Effects of Nutrition on Cognitive Health

0
301

Abstract

The research on the relationship involving diet and mental capacity is still in its early stages. However, it has been discovered that nutrition has a connection with dietary intake. Scientists found that maintaining a healthy gut microbiome by having a healthy diet enhances cognition. There also exists proof that throughout childhood the rapid process of maturation, neural growth, and brain tissue can become especially susceptible to the consequences of these harmful foods. This paper reviews the recent studies that have been conducted on nutrients that have an impact on cognition. A comprehensive analysis was conducted to assess the influence of nutrition on the development of function. Each data was rigorously examined for validity.  While experts proved that maintaining a high protein and abundant water diet increases mental capacity, nutritional components that induce obesity, which include non-complex carbohydrates and trans fats, have been scientifically connected to hippocampus malfunction and issues with memory retrieval.  Since it has been demonstrated that nourishment impacts cognitive function, medical researchers can conduct additional studies on the matter to design an optimum diet to reduce human mental capacity decline.

Key words: Behavioral and Social Sciences, Cognitive Psychology, Brain Function, Cognitive Health, Nutrition, Gut Health, Gut Hormones

Introduction

Nutrition was originally thought of as a way to supply the fuel to actualize bodily functions, yet research is beginning to show that it can also safeguard one’s health from illness1. Recent research provides compelling proof of the impact of nutritional variables on various biochemical processes and pathways that sustain cognitive function2. The primary characteristics of cognitive function, sometimes referred to as mental function, include thinking, learning, and remembering.

Human beings have to adapt to different life circumstances to survive. People with a state of excellent health in the brain can recognize their talents and modify their mental skills including social, and behavioral functioning. Therefore, the well-being of the brain is crucial. The well-being of the brain is influenced by a variety of circumstances, including illnesses, accidents, personality disorders, drug use, and alteration due to aging2. There has been research on numerous controllable aspects of daily life, including nutrition and exercise, socializing, mental activity, and drinking alcohol, that could maintain or augment deteriorating mental abilities, even though certain ones are unable to be adjusted2. These variables are believed to either enhance or impair cognition and operate through a variety of pathways.

In fact, there appears to be a major necessity for comprehension of the impact of nutritional and dietary determinants in mental decline, which will allow for the adoption of innovative technologies for early detection, and medication, of nutrition-related illnesses. In addition, further explanation of the relationship that exists between food and mental ability through studies is essential2. This is because finding reliable proof of a potential connection would strengthen the case for clinical studies testing the efficacy of nourishment rehabilitation in hindering cognitive impairment and memory impairment2. In this literature review, five main sections are going to be discussed to identify the correlation between nutrition. These sections include the related brain region to cognition, gut health and cognitive function, the correlation between nutrition and cognition, correlation between gut hormones and cognition, the correlation between key nutrients and cognition. Each section will provide information for the reader to build up the knowledge to fully understand the correlation between nutrition and cognition and its effect on daily life.

Discussion

Although there are numerous common myths about the psychological and behavioral impacts of food, scientific investigation of the relations between nutrition and behavior is a relatively young field of research. Several common assumptions about the relationship between food and behavior have been confirmed to be correct, such as the anecdotal discovery that drowsiness frequently results from heavy meals3. Nevertheless, there are currently new additional beliefs regarding the relationship between nutrition and behavior, such that there are key nutrients that influence cognitive ability. When the effects of nutrition on the brain and cognition are regarded, research indicates that nutrition has a significant role in brain function1.

Brain Regions and Cognitive function

 The human brain is the nervous system’s control center, enabling ideas, recall, motion, and feelings through an intricate process that is the most advanced output of evolution in biology. The ultimate objective in pursuing long-term wellness is to maintain a healthy brain throughout one’s life. The brain, lying beneath its skeletal shell and cleansed by a protecting fluid, establishes the base of all the features that constitute humanity4. The brain circulates chemical and electrical messages throughout the body; various signals govern numerous functions, and the human brain analyzes each, allowing physical motion and mental regulation like cognitive function5.

Mental capacity, frequently referred to as cognitive function, is critical for mankind’s adaptability along with survivability. The ability to “contemplate, organize, find solutions, conceptualize, understand intricate concepts, acquire knowledge rapidly, and absorb information from experiencing” is included. Mental capacity, in addition to memorizing and mimicry, promotes the capacity to analyze circumstances, identify what is required, and determine a strategy of operation. Academic success, profession, and medical consequences are all strongly linked to mental capacity3.

The four main regions of the brain -referred to as lobes- are the occipital region, parietal region temporal region, and frontal region located in both halves of the cerebral cortex. Particular processes are governed by every lobe. The Frontal lobe has a function of regulating cognition and thinking. Specifically beneath the forehead exist two prefrontal regions which go through an ongoing development for nearly 21 years.  Both of these lobes perform a large portion of the task when you make plans, visualize the potential future, or employ rational claims. The frontal brain lobes appear to accomplish these functions, by serving as a temporary location for memory storage that enables the retention of a particular notion while multiple concepts are being evaluated.

Communication between the prefrontal cortex and the brain’s hippocampus facilitates the ability to produce context dependent images linked with experiences and then use these mental models to recall memories relevant to a given circumstance. Nutrition both directly affects the prefrontal lobe and hippocampus since it regulates brain-derived neurotrophic factor (BDNF).  BDNF executes the process of neurogenesis which establishes new neurons and increases synaptic plasticity. The type of nutrient determines the BDNF secretion which allows for the hippocampus and prefrontal cortex to function properly depending on the neuroplasticity. Enhanced neuroplasticity in the hippocampus and prefrontal cortex benefits one’s cognitive abilities, retention, and attitude with proper nutrition.

