Exercise as a therapy for preventing cognitive decline

Summary: The recent paradigm for the treatment of cognitive impairment has shifted to non pharmacological interventions such as exercise.  Some results published recently have shown a positive role of exercise in preventing cognitive decline. The common message of all these studies involving different population and different cultures is that exercise is beneficial in preventing the cognitive decline. In the future,  evidence based exercise therapy can be introduced  by developing a thorough systematic exercise protocol  and integrating it with molecular profiling of the underlying cellular and molecular changes induced by the exercise protocol.   

Cognitive impairment is one of the major public health problem faced by the modern society affecting primarily the elderly population. It can have many possible causes such as metabolic and endocrine dysfunction, medicinal side effects, depression and Alzheimer’s disease. While there are some medications that are used as cognitive enhancers, no known medication that could prevent or treat the cognitive decline have been developed yet.  Developing a drug that could prevent or treat cognitive decline is a challenging prospect. Therefore, more efforts have been put into conventional or non pharmacological interventions such as diet and exercise. Assessing the current studies, the results are encouraging and in the near future we could be up for some type of exercise therapy for the prevention/treatment of cognitive impairment. Here, I am trying to summarize some of the studies related to exercise and cognition published in 2017. The common message of all these studies involving different population and cultures is that exercise is beneficial in preventing cognitive decline.

A systematic review published in the British Journal of Sports Medicine showed that physical exercise improves cognitive function in the elderly. This meta analyses took into the account 39 different studies till November 2016.  The study looked into several different types  of aerobic exercise, such as resistance training , multicomponent training and tai chi (Chinese martial art),  and found that moderate intensity aerobic exercise decreases the cognitive decline in patients older than 50 years irrespective of their cognitive status.

Similar result was obtained in another study published by Piedra et al. in the Journal of Alzheimer’s Disease. The study investigated the effects of exercise intervention on cognitive function in the elderly latinos/hispanic population (older than 60 years). The participants were examined for their cognitive function(baseline) before initiating the exercise intervention program.  Then, following the exercise intervention program, the cognitive function was again measured after 1 year and 2 year periods.   The results showed that participants involved in the exercise intervention program had higher cognitive function scores after 1 year and 2 year follow ups as compared to their initial baseline scores.

Not only is exercise beneficial to the elderly people. It is also beneficial to the adults of any age suffering from chronic diseases. The study published by Cai et al. in Clinical Interventions in Aging have found that exercise is beneficial in preventing the cognitive decline in the adults (older than 18 years) with chronic disease. This metaanalyses and systematic review took into account 36 different studies till September 2016. The studied participants were diagnosed with chronic diseases such as arthritis, asthma, cancer, COPD, diabetes, heart disease, or AIDS. This study found that exercise is beneficial in improving the cognitive function of patient suffering from chronic disease irrespective of  the type of clinical disease, type of exercise, frequency, and intensity of the exercise intervention.

These are some of the recently published studies related to exercise and cognition in 2017. The results of these studies clearly showed that exercise could potentially act as a non pharmacological therapy in preventing cognitive decline.  However, development of a systematic exercise protocol supported by molecular profiling of underlying exercise induced changes could be of immense help in establishing evidence based exercise therapy. 

Particularly,in regards to exercise, the rule of thumb is any amount of physical activity is beneficial and as the above studies suggest, it is beneficial to prevent/slow the cognitive decline as well.


Northey JM, Cherbuin N, Pumpa KL, Smee DJ, Rattray B. Exercise interventions for cognitive function in adults older than 50: a systematic review with meta-analysis. Br J Sports Med. 2017 Apr 24. pii: bjsports-2016-096587. doi: 10.1136/bjsports-2016-096587. [Epub ahead of print] Review.

Piedra LM, Andrade FC, Hernandez R, Boughton SW, Trejo L, Sarkisian CA. The Influence of Exercise on Cognitive Function in Older Hispanic/Latino Adults: Results From the “¡Caminemos!” Study. Gerontologist. 2017 Mar 15. doi: 10.1093/geront/gnw256. [Epub ahead of print] 

Cai H, Li G, Hua S, Liu Y, Chen L. Effect of exercise on cognitive function in chronic disease patients: a meta-analysis and systematic review of randomized controlled trials.Clin Interv Aging. 2017 May 11;12:773-783. doi: 10.2147/CIA.S135700. eCollection 2017. Review.

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Nutrition and Neurodegenerative diseases

“You are what you eat”. The importance of nutrition for the human health has been known since the ancient times. There is no doubt that nutrition is one of the prime factors that affect the health of any living being, plants or animals alike.

Recently, a lot of research has been focused in the role of nutrition in human health. Epidemiological studies in human and experimental animal studies have been conducted to see if there is any particular association between human diet and diseases.

One of the areas that scientists are prioritizing is Neurodegenerative diseases which include dementia and Alzheimer’s disease. It has been estimated that 30% of the total population will be over 65 years of age by 2050. With the increasing population, there will also be an increase in the economic burden to take care and to treat the age related disorders which might call for the measures for preventing or even reversing the age related health disorders. Among the potential option for achieving this is the use of nutritional substances for the prevention of the age related diseases.

The relationship between nutrition and cognitive decline is complex and it might be multifactorial involving several environemental factors such as nutrients, pollutants, chemicals, physical activity, lifestyle, physical and mental stress.

Epidemiological studies have shown that micronutrients such as Vitamin B, C D and E, flavonoids, polyunsaturated omega-3-fatty acids to have protective role in the prevention of cognitive decline, dementia and AD. So, consumption of these foods containing these micronutrients might help in preventing the neurodegeneration and other health related disorders associated with aging.

