In an article published online on January 31st in the Proceedings of the National Academy of Sciences, researchers show again that regular walking can make a difference in cognition. This study is new because the researchers also looked at the volume of the hippocampus with imaging techniques and looked at BDNF levels.

Exercise and BDNF levels may also be related to the way that antidepressants work to reduce depression, and we know that for many individuals exercise improves mood. While we think of the hippocampus most often because of its role in memory, it also has important effects in regulating emotion.

You can find the abstract here. The full article is available to subscribers only.

A lot of people are skeptical about this idea, perhaps because most of us are taught that the cells in our brains are pretty much fixed and don’t change over time, except for dying off as we get older.

More recent studies, though, now have shown that the brain can grow new cells. Other studies have shown that some kinds of brain training change how some of the chemicals in the brain work. And still other studies have shown that cognitive training can have long-lasting effects.

So what can you do to improve your brain fitness?

• Find a rut and get out of it. What habit are you in, and how can you get out of it? Do you collapse on the couch every night and watch TV? Try going for a walk. Record your favorite TV show and instead spend a half hour searching the Internet for something that interests you.
• Learn a little bit of a new language. Learning a new language may be one of the best ways to rewire your brain. Maybe you won’t learn enough to be fluent, but learning about the sounds in a new language may help your ability to pay attention to sounds, and learning new ways to express a concept may help you keep your thinking flexible. You could take a class, but more and more language resources are on the Web.

Although we still don’t know exactly how to improve brain fitness for everyone, research gives us some promising directions.

Results of the overall study were negative – DHA at a dose of 2 grams a day didn’t slow how much patients’ cognitive abilities declined over 18 months.

One finding of the study has been largely ignored in media reports. In a planned subgroup analysis, though, patients treated with DHA and who did not have the ApoE 4 allele had slower cognitive decline. ApoE 4 is a gene that has been associated with greater risk for having Alzheimer’s disease. It may be related to how fatty substances in the body are used by the body.

Although the findings of the main trial are negative, one subgroup may have benefited from DHA treatment.

This study thus adds to a series of studies based on observations that people who take vitamins, nonsteroidal anti-inflammatory drugs, and fish oil supplements have lower risks for Alzheimer’s disease. The logic of the trials has been to evaluate things associated with lower risk as treatments, but none has turned out to be effective.

Click here to read the full article.

Reference:

Quinn JF et al (2010). Docosahexaenoic acid supplementation and cognitive decline in Alzheimer disease. JAMA, 304, 1903-1911.

The intervention focused on improving healthy older adults’ ability to perform a task while subjected to audio and video distractors.The key goal was to improve participants’ ability to screen out irrelevant information while paying attention to what was important. The training worked. Participants got better at screening out distracting information. Another group completed an educational intervention; they didn’t show improvements in their ability to ignore distractors.

Functional MRI data were collected on some of the participants. They showed that participants had increased blood flow to an area in the right inferior prefrontal cortex than did control participants.This area of the cortex has been associated with the ability to sustain attention and complete several tasks simultaneously.

The significance of these findings is in showing once again that cognitive training can have a substantial impact on biological parameters in areas of the brain known to be important for cognitive function. Issues remaining include determining the best ways to train, how much and how often to train, and how much training will translate into real-world behaviors.

Reference:

Mozolic JL et al. (2010). A cognitive training intervention increases resting cerebral blood flow in health older adults. Frontiers in Human Neuroscience, March 2010, volume 4, article 16. doi: 10.3389/neuro.09.016.2010 Link to article here.

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.