Cognitive ability was initially assumed to be solely managed by what is known as the brain’s central nervous system, with neuroplasticity aiding in memory formation and retention. Nevertheless, other bodily structures and functions, like the autoimmune mechanism and, the bacterial inhabitants of the digestive system, are currently being shown to govern our ability to generate, interpret, and retain memories, which results in mental processes6. Data for abnormalities in cognition recently came to light in a variety of gastric and extraintestinal disorders, emphasizing the need to identify these impairments and the biological processes through which they occur in individuals. Since cognition is essential for humans it is important to acknowledge the brain region that has a connection with mental abilities.

The term “activities of daily living” is frequently mentioned in research that involve cognition. The daily activities of a person can frequently be separated into two categories: vital and personal. While activities that involve maintaining one’s hygiene, putting on clothes, consuming food, and bathing can be considered vital, household responsibility, financial management, purchasing goods, and using public transport are daily activities based on one’s personal needs. Personal tasks for independent living require greater cognitive skills than fundamental activities of daily living and are necessary for maintaining a self-sufficient existence in the community1.

To have a better understanding of what cognition is one should have an idea of what happens when the cognition is impaired. An individual with cognitive decline experiences difficulties with memory, acquiring novel knowledge, focusing, or decision-making that has an impact on their day-to-day activities. There are several levels of cognitive dysfunction. The main factor contributing to cognitive deterioration is age. A person’s genetic heritage, lack of exercise, and illnesses like obesity, cardiovascular illness, and brain damage are additional risk factors7. The impairment of cognition is also greatly affected by diet, which is this paper’s main objective. Therefore, the nourishment of an individual is critical to keep a well-functioning brain.

Existing studies indicate that cognitive impairment affects tasks such as using smartphones and transit systems, as well as managing medicinal products and financial matters. Difficulties in such tasks can be observed even before a cognitive impairment like dementia. Cognitive impairment that occurs due to age reduces an individual’s capacity to execute complicated everyday tasks and raises the likelihood of memory loss.  Once the initial indications of mental limitation appear, the capacity to execute basic daily functions remains stable, however, one’s capacity to conduct complicated (personal) tasks is more likely to decline when retention, focus, along managerial abilities degrade8. Slower performance of tasks may be a visible sign of a physiological decline in cognitive function. Furthermore, academic accomplishment is influenced by competencies associated with cognition. The capacity for cognition enables one to plan, organize, and self-control, all of which ultimately lead to scholastic success. As mentioned, the development of the prefrontal cortex is a process of approximately 21 years from fetal neurodevelopment to adulthood. There are essential nutrients that should be consumed for the prefrontal cortex to fully mature.

The Correlation Between Gut Health and Cognitive Function

The gastrointestinal tract digests meals and captures minerals to keep an individual’s entire system functioning. In the field of medicine, there is a collection of studies on the significance of the intestine concerning our well-being in general.  Every single system in the human body is impacted by the intestinal flora9,10. Everything that someone consumes affects the microorganisms in that person’s gut.

The varied ecology of microorganisms that inhabit the intestinal tract, as well as their genetic material, and chemical compounds, is referred to as the “gut microbiota.” Human cognitive well-being is now recognized as profiting from healthy-microbe harmony, with increasing research indicating that the relationship between the stomach and the brain is critical for preserving cognitive function through a reciprocal relationship between the bacteria and the brain’s neurons.  It also has an impact on the behavior of humans and the etiology of psychological disorders.11.

To maintain a healthy gut bacteria (microbiome), one must provide oneself with proper nutrition. Eating habits and particular foods may have an impact on the quantity of various microorganisms in the gastrointestinal tract, which may ultimately have an impact on the state of health.  Eating a variety of healthy nutrients, predominantly from plant-based foods including veggies, fruits, and whole-grain products, is the most effective method to keep the gut bacteria balanced and healthy. Since the gut and brain have a neural connection, maintaining a healthy gut microbiome enhances cognitive abilities12.

The microbiome-gut-brain axis, which describes the dual relationship between the digestive tract and the neural network, is now widely understood. The significance of the gut microbiota in the process of mutually beneficial communication—that is, allowing the human brain to interact with the stomach has been highlighted by recent data11,12,13.

The brain of an individual contains about 100 billion nerve cells. The cerebral cortex and the brain’s nerve cells contain neural networks, a type of cells to instruct the human body on exactly how to function. It is believed that the largest nerve that connects the brain and stomach is known as the vagus nerve.  It is essential to note that five hundred million nerve cells originate from the cerebral cortex and end in the gastrointestinal tract which shows the strong interaction between the gut and the brain. Those nerve cells transmit impulses both ways. Numerous chemical messengers known as neurotransmitters carry messages from the intestine to one’s brain11. Those neurotransmitters are either produced or secreted by gut microorganisms. For example, microorganisms in the gut may interact and lead to alteration in the central nervous system (CNS) by releasing chemical messengers such as serotonin along with other compounds like short-chain fatty acids. Recent research claims that by the help of bacteria such as lactobacillaceae and ruminococcaeae, complex carbohydrates like dietary fibers are altered to short-chain fatty acids which can move into the bloodstream and penetrate the barrier between the brain and the bloodstream.  These short-chain fatty acids, which are modified through the interaction of gut bacteria and CNS, are capable of strengthening the unity of the blood-brain barrier. Thus, with these short-chain fatty acids greater transfer of nutrient-rich substances or chemicals from the bloodstream to the brain might stimulate the brain’s development and progression in general.  Other chemicals or neurotransmitters in the body can have an efffect on cognition. Therefore the gut microbiome is important to understand the synthesis of neurotransmitters and its effects on someone’s cognition13.

The Correlation between Gut Hormones and Cognitive Function

Apart from the gut’s ability to influence cellular networks linked to the plasticity of synapses, several gastrointestinal hormones including ghrelin, glucagon-like peptide 1 (GLP1), leptin, and a hormone known as insulin are also linked with cognition and mental abilities. These hormones have a direct impact on cognition and have the potential to alter cognitive abilities due to contact throughout the intestinal tract and the brain’s nervous system.

