Lynne Franks: Tell me first about your early life.

Maryon Stewart: I was born in Clapton which officially makes me a Cockney. For some reason my mother ended up having me in the Mother's Home which was run by nuns. When I was born, apparently the nuns made her get down on the floor and pray because she was bringing me into the wicked world. I grew up in Clayhall, near Ilford.

My dad's parents came from Russia and Poland. My mum's parents were English but their parents were Romanian. My grandfather, my dad's dad, he had 14 brothers and sisters. I think they all went to America except for him. It is an absolutely massive family.

I can remember when I was little we always used to go and see cousins at the weekends, and aunts and uncles and cousins would always be popping in. That was just the way we lived really. It was so different to how life is now when you hardly see your family at all. It was good. Neither of my parents were religious but I was brought up in the Orthodox community. We used to go to Cheder on Sundays and Tuesdays and Thursdays. Then my dad was the chairman of the Kosher Meals Society or whatever it was called - they used to pick us up from school and take us by coach to have a kosher meal at lunchtime. It was just like an outing with all your Jewish friends because there are loads of Jewish children in the class.

I think I had a really happy childhood. One strong memory is that I opened a library in my parent's garage when I was about 11. I went around and got all the neighbours to donate books. I was very enamoured with the cataloguing system. I replicated that in the garage and it was all going really well until one day the mother of one of the kids came to express her displeasure to my mother because I had charged her daughter overdue fines on a book that she donated, so I had to close the library down.

At school the expectations of my teachers were that I would be a fashion buyer or a window dresser or something like that.

LF: What did you think?

MS: I didn't know. I had absolutely no idea.

LF: You didn't have any burning ambitions that you had to fulfil?

MS: Not really. When I was in my teens I always did charity work. I got involved with the National Heart Foundation. We arranged fund-raising events. Then I got involved with Ravenswood. We used to go and relieve the carers. Thinking back - and I have thought about this quite a lot, actually - I always enjoyed doing things for other people. I always enjoyed helping people and I always enjoyed organising, like with the library.

Anyway, when I was 16 I won a competition to be Miss Ravenswood. The prize was a modelling course. It was fun. I enjoyed it but it wasn't what I wanted to do. I wanted something that was more to do with helping people. I always wanted to help people. That was my thing. And change things for people, make it better somehow.

LF: Did you go to university?

MS: I trained as a dental hygienist..

LF: That was a slightly more medical career choice than ending up as a fashion buyer.

MS: Well, I nearly had a job as a fashion buyer because when I was 15 or 16, I worked at the London Fashion Centre in Oxford Street. The senior buyer there said I was really good and he talked to my parents about taking me on as an apprentice. Then he invited me to Paris to do some buying, but he really had other things in mind. I found him totally scary so I ran away from that. I worked as a dental hygienist until I got married.

LF: And your husband, Alan, was a doctor?

MS: Yes. I was on a committee which was helping to improve rights for mental patients and he was the medical adviser. At the time they were doing lots of ECT and they were taking out bits of people's brains without consent and there were all sorts of things going on that surgeons were up to and we were trying to just educate people about the situation.

LF: How did your parents feel about Alan not being Jewish?

MS: Oh gosh! That was just the end of the world for my dad. He was actually going to sit shivah for me. It was awful. He was my only non-Jewish boyfriend and I remember one night his parents came around to my parents' house and we all had dinner and I thought maybe things are looking up. Then Alan and I got sent off to wash up and when we got came back into the room they said that they had decided that we shouldn't get married at all. They had mutually decided.

LF: How old were you at that point?

MS: I was 26. We did get married. We planned the wedding and they all said they weren't coming, but then the night before my parents said that if we postponed it they would come. So we delayed for another six weeks and then we did get married. Then the following Sunday they all came around for tea. Although Alan wasn't Jewish and he didn't convert physically, our children were all brought up Jewish. We decided that we would send them to Jewish nursery and they all had barmitzvahs and bat chayils. Alan came to shul and just did what a father would do. His stomach became Jewish. My parents did actually look upon him as a wholesome son-in-law. They didn't resent the fact that he wasn't Jewish, so it was OK.

LF: And you had four children?

MS: Yes, and they weren't planned at all. Phoebe and Chesney arrived early on in my marriage. Then I had an ectopic pregnancy in 1986 which resulted in a real emergency. I only had two hours to live. I did lose a tube and they said I wouldn't have children again. So I didn't bother to use any contraception and then I fell pregnant with Hester. She was born in 1987. Four-and-a-half years later I had another ectopic pregnancy. I was about to be taken in for a termination and they did a final scan, and the day before the operation the baby jumped into the uterus, so I ended up having a fourth child, a boy.

