What is Dementia?
Dementia isn't a specific disease, it is a name that describes a decline of mental ability in older people that is so severe that it interferes with everyday activities.
Dementia is characterized by symptoms such as memory decline, loss of focus and concentration and the impairment of intellectual abilities such as reasoning, communication, language.
Although Alzheimer's disease (AD) is one of the leading causes of dementia (around 70% of the cases), there are other causes such as strokes, which cause Vascular dementia.
At one time it was known as "senility" or "senile dementia" and was taken as a normal stage in late life. But the viewpoint has shifted,
Many older people have memory loss issues and that does not mean that they have dementia or Alzheimer's.
What Causes Dementia?
When the brain cells are damaged they cannot communicate efficiently with each other and this disrupts the normal functioning of the brain: thinking, feeling, communicating can be affected.
Different parts of the brain perform different functions and damage to these areas hinders their function (movement or abstract thought for instance).
Alzheimer's disease or AD, (named after Alois Alzheimer who described it in 1906) is caused by certain proteins that accumulate inside the brain's tissue, both inside the brain cells or neurons and outside of them. The proteins agglomerate, forming amyloid plaques which kill the cells.
Alzheimer's appears in a part of the brain known as the "hippocampus" (more on it below) which has an important role in memory processing and learning. That is why the onset of the disease causes severe memory loss.
Some other factors such as vitamin deficiencies, alcoholism, thyroid problems and side effects of certain medications may cause dementia-like symptoms and memory issues but they may improve if these factors are treated.
Below we will see the lifestyle behaviors that may help reduce the risk of dementia (and those which may increase it).
Lifestyle choices, behaviors and their link with Dementia
Cardiovascular disease and diabetes can cause health problems that lead to dementia. Alzheimer's also has a genetic component which may or may not manifest itself. There are triggering factors that can alter a cell's DNA and modify the way in which its genes express themselves. These triggers are called "epigenetic" factors.
These factors can be environmental, chemical, even stress caused by famine and may produce harmful changes in the expression of genes. However some epigenetic factors may produce benign changes, which can protect the individual from his or her genetic inheritance.
Alzheimer's may be triggered by lifestyle choices and below we will see how these interplay with the disease.
Better Educaction and Health Care reduces Risk for Dementia
According to a study by Langa (2017) ( 1 ), the prevalence of dementia among Americans aged 65 or older, decreased from 11.6% to 8.8% between 2000 and 2012.
Langa found a positive correlation between being better educated and lower risk for dementia, and he attributes it to the healthier behaviors associated with more years of education (i.e. a college graduate vs. a highschool grad); meaning less smoking, better eating habits and more physical activity and also occupations that require more use of cognitive functions and, equally important better access to health care.
The risk for dementia due to heart-disease and diabetes also decreased due to improved cardiovascular and diabetes treatments.
Langa concludes that "Our study, along with prior studies, supports the notion that "cognitive reserve" resulting from early-life and life-long education and cognitive stimulation may be a potent strategy for the primary prevention of dementia".
Alzheimer's disease and Education
Margaret Gatz, (2005) ( 7 ) reports that "the risk of Alzheimer disease is two to four times higher in those who have fewer years of education, as compared to those who have more years of education".
Physical Fitness Protects against Dementia
A team led by Nieboer (2014) ( 2 ) looked into the effects of a healthy physically active lifestyle on the brain. To do so, they studied a group of 219 healthy adults aged 41 to 44 and found that their intelligence quotient or IQ was related to their cardio respiratory fitness. Fitness also increased global neuronal network integration linking different parts of the brain.
More recently, Fernandes RM et., al (2018) ( 9 ) reported "An association between moderate physical exercise and cognition" which reduced simple reaction time, improved response precision and working memory.
In their overview of different studies, Gregory J. Christie, et al., (2017) ( 6 ) found that being fit besides improving quality of life in older adults (because they maintain their independence to do things by themselves), also reduces the chance of falls and bone fractures (older adults with dementia fall 3 times more often than cognitively healthy seniors.
Christie's review also looked into the effects of exercise on the brain:
- A study of 5,925 older women followed-up during a 6 to 8 year period found "that women with greater levels of physical activity were less likely to experience cognitive decline".
- Most studies focused on aerobic exercise, but resistance or strength training also had a positive effect.
- But, they couldn't determine which element of exercising is critical for brain health (intensity, frequency or duration of exercise).