Several hormones have the potential to alter cognitive abilities due to contact throughout the intestinal tract and the brain’s nervous system.  Ghrelin, commonly known as the hormone that arouses the feeling of hunger, has the unusual capacity to reach the central nervous system and communicate with a development factor called secret receptor (GHS-R) in the hippocampal region.  When ghrelin interacts with this receptor, a change in configuration leads to a rise in factors of transcription, which promotes a wide range of physiological alterations as a consequence of calorie shortage. Ghrelin, which is highly concentrated in the hippocampus, may enhance retention, acquiring knowledge, and cognition. Furthermore, when ghrelin is present in the hippocampus, there is evidence it exerts both neuroprotective and neuromodulatory effects14.

Increased amounts of ghrelin hormone can influence cognition via the GHS-R, providing a potential connection to the medication for various illnesses associated with neurological malfunction.  Alzheimer’s illness has recently become a top focus for ghrelin neuroreceptor treatment. Various studies demonstrate that ghrelin inhibits this degenerative process by triggering a healing and restorative response. Though studies continue to be ongoing, additional study is recommended since initial results on this supplemental medication are encouraging14.

Produced by cells in the gut, glucagon-like peptide 1 controls the breakdown of carbohydrates by reducing dietary intake via acts on the brain’s hypothalamus and by promoting insulin production and consequent muscular cell digestion of carbohydrates. It has been demonstrated that injecting GLP1 into the brain of mice -that have a similar genetic composition to human- enhances their episodic and contextual memory. Because ghrelin, leptin, and GLP1 act on both physical and neurological objectives they may incorporate activities that affect mood and thought.

The fat in the abdomen produces leptin, which instructs the neural network to suppress hunger and enhance memory. Numerous brain regions, notably the area known as the hippocampus and the cerebellum have been found to contain leptin hormone. Animals that are inherently overweight and have malfunctioning hormone receptors for leptin have deficits in chronic depressive disorder and long-term potentiation, as well as challenges with cognitive mapping which is the ability to comprehend the position of mobile objects. Leptin injections into the hippocampal regions prevent these effects. There is evidence from recent research that leptin influences hippocampus plasticity directly by facilitating fast alterations in dendrite anatomy. Since the leptin hormone also increases the brain-derived neurotrophic factor which contributes to the brain plasticity that has a significant function in learning and memory, it is essential for proper brain function13.

Lastly, it has been discovered that the hormone insulin, which is thought to be an intestinal hormone made by the pancreas, also affects neural activity and memory retention. Mentally anticipating a meal typically triggers the release of insulin, which is then sustained throughout ingestion and circulatory uptake15. Certain brain regions, like the hippocampus, have distinct signal-transduction sensors that the hormone insulin may communicate with.  The equilibrium of the release of insulin encounters a major decline when a nutritious meal is missing, and this could ultimately result in a decrease in blood sugar concentrations16. Therefore, the brain is unable to access the nutrition that is necessary for it to function, and concentration and capacity to solve problems amongst other cognitive abilities begin to deteriorate. In general, the data appears to point to the possibility that eating itself can affect cognitive functions on two different levels: by releasing gut hormones into the circulation and by altering neuronal networks that link the mind and the gastrointestinal tract16.

The Correlation Between Nutrition and Cognitive Function

To completely understand the connection between food sources and brain function, it is vital to take into account the link that exists between nourishment and cognition from the beginning of conception. The relationship between nutrition and the cognitive system starts throughout pregnancy, which is important to consider to fully comprehend the interaction between dietary nutrients and the brain. In actuality, fetal neurodevelopment is a complicated process that depends on a variety of variables, including the mother’s microbiome’s chemical signals such as the gut microbiome of the mother, and external aspects like nutrition and exercise.  In both animal models and human subjects, the mother’s microorganisms in the digestive tract can have an impact on the brain development, microbiota, and mental ability of the offspring. This indicates that cognition is not only relevant to genetic factors but it also gets affected by environmental factors. Although researchers suggest that cognition is one of the most significantly inherited aspects of behavior, mental abilities are also dependent on environmental factors involving nutrition17.

The human genotype, the complete set of genetic material in an organism, in conjunction with a variety of external variables including diet, parental attention, interpersonal relationships, anxiety, and illnesses, forms the foundation for brain growth and functional characteristics. The link between eating habits and mental wellness has recently become more apparent, and nourishment has emerged as an essential supplementary issue in the treatment of mental illnesses.  This has given rise to the idea that foods have the potential to improve cognitive abilities. Recent studies have shown an even greater link between eating behaviors and mental health. Research has led to the notion that eating certain meals could enhance mental capacity18,19,20.

Nutrition is essential for the human body as it supplies the brain cells its necessary components to sustain neural relations, which results in increased cognitive function and academic success. Specific key nutrients can have different impacts on the human body. For instance, omega-3 fatty acid chains, which are frequently present in high quantities in fish and green algae, are essential structural elements of the brain.  Furthermore, protein consumption has been connected to enhancements in verbal skills, the capacity to process information, and concentration, while diets high in sugar, simple carbohydrates trans fats, are thought to be detrimental to brain activity because they impair the plasticity of synapses which improves the cognition of a person by enhancing the neural connection in the brain cells.  Changes in the amount and composition of food consumed by healthy humans can affect their cognition1.

The Correlation Hydration Status and Cognitive Function

Although there exists plenty of studies on how different workout routines are performed when dehydrated, dehydration additionally has a direct impact on the way the brain works.  Though there currently is insufficient confirmation that lack of water alters the volume of the brain, not all investigations have shown this effect. It appears that with gradually increasing hydration levels, healthy participants show cognitive (homeostasis) adaptive mechanisms to compensate for higher levels of fatigue and decreased attentiveness. In an MRI investigation, a study demonstrated that volunteers had to spend more effort using their mental ability to accomplish a similar level of achievement of the same task when they were dehydrated21. This result indicates that sustained insufficient water consumption may negatively affect executive processes of thinking and visualization due to a scarce supply of water. This could have an impact on collaborative and disciplined activities such as school projects, sports, and academic work where making decisions is crucial22.