LF: Were you working through all this?

MS: I went back to work five months after Phoebe was born, part-time as a dental hygienist in Hove because we were in living Brighton then. By this time Alan had spent a year at the Royal Homeopathic Hospital and he wasn't happy with the National Health Service and wanted to do something else. So he and three other doctors decided to set up something called the British Society for Nutritional Medicine. They gathered together 10,000 medical papers on nutrition and non-drug medicine. I had just had Chesney by then and was on maternity leave, so they gave me the 10,000 papers to sort out because they didn't think I had much to do. It was while I was doing that that I found 200 papers on premenstrual syndrome. I was so amazed that they existed. It was all a non-drug approach. I was really interested in it because I knew that a lot of women suffered with PMS and that the medical profession at that time couldn't agree whether to give hormones or anti-depressants, and they didn't know what the underlying cause of PMS was. Yet they were millions of women who were violent, aggressive, suicidal as a result of PMS. So I decided that I would train Alan's nurse to help women by applying the knowledge in these medical papers. Because I read them all and I thought: "This is easy. If we just follow this, we can provide a service".

LF: When was this?

MS: It was 1984 when I started the advisory service. After a while a journalist came along as a patient of Alan and he happened to mention what I was doing. The journalist asked if she could write about it because by this time we had patients recommending us to relatives in other parts of the country. To help them we started to post out our questionnaire and advice sheets. We ran the postal thing for a while. The local journalists wrote about it. Then a health magazine picked it up. Then Cosmopolitan picked it up and then the News of the World. We had about four column inches in the News of the World and as a result of that 10,000 people wrote to me. Then I got invited onto breakfast television. From then on we had between 650 letters a day, and at one point, when we had big media, we had 2,232 letters in one day.

We categorised the women according to whether they were severe sufferers or moderate sufferers and so on, and we had different advice sheets that we sent out to people. At one point I had a team of 13 nurses and nutritionists working on it. It became such a huge thing. That was how the books began. We had so much media coverage, I got headhunted by four publishers.

LF: How many books have you written?

MS: So far, 26. What happened was that we discovered 69 per cent of women who followed our advice on non-drug treatment were symptom-free within the space of a few months. We were really interested to know why that was and we discovered that very often the women had low levels of important nutrients, like magnesium, B vitamins and zinc, iron, calcium, and essential fatty acids. By following our advice, which included nutritional advice, not only were women getting over their PMS but they were also getting over all sorts of other things - fatigue or migraines or aches and pains or low libido, cravings.They were even losing weight without having to diet.

So I started writing books about that. I wrote one on cravings, and on irritable bowel syndrome. I did one on preconception, pregnancy weaning, fatigue, and then I got interested in the menopause. In 1990, there was already enough research to show that you could actually go through your menopause naturally too, and as time has gone on there is more research showing that you can prevent bone thinning the same way. You can prevent osteoporosis. You can prevent heart disease and you can also prevent dementia.

Apart from the books I have done a lot of series on TV. I have now got this programme called the Really Useful Health Show where I look at how to deal with different conditions.

LF: How does the medical establishment respond to your work?

MS: It is a bit of a mixed bag actually. I think there are some people who are very sceptical and will die sceptical. There are other people who are much more open-minded. Unbelievably, it is not on the medical curriculum to teach doctors about holistic medicine that is scientifically based. That has got to change because the internet now allows patients to know far more than their doctors. And why would you want to be on one pill and then another pill and then another pill, with all the side effects? Some people end up on so much medication.

You don't have to be a crank to just get the balance right in your life, and that is what this is all about. It is learning to meet your needs at whatever life stage you are at. So many women are so busy- they are working, they have children, they have husbands and homes to look after - that they don't actually spend much time looking after themselves. As a result, they get themselves in a mess - they get PMS or something else - and it stops them in their tracks. Learning to meet your needs can make all the difference.

LF: Let's talk about the Angelus Foundation, and your daughter Hester. She died in 2009.

MS: Yes, it will be three years on April 26. She was 21. She was a medical student at Sussex University. She was at an awards dinner where she met up with an old boyfriend and eventually went home with him. She had had a few drinks during the evening and apparently he gave her half a dose of something called GBL, which is paint stripper and was at the time a legal high. Coupled with a small amount of alcohol it can shut down your respiratory system and that is what happened to Hester. It closed her respiratory system and she went to sleep and she didn't wake up.