- Exercising during youth protected against dementia: a study of 1,241 men and women aged 62 to 85 years found that regular physical activity in early life (ages 15 to 25), but only in men resulted in a f aster processing speed in older age.
Take home point
Physical exercise, even if moderate, improves cognition
Myuri Ruthirakuhan et al., (2012) ( 14 ) report that Alzheimer disease patients "showed significant cognitive improvements" when they performed "cycling training and somatic and isotonic-relaxation exercises".
Musical experience and Dancing
Musical activities even if brief (one hour per week during a 6 month period) improve the physical and cognitive fitness in older adults (Dinse et al., 2013) ( 12 ), if these activities involve dancing, it stimulates brain processes that control attention, muscular coordination, memory (learning and rehearsing dance sequences), stimulus perceptions, emotions and also impacts on cardiovascular fitness.(6)
Dancing produces greater cognitive improvements than Tai Chi and "may be more effective at preserving brain white matter than aerobic and nutritional supplementation." (6)
Weigmann (10) agrees: "Dancing -which is in itself physically and mentally challenging- may be a good measure to keep the brain fit and help prevent Alzheimer disease".
Take home point
Dance! and enjoy music
How does Exercise protect you against dementia?
Helena Hörder et al., (2018) ( 8 ) looked into a group of 1,462 Swedish women of 38 to 60 years of age who were examined over a 44-year period and found that:
- "High cardiovascular fitness in midlife was associated with a decreased risk of subsequent dementia."
- "High fitness delayed age at dementia onset by 9.5 years and time to dementia onset by 5 years compared to medium fitness."
Hörder postulates two types of effects to explain how physical activity reduces the risk of dementia:
Being fit results in lower blood pressure, low cholesterol levels, lower body weight which in turn reduce the risk of diabetes and its dire consequences.
Such as enhancement of the brains's neuronal structures, its production of neurotransmitters and growth factor chemicals. Which help to maintain the brain's structure and abilities.
They mention a study that found "Smaller brain volume" was linked to lower cardiovascular fitness.
Furthermore physical activity seems to have greatest influence on the hippocampus region of the brain which is the region most vulnerable to Alzheimer's disease.
The Hippocampus and its relation to dementia
Aranzi discovered it in the late 1500s and as he thought it looked like a "sea horse" he gave it the animal's (it is a fish) Latin name.
The hippocampus is involved in our higher cognitive functions and especially in memory processes and also some behaviors related to emotions.
Neurons form within the hippocampus in a process known as neurogenesis, and this birth of new brain cells takes place across our whole life span, but it decreases with age.
Katrin Weigmann (2014) ( 10 ) points out that animal studies indicate that physical exercise "increases the proliferation of hippocampal neurons", in other word, exercise helps create new neurons in the hippocampus.
But birth of new nerurons is not enough, and it is learning that keeps them alive.
Gerd Kempermann, Hongjun Song and Fred H. Gag (2015) ( 11 ) add that these new neurons are the clue to the "plasticity" of the adult brain. Flexibility which results from the combination of physical and mental activity, which combined boost the birth of new hippocampal neurons and keep them alive.
Weigmann states that "A combination of exercising and mental activity has been shown to be most effective in preventing cognitive decline".
Mental Training won't prevent Dementia
Well, at least not ALL types of dementia, but maybe some:
A team led by Unverzagt (2012) ( 3 ) examined whether cognitive training helped to reduced the rate of dementia. Their subjects were part of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study, involving 2,802 individuals (men, women, white and African American) with an average age of 74 years and 13 years of education on average.
Their study revealed that "cognitive training was not associated with a lower rate of incident dementia [and ] did not affect rates of incident dementia after 5 years of follow-up".
The type of cognitive training used during the ACTIVE study was focused on memory, reasoning, and speed of processing information.
Gatz (7) also finds "little evidence that mental practice will help prevent the development of dementia." yet mentions that some epidemiological studies have shown that enaging in mentally stimulating activities have a lower prevalence of Alzheimer's.
But Some Cognitive Activities may prevent VCI dementia
Don't despair, Verghese and his colleagues (2009) ( 13 ) investigated if engaging in different leisure activities (such as reading, playing board games or musical instruments) reduced the risk of dementia.
They found that an age related cognitive impairment known as "vascular cognitive impairment" (VCI for short) which can range from "mild impairment" to "dementia", and which is caused by vascular risk factors, can be offset by different types of leisure activities.
