Miami Brain Fitness » Cardiovascular Disease

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.

DHA for Brain Fitness? Mixed Results

rlo — Mon, 08 Nov 2010 11:30:51 +0000

A paper in last week’s JAMA reports on a clinical trial of docosahexaenoic acid (DHA) in preventing cognitive decline in patients with Alzheimer’s disease. DHA is a component of fish oil supplements that have been recommended for the prevention of heart disease and, possibly, to prevent aging-related cognitive decline.

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.

Smoking and Brain Fitness

rlo — Tue, 26 Oct 2010 08:13:32 +0000

As though there wasn’t already enough evidence that smoking tobacco is bad for you, a new study shows a significant relation between smoking in your late 50’s and the chance of developing dementia about 20 years later. Smoking has multiple effects on your body, especially your heart, and this study again supports the idea that things that are bad for your heart are also bad for brain fitness.

The study published online in the Archives of Internal Medicine used data from more than 20,000 members of a health care organization. They completed surveys in the late 1970s to the early 1980s. The authors of the study looked at how many of them were later diagnosed with dementia.

Results showed that the risk of getting dementia (either Alzheimer’s disease or vascular dementia) increased steadily the more people reported smoking. For less than a pack a day, the increase was small and not statistically significant. But for larger amounts of smoking, the increased risk was significant, and for people smoking more than two packs per day, the risk was doubled.

This study once again shows that brain fitness is also cardiovascular fitness. The same things that cause clogged arteries around your heart may very well result in clogged arteries in your brain.

One good note: people who described themselves as former smokers had the same risk as those who never smoked. So quitting now may help reduce your risk later.

Reference:

Rusanen M et al (2010). Heavy smoking in midlife and long-term risk of Alzheimer disease and vascular dementia. Archives of Internal Medicine. Published online October 25, 2010. View the abstract here.

Bored to Death?

rlo — Fri, 12 Feb 2010 12:24:42 +0000

Being bored can increase your risk of death from cardiovascular disease according to a recent report. If brain fitness means keeping interested in life and mentally active, then an active brain fitness program may help you avoid the risk associated with boredom.

Brain fitness may help you avoid the risk of being bored, and that’s almost undoubtedly a good thing. In an ongoing study in the UK, researchers found that those who reported the most boredom when they were evaluated in the late 1980s were two and a half times more likely to die by 2009.

But it’s not clear exactly why boredom might increase someone’s risk of death. The authors of the study in the International Journal of Epidemiology suggest that a report of boredom probably represents some other problem. Bored people may be depressed or anxious, for example, factors that have already been related to disease risk in a number of studies. They may be more likely to drink excessively or smoke and less likely to exercise, all factors that might increase risk for cardiovascular disease.

An important part of any brain fitness program is staying actively engaged with friends and the community. Other studies have shown, for example, that having friends or being involved in a volunteer program can reduce the risk of cognitive decline. This finding underlines the fact that your thoughts, feeling, and behavior can have significant effects on your health.

Reference:

Britton A, Shipley MJ. Bored to death? International Journal of Epidemiology, available online February 1, 2010.

Available online (free) at the journal website.

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.