The next morning I had two police women on my doorstep who broke the news to me that my daughter had died. It was horrifying. It was such a shock because she wasn't a drug-taker.

None of her friends knew what GBL was and even the vice chancellor of Sussex University who is a professor of medicine had never heard of GBL. So I started to Google it and I found that GBL had been banned in many other countries around the world four years before Hester died. Eighteen months before there had been a report by the European Committee on Drug Abuse and it had basically said that GBL plus alcohol equals death. As a result of that they had had poster campaigns in nightclubs in Europe, and the communities had got together with charities and the police and the nightclubs and they had had an awareness campaign so that young people knew about it.

I knew that if there had been an awareness campaign here and she knew that it was dangerous, GBL would never have crossed her lips. I was really angry with the Home Secretary, Jackie Smith, for her inactivity. When Hester died, we got a call from the Daily Telegraph who talked to me about going to see Jackie Smith and about them reporting on it.

That was how it all began really. My eldest daughter at the time was working at O and the communications director there was a Jewish guy called Glenn Manoff who heard what happened and phoned me to say could he help? He introduced me to a PR agency that specialised in video. Jackie Smith had resigned the day before I was meant to see her so I went to see her replacement, Alan Johnson. Every time he wouldn't do something we wanted, we would just get eight TV cameras outside his office. I was on all the morning shows.

This thing then started to take on a life of its own. My mission was to ban GBL and I thought that if I did that, that would be the end of it. But I didn't know that GBL was just one of a number of legal highs. As soon as we got it banned, other things came onto the market. In fact, in 2010 there were 41 new substances and no one really knew what was in them except that they were often a cocktail of class B drugs and chemicals - paint stripper, plant food, fish food, bath salts - never intended for human consumption.

I wanted to set up something in memory of Hester. I decided to call it the Angelus Foundation because she had had a dozen dolls and they were all called Angelus. When I was told that she had passed away I felt that I could still communicate with her and I could feel that she was absolutely screaming out for me because she was so shocked at what had happened to her. I spent quite a lot of time just communicating with her. I feel like she is with me all the time and I feel like the whole Angelus thing is a joint initiative between us. That may sound kooky but I just feel that she is working still to make this thing happen.

The aims of the foundation are to raise awareness so that young people make smarter choices and that their parents have wise conversations with them and keep them safe. Earlier this month we announced our Wise-Up campaign which will be launched at the beginning of May. Part of it is called Wise-Up Parents, which aims to make parents aware of the dangers their kids face, because it has become very normal for kids to take this stuff when they go to clubs and parties. The are side-effects parents can look out for - anything from psychosis to severe depression, anxiety, panic attacks, difficulty in breathing, heavy nosebleeds. And we need to wise up parents so they can have smarter conversations with their kids about the dangers.

We are also going to set up a website for young people so that we can communicate the right message. A lot of kids are taking these things because of peer pressure, but also because they think they are safe because they are legal.

LF: And they are quite cheap?

MS: Yes, and you don't need ID to buy them. Our big challenge is to get kids to understand that they don't need these drugs, that they can get high from sports and dancing and music and good relationships.

LF: You said that you have recently been started to work with Mitch Winehouse and his wife?

MS: I have got another woman working with me called Vicky Unwin. She is half Jewish. Her daughter Louise died last year. She was 21. Vicky and I have become quite close. Together we have had several meetings with the Winehouse family. Obviously we have got a great deal in common because they lost Amy, and we lost our girls.

One of the foundation's goals is to get drugs education back on the National Curriculum. And we're going to campaign for a separate ministry for drugs and alcohol like they have in France, that answers directly to the Prime Minister and has adequate funds to tackle the problem. Right now there isn't even a laboratory that can measure all this stuff so that we know what is in it. We haven't got the faintest clue what these things do to the brain and the organs and fertility and life expectancy. We know that some of them are addictive. We know that some of them are dangerous, but we can't quantify it. So there needs to be a centre of excellence. We are applying for funding from the Lottery, from different trusts and foundations to make this happen.

LF: The foundation is clearly important to you.

MS: I have had to work 16 or 17 hour days to get it to where it is now. It has been my therapy to be perfectly honest, it has helped with the grief. Yes, Angelus is so important to me.

Details of Maryon Stewart's campaign and petition against legal highs is at www.angelusfoundation.com

Information on Lynne Franks's empowerment workshops for women is at www.lynnefranks.com/www.seednetwork.com