Their study followed subjects that were initially free of VCI and dementia over a 21-year period.
- Those who took part of the cognitive leisure activities -but not the physical leisure activities had a lower risk of VCI (with or without dementia).
Take home point
Reading, playing board games or musical instruments can help reduce the risk of VCI.
In the case of Alzheimer's Disease (AD), Myuri Ruthirakuhan et al., (2012) ( 14 ) mention the effects of different types of intellectual activities on patients suffering from it:
Cognitive stimulation therapy (CS)
CS are informal passive or active activities designed to stimulate the brain such as playing a game or listening to music. CS can include Reality Orientation, which orients the AD patient regarding places, persons and time.
CS and RO therapy resulted in improved cognitive functions in AD patients and brought some "positive changes to social and communicative functioning and quality of life".
Cognitive training and Rehabilitation
Accorging to Ruthirakuhan, " There is a lack of a consensus ... Although some studies show promising results... others reveal improvement only in specific areas of cognitive training, such as learning personal information and aspects of attention".
Patients suffering from Alzheimer's Disease realize that their condition isolates them, this affects their self-confidence and causes anxiety, depression and withdrawal. So the effect of improving social interactions may have a positive effect by reducing the reisk of AD and improving the patients quality of life.
Michelle E. Kelly et al., (2017) ( 15 ) reviewed 39 studies and found that there is a positive association between increased socialization and cognitive function, but that the "exact nature of this association remains unclear".
They found that:
Social activity is linked to working memory, visual and spatial abilities, processing speed and global cognition but is unrelated to verbal fluency, attention, reasoning or episodic memory.
Social network is linked to global cognition but not to episodic memory.
Social support is associated with global cognition and episodic memory but not with processing speed or attention
Take home point
Keep socially active to maintain your mental fitness.
Obesity in midlife is linked to dementia
According to a meta-analysis (Albanese, 2017) ( 4 ), being obese in midlife increased the risk of dementia in old age.
They reviewed 19 studies and 589,649 participants which were followed up for up to 42 years and found that "being obese during Midlife (age 35 to 65 years) with a body mass index over 30 was associated with dementia late in life. There was no link for those who were only overweight (with a BMI between 25 and 30).".
Take home point
Keep your BMI below 30 (try not to be obese)
You can calculate your BMI with our BMI (Body Mass Index) Calculator.
Mediterranean Diet improves mental abilities in older adults
A team led by Loughrey (2017) ( 5 ) conducted a meta-analysis that involved more than 41,500 subjects in both cohort studies and randomized controlled trials to find out if there was a relation beween cognitive function and the Mediterranean diet.
The Mediterranean Diet
This diet originated around the Mediterranean sea and was recognized by the UNESCO as an Intangible Cultural Heritage of Humanity in 2010.
It is based on vegetables, whole grains, legumes, fruits, olive oil and it focuses on fish and poultry as a source for animal protein (instead of using red meat). It also includes moderate quantities of red wine. It is a diet rich in fiber, nutrients, healthy fats, vitamins and antioxidants.
The cohort studies found significant association between the Mediterranean Diet and:
- Episodic memory
- Global cognition
The Randomized trials found that the diet improved:
- Delayed recall
- Working memory
- Global Cognition
However it didn't have any effect on semantic memory, immediate recall, paired associates, attention, processing speed or verbal fluency.
Take home point
Eating a mediterranean diet will have a beneficial effect on your global cognition levels.
Meditation and Dementia
Gregory J. Christie's team (6) found insufficient data to determine the effectiveness of on improved cardiovascular risk and admitted that the evidence linking meditation to improved cognition in old age is still in its early stages.
Your old-age brain health depends on many different factors. Genetic influences are very important (roughly 50% of the total effect) and may help explain who develops Alzheimer's disease (AD) and who does not.
However lifestyle decisions make up the other 50%, and these choice even if taken early in life have a profound impact on brain health: exercising during youth (in your teens and early twenties) can influence your old-age cognitive abilities. Obesity during midlife, your level of education (going to college or not) are also choices taken before you age which impact on your brain development.
As you age, you should try to eat a balanced nutritious diet, manage stress, keep strong social bonds, and keep physically activite (do exercise, walk, dance, cycle) and maintain your vascular health. Cognitive activities, learning, playing games or musical instruments may help a little too but there is no firm evidence that they can prevent AD.
