All aging humans will develop some grade of decline in cognitive capacity as time progresses.
Data displays that deterioration of the biological framework that underlies the aptitude to think and reason begins as early as the mid twenties and includes a drop in regional brain volume. Cumulatively these changes give rise to a change of symptoms associated with ageing, such as forgetfulness, reduced ability to uphold focus, and reduced problem solving ability. If left unhindered, symptoms often progress into more severe conditions, such as dementia, depression or even Alzheimer’s disease.
Frequently Asked Questions
- 1What impact does the aging process have on the brain?
- 2What are the factors that influence cognitive decline?
- 3What are the limitations physically?
- 4What are the risks of age related cognitive decline?
- 5Brain Renewal Tip: What are the ways to prevent cognitive decline?
The aging process deeply impacts the brain in ways that can be pragmatic on multiple levels, ranging from sub-cellular to macro-structurally. On a diminutive; ageing causes damage of the very cells that we use in our brains, neurons. Even their length diminishes with age. Also, the substances they use to transmit signals, called neurotransmitters, are less in quantity but are also less effective.
In a broader sense, the physical assembly of the brain as a whole also deteriorates with age. Shrinkage and death of neurons, and reductions in the amount of synaptic spines and functional synapses contribute to annual decline of as much as 0.5% to 1.0% in cortical thickness. This essentially means the brain is smaller! Specifically, even in healthy humans, aging accounts for volume variances of 37% in the thalamus, which is involved in sight, hearing, and the sleep-wake cycle; 36% in the nucleus accumbens, which plays a major role in mood regulation (e.g. pleasure, fear, reward); and 33% in the hippocampus, a critical site for consolidation of short-term to long-term memory.
Taken together, age related neuroanatomical changes account for an estimated 25% to 100% of the variance in cognitive ability between young and aged individuals. In other words, age related cognitive decline occurs in tandem with the physical dilapidation of brain structure. Thus, conserving cognitive vigilance into late life requires early and aggressive intervention to preserve the brain in its youthful physical and functional state.
Cognitive decline does not affect all individuals similarly; clear associations exist between the rate and severity of cognitive decline as well as a variety of factors, including oxidative stress and free radical damage, chronic low-level inflammation, declining hormone levels, endothelial dysfunction, excess body weight, suboptimal nutrition, lifestyle and social network to name a few. Fortunately, many of these factors are changeable to a significant extent, and proactive lifestyle changes, cognitive training, and nutritional interventions have shown to decrease the rate of intellectual decay and potentially reverse age-related cognitive decline.
1. Psychological Risk Factors Contributing to Cognitive Decline
There is a tendency to focus on the biological aspects of a disease state because they are perceived as tangible, measurable, and modifiable. However, more loosely defined facets of our lives related to our psychological condition contribute to our mental fluency as well. The ways in which the brain is utilized and stimulated impact its functional state at all ages. Psychoanalytical tests have found that cognitive impairment is closely correlated with traits such as boredom-proneness, loneliness, small social network, and high stress.
2. Anxiety and Stress
Research in patients with anxiety has shown that, compared to non-anxious control subjects, those with high-anxiety levels must exert greater effort (dedicate more brain resources) to maintain the same level of performance on cognitive tests.
Posttraumatic stress disorder (PTSD) is a condition characterized by chronic, lingering anxiety and stress related to a traumatic event in the past. A comprehensive review of eight studies highlighted a strong association between PTSD and smaller brain size (total brain volume). The duration of PTSD influences the extent to which the brain deteriorates; developing effective coping strategies as soon as possible may help to limit PTSD-induced decreases in brain volume.
An intimate relationship exists between depression and cognitive dysfunction. Many studies have closely examined this link and allude to the intertwinement of these two conditions, rather than a causal effect of one on the other. Interestingly, depression seems to worsen cognitive dysfunction, but poorer cognitive health predisposes aging individuals to depression as well.
