WHERE does an open mind give way to scepticism? For me it happens part-way down a list of alternative therapies.

Acupuncture? There is some science to prove it works.

Reflexology and homeopathy? If acupuncture can do the trick, then why not those two?

But crystal healing? Oh, come on. I'll take that with a pinch of salt – the only kind of crystal that works for me gets sprinkled on fish and chips.

Which is unfortunate, because I'm off to Plymouth's hotbed of unconventional medicine, the Natural Health and Healing Centre to meet the chairman, Gillian Fordham.

She looks like actress June Whitfield meets singer Dame Vera Lynn with a hint of former PM Margaret Thatcher; aged 69 and every inch somebody's granny, from the back-combed silver hair to her comfy shoes.

She is dressed entirely in shades of purple (her favourite and the colour of healing, she tells me), which adds a New Age touch to the old-age cardigan combination.

"How are you?" Gillian asks, clasping my offered hand in both of hers and holding on as she fixes me with a kindly smile as if searching for something in my face.

I wonder if she was searching for signs of that open mind – and I think she failed to find one because she leads me straight to a framed photo on the wall in the reception.

"That's Dr Alec Forbes, a consultant, who had a dream of setting up a complementary therapy centre in Plymouth," she explains. He founded the Plymouth Natural Health Centre in the early 1970s and it merged with the Natural Healing Centre – which Gillian set up at about the same time – in premises at the Barbican Theatre in 1980. The expanded charity moved to 175 Outland Road about 20 years ago.

I have learned a couple of things already. First, that Gillian is a perceptive woman. She quickly saw the need to point out that there are many in the medical profession who are less sceptical about non-conventional therapies than is this reporter. Second that I need to get my terminology right.

"All the therapies practised here are complementary," she explains. "All the practitioners work with conventional medicine. They are not alternatives."

There is a long list at the centre, from acupuncture and astrology through homeopathy and Indian head massage to reflexology. Gillian has trained in 'umpteen' of them but her strength is in spiritual healing, she says.

"I feel I am connected to the divine source, the God source," she adds. "Healing is love. God is love."

When did it first manifest itself?

She smiles and seems reluctant to go on, again perhaps sensing my scepticism.

"When I was in late early twenties," she says.

Pause.

Was there a particular incident or a feeling?

"Yes."

Pause.

What was it?

"Ha! Ha! Ha! There was a lady who was very ill with cancer. She was given only hours to live. I was called and went to the hospital. She had been like a mother to me.

"I knelt by her bed and I prayed and I cried. She lived for another seven years."

There are Christians and non-Christians who practise at the centre, though. "There are many gifts of the spirit. My way is my way, other people have theirs. You cannot explain it."

However, I can explain where Gillian Fordham is from, but it takes time. She is given to pausing after short, enigmatic responses to question, and tends to go off on themes.

She was born and grew up in Saltash, she explains, which leads her on to religion and to talk of her own church-going – St Andrew's in the city centre and Emmanuel, Mannamead – and that of her two daughters and a son.

We divert through horticulture (in which she worked for seven years) and marriage (to Raymond, an accountant, who is the centre treasurer and a trustee) and back to the health and healing organisation, which survives through donations and charges for the therapy and healing and the various lectures, workshops, training courses held there.

Time to bring my scepticism into the open. Crystal colour healing? Somebody moving a piece of quartz over me? It's absolute nonsense which makes me question some of the centre's other therapies.

"That is fine," says Gillian, calmly. "We are not here to say it is for everybody. I am a great believer in positive thinking, mind over matter.

"There are people who are drawn to crystal healing and believe their healing power is within the crystal. The crystal is a tool, mental and physical."

So if it is harmless and somebody believes it to work, that is enough to embrace it?

"I'd agree," she says, adding that the only time the centre has declined to allow a therapy to be carried out on the premises is because the practitioner did not seem to fit.

But where is the science to prove that complementary therapies work? What about the double-blind trials?

Cue another enigmatic reply, about how the centre has treated 'many, many' medics over the years although Gillian won't expand, fearing a delicate relationship could be harmed.

She will say, though, that "the medical profession is closer to us now than when we started. We work very closely with them".

And as for rooting out the placebo effect to look for hard evidence of what works rather than what patients think works, I'm missing the point.

Gillian says: "The mind tells the body what to do. The way we programme our mind – that is what we become. I am a great believer that we are mind, body, spirit and soul. You cannot separate that.

"The doctor treats the physical, we treat the mental, emotional, spiritual. We would never, ever say to a client that they should not have physical (conventional medical) treatment."

At which point I might have started to switch off. What is the point of trying to examine the efficacy of something that is beyond science, concerning one concept that no scientist fully understands (the mind) and another that many scientists do not recognise (the soul)?

I didn't, though, because something strange happened. The change was gradual and down to Gillian's presence – she has the most extraordinary stillness and calmness about her.

I started to think, 'why not?'

Not only 'why not' accept harmless complementary medicine when conventional doctoring doesn't work?

But 'why not' turn my scepticism on to science and conventional medicine? Some scientific research has shown not only can placebos work as well as some medicines, but that even pretend surgery can prove as effective as the real thing. One United States study, published in the New England Journal of Medicine in 2002, showed that patients with arthritic knees who had fake operations fared just as well – and in some aspects better – than those with real operations.

On the other hand, why doesn't spiritual healing work in every case?

"It is God's will," says Gillian. "If he wants this person to be healed then we act as a channel. In some cases miracles happen. In some cases it does not work. I never promise that I can help a person. I promise that I will do my best in whatever way I can."

Does that make it the patient's fault if they don't get better; they failed to believe? Their mind wasn't strong enough?

"No. We never put pressure on people. We have helped thousands of people over the years, many who it was thought would not survive are still with us 20 years later.

"But I do not want to raise people's hopes, thinking that they will come here and be cured."

Her own faith, in healing and in the power behind it, began in the innocent world of childhood – and stayed with her through the cold and sceptical, logical world of adults.

It is another anecdote which Gillian seems unwilling to share. After some persuasion, she begins.

"I have walked hand in hand with Jesus Christ since I was a little girl.

"I was about five. I had gone blind and deaf. I was too ill to get upstairs so my bed was brought down.

"I had a vision that Jesus Christ took my hand and I was cured. All my life I have continued to walk hand in hand with him.

"I believe I was born to heal."

And after an hour with her, so do I.