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."