Research Shows Older Adults have a Secondary Internal Clock

Changes in Sleep with Age

Everyone is familiar with the natural sleep cycle of sleeping at night and being awake during the day, but humans actually have several different natural sleep cycles that come into play during different stages of life. This is especially true for older adults whose internal clocks change with time.

Humans have genes that keep our bodies on a 24-hour cycle. With your eyes closed deep in a cave for several days, your body will be aware of days passing on this cycle and will continue wake/sleep cycles, at least for the first while. These 24-hour genes help wake us up in the morning and put us to sleep at night, cortisol in the morning and melatonin at night. However, for older adults, it seems that these genes do not work in quite the same way.

We have been joking about early bird dinners and grandparents’ naps for so long that researchers took a look at the subject to deduce a scientific explanation for the reason for the disruption of these natural cycles. Researchers looked at the brain tissue from 150 people of all ages, taken immediately after their death. The samples showed which genes were expressed in the prefrontal cortex, the part of the brain that is behind the forehead and is responsible for memory and cognition, at the moment the person died. These different samples indicated that older people have less rhythmicity in many core clock genes, but why is still a mystery.

This study revealed something else that surprised the researchers. It appears that in older brains, genes were evident that showed another, secondary rhythm that was not present in the younger brains. Scientists are speculating that this may be a “backup clock” when the genes on the original start to fail. After all, an internal clock is nothing to dismiss. An off-kilter clock can disrupt digestion, alter behavioral patterns, and harm sleep and memory.

Researchers are studying what makes our internal clocks tick and what ages over time, both to weaken our internal clocks and to strengthen the secondary clock that is not available to younger people. Scientists and doctors hope that findings from these studies can shed light on why age increases risk for diseases like Alzheimer’s and Parkinson’s, as these disease have rhythmic qualities that doctors have been able to identify.

It is important for older adults to stick to a regulated awake-sleep time to maintain strong internal processes and remain healthy.