Great British Bake Off star Mary Berry has said that she does not want to live beyond 90 and that she would like her children to be able to "give me a pill" if her health deteriorated and she became a "burden".
The cookery writer turned TV star, 79, who is exploring her family roots in BBC1 genealogy show Who Do You Think You Are?, has seen her career blossom late in life.
But she said that she did not want to follow in the footsteps of her mother, who lived until she was 105.
The baking queen told Radio Times magazine: "I have no desire to be a centenarian. I think 90 is a great time. You've had a good innings."
She added: "You have to deal with the cards that have been dealt, of course, but I don't think very old age, if you haven't got your marbles, can be very nice.
"My mother was in very good health until the last few months. And health is key, isn't it?"
Berry, whose father died in the 1990s aged 85, added: "I certainly don't want to be a burden, although under British law you can do nothing about it."
Suggesting that she would like to see a change in the law on assisted dying, Berry said: "But I would love my children to be able to give me a pill, although of course I do understand that could be abused."
She said of her parents: "My father was the leader of the family and we thought she would go downhill after he died, but far from it.
"She was very cross that everyone kept dying around her - 'Another member of the bridge team gone', that sort of thing.
"She drove her car until she was 95, when we had to persuade the doctor to say she couldn't do it any longer."
Berry made the surprise discovery, from an 1856 census shown to her on Who Do You Think You Are?, that her great-great-grandfather Robert Houghton was a master baker.
The owner of a bakery in Norwich, he ran his own shop, while also providing the local prison and workhouse with their daily bread.
"I almost had a seizure. To think I had a master baker in the family. It was really thrilling," she said.
But during Houghton's time as a baker in the mid-19th Century, conditions were "brutal" and "ghastly".
Bakers worked 18-hour days in dimly lit, stifling hot conditions and lung diseases, caused by inhaling flour dust, were common.
"It was a tremendous amount of work. There were three of them in the bakery, Robert and his wife and another worker, all churning out bread in the most awful conditions. They seemed to work all day and all night to achieve rather little," Berry said.
By 1867, after complaints were made about the quality of his bread, Houghton lost his workhouse and prison contract and went on to run a builders' yard .
Berry told the magazine: "The prison bread had the very poorest ingredients because it had to be cheap. It wasn't uncommon to add ground-up animal bones to spin it out, although as far as I know he didn't."
She added: "I can hardly bear to think about life for my relatives at the time. How dare anyone complain now - we've got drainage, clean water, warm homes.
"Times have changed so much. All the time as I was filming I was thinking how blessed we are. I think if my own great-great-grandchildren came poking around in 150 years they would think I was very lucky."
She said of the discoveries she made about her ancestors: "I thought we were just an ordinary family and I vowed not to be upset - but I am afraid I rather broke my rule."
The Bake Off judge said of her own life: "I have no remaining ambitions. I want to continue to be a good granny and a good wife. My great privilege is that I can say 'no' to things, so I only do what I love. And I really do love Bake Off - they're my other family."