And there are crackpot wheezes aplenty in her new book, Grow, if you care to interpret them as such.

Like the instruction to close your eyes and visualise your inner goddess: “Is she Aphrodite, the Greek Goddess of Love, or Kuan-Yin, the Chinese Goddess of Boundless Compassion?” Or to conjure up the man of your dreams with a fruit smoothie: apple for integrity, cherries for enthusiasm, passion fruit for, er, passion. And, when you’ve juiced him into existence, to invite him to join you on a “sacred sexual journey”.

But, easy laughs aside, if Lynne Franks is barking mad, then so am I. And many of my female friends. And the high-flying women you read about every day who, at about the age of 35 to 45, burn out and leave the corporate world they once thought they could conquer.

Franks argues that in the workplace women are “living a male role in a female body” which makes us miserable and is toxic to our health. Rather, we must bring “the feminine back into our lives”; rediscover the pleasures of cooking, gardening, creativity and spirituality. And we must run our careers along “feminine” lines, finding a true balance between family and work, or we should set up small businesses on ethical and co-operative lines.

Look around and you have to admit that Franks is on to something. Young women are exhibiting worrying signs of stress: rates of smoking, binge drinking and breast cancer continue to rise. Meanwhile their older sisters are electing to work part-time or from home. Top lawyers are retraining as therapists. School-gate mates start up catalogue companies from back bedrooms. Boardroom Boadiceas concede to a sudden longing for Kinder and Küche.

“Young women enter work from university very positive and optimistic (believing) that they can do anything at all,” says Franks. “They are encouraged to behave and dress as men, in that classic black trouser suit and white shirt.

“But, at about 35, they realise that if they are going to break through the glass ceiling they will have to sacrifice many things. The culture of these big companies doesn’t reflect their values and who they are. They have lost their individuality and their feminine side. They think ‘I’ve given 15 years working this way: let’s try something different’. Women, much more so than men, are not scared of change. In fact, we crave it.”

Franks is chugging down a fistful of vitamin supplements with murky green vegetable juice. By the kettle is a whole wall of herbal tea boxes; a scented candle is lit on her kitchen table. Beyond is the living room, a rich, hippy den of bright throws and ethnic objets. This West London maisonette is her home/office — a PA takes calls upstairs — when she is not in her retreat in Deià, Majorca.

It is the tanned, calm, no-longer-busy-for-busy’s-sake Franks, 56, who is here eating organic porridge. Nevertheless, her phone rings off the hook and she talks 1,000 ideas a minute, making lightning associations between disparate trends and global events. One fashionista describes her as an “idiot savant”, almost unconsciously channelling the Zeitgeist.

Grow — an acronym for the rather icky Gorgeous Real Original Woman — is the result of Franks’s own midlife journey. In 1992, when her husband, the erstwhile fashion designer Paul Howie, left her for one of her friends, she sold her hugely successful PR company and gave up the Buddhist meditation she’d practised for ten years.

“My self-esteem was absolutely zero. I was like any other middle-aged woman who had been dumped by her husband, it was horrible,” she says. “I went into free fall, I’d given up everything I thought I was. And at the same time Absolutely Fabulous was on TV, so there was this parody of my life. I was thinking there is this Lynne Franks PR person, but who the hell am I?” So she moved to Los Angeles to find out. And much of Grow is a pick’n’mix of Californian panaceas: raw food, exercise, self-development, meditation, colonic irrigation.

But, most importantly, Franks says she stopped being dominated by her ambitious masculine side, which had enabled her to create her business, and learned about “living life in my feminine energy”.

Grow purports to be a feminist manifesto but will have biological determinist reactionaries claiming victory. And old-school feminists will exclaim: “So, after a century of struggle for professional equality, you’re saying we’d simply have been happier at home?” or “How is my ‘feminine self’ going to kick ass and get the big boys’ jobs?” Moreover, what of poor men, forced to tread the corporate gerbil wheel so that the career girls they married can stay at home and bake brownies? “I don’t think men like the corporate world any more than women, but by their nature they are suited to it,” says Franks. “They are more into the archetypal hunter-warrior role. But for women, who archetypally want to co-operate, share childcare and work in the community, it is less natural.”