The Correlation between Branched-Chain Amino Acids and Cognitive Function

There are several essential amino acids which are the bases of proteins that are necessary for brain function. These proteins are known as isoleucine, valine, and BCAAs23. There was a research conducted in Japan, Tokyo Metropolitan Institute of Gerontology, by Professor Ajinomoto about the effectiveness of seven essential amino acids on cognition24. Three categories of individuals were randomly allocated; one group received 3 grams of amino acids (group 1), the other group received 6g of amino acids (group 2) and a placebo group (group 3). The substance being used was specially created by Ajinomoto for this experiment. The powder contained phenylalanine, leucine, phenylalanine, tryptophan lysine hydrochloride, isoleucine, histidine hydrochloride, valine, and lysine which are believed to be essential amino acids for brain function. Participants in the first group received 3 grams of the substance on two separate occasions. The individuals in the second group consumed 6 grams of the substance twice a day. The combination of starch and powdered milk served as the substance for the placebo group. The study continued for 12 weeks and each group consumed their substance. The results demonstrated that individuals in group 1 completed assignments 14.6 seconds faster than those in the third group. The quicker execution indicates an increase in cognitive capacity, which is connected to how well one can focus on an assignment, remain attentive to several tasks, and memorize details required to perform assignments. These findings suggest that consuming 6 g of amino acids daily helps to enhance cognitive abilities and memory. According to scientists, the conveyance of amino acids from the diet to the brain, particularly the prefrontal region, significantly impacts brain activity when necessary amino acids are consumed25.

The Correlation between Carbohydrates and Cognitive Function

Nutrition of highly complex carbs is linked with effective brain development and enhanced recall over a lifetime while eating simple carbs as known as sugars has been linked to lower overall cognition2. A nourishment’s classification as a complex or simple carbohydrate depends on its chemical composition as well as how swiftly the human body breaks it down. Glucose concentration rises are less common with complicated carbohydrates. They additionally involve nutrients such as vitamins and minerals that are essential for the human body to work. For instance, fiber is a type of carbohydrate that decreases the risk of cardiovascular illnesses, and elevated cholesterol levels and improves gut health2. Although the body needs complex carbohydrates for existence and mental activity, simple carbohydrates are not necessary for survival. Overindulging in simple carbohydrates can result in obesity. It may also raise your chance of high levels of cholesterol, obesity, and cardiovascular illnesses26. While black beans, chickpeas, lentils, and potatoes are considered complex carbohydrates, processed food, candy bars, and other substances similar to that are considered simple carbs. Studies have indicated that simple carbs usually harm the human body while complex carbs have a beneficial effect.

A previous study done by The National Health and Nutrition Examination Survey experimented to determine the relationship between diet intake of carbohydrates and mental abilities amongst people who fasted for approximately 16 hours per day. In the present investigation, It has been discovered that a regular fasting period might ameliorate the connection between nutritional intake of carbohydrates and memory loss among those over 55 in the United States27. Once individuals were separated by daily fasting period, the previously mentioned relationship persisted amongst those who fasted for less than 16 hours, but not for those who fasted for more than 16 hours. Nevertheless, there are some drawbacks in the present investigation. In the first place, nutritional data has been implemented and evaluated via two 24-hour nutritional recalls, that are unable to accurately represent the actual intake of the humans. Furthermore, causation was unable to be established due to the cross-sectional research methodology.  Lastly, remaining confounding variables may persist even after a substantial number of variables have been controlled27.

The Correlation between Fats and cognitive Function

Fatty acids which are monomers of lipids are crucial for brain function.There are two types of fatty acids; unsaturated and saturated. While the unsatured one aids the development of cognition, the saturated one declines cognition. Having a saturated high-fat diet causes the region of the hippocampal cortex to become activated when exposed to even a minor immunological assault, which can lead to impairments in retention27. A diet heavy in fat raises the likelihood of being overweight, developing diabetes, and dementia. Recognized indicators of risk for cognitive decline including elevated insulin levels, poor glucose uptake, and diabetes.

In the brain, fatty acids that are not saturated control the construction and operation of neural networks, vascular cells, and cell types known as glial.  The omega-3 fatty acids, including Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA), affect neural communication, lessen neuro-inflammatory responses, and encourage the survival and growth of new neurons2. Docosahexaenoic acid is essential for synaptic development, growth of neurons, the fatty acid content of membranes, mobility, and neural relocation, all of which impact neurological networks, especially the retinal function2. Such brain regions control impulsiveness and concentration. It is proven that due to their anti-thrombotic and anti-inflammatory qualities in brain activity, polyunsaturated fatty acids help preserve mental abilities and avoid Alzheimer’s28. Unlike high saturated fat diets, diets with unsaturated fats prevent cognitive impairment. While saturated fats such as palmitic acid led to cognitive decline unsaturated fats like Omega-3 fatty acids oleic acid EPA and DHA enhance cognition.

The Correlation between Caffeine and Cognitive Function

Although coffee drinking and consumption of caffeinated products have not been adequately investigated for their impact on cognition, it has been discovered that it has effects on long-term and short-term memory. While it occasionally has a facilitating or inhibiting impact on learning and retention, coffee often does not influence on how well one performs on retention and comprehension tasks. When knowledge is provided unconsciously, caffeine helps with learning; however, it has no impact when studying content consciously29. To a certain degree, caffeinated products help with short-term memory-related activities. Students who are in college typically endure occasional sleep loss and frequently consume coffee daily to improve their academic achievement by boosting vitality and mental alertness.  Caffeine’s indirect impact on attitude, stimulation, and memory indicates that it may enhance short-term memory which is the ability to keep a small quantity of knowledge active and easily accessible for a brief period. Consuming low to substantial amounts of caffeinated substances (40 mg to 300 mg) can enhance vigilant behavior, focus, concentration, and quickness of response. For instance, chronic paraxanthine, an example of caffeine metabolite, has been shown to improve the “capacity to retain and access knowledge with the enhancement of short-term memory”. Nevertheless, these consequences do not affect more complex mental processes or long-term memory30. Though there is not enough research on caffeine’s effect on long-term memory, scientists express that caffeine use is not suspected to have an impact on long-term memory in which data is stored for a significant amount of time.  Apart from affecting cognition, the stimulant caffeine enhances emotions and lessens anxiety at moderate dosages; nevertheless, excessive dosages cause muscular arousal, which includes anxiousness, nervousness, and uneasiness30. The greater efficiency gain in tired individuals is evidence that coffee is a relatively mild stimulator. 

