Two things in life are inevitable – death and taxes. And one thing leads to both – ageing. But what if ageing wasn’t inevitable as we currently see it? What if we could treat it, as if we were taking pills for high blood pressure? Well, as we better understand the ageing process, this may become a possibility.
One possible factor in ageing is the Hayflick number, the limited number of times a cell can divide. This varies between cells, and when cells reach their Hayflick number they may enter a state called senescence – where they are alive but dividing. These can be beneficial in the body’s repair process and when we are young, the immune system clears these cells fairly quickly. As we get older, they stick around longer and cause inflammation, which is a known risk factor for multiple diseases including cancer.
Genetics may also play its part, as our DNA can be damaged in many ways, for example by UV radiation from the sun. Cells can repair the damage, but if they miss some or make a mistake in the process, it can lead to cancer. Our chromosomes also play their role with each one having telomeres at the end, which are repeated bits of DNA that protect the important genes from being damaged if they are not properly copied. As we age, these telomeres slowly get shorter, as less is copied to the new cell each time.
Researchers are finding that some drugs appear to improve lifespan, and our view of ageing may change as more light is shed on this area. For example, some diabetic patients have been seen to live longer when taking metformin whilst senolytics are beginning to emerge which can help clear senescent cells.
