Miami Brain Fitness » cognition

Exercise, Mitochondrial DNA, and Brain Fitness

rlo — Sat, 12 Mar 2011 01:54:32 +0000

One very influential theory of why our physical and mental functions decline with age holds that changes in our DNA accumulate over time so that out cells don’t work any more. Perhaps the most important part of our DNA exists in every cell in a special part called the mitochondia. Mitochondria are especially important because they are the part of the cell that helps it generate energy. DNA contains the programs that generate energy, but over time errors accumulate in the programs until eventually they don’t work very well any more. Errors in the programs that run our cells happen all the time — but when we’re younger the cells can fix themselves. As we get older, the cells don’t fix themselves as well. The result: our bodies don’t work as well as they used to. Over time, things start breaking and can’t be fixed. Eventually . . .

A recent study reported in the Proceedings of the National Academy of Science reports on a way to reduce the errors, at least in mice who are prone to an increased number of DNA errors. These mice have an increased number of errors in their DNA, and even early in life start to show signs of aging that are eerily similar to those seen in humans: hair loss, graying, low of body weight, and problems in mobility. Researchers at McMaster University in Ontario, Canada, compared mice with the increased number of errors to regular mice, and looked at what happened if some of the error-prone mice spent time exercising.

The group of the mice who had DNA errors exercised for 45 minutes on three days a week for 5 months. The researchers then compared the three groups: (1) DNA error-prone who didn’t exercise, (2) DNA error-prone who exercised, and (3) regualr mice who had normal DNA. Result: The error-prone mice who exercised looked the same as the regular mice. They weren’t just stronger, or in better shape, or able to run longer. They “lacked visible features of the accelerated aging phenotype (alopecia and graying hair) and were visually indistinguishable from age-matched … littermates” (page 4135).

Does this mean that if you start exercising regularly you can reverse aging? Probably not. But good research continues to accumulate that shows that exercise can improve cognition and keep the effects of aging to a minimum.

You can find an abstract for the article here. To read the full article, you will need a subscription to the journal.

5 Ways to Train Working Memory for Brain Fitness

rlo — Tue, 02 Nov 2010 12:31:46 +0000

If working memory is important for brain fitness, and training it may make it better (and even improve scores on other cognitive measures), how do you train it?

Here are 5 ways to train working memory:

The single best way to train working memory for brain fitness is to use (almost the) same computer program used by Jaeggi et al. in her study. You can’t get exactly the same software that will automate something called n-back training. You can, however, use Brain Workshop, free open-source software that closely imitates the procedures used in studies of working memory. The software for brain fitness training is free, and you can download it here.

As useful as n-back training is, you may want to branch out and do other things. A visual game that can train working memory is called concentration, a matching game that makes you remember the position of pictures while you look for a match. There are lots of these kinds of games on the web (and one version is included in the Posit Science brain training software. I put one up on the Web – click here to try it out. (I borrowed the code for this game from a book called ActionScript Game Programming University and can’t take personal credit for it. It’s a great book about Flash game programming, and you can find the author’s website here.)

Away from your computer? Why not try Sudoku? You can do it on paper in books, and you can find a number of applications for your phone or handheld game device. You can even download and print them from the web. I found several sources, including here. Don’t know what Sudoku is? Find out more about it here.

Standing in line at the grocery store? Pick out numbers off the cover of the magazines and add them in your head. Too easy? Subtract them and multiply by another number. Still too easy? When was the last time you did a square root in your head?

Sitting on the couch at home? Spend time visualizing the route from your home to a place you only go to once in a while. Get a mental picture of your own home, then create a mental image of the first turn, and then the next, and the next. Did you get there? Now reverse the route until you get home.

Brain Fitness Tip: Stop Catastrophizing!

rlo — Wed, 02 Dec 2009 12:19:33 +0000

Anxiety makes your memory worse, and worrying about your memory can make your anxiety even worse.

Just as studies have shown that stress can have a negative effect on your memory, it’s pretty clear that anxiety can make it harder to remember things, too. We’ve probably all had the experience of trying to remember a name or a word and feeling frustrated about not being able to come up with it. Paradoxically, the harder you try to remember, the less you’ll be able to do so.

So far, that’s pretty normal. Younger people have the same kind of trouble with their memory occasionally, although it may happen more frequently as we get older. It’s what happens next that makes it different for older persons.