The Correlation between Micronutrients and Cognitive Function

The human body uses small-molecule nutrients such as vitamins to generate chemical messengers and other substances necessary for a healthy maturing and development process. Deficits in vitamin A and minerals such as iodine and iron are the most serious problems facing public health because they have a major effect on people’s health worldwide, especially on kids and expectant mothers. Over the last ten years, substantial studies have been conducted to investigate the impact of vitamins that are fat-soluble on early maturation of cognition31.

Throughout a variety of processes, both the development and operation of the brain depend on vitamin B because of its function in neural myelitis, and cognitive development. Scientists stressed the significance of maintaining an appropriate vitamin B-12 status, especially during conception and during the initial months of infancy31.

 A single study conducted on adult Americans found a correlation between improved mature cognitive performance and B vitamins. Low folate (a type of vitamin B) consumption may raise the chance of developing Alzheimer’s or mild cognitive impairment in later life among postmenopausal women32.

Findings of reduced serum 25-hydroxyvitamin D concentrations in Alzheimer patients compared to healthy individuals are raising questions about the significance of vitamin D in brain wellness and memory. Furthermore, seven years later, low levels of vitamin D raised the chance of dementia. Only visual recall was enhanced by high-dose vitamin D3 intake throughout 4 months in normal individuals, with no improvement observed in other areas of cognition33.

There are conflicting findings even though numerous research demonstrates that consuming vitamins rich in antioxidants (E and C) lowers the risk of mental deterioration. In an upcoming Canadian cohort, the usage of vitamin E and C supplementation was associated with a decreased likelihood of cognitive deterioration33. Research has also shown that vitamins and cognition have neither a positive nor a negative correlation34. The cross-sectional research conducted in the US found that greater vitamin E intake was linked to improved verbal proficiency, verbal recollection, and quick recall scores35. A cross-sectional investigation conducted on older French individuals by Chouet et al. found that improved cognition-related actions in older adults were correlated with greater levels of the organic molecule vitamin K.19

Because iron is a component of the protein hemoglobin oxygen must be able to reach all of the organs that make up the body, especially the cerebral cortex. Cognitive decline, both acute and chronic, is at risk for people with a lack of iron minerals. Iron deficiency in the human body has been linked to impaired physical and intellectual growth in early life as well as decreased memory and academic performance in adolescence18. Scientists agrees that avoiding iron deficiency should start from the fetal development of the child to prevent cognitive impairment. The nervous system’s iron deficit is linked to abnormal neurophysiological processes, which can impede the growth of muscular and mental skills. Conversely, overexposure to iron minerals can also affect neurological processes, including neural cell death, and is linked to a reduction in cognition.

Furthermore, E. Huskisson, S. Maginni, and M. Ruf’s medical research reveals that there are two primary categories of micronutrients such as calcium, magnesium, zinc, and vitamins B and C (water-soluble vitamins) which are required for proper mental achievement. Due to their biological interdependent relationships, the vitamins that make up the B complex must be treated as an operational component, with each of its components acting as linkages in an ordered sequence of biochemical processes.  There are biochemical processes in metabolic activity that involve all eight vitamin B complexes to act as cofactors for multiple digestive enzymes. Numerous relationships exist among several components of the complex. Even though the antioxidant vitamin C is required for the production of collagen in the epidermis, it is important to keep in mind that the greatest quantities of this antioxidant can be detected in the tissue of the brain.  Brain vitamin C has been shown to work effectively with vitamin B complexes to sustain multiple facets of mental function and efficiency.

 The mineral calcium, zinc, and magnesium are necessary as cofactors for a wide range of vitamin-dependent enzymatic processes as well as for nervous system activity and neural communication.  Except for the mineral calcium, not a single one of these micronutrients is kept in significant amounts within the human body, hence enough daily intake is required.

Vitamins and minerals impact mental performance via four key processes: their function in brain chemical production, neural membrane and receptor alterations, and neural power demands. Medical research suggests that many people in advanced nations face minor nutritional deficits. Significant populations at risk include young to middle-aged persons with stressful occupations and insufficient time, as well as the old.  Insufficient levels of micronutrients can affect brain function throughout life and have been linked to cognitive decline due to age. Micronutrient supplementation can help prevent deficiencies in those at risk and may therefore help to maintain cognitive performance. Doctors confronted with stressed or elderly patients complaining of non-specific, especially cognitive, symptoms should consider the possibility of marginal micronutrient deficiency and the potential benefits of micronutrient supplementation. One should include the necessary vitamins and minerals addressed above for optimum cognitive performance.

