Dementia Risk Factors


Dementia is a general term referring to mental health disorders that are characterised by impaired memory, thinking abilities and social capabilities that can severely impair daily functioning of an individual.

According to Mayo Clinic, it is a by-product of another disease and seldom manifests on its own. It is characterised by severe cognitive and psychological changes. Some key signs and symptoms are: 

  • Impaired memory loss
  • Difficulty concentrating
  • Difficulty speaking or thinking, reasoning abilities
  • Difficulty with visual and spatial abilities
  • Impaired motor abilities
  • Confusion, depression, loss of appetite.
  • Inappropriate behaviour, hallucinations, and general agitation

Dementia can be caused by many genetic and lifestyle factors. Dementia is caused by problems with nerve cells or loss of nerve cells in the brain causing permanent damage to the brain functions. Primarily, dementia is caused by Alzheimer's disease, stroke, HIV, excessive drinking, and repetitive brain injury.

Anxiety, depression, delirium, and Creutzfeldt-Jakob disease can also create memory loss resembling dementia. Some reversible dementia can be caused by nutritional deficiency, infections, immune disorders, medication side effects, and endocrine abnormalities

Dementia is the seventh leading cause of death globally in the elderly population.  According to the World Health Organisation, 60% of 55 million people living with dementia live in low and middle income countries. This number is expected to rise to 78 million by 2030. More women than men are affected by dementia.    

It is highly important to consider the impacts of dementia at a personal, social, and economic level. It is key that this disease be addressed and treated as it affects not only the patient but their family, carers, and their community. 
Dementia is diagnosed by blood tests, cognitive and behavioural tests, brain scans, and genetic tests. Non-pharmacological interventions such as walking, reading, moderate physical exercise, and family gatherings are the first mode of treatment for dementia.

Some pharmacologically approved medications for Alzheimer's disease include acetylcholinesterase inhibitors such as donepezil and memantine.1

Risk factors

1. Nutrition

Dementia is heavily affected by nutritional deficiencies. Alzheimer's-induced dementia occurs in thiamine (Vitamin B1) deficiency. Thiamine is also important for brain functioning in older people. Dehydration is another factor that can also cause dementia.

The brain needs lots of calories and nutrient rich food, so any compromise on quantity and quality of food intake can severely undermine its function.

Foods rich in trans fat and unsaturated fats increase this risk of dementia. A westernised diet has a risk of aiding faster decline of cognitive abilities.

MIND (Mediterranean–DASH Intervention for Neurodegenerative Delay) and DASH diet (Dietary Approaches to Stop Hypertension) are plant based alternatives with no red meat, where MIND focuses on monounsaturated fatty acids with fish and DASH emphasises dairy consumption and reducing commercial sweets and sodium.2

2. Physical activity

A sedentary lifestyle is a high risk factor for metabolic and endocrine complications in the body that can lead to dementia. Physical activity can increase neural plasticity and mood-boosting endorphins, and can stabilise brain-damaging antioxidant production.

Physical activity has been shown to promote neuronal recovery after ischemic insult and injury. It is also possible that reduced gait speed can precede dementia by 7 years. Many studies have shown moderate physical activity has a reducing effect on cognitive decline associated with dementia.3,7

3. Smoking

Smoking is related to a higher risk of cognitive decline and dementia. Smoking is also associated with cardiovascular disease like atherosclerosis that can give rise to dementia. The two most common forms of dementia, Alzhiemers dementia and vascular dementia have been linked to heart and blood vessels malfunctioning, meaning that smokers have a higher chance of being affected.

Moreover, smoking can also cause strokes that create a higher chance of contracting dementia. Oxidative damage, inflammation, and toxins in cigarette smoke can also raise the risk of cognitive decline. 

4. Alcohol

Drinking alcohol is also associated with dementia. Moderate drinking has been shown in clinical studies to be a lower risk factor for dementia, but excessive alcohol can cause irreversible brain damage. However, drinking wine in moderation can help promote brain health and reduce Alzheimer's risk, as wine has been shown to have neuroprotective effects through betterment of cardiovascular health.

5. Hydration

The risk of dehydration is higher in older people and aids cognitive decline. Memory loss results in inability to remember to drink water, resulting in exacerbating existing dementia conditions. As the brain needs water for proper functioning, it gets affected because of this. A 2% reduced water intake can cause reduced memory, confusion, dizziness, and improper motor and spatial skills. 

6. Sleep

Sleep is an important physiological process that is vital for proper brain functioning. It is also important to maintain the circadian rhythm of the body that is responsible for proper metabolic, cardiovascular, and endocrine system functioning.

People who sleep more than 9 hours a night have a higher risk of dementia and Alzheimer's disease. Poor sleep can contribute to neuronal damage in the form of amyloid beta plaques that contribute to Alzheimer's disease.4

7. Weight/BMI

Thinner people have a higher risk of dementia. It has been shown in studies that people with a low BMI have a 34% higher chance of getting dementia.5

8. Gender

Dementia risk factors manifest themselves at a higher rate in women across the world. 65% of total deaths due to dementia involve women, and they also exhibit more years in dementia when compared to men. Females are more susceptible to Alzheimer's disease dementia and men to vascular dementia.6


Dementia is a highly progressive and chronic medical condition characterised by severe and impaired reasoning and thinking abilities. The risk factors include improper sleep, smoking, excessive drinking, malnutrition, weight, gender, and physical inactivity. 

Age is the most common risk factor for dementia, as it primarily affects elderly people, but there are lifestyle changes that can be made to reduce the risk of dementia. Eating healthy and nutritious food, maintaining a normal BMI, reducing alcohol consumption, and quitting smoking are positive ways to reduce toxins and neuronal damage-inducing factors. 


  1. Arvanitakis, Z., Shah, R. and Bennett, D., 2019. Diagnosis and Management of Dementia: Review. JAMA, 322(16), p.1589.
  2. Morris, M., 2016. Nutrition and risk of dementia: overview and methodological issues. Annals of the New York Academy of Sciences, 1367(1), pp.31-37.
  3. Zhao, C., Noble, J., Marder, K., Hartman, J., Gu, Y. and Scarmeas, N., 2018. Dietary Patterns, Physical Activity, Sleep, and Risk for Dementia and Cognitive Decline. Current Nutrition Reports, 7(4), pp.335-345.
  4. Spira, A., Chen-Edinboro, L., Wu, M. and Yaffe, K., 2014. Impact of sleep on the risk of cognitive decline and dementia. Current Opinion in Psychiatry, 27(6), pp.478-483.
  5. Qizilbash, N., Gregson, J., Johnson, M., Pearce, N., Douglas, I., Wing, K., Evans, S. and Pocock, S., 2015. BMI and risk of dementia in two million people over two decades: a retrospective cohort study. The Lancet Diabetes & Endocrinology, 3(6), pp.431-436.
  6. Sex Differences, 2016. Considering sex and gender in Alzheimer disease and other dementias. 18(4), pp.437-446.
  7. Mateos-Aparicio P, Rodríguez-Moreno A. The impact of studying brain plasticity. Frontiers in cellular neuroscience. 2019 Feb 27;13:66.

Aarthi Narayan

Master of Science (M.S.), Biological science, University of Illinois Chicago

Scientist with 10+ years of strong industry, academic experience in Molecular biology, Tissue culture, Protein purification techniques. Mid-level experience in Diagnostics and start-ups. Excellent at completing large scale projects and experiments with minimal supervision in a timely and efficient manner. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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