The following Mark's Daily Apple article was written by Mark Sisson,

and is narrated by Tina Lehman.

Four ways winter affects your physical health.

With winter all but officially upon us,

we might already be feeling the season,

maybe even planning warm weather vacations.

I venture most of us have wondered if we're not somehow healthier during the summer months.

Is it just a mental vitality from the additional daylight hours

and relative ease of outdoor time?

Or is there something more at work? Does our health really take a hit in winter? For those who enjoy

this brand of trivia, there's an actual field of study devoted to this called biometeurology.

And with the minutely detailed research into epigenetic activity,

we're getting a fuller picture all the time of astonishing nuances as well as big picture shifts.

To a primal mind, it all makes sense. Humans evolved with a seasonal context,

without any of the modern accommodations that would buffer climate

or weather influences.

Why would our bodies not have adapted with responsive wiring?

With the span of modern research, everything from massive epidemiological analysis to epigenetic

science were seeing both the finer nuances and the global patterns in

environmental biology interaction. One recent study earlier this year, for example,

revealed the activity of nearly a quarter of our genes varies depending on time of year,

with seasonality cues that are remarkably geographically specific. The shifts influence our immune

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