They've been happily married for 51 years. But now Marge has Alzheimer's.

Lay all the way back in the shampoo bowl, as far as you can make it.

I can't.

Sure, you can. Back you go.

Little bit more.

She's unable to do anything for herself, and her husband cares for her. Caring for his wife every moment of the day causes Franklin constant distress.

It isn't easy. In one way, it's worse than it was in the blinkin' war, when I was getting shot at. After it was over, you could say to yourself, son of a gun missed me. And on this, you know it isn't going to get better. It's always going to be worse.

Just a little bit more. We're almost done.

Just a little more. Well, the worst part is the contrast of what she is to what she used to be. She used to manage hospitals and sell real estate, do all the things that successful people do.

Sure, you can.

Jan and Ron Glazer planned a detailed study to examine the effects of stress on health. They choose people under continuous high stress, people like Franklin, who cared for loved ones with Alzheimer's.

When someone's providing care for a spouse with progressive dementia like Alzheimer's disease, what you have is a very long-term, very chronic stress that is only, by and large, going to get worse over time. So that for caregivers, they describe it in some ways as kind of a living bereavement, as they watch pieces of the person they love disappear over time.

Not surprisingly, the Glazers found that psychological stress had lowered Franklin's immune response.

In a lot of studies, both in animals and human subjects, people find statistically significant differences in different aspects of the immune response as it relates to stress. And that's fine. That's interesting.

But the real important question is, are those changes big enough to have a health effect? Are they biologically significant, as well as statistically significant?

The study went on to address that question, by seeing if high stress and low immune function actually impaired the body's ability to heal itself. Small identical wounds were made on the arms of all the volunteers. The Glazers then measured the time it took for the wounds to heal.

They found that the wounds of overstressed carers, like Frank, took 24% longer to heal than did those of unstressed people. Here at last was a demonstration that stress could lower immune function to the point of affecting your health.