Many of my older patients may have a problem with remembering a word or a name, but they go one step further: When they can’t remember something, they start worrying about it. They may interpret the fact that they can’t remember means they have a memory problem, maybe even Alzheimer’s disease!

Sometimes, when people start worrying about a problem, they think of the absolutely worst thing that it could mean. A cloud in the sky, for example, may mean that a tornado is coming. We call that catastrophizing. It’s not good English, but it is pretty clear what it means. It means taking a real problem and magnifying it by exaggerating it to the worst possible outcome.

How do you avoid catastrophizing? When you begin to feel worried or anxious, try to stop and consider alternate explanations for whatever you’re worried about. Could that cloud just mean that there’s a cloud, not that a tornado is coming? Odds are that the answer is yes. Is having trouble remembering annoying. Yes. Does it mean that you have a serious memory disorder or neurological disease? Probably not.

As always, there’s no substitute for a thorough evaluation of your memory by a competent clinician. An evaluation ought to include assessment of your general ability, concentration, and memory. And never forget the importance of taking care of other medical problems, such as high blood pressure or diabetes.

Brain Fitness Tip of the Week: Frailty

rlo — Tue, 15 Sep 2009 11:56:12 +0000

Clinicians and researchers working with older persons often are concerned that their patients will develop a syndrome called frailty. Frailty is usually defined by the occurrence of muscle weakness, slow walking speed, exhaustion, weight loss, and low levels of physical activity.

Frailty may make you think about someone who is quite old and infirm, but at least some people think of frailty as a physical equivalent to developing cognitive problems. Pre-frailty (having just a few of the characteristics of frailty) may be like mild cognitive impairment, a milder form of memory or other cognitive problems that may lead to dementia.

From this point of view, preventing frailty may be a route to preventing decline. Although frailty is defined by things like slow walking and muscle weakness, research shows that frailty is associated with memory problems and depression.

It might seem odd that muscle strength and walking speed go along with memory and depression. But besides the research that show they are related, there’s a good reason why they are linked. Frailty has been linked to higher levels of markers of inflammation such as the pro-inflammatory substances called cytokines. There are substances in your body that are increased when you are sick, but they also increase as you get older.

Evidence suggests that low grade but chronic inflammation may be a key factor in aging. Researchers are still studying the best ways to reduce the effects of inflammation, but it’s likely that exercise reduces levels of inflammatory substances. It is also possible (but not proven) that antioxidant supplements and some diets may help to reduce inflammation. These same things may help prevent frailty. Exercise may be an important defense against developing frailty as well as helping with cognitive decline.

Mediterranean Diet, Physical Activity, and Risk for Alzheimer’s

rlo — Thu, 13 Aug 2009 15:51:45 +0000

Studies reported in this week’s Journal of the American Medical Association (August 12, 2009) support the relation of physical activity and the Mediterranean diet to reduced risk for Alzheimer’s disease. The first study, by Scarmeas and his colleagues, showed that persons who report following the Mediterranean diet and who are more physically active were less likely to develop Alzheimer’s disease over several years. The average age of the participants was 77 years, so this group (called the Northern Manhattan cohort) would have been at higher risk than younger individuals.

The second study, by Feart and her colleagues, looked at adherence to the Mediterranean diet and risk for having problems on certain mental ability tests. Here again, the study suggests that following the Mediterranean diet was associated with a reduced risk of developing certain kinds of cognitive problems.

The study was discussed by Dr. Nancy Snyderman on the Today Show. You can find a link to a page that will let you see the segment from the show here. (Look for a link to “Study: Mediterranean diet cuts Alzheimer’s risk.” You also have to watch a commercial; that’s NBC, not me). I think that she may overstate the case based on the research; there’s a very nice editorial in this same issue of the Journal by well-known neurologist David Knopman. He points out a number of possible reasons for these findings that might affect the conclusion that the Mediterranean diet and exercise reduce the risk of Alzheimer’s. He suggests we should “nibble and savor” the results of these studies, not “swallow them whole.”

It’s still premature to be sure that following the Mediterranean diet or being physically activity will prevent Alzheimer’s disease. Given what we know about the relation of cardiovascular health and risk for Alzheimer’s, and what we know about diet and exercise and cardiovascular health, though, I think it’s a good idea to pay close attention to your diet and to exercise safely.