Exercise as it relates to Disease/Physical Activity and its effect on cognitive function in older women

This is an analysis of the journal article “Physical activity, including walking, and cognitive function in older women” by Weuve et al (2004)

What is the background to this research?
It is well documented that physical activity can provide many health benefits like, reducing the risk of cardiovascular disease, some cancers and type 2 diabetes. It’ also assists in improving weight control and mental health. What is not as well-known to the public is how physical activity impacts cognitive ability.

The latest life expectancy to come from the World Health organisation states that for anyone born in 2015 the average life expectancy for them is 71.4 years which is 5 more than the expectancy in 2000 which shows we are getting older as a population.

An unavoidable part of ageing is a decline in cognitive function. Cognitive function encompasses the skills of reading, memory, awareness, multi-tasking, processing and reasoning as well as many other functions of the brain. Not all of these skills are age related however a lot are like process speed and multi-tasking which can make simple daily activities extremely difficult for older people. Without treatment these mild cognitive impairments can develop into awful diseases like dementia and amnesia.

Physical activity has been called in once again to save the day as research is showing that physical activity can slow and even reverse the effects of age related cognitive decline. Walking is enough exercise to display significantly better cognitive function and less cognitive decline suggested by Weuve et al.

Where is the research from?
Weuve et al from Harvard University, Cambridge conducted their research across all of the US using the Nurses’ health study.

What kind of research was this?
Two different types of data gathering was used. For collecting information on physical activity a questionnaire was sent out to all participants where they would judge what level and type of physical activity they took part in. Cognitive testing was administered using telephone interviews conducted by trained nurses.

What did the research involve?
A random sample of 18,766 women aged over 70 participated in the telephone cognitive tests. The cognitive tests were conducted twice with an average of 1.8 years between the initial and follow up test.

These telephone tests occurred between 1995–2001 and were compared to research gathered from a physical activity questionnaire that was administered every two years after 1986. The questionnaire asked the women to estimate the average time per week that they participated in a variety of physical activity, including running, walking, swimming, yoga and vigorous activities like lawn mowing. Participants were also asked to indicate their own walking pace.

What are the basic results?
Weuve et al found that higher levels of physical activity was associated with greater cognitive performance. Women in the highest quintile for physical activity were found to have a 20% lower risk of cognitive impairment compared to the women in the lowest quintile for physical activity. They also found a reduction in cognitive decline for the women in the top two quintiles for physical activity. For individuals that can’t participate in vigorous exercise Weuve et al also found that walking at a normal pace for 1.5 hours a week was associated with better cognitive performance.

How did the researchers interrupt the results?
Their interpretation of the results was that there is a positive relationship between physical activity and cognitive performance. The researchers did point out that there are several limitations to the results. The key ones are that there were many unmeasured factors that could influence an individual’s cognitive performance. The researches did take into account health and educational factors however some big factors I think they missed. On the questionnaire there is no mention of concussion history and no mention of family history of cognitive disease like Huntington’s disease which is heredity. This concern of mine is partially explained by the researches as another one of their limitations was that pre-existing cognitive impairments might have effected some individual’s physical activity levels. The reliability of the results is also determined by the truthfulness of the women participating. It is often seen that people will report false information on questionnaires in order to paint a favourable image of themselves. All these factors need to be taken into account when analysing the results.

What conclusions can be taken away from this research?
Physical activity definitely has a positive impact on cognitive performance in older women. It has also shown that it could possibly combat and potentially reverse age related cognitive decline. There is plenty of literature on this topic and the majority of it has had similar findings of a positive correlation between physical activity and cognitive performance. Even this year there has been research done with a certain group looking at the relationship between physical activity and cognitive function but by using accelerometers instead of self-reporting to measure physical activity. They also found that more physical activity leads to better cognitive function.

What are the implications for this research?
The research has shown that physical activity is an effective method for improving and maintaining cognitive performance. This is important because our cognitive is what allows us to do our daily tasks freely and easily. With an ageing population we become exposed to more aged related diseases like dementia and cognitive decline so therefore it is important that there are methods like physical activity that can be used to prevent or delay these issues. If you do decide to go out and exercise because you have been inspired by this research it is important to go through some form of pre-screening with a qualified health practitioner first.