Cite this article:
A. Whittall. ©2018. Mental Fitness. Patagonia Wellness, Oct. 30 2018. http://www.patagoniawellness.com/wellness/mental-fitness.html
Subject: Mental Fitness: what you can do to keep your mental health, ward off dementia and try to prevent Alzheimer's disease: exercise, keep physically, socially and mentally active, lose weight and eat well.
References and Further Reading
(1) Kenneth M. Langa, (2017). A Comparison of the Prevalence of Dementia in the United States in 2000 and 2012. JAMA Intern Med. 2017 Jan 1; 177(1): 51-58. doi: [10.1001/jamainternmed.2016.6807]
(2) Douw L, Nieboer D, van Dijk BW, Stam CJ, Twisk JW, (2014). A healthy brain in a healthy body: brain network correlates of physical and mental fitness. PLoS One. 2014 Feb 3;9(2):e88202. doi: 10.1371/journal.pone.0088202. eCollection 2014
(3) Frederick W. Unverzagt, et al., (2012). ACTIVE Cognitive Training and Rates of Incident Dementia. J Int Neuropsychol Soc. 2012 Jul; 18(4): 669-677. 2012 Mar 9. doi: [10.1017/S1355617711001470]
(4) Albanese E. et al., (2017). Body mass index in midlife and dementia: Systematic review and meta-regression analysis of 589,649 men and women followed in longitudinal studies. Alzheimers Dement (Amst). 2017 Jun 20;8:165-178. doi: 10.1016/j.dadm.2017.05.007. eCollection 2017
(5) Loughrey DG, et al., (2017). The Impact of the Mediterranean Diet on the Cognitive Functioning of Healthy Older Adults: A Systematic Review and Meta-Analysis. Adv Nutr. 2017 Jul 14;8(4):571-586. doi: 10.3945/an.117.015495. Print 2017 Jul
(6) Gregory J. Christie, et al., (2017). Do Lifestyle Activities Protect Against Cognitive Decline in Aging? A Review. Front Aging Neurosci. 2017; 9: 381. 2017 Nov 20. doi: [10.3389/fnagi.2017.00381]
(7) Margaret Gatz, (2005). Educating the Brain to Avoid Dementia: Can Mental Exercise Prevent Alzheimer Disease?. PLoS Med. 2005 Jan; 2(1): e7. 2005 Jan 25. doi: [10.1371/journal.pmed.0020007]
(8) Helena Hörder et al., (2018). Midlife cardiovascular fitness and dementia A 44-year longitudinal population study in women. Neurology. 2018 Apr 10; 90(15): e1298-e1305. doi: [10.1212/WNL.0000000000005290]
(9) Fernandes RM et., al (2018). The Effects of Moderate Physical Exercise on Adult Cognition: A Systematic Review. Front Physiol. 2018 Jun 8;9:667. doi: 10.3389/fphys.2018.00667. eCollection 2018
(10) Katrin Weigmann (2014). Why exercise is good for your brain - A closer look at the underlying mechanisms suggests that some sports, especially combined with mental activity, may be more effective than others. EMBO reports (2014) 15, 745-748 DOI 10.15252/embr.201439051
(11) Gerd Kempermann, Hongjun Song and Fred H. Gag, (2015). Neurogenesis in the Adult Hippocampus. Cold Spring Harb Perspect Biol September 2015;7:a018812, doi: 10.1101/cshperspect.a018812
(12) Kattenstroth J-C, Kalisch T, Holt S, Tegenthoff M, Dinse HR (2013). Six months of dance intervention enhances postural, sensorimotor, and cognitive performance in elderly without affecting cardio-respiratory functions. Front Aging Neurosci 5: 5
(13) Verghese J, Cuiling W, Katz MJ, Sanders A, Lipton RB (2009). Leisure activities and risk of vascular cognitive impairment in older adults. J Geriatr Psychiatry Neurol 22: 110-118
(14) Myuri Ruthirakuhan et al., (2012). Use of Physical and Intellectual Activities and Socialization in the Management of Cognitive Decline of Aging and in Dementia: A Review. J Aging Res. 2012; 2012: 384875. 2012 Dec 31. doi: [10.1155/2012/384875]
(15) Michelle E. Kelly et al., (2017). The impact of social activities, social networks, social support and social relationships on the cognitive functioning of healthy older adults: a systematic review. Syst Rev. 2017; 6: 259. 2017 Dec 19. doi: [10.1186/s13643-017-0632-2]