Is the statement "medical sciences prolong life" true?

Those with medical expertise may benefit from their knowledge in preventing diseases, but this does not increase the lifespan decreed by Allah. Lifespans are written and predestined; they neither advance nor delay. "For every nation there is a [specified] term. So when their time comes, they will not remain an hour behind it, nor will they precede it." (Quran 7:34). The lifespan of every person is written while they are in their mother's womb. There is no cure for death. "The black seed contains a cure for every disease except al-sam," which is death. And good health and prevention do not guarantee salvation from death, for many a healthy person dies suddenly.