Life and death
The balance between cell renewal and cell death is regulated to perfection
All your 37 trillion cells in the body come from a single, first stem cell – the fertilized egg. It divides over and over again, and it continues throughout your life.
In the same way that new cells are created, approximately 1 million cells die every second. In 24 hours, approximately 1.2 kilos of cells die in your body. It may sound disturbing, but it is actually a necessity for life. Old and broken cells, or parts of cells that collapsed or were created wrong from the beginning – must be removed. Cell renewal and cell death are like a cycle of cellular building blocks. If the balance of the natural cell death in our bodies is disturbed, it causes, in whole or in part, over 50 different diseases such as cancer, Alzheimer’s and rheumatism.
Just like a stop in the plastic bottle recycling machine at your local grocery store, problems can arise when there is something wrong with the recycling process. As for example in cancer when the cells refuse to die and grow into a tumour. Or when the opposite happens, when brain cells die even though they are not meant to die, in diseases such as Alzheimer’s or Parkinson’s disease.
“Cancer and Alzheimer’s disease are like two sides of the same coin,” says Maria Ankarcrona, researcher at Karolinska Institutet’s Alzheimer’s Center in Huddinge. “The mechanisms are very similar, but vice versa. In cancer, too few cells die and in the brain [in Alzheimer’s] cells die that should not really have died.”
That there is a connection between the diseases can be clearly seen in new studies that show that cancer survivors have a lower risk of developing Alzheimer’s and in a similar way, people with Alzheimer’s do not get cancer as often.
Today, there are many studies in which researchers are trying to find treatment for a variety of diseases using stem cells, of which Alzheimer’s and cancer are of course two of them.
The text is based on Fredrik Hedlund’s article, published in the journal Medicinsk Vetenskap number 2, 2014