Body clocks could keep time on health

TUNING IN to your body’s inner clocks could keep your health ticking over, according to US-based scientist and physician Prof Garret FitzGerald, who spoke in Dublin on Friday.

Our bodies have internal systems that regulate bodily functions each day and night, explained Prof FitzGerald in the inaugural Joan Kearney science lecture at Alexandra College.

"We live on a rotating planet that has light and darkness and we have got to adapt to that in terms of the cycles of our existence," he told The Irish Timesahead of the talk.

The changing lengths of day and night as we rotate around the sun mean a simple timing device won’t work, so we have come up with more sophisticated “molecular clocks”, explained Prof FitzGerald, who is professor of medicine and pharmacology at the University of Pennsylvania.

“We have a rather robust and complicated molecular feedforward and feedback system that is reset every day by sunlight impinging on particular cells in our [eyes] that connect to the master clock, which is a nucleus buried deep in our brain,” he said.

That master clock orchestrates semi-autonomous peripheral clocks in tissues around the body that drive changes in factors like body temperature, hormone levels and sleep/wake cycles.

There can also be a periodicity in symptoms of diseases such as asthma, stroke and depression, and the clock has been implicated in ageing, noted Prof FitzGerald.

“So there’s a big interest now in looking at to what degree does dysfunction of the clock impinge on the periodicity of events.

“And if we can get a handle on how to regulate or maintain the clock, we may have a way of potentially impacting all these diseases that are relevant to it, and also the ageing process,” he said.

Even pharmaceutical treatments could potentially be enhanced by exploiting the clock mechanism to make specific tissues more sensitive to drugs, he said.

But scientists have yet to hammer out the details of how individuals can best work in harmony with their internal time- setters by choosing eating or sleeping patterns.

“We are all to some degree programmed in terms of our own clock – there are early birds and night owls, some people like to run in the morning and others in the evening.

“I think what’s interesting is how do those experiments of nature translate into differences that we might care about in terms of disease evolution or prognosis,” said Prof FitzGerald. “It’s only beginning to be explored.”