4. Social Network and Personal Relationships
Several studies have suggested that maintaining a large network of friends and other personal relationships, and regularly engaging in social and productive activities is associated with a decreased risk of cognitive decline. Conversely, social disengagement, defined as having very few or no social relationships, is a strong risk factor for cognitive decline.
5. Mental and Physical Activity
The brain consists of a vast network of approximately 90 billion neurons interconnected by 1,000 trillion synaptic junctions. Each mental and physical task that we perform stimulates this massive network in a unique way. Regular stimulation of diverse synaptic pathways by engaging in a wide range of mentally and physically challenging activities directly influences our ability to learn by enhancing synaptic plasticity, and initiating the process of neurogenesis in critical areas of the brain. In fact, it is now clear that neural plasticity allows the structure and function of the adult human brain to change significantly as a result of new experiences.
6. Physical Activity and Brain-Derived Neurotrophic Factor
A critical driving force behind neural plasticity (and therefore overall cognitive function) is a protein called brain-derived neurotrophic factor, or BDNF. BDNF acts upon areas of the brain involved in learning, memory, and higher-order thinking to stimulate genesis of new neurons, survival of existing neurons, and synaptic adaptation. Low levels of BDNF are observed in a variety of brain disorders, including cognitive decline, depression, dementia, and Alzheimer’s disease.
Physical exercise is known to enhance cognitive function in humans and other animals, and many researchers now believe that an increase in levels of BDNF induced by exercise mediates this improvement. Several studies have demonstrated that moderate to high intensity aerobic or anaerobic exercise induces sharp (intensity-dependent) increases in BDNF levels in humans. The beneficial effects of exercise on brain health appear to be limited only by the duration of exercise.
7. Mental Activity, Brain Plasticity, and Cognitive Reserve
Neural plasticity, the dynamic ability of the brain to adapt and respond to novel stimuli in a unique and reinforce able way, is a pivotal aspect of cognition. Plasticity serves as a key medium for the effects of practicing a physical activity – i.e. getting better at a physical task over time. As we practice an activity repetitively, signals are transmitted through the brain in a specific pattern over and over again. This redundant signaling ultimately strengthens the connections between neurons in the signaling pathway required to execute the task, leading to greater efficiency and accuracy of signal transmission.
An important limitation of physical practice, though, is that improvements in ability are generally confined to the task being practiced. In other words, practicing tennis does not increase proficiency in bowling. Repetitive mental stimulation, on the other hand, exerts domain-wide improvements that impact other tasks as well. To elaborate, practicing a mentally challenging activity that requires utilisation of higher-order cognitive processes, playing chess for example, can improve fluency in other activities that require similar cognitive processes, like driving a vehicle.
Just as the desire to maintain a fit and functional body into late life necessitates regular physical exercise, ensuring cognitive dexterity with advancing age requires constantly pushing the brain to new limits in order to evoke plastic changes that strengthen existing, and encourage new, synaptic connections. This becomes clear when considering that individuals with mentally demanding careers appear to be at significantly decreased risk of developing Alzheimer’s dementia in later life, compared to those whose careers centred on physical labor.
Plasticity is an intrinsic property of the brain maintained throughout life; and so cognitive stimulation and training enhance cognitive reserve and convey protection against loss of brain function regardless of age.
Speaking more than one language is also a strong inducer of plasticity and cognitive reserve. Learning a second language requires the brain to constantly categorise information in ways that are unnecessary when only a single language is spoken; this establishes numerous new neuronal communication streams. A lifestyle incorporating frequent physical exercise, continual learning, and regular cognitive stimulation is likely to be the most effective means for preserving, and possibly enhancing, cognitive function at any age.
The risks of the condition are simple: inability to function within society and the need for 24/7 support as a worst scenario. Or, in mild cognitive decline, the absolute frustration of not being able to complete tasks you were able to complete before, not remembering simple things, not being able to converse coherently. The conventional treatments for cognitive decline are not fully understood. They are generally used as a hit/miss advent due to this. Despite the fact that their side effects are all due to changing important substances WITHIN the brain in a chemical fashion, they don’t always do what we expect.