Key nutrients and Cognition
Nutrient TypeImpacts on Cognition
WaterHydration increases attentiveness19.Sustained insufficient water consumption may negatively affect executive processes of thinking and visualization20.
ProteinProteins such as isoleucine, valine and BCAAs enhance cognitive abilities and memory20,21
CarbohydratesComplex carbohydrates enhances bodily functions and cognition2Simple carbohydrates can trigger in cholesterol, obesity, and cardiovascular ilnesses26.
FatsDue to their anti-thrombotic and anti-inflammatory qualities in brain activity, polyunsaturated fatty acids help preserve mental abilities and avoid Alzheimer26. Eicosapentaenoic acid ( EPA) and Docosahexaenoic acid (DHA) affect neural communication, lessen neuro-inflammatory responses, and encourage the survival and growth of new neurons2.Having a saturated high-fat diet causes the region of the hippocampal cortex to become activated when exposed to even a minor immunological assault, which can lead to impairments in retention28.
CaffeineCaffeine has a facilitating or inhibiting impact on learning and retention, coffee often has no influence on how well one performs on retention and comprehension tasks29.To a certain degree, caffeinated products help with short-term memory-related activities29.Caffeine use is not suspected to have an impact on memory over a long period30.
MicronutrientsVitamin B consumption decreases the chance of developing alzeihmer32Low levels of vitamin D raised the chance of dementia33  Vitamins rich in antioxidants (E and C) improve growing neuronal circuits34Vitamin B consumption decreases the chance of developing alzeihmer32.

Methodology

A systematic review was undertaken to evaluate the nutrition’s role in shaping function. The database Google Scholar was accessed to find more than thirty pertinent academic publications. All provided information underwent a strict review for accuracy.  The articles cited were located solely via the earlier specified respected research, ensuring the reliability of the studies and preventing the utilization of invalid data.  Articles examined are required to contain the aforementioned keywords; Behavioral and Social Sciences, Cognitive Psychology, Brain Function, Cognitive Health, Nutrition, Gut Health, Gut Hormones. Several filtering criteria were used: papers had to be published approximately within the past twenty years, be cited multiple times or more, contain no fewer than two of the terms listed beforehand, and be either an original investigation piece or a comprehensive review of the literature.  Extensive study analysis of the selected publications was conducted by carefully reviewing each article that met the requirements for the search criteria and writing brief overviews detailing the general findings for every study.  Analyses were then assessed to identify important commonalities as well as variations among the studies examined. These commonalities or contrasts were employed to develop responses to the study topic posed in this article.  Inconsistencies were recognized as possible inefficiencies and examined and settled using informed assumptions.

Limitations

A substantial amount of study is needed on the impact of race and ethnic background on the microbiome-gut-brain-axis formation. Nevertheless, emerging research suggests that ethnic background and gender have the potential to have major effects on the gastrointestinal flora. The gut microbiome may influence neurological growth in a sex-specific way, with females being much more prone to fall ill from anxiety-related and gastrointestinal diseases. However, in models of animals, the brain of males tends to be far more vulnerable to microbiota perturbations compared to the female brain. Such sex-specific consequences have prompted justifiable demands for further investigation of the field of “microgenderome”.While race-related variety of the intestinal microbiome is currently being studied in cancer along with various illnesses, there has been less research on how race affects gut microbiota and its link with brain-gut axis disorders. Present studies, nonetheless, highlight the importance of understanding how gender differences and ethnic diversity affect the microbiota and lead to brain-gut axis diseases.

The cause-and-effect link between cognition and gut microbiota, however, is extremely ambiguous.  It is unknown if a gastrointestinal imbalance leads to a particular illness, is an outcome of a disease, or is an accumulation of both. Furthermore, comprehension of these findings remains challenging since modifications in the gut microbiome composition in a particular disease condition are frequently differing.  Several biological variables might be responsible for the differing results, including the medical care status of the patient (medicated/unmedicated), variances in the course of a specific disease, food, comorbidities, sports participation, individual age, and so on. Furthermore, methodology variations in experiments can cause inconsistency in the findings of microbiome investigations. Technological challenges influencing the microbial community involve specimen gathering and preservation practices, genetic material extraction approaches, primer choice, and computational examination, particularly the matter of several evaluations. Nevertheless, in the majority of investigations, the lack of a large sample size appears to be the primary factor contributing to the diversity of stated outcomes.

Conclusion

A person with a healthy brain can understand their capabilities and modify their mental and emotional functioning in response to different scenarios in life. The recognition of gastrointestinal signals as critical components in the management of mental health conditions is hardly unexpected. Thus, gut microbiota does affect the cellular pathways governing memory formation ability, and general brain function. Recent research has shown a stronger connection between food choices and psychological well-being, and nutrition is now recognized as a crucial secondary factor in the medical management of mental diseases.  Research has led to the notion that eating certain meals could enhance cognition. Studies suggest that prolonged dehydration could cause an adverse impact on mental processes related to cognition and vision because of a limited source of water. This might influence teamwork and discipline-related activities including schoolwork, and athletics where making choices becomes essential. Research indicates that a proper amount of protein may benefit specific cognitive assessments. These findings further emphasize the need for an appropriate intake of proteins involving phenylalanine, leucine, phenylalanine, tryptophan lysine hydrochloride, and isoleucine.

It has been demonstrated that simple carbohydrates produce a detrimental impact on brain cells, which lower mental ability and cause degenerative decline in cognition. Meanwhile, carbs with complex structures have been shown to strengthen blood sugar balance and lessen metabolism dysfunction, which is good for cognitive function. Furthermore, evidence points to increased consumption of beneficial (unsaturated) fats.  For instance, diets heavy in saturated fats are currently demonstrated to negatively correlate with overall mental performance, whereas diets that contain unsaturated fats have been associated with enhancing memory and thinking abilities. Following a summary of data primarily from research involving animals, scientists concluded that high carbohydrate-fat intake throughout the prenatal and adolescent stages may especially harm cognition, specifically for memory and thinking. It has been discovered that a rich-sugar, high-fat lifestyle affects memory retention more than just obesity, metabolic disorders, or unrestricted calorie consumption. This suggests that processed fat and a diet heavy in simple carbohydrates are independent causes of memory-harming effects.