One of the mechanisms behind the age related disorders is oxidative stress. It is involved in almost all of the diseases associated with old age such as neurodegenerative diseases, diabetes and cardiovascular diseases. To decrease the oxidative stress in our cells, we have to have proper nutrition containing antioxidants. In addition meditation, exercise might also help in reducing the stress which might be involved in oxidative stress.

Brain is a plastic organ that can be molded into different ways and nutrition definitely plays a big role in molding the brain by facilitating in creating the good brain environment. However, we should not forget a big picture that a proper nutrition is beneficial not only to our brain, but also to all the organs of our body.


Aerobic training might be an answer to alzheimer’s disease(AD)


Picture taken from http://guardianlv.com/

Alzheimer’s disease(AD) is a neurodegenerative disease responsible for most cases of dementia in elderly population. A lot of trials with drugs are ongoing in order to find the prevention and cure of AD. But recent research have shown life style modification and behavioral changes to be as effective as drugs in the prevention of AD.

A study published in the journal of gerontology has shown 6 months of aerobic exercise effective in reducing the symptoms of AD in the elderly population.

This study used 6-month cycling intervention to older adults of a selected community with mild-to-moderate AD. The exercise was a standardized, supervised, and individualized, moderate intensity cycling for 15 to 45 min a session (excluding 10-min warm-up and 10-min cool-down activities), 3 times a week for 6 months.

The outcomes of this training regimen were evaluated by measuring the cognition, ADL(Activities of daily living), BPSD(Behavioral and psychological symptoms of dementia) and caregiver distress at the end of the experiment.

The data was collected from older adults with mild to moderate AD and they were followed up for 6 months. The results showed neither significant cognitive decline nor deterioration of the neuropsychiatric symptoms during the 6 month period. Also, aerobic exercise significantly reduced the stress in the caregivers.

There are other papers which have shown the benefit of exercise in neuropsychiatric as well as neurological disorders. Nevertheless, every research paper has its own limitations. But this finding that showed the effectiveness of exercise in preventing the progression of AD is very encouraging. Although, more detailed and precise research need to be done, opening of sports center for the elderly people to engage them in mild-moderate intensity aerobic exercise might be a good idea. Like they say prevention is better than cure, these type of sports center for elderly people might help in preventing AD, thus preventing the social as well and economic burden in the future.

For more details, see the reference article below:

Impact of 6-Month Aerobic Exercise on Alzheimer’s Symptoms                                     Fang Yu, William Thomas, Nathaniel W. Nelson, Ulf G. Bronas, Maurice Dysken,and Jean F. Wyman, Journal of Applied Gerontology published online 11 December 2013,DOI: 10.1177/0733464813512895


Withania Somnifera (Ashwagandha) and its neuroprotective effects

What is Ashwagandha or Withania Somnifera?

Withania Somnifera(WS), also called Ashwagandha in Sanskrit is a herbal plant widely mentioned and used in ayurvedic medicine. In Ayurveda, Ashwagandha is used to enhance mental health and memory and research have proved that it, in fact, enhances memory. Recent studies have also shown that the ashwagandha root have other wide range of therapeutic properties like antistress, immunomodulatory and antioxidant.

Berry of the Withania somnifera plant

Berry of the Withania somnifera plant

Ashwagandha its use in neurodegenerative diseases:

The roots of Ashwagandha extracts have shown to reduce the number of hippocampal degenerating cells significantly in the brains of stressed rodents and were neuroprotective in animal models of Parkinson’s disease.

Studies done in rats at Defense Institute of Physiology and Allied Sciences, India have shown that withania somnifera roots can improve the hypobaric hypoxic induced memory impairment and neuronal degeneration. Likewise, study done in Human neuronal cells at Herbert Wertheim College of Medicine, USA showed that Ashwagandha(Withania Somnifera) benefits in Alzheimer’s disease(AD). It shows neuroprotective effects in AD.

Animal studies have shown that withania somnifera reverses the behavioral deficits, plaque pathology and accumulation of β-amyloid peptides (Aβ) in the brain. The roots of WS reverse the effect of beta amyloid induced toxicity in AD. Accumulation of β-amyloid is known to be one of the major pathogenesis associated with AD. Thus withania somnifera (WS) extracts can be used as an agent for the prevention of AD. β-amyloid and ashwagandha treated cells  showed no reduction in spine density, spine area, spine length and number of spines as compared to untreated control thus showing the protective effect of ashwagandha on spine density. It is the reduction of spine area, spine length and number of spines which are related to neurodegenerative diseases causing decrease in synaptic plasticity and thus compromising learning and memory. Study done at Chonbuk National University, South Korea has shown that WS stimulates the NMDA receptor in hippocampal cells which is the brain area important for learning and memory.

So, Ashwagandha is an important herb and recent studies have shown promising results regarding its medical benefits, nevertheless in neurodegenerative diseases.


Janardhan Prasad Bhattarai, Soo Joung Park, and Seong Kyu Han, Potentiation of NMDA receptors by Withania somnifera on hippocampal CA1 pyramidal neurons

Am. J. Chin. Med. 41, 503 (2013). DOI: 10.1142/S0192415X13500365

Baitharu I, Jain V, Deep SN, Hota KB, Hota SK, Prasad D, IIavazhagan G, Withania somnifera root extract ameliorates hypobaric hypoxia induced memory impairment in rats.

J Ethnopharmacol. 2013 Jan 30;145(2):431-41. doi: 10.1016/j.jep.2012.10.063. Epub 2012 Dec 2

Kurapati KR, Atluri VS, Samikkannu T, Nair MP, Ashwangha (Withania somnifera) Reverses β-amyloid 1-42 Induced Toxicity in Human Neuronal Cells: Implications in HIV-Associated Neurocognitive Disorders (HAND) PLoS One. 2013 Oct 16;8(10):e77624. doi: 10.1371/journal.pone.0077624