It takes a steely singlemindedness for the daughter of a privileged Catholic family to convert to Islam and agree to an arranged marriage. The same qualities propelled Sarah Joseph to become a voice of Muslim moderation and to denounce Sheikh Omar Bakri Mohammed as an extremist “nutcase”.

The 34-year-old Londoner crossed another threshold by launching a Muslim lifestyle magazine that targets non-Muslim readers, funded from her savings. It is now the first Muslim magazine to go mainstream, and will be stocked by such outlets as Asda, Tesco and WH Smith.

Titled emel, the Arabic word for hope, the glossy embodies Joseph’s mission to present normal images of Muslims and accentuate the contribution they have made to building British society. With a mixture of fashion, food, polemical commentaries, travel, gardening and design, its layout is striking and the content absorbing. The message is that there is more to Muslim communities than religious dogma and politics.

“Unfortunately, all people see is protest and dissent,” says Joseph, who also edits emel. “A Muslim is depicted as someone who wears this and eats that. We’re offering a window into Muslim communities, away from the clichés.”

Framed by the white hijab she adopted at 17, Joseph’s serious eyes and alabaster features impart an ethereal air at odds with the mirth that can bubble up at her own expense. “Someone from the BBC guessed our seed capital was £3m-£5m and I collapsed laughing. We started with £20,000 and it’s all been done on a shoestring.”

Joseph’s blend of common sense and idealism has put her in demand as a consultant on Islam. Awarded an OBE last year for services to “interfaith dialogue”, she was a member of the Muslim delegation invited to No 10 after the London bombing of July 7.

With hate crimes and Islamophobia reported to be on the rise, is this the best time to court non-Muslim readers? “We could say, ‘Let’s keep our heads down.’ But if we stay entrenched, that kind of hostility is never going to be resolved.”

When she first published emel two years ago, the concept of a Muslim glossy prompted blank looks. But it soon became apparent emel had hit an untapped market that pushed circulation to 20,000 in 30 countries. The realisation that non-Muslims were buying it has led to the launch of a more accessible version.

Joseph is keen to foster the idea among Muslim readers that they are “stakeholders” in British society by virtue of Islam’s past and present influence. Her own British roots go back to the Norman conquest. The daughter of an accountant and the owner of a model agency, she was schooled in Mayfair and Sloane Square. “I grew up in a world where everyone was slim and beautiful.”

She recalls pursuing the 14-year-old Naomi Campbell to sign her up as a model at the behest of her mother, who had spotted her in the street. “Bored as only a teenager can be, I ran after her and said, ‘Excuse me, my mum owns a model agency and thinks you’re really beautiful. She wants you to see her’.”

Her religious conversion began at 16 when, to her alarm and anger, her elder brother embraced Islam to marry a Muslim. Determined to confront her negative image of Muslims, she began reading about the religion. At the same time, she rejected Catholicism. “Slowly, Islam kept answering many of the questions which I had until I wanted to be a Muslim.”

At first her parents were upset, treating her conversion as “a bereavement”, and recoiled from the hijab. In Joseph’s view, wearing the headscarf must be a matter of choice but for her it was a feminist statement. “I wanted to be judged by what I say, not according to what I look like,” she decided.

She had always been a rebel, turning out for CND and anti-apartheid marches; the hijab was her answer to the values of the fashion industry she had grown up with.

In 1992 she agreed to an arranged marriage to Mahmud, a human rights lawyer whose parents had come to Britain from Bangladesh in the 1960s. Her then boss and a friend introduced them. “I think my family was totally relieved because he was a barrister and didn’t look like Obi-Wan Kenobi with a beard.”

The couple now have three children, Hasan, 9, Sumayah, 6, and Amirah, 3. To answer the torrent of questions about militant Islam after September 11, Joseph and her husband set off on a lecture tour of Britain that lasted a year.

Exhausted, they realised they could not go on denouncing terrorism without a more positive message. “You can’t keep saying, ‘This is monstrous’. You need to frame your life by what you are for. That’s when we really had the idea for the magazine.”

Now based in Whitechapel in east London, with a staff of six and several volunteers, emel is beginning to break even.

Joseph says that being a member of two communities places a distinct obligation on her. “I feel this tremendous sense that I have to get them to talk to one another. I think my whole life has been about bridge-building.”