Moreover, It has been discovered that caffeine itself can particularly enhance or inhibit learning although it has no impact on how well one performs on a task. Scientists also found out that caffeine does not have an effect on long-term memory but can have an impact on short-term memory. Apart from overall inadequate nutrition in macronutrients, specific nutritional deficits can significantly impact brain growth and the following state of cognition. Vitamins including A, B, C, D, E, and iron are micronutrients that are essential for brain function. To have a better understanding of the relationship between nutrition and cognition scientists have conducted experiments and research about the interaction between gut health and the brain in the last few decades. It has been found that adverse extrinsic lifestyles also represent significant risk factors for the occurrence of dementia, which include poor food, lack of sleep, and a lack of activity, but most importantly nutrition has a significant impact on the gut flora. Information about the advantages of fiber found in food in regulating gut microorganisms is rapidly developing. The intriguing prospect that dietary modifications are a workable method for improving cognitive capacities and shielding brain cells from harm, encouraging healing, and mitigating the consequences of aging is suggested by the findings of the link between nutrition and cognition. As it is known that nutrition affects cognition, medicals can do further research on this topic to design an ideal diet to minimize the deterioration in the mental capacities of humans.

Acknowledgements

The author would like to thank all of the individuals who helped make this project a success. Thank you to my mentor Metasebya Solomon and publication strategist Anustup Garai.

