The family of a woman who suffered brain damage following a "detox" diet yesterday warned of the dangers of such regimes. Dawn Page received more than £800,000 in an out-of-court settlement after a diet in which she increased her water intake and decreased the amount of salt she consumed.

Page, 52, a mother of two, from Faringdon, Oxfordshire, began vomiting severely soon after starting the "hydration diet" in 2001. She was left with epilepsy and a brain injury affecting her memory, concentration and ability to speak normally. She gave up her job as conference organiser and her family says she will not work again.

Barbara Nash, the nutritional therapist she consulted, allegedly assured her that the vomiting was part of the detoxification process. Nash, who calls herself a "nutritional therapist and life coach", denies liability in the case and insists she was not guilty of substandard practice.

But Page's husband, Geoff, 54, yesterday warned of the dangers of "fad-type" diets. He said his wife was not obese but had just wanted to lose some weight. "Just days after she started the hydration diet, she began to feel unwell ... Things went from bad to worse ... Her life has been seriously affected, perhaps ruined." He said his wife was advised to drink at least four pints of water a day. The therapy was known as the Amazing Hydration Diet. He added: "It's important people understand how dangerous diets like these are."

Nash has a diploma from the College of Natural Nutrition, based in Tiverton, Devon. Plexus Law, the firm that represented her in court, said all allegations of substandard practice made in the litigation would continue to be "firmly denied", and the settlement agreed was less than half the total claimed.