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.

A recent study in the Archives of Internal Medicine shows that strength training can improve executive functions. Executive functions are important because they are a mental ability that helps us make decisions and do several things at once (like driving). Executive functions get worse as we get older, so finding a way to maintain or improve them may be a way to keep your brain fit as you get older. This study evaluated the effects of resistance training compared to balance and tone training on older women’s abilities on several cognitive measures. The researchers evaluated whether weight training (generally thought to improve muscular strength) or balance training (thought to improve balance, but also such things as walking ability and risk of falls) also had an effect on participants’ mental functioning.

Compared to the balance and toning group, the strength training group showed small but significant gains in their performance on the Stroop Test. The Stroop measures a person’s ability to deal with conflicting stimuli – someone’s tendency to read a word (a habit) compared to their ability to resist the habit and say the color of the type used to print the word. Performance on this measure is often interpreted as an aspect of executive functions, a group of mental abilities that includes such things as coordinating two mental activities at once (think about driving).

The study only included older women (average age about 70 years), so it’s not clear how strength training would affect younger persons’ or men’s functioning. On the other hand, the study adds to the growing body of research that shows that strength training may be important for  maintaining your brain fitness.

Reference:

Liu-Ambrose T et al. Resistance training and executive functions. Archives of Internal Medicine, 170, 170-178.

The mice who ran performed much better on several tasks that required that they tell the difference between two visual patterns.The effect of running was very clear in adult mice. In mice who were very old, though, running didn’t make much difference, and they didn’t get much boost from the exercise.

John Grohol at PsychCentral also posted about the article, noting that some newspaper accounts barely mentioned the fact that the study was done with mice. He even points out that it was done with a specific variety of mice, and suggests that the relevance of the study may be limited. It’s true that it is very hard to know whether studies about mice really mean much for humans, since findings in animals often don’t generalize to humans.

As Grohol notes, the research is pretty clear that exercise can improve cognitive functioning in people as well as animals.But I’m not as concerned as he is that the results of this study will only apply to one strain of mice. Animal research has its problems when we apply it to human research, but in this case studies in humans have consistently shown similar results to those in animals. It may still be true that the reasons for changes in cognitive function in humans and animals may be different, but that means we would have to come up with two separate mechanisms for change. That’s actually making the situation more, rather than less, complex.

Dr Grohol makes an excellent point about human and animal research. Too often, we jump from preliminary findings to the real world. In areas in which animal and human studies generally agree,though, animals studies can extend and help find new directions for research at considerably less cost than similar studies in humans.

Reference:

Creer DJ et al. Running enhances spatial pattern separation in mice. Proceedings of the National Academy of Sciences, published online first January 19,2010 doi:10.1073/pnas.0911725107

While I doubt that most of the free games or training programs have the same impact as better-designed programs such as Dakim, Lumosity, CogniFit, or Posit, I think that it is likely that trying something new is good for your brain.

Some of you may have heard about the studies on Internet searching done by Dr. Gary Small and his colleagues. They have shown that Internet searching activates key brain centers that may be helpful in keeping your brain healthy. You can read more in an LA Times article here.

Maybe one of the keys is novelty. Doing something, almost anything, that is new may ask your brain to make new connections. Although the science is speculative, when you look at the direction that research is going it looks as though doing new things that make your mind process information in new ways may be essential in improving brain fitness.

In a recent post on this site, I talked about  reducing anxiety by not catastrophizing. Gary Dashney at www.onlinebraingamesblog.com made a comment, and that led me to look at his site. He has collected an impressive list of games, and wrote an excellent post on his thoughts on the characteristics of good brain games. You can find the article on his blog here. The site also has an extensive list of free brain games online here. Even if you don’t use all (or any) of them regularly, if you look through Gary’s list you can become more familiar with what’s on the Internet.

For those of you not familiar with Posit’s programs, they are based on key ideas developed by the company’s president Dr. Michael Merzenich. He has argued that it’s possible to change the functioning of the brain through targeted computer training, and the software focuses on key abilities such as the ability to detect rapidly-changing sounds and following lengthy sets of directions. Users of the software are encouraged to use it for about one hour a day, five days a week, for eight weeks.

One of the best things about this study is the control group used by the investigators. People in the control group (the one compared) were asked to do cognitive stimulation activities that are similar to those many people believe might be helpful — viewing an educational video and answering questions about it.

The IMPACT study showed that people who completed the computer-based training did better on outcome measures than the people in the control group. These outcome measures were neuropsychological measures in a battery given to participants both before and after they either used the program or were in the control group.

Statistical analyses showed that people who used the computer program scored better on these measures than the people in the control group. The authors conclude that the program may be helpful.

The differences between the groups were statistically significant, and that’s important for all of us to know. But it’s also important to look at how big the effect of using the program was. One measure, the Auditory Verbal Learning Test or AVLT, showed a significant difference. The AVLT asks someone to remember a list of 15 words. In this study, the people who used the computer program remembered, on average, about six tenths of a word more after using it.

This doesn’t mean the program isn’t useful. This amount of improvement is similar to that seen with some prescription medications used for Alzheimer’s disease, for example, and some people may have done much better than the average. It also doesn’t tell us how much change would occur for people who use the program over longer periods, too. But it seems to me that most people would want a clear idea of how well the program works before investing in it.