Islamabad - Physically fit, healthy older adults who stopped exercising for only 10 days showed signs of significant decreases in blood flow to parts of the brain that are important for thinking, learning, and memory - such as the hippocampus.

Lead author J Carson Smith, associate professor of kinesiology at UMD says we know that the hippocampus is important for learning and memory.

He explains that studies of mice and rats have shown exercise increases growth of new blood vessels and brain cells. Also, research shows that in older people, exercise can protect the hippocampus from shrinking. He notes:

“So, it is significant that people who stopped exercising for only 10 days showed a decrease in blood flow to brain regions that are important for maintaining cognitive health.”

Using magnetic resonance imaging (MRI) brain scans, the team measured brain blood flow in healthy, physically fit older adults aged from 50-89 years (average 61) before and after a 10-day period during which they stopped all exercise.

The results showed significant reductions in resting brain blood flow in eight brain regions - including the right and left hippocampus.

The other regions included parts of the “default mode network” - a brain structure that is known to deteriorate quickly in people with Alzheimer’s disease.

However, the researchers found no significant change in cognitive function - measured using verbal fluency tests - in the participants from before to after they stopped exercising.

The participants who volunteered for the study were all “master athletes” whom the researchers describe as “a unique population and should not be considered equivalent to older adults who engage in regular moderate to vigorous intensity leisure-time physical activity.”

The researchers were not surprised to find these senior athletes scored high for their age on aerobic fitness. Their VO2 max was in the top 10 percent for their age group (above the 90th percentile). VO2 max is the volume of oxygen a person consumes while exercising at their maximum capacity.

With an average continuous endurance training history of around 29 years, the volunteers regularly took part in national and regional events.

Just before taking part in the study, they were running an average of 59 kilometers a week and training on 5 days a week.

Prof. J. Carson Smith said that “We know that if you are less physically active, you are more likely to have cognitive problems and dementia as you age. However, we did not find any evidence that cognitive abilities worsened after stopping exercising for just 10 days. But the take home message is simple - if you do stop exercising for 10 days, just as you will quickly lose your cardiovascular fitness, you will also experience a decrease in blood brain flow.”

The researchers say their findings point to a need for further research to discover how fast the brain blood flow changes occur, what their long-term effects could be, and whether they can be reversed by taking up exercise again.

Folic acid may protect against congenital heart defects

Foods fortified with folic acid decrease rates of some types of congenital heart defects in Canada, finds new research. Folic acid is a B vitamin that our bodies use to make new cells, and it is important for the development of a healthy fetus.

Dr Joseph and colleagues also noted that the beneficial effects of folic acid were only observed in some types of CHDs.

Also, a 15 percent reduction was seen in atrial and ventricular septal defects, which are the holes in the wall that separate the heart chambers. No change was observed concerning chromosomally associated defects - an abnormality in the number of an infant’s chromosomes.

The authors say: “Our study shows associations between food fortification with folic acid and reductions in the birth prevalence of specific CHD subtypes. The associations were stronger for conotruncal defects and coarctation of the aorta and more modest for septal defects.”

“Older maternal age, prepregnancy diabetes mellitus, and preterm preeclampsia were also associated with population rates of CHDs,” they add.

Dr Joseph highlights the importance of taking folic acid for women who are trying to become pregnant, as they may not receive an adequate amount of folate from diet alone.

While food fortification with folic acid was aimed at reducing neural tube defects, the study shows that folic acid may also have a beneficial effect on specific types of CHDs, which are collectively more common.