Help pack a million meals for struggling seniors on Sept. 11. Volunteer today


AARP Staying Sharp: Keep Your Brain Healthy


The tablet with free 24/7 customer support. Learn More


Military and Veterans Discount


AARP’s Picture Your Retirement Sweepstakes

Enter the $50K Picture Your Retirement Sweepstakes. Ends 8/31/15. No purchase necessary. Enter for Official Rules.


AARP Games - Play Now!


Learn From the Experts

Sign up now for an upcoming webinar or find materials from a past session.


Planning for Long-Term Care for Dummies

Get expert advice on planning for your own or a relative’s future care needs.

Learning centers

Get smart strategies for managing health conditions.



Heart Disease


Most Popular


The Promise of a Good Night's Sleep

People with chronic sleep problems can benefit from a simple new therapy.

The tide of enzymes and hormones produced in our body surges and subsides throughout the day in rhythm with these molecular signals. Because our internal rhythm runs on a cycle that is slightly longer than the solar day, the master clock is like an orchestra conductor, prompting the entire body to stay in step with the 24-hour solar cycle.

Riding the circadian cycle

Modern life, with artificial lighting that permits people to work or play all night long, makes it harder to maintain healthy circadian cycles. But people disrupt these rhythms at their peril, Sassone-Corsi says. Women who regularly work night shifts, like nurses, “have something like three to four times more chance to get breast cancer,” he observes.

Mariana Figueiro likes to say that people are natural “blue sky detectors.” We need a certain level of daylight, ideally soon after sunrise, to stay in sync, she says. The light needed to stimulate our circadian rhythms is more intense than that required for vision, which is why it is important to be outdoors.

“The circadian system is looking at the contrast between dark and light,” she says. The best light to stimulate the system during the daytime is in the blue wavelengths with at least an hour of exposure per day.

Seeing the light of day

But for older people, in addition to physiological changes, “you have behavioral change,” Figueiro says. “Older people don’t go out as often. They tend to stay indoors.” While taking a daily morning walk is ideal, an alternative is to improve indoor lighting. “It’s important to have higher lighting levels—bluish-white daytime lighting and a lower, warmer, incandescent spectrum at night,” she says.

Blue light at the right time of day—around sunrise—suppresses melatonin and tells the body it is daytime, Figueiro says, and the light should be at least eight times more intense than the lighting typically found in nursing homes. People should avoid blue light in the evening, when the body is supposed to be making more melatonin in preparation for sleep.

Figueiro is also conducting preliminary studies using light to help people with early-onset Alzheimer’s disease, which is frequently characterized by fragmented sleep. “It’s one of the biggest reasons they’re institutionalized,” she says.

As for Katherine Closson, she admits that she doesn’t get outdoors as often she used to since developing a hip infection a couple of years ago. But she has kept the bright blue-white bulbs she was given for the circadian study. “I’m as happy as a lark,” she says.

Michael Haederle is a freelance writer whose work has appeared in People, the New York Times and the Los Angeles Times.

Topic Alerts

You can get weekly email alerts on the topics below. Just click “Follow.”

Manage Alerts


Please wait...

progress bar, please wait

Tell Us WhatYou Think

Please leave your comment below.


Discounts & Benefits

From companies that meet the high standards of service and quality set by AARP.

Walgreens 1 discount membership aarp

Members can earn 50 points per $1 spent on select health & wellness products at Walgreens.

member benefit aarp hear usa

Members save 15% on easy listening devices and more at the HearUSA Hearing Shop.

Eye Med 4 Membership Benefit AARP Discount

Members save up to 60% on eye exams and 30% on glasses at Target Optical.

Membership Benefits Discounts Email Genius

Brain boost? Get AARP email for access to memory exercises & more that help you focus.

Rewards for Good

Your Points Balance:

Learn More

Earn points for completing free online activities designed to enrich your life.

Find more ways to earn points

Redeem your points to save on merchandise, travel, and more.

Find more ways to redeem points