References

  1. Pierre Guesry,The Role of Nutrition in Brain Development,Preventive Medicine,Volume 27, Issue 2,Pages 189-194,ISSN 0091-7435,https://doi.org/10.1006/pmed.1998.0292. (1998). [] [] [] []
  2. Anne-Katrin Muth, Soyoung Q. Park, The impact of dietary macronutrient intake on cognitive function and the brain,Clinical Nutrition,Volume 40, Issue 6, Pages 3999-4010,ISSN 0261-5614, https://doi.org/10.1016/j.clnu.2021.04.043. (2021). [] [] [] [] [] [] [] [] [] [] []
  3. Nutrition, brain function and cognitive performance. Lieberman HR. Appetite. Jun;40(3):245-54. doi: 10.1016/s0195-6663(03)00010-2. PMID: 12798782. (2003). [] []
  4. Wang Y, Pan Y, Li H. What is brain health and why is it important? BMJ;371:m3683. doi: 10.1136/bmj.m3683. PMID: 33037002; PMCID: PMC7555053. (2020). []
  5. Brain Basics: Know Your Brain. National Institute of Neurological Disorders and Stroke. https://www.ninds.nih.gov/health-information/public-education/brain-basics/brain-basics-know-your-brain (2023). []
  6. Amunts K, DeFelipe J, Pennartz C, Destexhe A, Migliore M, Ryvlin P, Furber S, Knoll A, Bitsch L, Bjaalie JG, Ioannidis Y, Lippert T, Sanchez-Vives MV, Goebel R, Jirsa V. Linking Brain Structure, Activity, and Cognitive Function through Computation. eNeuro;9(2):ENEURO.0316-21.2022. doi: 10.1523/ENEURO.0316-21.2022. PMID: 35217544; PMCID: PMC8925650. (2022). []
  7. Paige A. Moorhouse, Kenneth Rockwood,CHAPTER 55 – Vascular Cognitive Impairment,Editor(s): Howard M. Fillit, Kenneth Rockwood, Kenneth Woodhouse,Brocklehurst’s Textbook of Geriatric Medicine and Gerontology (Seventh Edition),W.B. Saunders, Pages 421-427,ISBN 9781416062318,https://doi.org/10.1016/B978-1-4160-6231-8.10055-8. (2010). []
  8. Scarmeas N, Anastasiou CA, Yannakoulia M. Nutrition and prevention of cognitive impairment. Lancet Neurol. 17(11):1006-1015. doi: 10.1016/S1474-4422(18)30338-7. Epub 2018 Sep 21. PMID: 30244829. (2018). []
  9. Clapp, M.; Aurora, N.; Herrera, L.; Bhatia, M.; Wilen, E.; Wakefield, S. Gut Microbiota’s Effect on Mental Health: The Gut-Brain Axis. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5641835/ (2017). []
  10. Tooley KL. Effects of the Human Gut Microbiota on Cognitive Performance, Brain Structure and Function: A Narrative Review. Nutrients. 12(10):3009. doi: 10.3390/nu12103009. PMID: 33007941; PMCID: PMC7601389(2020). []
  11. Cooke MB, Catchlove S, Tooley KL. Examining the Influence of the Human Gut Microbiota on Cognition and Stress: A Systematic Review of the Literature. Nutrients. 14(21):4623. doi: 10.3390/nu14214623. PMID: 36364881; PMCID: PMC9656545. (2022). [] [] []
  12. L. Grant Canipe, Michael Sioda, Carol L. Cheatham, Diversity of the gut-microbiome related to cognitive behavioral outcomes in healthy older adults,Archives of Gerontology and Geriatrics,Volume 96,104464,ISSN 0167-4943, doi: 10.1016/j.archger.2021.104464. (2021). [] []
  13. Valdes A M, Walter J, Segal E, Spector T D. Role of the gut microbiota in nutrition and health  BMJ 2018;  361 :k2179 doi:10.1136/bmj.k2179(2018). [] [] []
  14. Seminara RS, Jeet C, Biswas S, Kanwal B, Iftikhar W, Sakibuzzaman M, Rutkofsky IH. The Neurocognitive Effects of Ghrelin-induced Signaling on the Hippocampus: A Promising Approach to Alzheimer’s Disease. Cureus. (9):e3285. doi: 10.7759/cureus.3285. PMID: 30443455; PMCID: PMC6235652(2018). [] []
  15. Margolis KG, Cryan JF, Mayer EA. The Microbiota-Gut-Brain Axis: From Motility to Mood. Gastroenterology. 160(5):1486-1501. doi: 10.1053/j.gastro.2020.10.066. Epub 2021 Jan 22. PMID: 33493503; PMCID: PMC8634751(2021). []
  16. Mandal A, Prabhavalkar KS, Bhatt LK. Gastrointestinal hormones in regulation of memory. Peptides. 2018 Apr;102:16-25. doi: 10.1016/j.peptides. Epub 2018 Feb 18. PMID: 29466709. (2018). [] []
  17. Polverino A, Sorrentino P, Pesoli M, Mandolesi L. Nutrition and cognition across the lifetime: an overview on epigenetic mechanisms. AIMS Neurosci. 8(4):448-476. doi: 10.3934/Neuroscience.2021024. PMID: 34877399; PMCID: (2021). []
  18. Puri S, Shaheen M, Grover B. Nutrition and cognitive health: A life course approach. Front Public Health. 11:1023907. doi: 10.3389/fpubh.2023.1023907. PMID: 37050953; PMCID: PMC10083484. (2023). [] []
  19. Ekstrand B, Scheers N, Rasmussen MK, Young JF, Ross AB, Landberg R. Brain foods – the role of diet in brain performance and health. Nutr Rev. 79(6):693-708. doi: 10.1093/nutrit/nuaa091. PMID: 32989449 (2021). [] []
  20. Meeusen R. Exercise, nutrition and the brain. Sports Med.;44 Suppl 1(Suppl 1):S47-56. doi: 10.1007/s40279-014-0150-5. PMID: 24791916; PMCID: PMC4008828.PMC8611190. (2014). [] [] []
  21. Adan A. Cognitive performance and dehydration. J Am Coll Nutr. 31(2):71-8. doi: 10.1080/07315724.2012.10720011. PMID: 22855911. (2012). [] []
  22. Masento et al., Natalie A. Effects of Hydration Status on Cognitive Performance and Mood, www.cambridge.org/core/services/aop-cambridge-core/content/view/1210B6BE585E03C71A299C52B51B22F7/S0007114513004455a.pdf/effects_of_hydration_status_on_cognitive_performance_and_mood.pdf. (2014 ). []
  23. Masento et al., Natalie A. Effects of Hydration Status on Cognitive Performance and Mood, www.cambridge.org/core/services/aop-cambridge-core/content/view/1210B6BE585E03C71A299C52B51B22F7/S0007114513004455a.pdf/effects_of_hydration_status_on_cognitive_performance_and_mood.pdf. (2014). []
  24. Suzuki H;Yamashiro D;Ogawa S;Kobayashi M;Cho D;Iizuka A;Tsukamoto-Yasui M;Takada M;Isokawa M;Nagao K;Fujiwara Y; Intake of Seven Essential Amino Acids Improves Cognitive Function and Psychological and Social Function in Middle-Aged and Older Adults: A Double-Blind, Randomized, Placebo-Controlled Trial. https://pubmed.ncbi.nlm.nih.gov/33324669/ (2020). []
  25. Lim, G. Y. Special Seven: Ajinomoto Study Shows Amino Acid Supplementation Improves Cognitive Function in Older People. https://www.nutraingredients-asia.com/Article/Special-seven-Ajinomoto-study-shows-amino-acid-supplementation-improves-cognitive-function-in-older-people (2021). []
  26. Hawkins MAW, Keirns NG, Helms Z. Carbohydrates and cognitive function. Curr Opin Clin Nutr Metab Care. 2018 Jul;21(4):302-307. doi: 10.1097/MCO.0000000000000471. PMID: 29851417. (2018). [] [] []
  27. Zhao, Shengnan, et al. “The Association of Diet Carbohydrates Consumption with Cognitive Function among Us Older Adults Modification by Daily Fasting Duration.” Frontiers, Frontiers, www.frontiersin.org/articles/10.3389/fnagi.2022.991007/full(2022). [] [] []
  28. Cao GY, Li M, Han L, Tayie F, Yao SS, Huang Z, Ai P, Liu YZ, Hu YH, Xu B. Dietary Fat Intake and Cognitive Function among Older Populations: A Systematic Review and Meta-Analysis. J Prev Alzheimers Dis.;6(3):204-211. doi: 10.14283/jpad.2019.9. PMID: 31062836. (2019). [] []
  29. Nehlig A. Is caffeine a cognitive enhancer? J Alzheimers Dis. 20 Suppl 1:S85-94. doi: 10.3233/JAD-2010-091315. PMID: 20182035. (2010). [] [] []
  30. Tom M. McLellan, John A. Caldwell, Harris R. Lieberman, A review of caffeine’s effects on cognitive, physical and occupational performance,Neuroscience & Biobehavioral Reviews,Volume 71, Pages 294-312,ISSN 0149 7634,https://doi.org/10.1016/j.neubiorev.2016.09.001. (2016). [] [] []
  31. Nooyens AC, Milder IE, van Gelder BM, Bueno-de-Mesquita HB, van Boxtel MPVWM. Diet and cognitive decline at middle age: the role of antioxidants. Br J Nutr. 113:1410–7. doi: 10.1017/S0007114515000720 (2015). [] []
  32. Chouet J, Ferland G, Féart C, Rolland Y, Presse N, Boucher K, et al. Dietary vitamin K intake is associated with cognition and behaviour among geriatric patients: the CLIP study. Nutrients. 7:6739–50. doi: 10.3390/nu7085306 (2015). [] [] []
  33. Beydoun MA, Fanelli-Kuczmarski MT, Kitner-Triolo MH, Beydoun HA, Kaufman JS, Mason MA, et al. Dietary antioxidant intake and its association with cognitive function in an ethnically diverse sample of US adults. Psychosom Med. 77:68–82. doi: 10.1097/PSY.0000000000000129 (2015). [] [] []
  34. Basambombo LL, Carmichael PH, Côté SLD. Use of Vitamin E and C supplements for the prevention of cognitive decline. Ann Pharmacother. 51:118–24. doi: 10.1177/1060028016673072 (2017). [] []
  35. Galasko DR, Peskind E, Clark CM, Quinn JF, Ringman JM, Jicha GA, et al. Antioxidants for Alzheimer disease: a randomized clinical trial with cerebrospinal fluid biomarker measures. Arch Neurol. 69:836–41. doi: 10.1001/archneurol.2012.85 (2012). []

LEAVE A REPLY

Please enter your comment!
Please enter your name here