There are a multitude of reasons for forgetfulness in seniors:
Co-morbidities i.e. other disorders may factor in, like Diabetes Mellitus, and Hypertension.
There may also be other medications like opioid pain killers (a substance akin to morphin), which can contribute to loss of memory.
Lack of physical activity – as in cessation of walking – causes mental decline. There are scientific studies which prove that memory is much enhanced after walking. The ‘term adult neurogenesis’ is used for stem cells turning into nerve cells in adults of all ages. This process occurs daily. It improves emotional well-being and memory. Unfortunately there is a programmed cell death for the newly born nerve cells, if walking cannot occur.