Leptin is an important regulatory hormone implicated in appetite and weight gain. It also has activity in the CA1 region of the hippocampus, an area of the brain this is critical for learning and memory. Weight loss in late life is associated with cognitive decline (see this post about frailty, a syndrome of weight loss and other forms of decline), so researchers thought that leptin might be involved. Even though higher levels of leptin are related to weight loss, patients with cognitive problems actually had lower levels of leptin.

The researchers looked at the relation of leptin and risk for Alzheimer’s disease, and between leptin and brain volume (how much brain tissue each person had). The results showed that people with higher levels of leptin were less likely to develop Alzheimer’s. And those with the highest levels of leptin had the largest brain volumes.

People who sleep less have been found to have lower levels of leptin. In fact, this may be a cause of increased weight in people with sleep problems. Being overweight in middle age is related to an increased risk for cognitive decline in later life. So it appears that there may be a complex relation between sleep, weight, and cognitive function.

Once again, getting enough sleep and maintaining a health body weight may be keys to long-term brain fitness.

Reference:

Lieb W et al. (2009)  Association of plasma leptin levels with incident Alzheimer disease and MRI measures of brain aging.  JAMA, 32, 2565-2572.

Most of us know how we feel when we don’t get enough sleep. Research shows that lack of sleep can affect your memory, raise your blood pressure, and increase your risk of stroke.

But how do you get a good night’s sleep?

If you feel as though you’re not getting enough sleep, or as though your sleep isn’t leaving you feeling refreshed in the morning, the most important thing is to figure out why. Some changes in sleep are normal with increasing age and may lead you to feel as though you’re not sleeping well. Click here to find out more about normal changes in sleep with aging. If you feel as though you’re not sleeping well, ask your doctor for help.

Many sleep problems can be treated. If someone tells you that you snore, you wake up with a dry mouth, or you feel just as tired when you wake up as when you went to bed, sleep apnea may be the cause. Sleep apnea is a condition that causes a person to stop breathing during the night – sometimes many times during the night. When that happens, you wake up (even though you may not remember it) and your normal sleep is disrupted.

Other causes of sleep problems include depression, too much mental activity before bed time, drinking caffeine or smoking, and bad sleep habits. You can find out more about how to improve your sleep here. The website of the National Sleep Foundation has a number of articles about sleep and how to get a good night’s sleep. Learn more about how to sleep better. Your brain will work better and you’ll feel better, too.

The truth is, though, that a great deal is happening during sleep. Scientists don’t understand everything that happens while we are sleeping, but we know a great deal about the consequences of not sleeping well.

When we don’t sleep well, we all know we don’t feel quite as sharp the next day. But there’s more. Research shows that when someone is deprived of sleep, they don’t perform as well on cognitive tests as they do when they are well rested. More, some levels of substances associated with inflammation are elevated as well. It looks as though poor sleep over time may have negative effects on your body and mind.

What can you do if you don’t sleep well? Adequate sleep hygiene is the first step. Make sure that you have a quiet place to sleep that is kept at a comfortable temperature. Keep distractions to a minimum. Avoid caffeine and alcohol near bed time. Some people can’t drink caffeinated beverages after noon, and some people have to quit drinking anything with caffeine at all. Smoking can disrupt sleep – nicotine can keep you awake, and some smokers wake up in the middle of night because their levels of nicotine go down during the night. Help your mind and body calm down at least an hour before going to sleep by stopping work or other mentally stimulating activities.

Probably one of the most important things you can do is to have a regular sleep schedule. Go to bed and get up at the same time every day, even on weekends. If you don’t sleep well on one night, don’t try to make up for it by sleeping late. Avoid naps during the day. Naps reduce the pressure to sleep at night, making it less likely that you’ll be able to sleep well. Exercising during the day, and getting exposure to sunlight during the morning may help you regulate the daily rhythms that help you to sleep.

If these things don’t work, see your doctor. A number of sleep problems may require special treatments. A qualified sleep doctor can help you sleep better, and sleeping better is a critical way for you to keep your brain fit.

How we sleep changes as we get older. Many people over 50 feel as though that they don’t sleep as well as they used to. Their perception is supported by research evidence. Studies of sleep and aging show that how people sleep change as people get older. The normal cycles of light sleep, deep sleep, and rapid-eye movement (REM) sleep don’t occur in the same way. Deep sleep is often associated with feeling rested when you get up in the morning, and studies show that older people may not get as much deep sleep. It may take you longer to get asleep, and you may wake up more often during the night.

Older adults may get sleepy earlier and take more naps during the day. It’s not unusual for me to see people who complain about waking up too early in the morning. When I ask about their sleep, though, I find out that they go to bed at 9:00 PM and wake up at 3:00 AM. It’s true that’s a little early – but often these folks take a two-hour nap in the afternoon. They get eight hours of sleep, but it’s distributed in a different way. Although it’s sometimes hard to stop taking naps entirely, it’s often helpful to try to keep them to a minimum. If you sleep a lot during the day, you may not sleep very well at night.

So what about brain fitness and sleep? Study after study has shown that sleep deprivation affects your mental abilities and mood. So if you feel as though you can’t concentrate or work as well as you’d like after you don’t get enough sleep, it’s probably true. This may be especially true for tasks that require attention for a long time. Some of those kinds of tasks are harder for older adults to begin with, and may be even harder if you don’t sleep. Don’t think that you can’t function at all if you don’t sleep well – you’ll usually be able to function. But odds are you won’t function as well as you would like.