1. Dietary Considerations for a Healthy Brain
The exceptionally high rate of metabolism in the brain makes it particularly responsive to the nutritional content of the diet. A Western dietary pattern, typified by excess consumption of simple carbohydrates and dietary fat (in particular saturated fat and omega-6 polyunsaturated fatty acids), is a detrimental, yet alterable, modulator of cognitive function. Numerous studies have identified high intakes of simple sugars and saturated fats as being especially deleterious for brain health. Transitioning to a slightly calorie-restricted Mediterranean diet high in mono- and poly- unsaturated omega-3 fats, fiber, and polyphenols will provide the brain with nutrition to function at high capacity and efficiency. Some dietary considerations that may be easily overlooked provide substantial brain benefits as well.
2. Brain Training
Your brain is central to everything; from how easily you remember to how fast you complete tasks and how easily you solve problems. Studies show that the gains you make from Brain Training are applicable to an almost endless variety of mental activities, from what you think, to what you do.
From the speed of your brain, memory, flexibility, attention, and problem solving, Brain Trainer ensures that its protocols provide the maximum benefit for your long term cognitive health. Brain training can improve your memory loss – it is the same principle when training a muscle to get stronger, here you train the brain to remember things more clearly.
3. Calorie Restriction
Calorie restriction is the restriction of caloric intake to a level modestly below normal, typically 20% to 30% less, but the diet should be dense with micronutrients to maintain optimal nutrition. Caloric restriction is well-known for its ability to induce favorable changes in peripheral insulin sensitivity, which enhances insulin signaling in the central nervous system. The brain relies heavily on proper insulin signaling for a variety of functions that impact cognition, and so it is not surprising that caloric restriction has been shown to benefit cognitive function in many animal and human studies.
4. Mediterranean Diet
A great deal of scientific literature validates the Mediterranean diet as a staple for those concerned with cardiovascular health, cognitive health, and longevity. The diet centers on “good” fats – mono- and poly-unsaturated fats, especially omega-3’s and olive oil, multi-colored fruits and vegetables, and moderate red wine consumption. Adherence to the Mediterranean diet has been linked with improved insulin sensitivity, lipid metabolism, blood pressure, reduced risk of developing cancer or metabolic syndrome, as well as an overall decrease in mortality.
The brain also benefits greatly from the health-promoting lipids and antioxidants that are ample in the Mediterranean diet. An abundance of scientific literature concedes that adherence to the Mediterranean diet is associated with better cognitive performance in a variety of populations.
5. Moderate Alcohol Consumption
While there is no question that heavy alcohol consumption is deleterious to nearly all aspects of health, including cognition, moderate alcohol consumption, characterized as two drinks daily, seems to convey protection against cognitive decline with aging. Fifteen studies were summarized in a recent comprehensive review, which included data for over 36,000 subjects; those classified, as “moderate” drinkers were roughly 25 – 30% less likely to develop Alzheimer’s disease, vascular dementia, or any-type dementia, than non-drinkers or heavy drinkers.
Evidence suggests that red wine may be the alcoholic beverage of choice for maintaining cognitive health, as it contains many phenolic antioxidant compounds that are suspected to impede the pathological progress of Alzheimer’s disease, and limit the neurological consequences of high cholesterol. Many of the benefits of moderate drinking are likely attributable to alcohol’s profound positive impact on levels of HDL (“good”) cholesterol and enhancement of cholesterol efflux.
6. Moderate Caffeinated Coffee Consumption
Coffee, like red wine, is an excellent source of antioxidant and neuroprotective compounds. However, it has been suggested recently that the antioxidant compounds in coffee may synergize with caffeine to enhance the protective effect against brain pathology, and that decaffeinated coffee does not provide the same level of neuroprotection observed with caffeinated coffee.