The role of vitamin E in the prevention of cognitive impairment

The role of vitamin E in the prevention of cognitive impairment

I. Vitamin E: Fundamentals and forms

Vitamin E is a group of fat -soluble compounds with powerful antioxidant properties. It plays a key role in protecting the cells from damage caused by free radicals, unstable molecules formed as a result of normal metabolic processes and the effects of environmental factors, such as pollution and ultraviolet radiation. Vitamin E is necessary to maintain the health of the nervous system, immune function and skin health.

In nature, vitamin E is found in eight different forms: four tocopherols (alpha, beta-, gamma- and delta-tocopherols) and four-tocotrienals (alpha, beta-, gamma and delt-tocotrienals). Each form has various biological activity and distribution in the body.

• Tocopherols: These are the most common forms of vitamin E in the western diet. Alpha-tocopherol is the most biologically active and widely studied form and is preferably supported in the human body. Alpha-Tocopherol is involved in protecting cell membranes from oxidative stress, modulation of immune function and regulation of genes expression. Other tocopherols (beta, gamma, delta) also have antioxidant activity, but are less effectively held in the body.

• Tokotrienols: Tokotrienols differ from tocopherols by the presence of three unsaturated connections in an isoprenoid side chain. These structural differences lead to unique biological properties, including higher antioxidant activity in some systems and potential neuroprotective activity. Tokotrienols are found in high concentrations in some vegetable oils, such as palm and rice oil, as well as in the germ of wheat and barley.

II. Cognitive disorders: spectrum and causes

Cognitive disorders cover a wide range of states characterized by a decrease in cognitive functions, such as memory, attention, language, executive functions and spatial thinking. The degree of cognitive disorders can vary from mild, barely noticeable changes to severe violations that affect everyday life and independence.

• Age cognitive decline: With age, many people have a gradual decrease in cognitive functions, which is considered part of a normal aging process. This decrease can manifest itself in the form of forgetfulness, difficulties with the concentration of attention or slowing down the speed of information processing.

• Light cognitive disorders (LKN): LKN is an intermediate state between normal cognitive aging and dementia. People with LKN have cognitive problems that are noticeable to them or others, but do not significantly affect their ability to perform everyday tasks. LKNs are often considered as a risk factor for dementia, especially Alzheimer’s disease.

• Dementia: Dementia is a general term for a group of diseases characterized by a progressive decrease in cognitive functions, serious enough to influence everyday life and independence. The most common cause of dementia is Alzheimer’s disease, followed by vascular dementia, dementia with Levy Taurus and Lob-Visa Dementia.

The causes of cognitive disorders are multi -factor and include:

• Age: Age is the main risk factor for the development of cognitive impairment.
• Genetics: A genetic predisposition plays a role in the development of certain forms of dementia, especially Alzheimer’s disease.
• Vascular risk factors: High blood pressure, high cholesterol, diabetes and smoking increase the risk of vascular dementia and Alzheimer’s disease.
• Oxidizing stress and inflammation: Oxidative stress and chronic inflammation in the brain contribute to damage to neurons and the development of cognitive disorders.
• Head injuries: Hodo-brain injuries can increase the risk of dementia at a later age.
• Lack of physical activity and malnutrition: A sedentary lifestyle and unbalanced nutrition are associated with an increased risk of cognitive impairment.
• Other diseases: Some diseases, such as Parkinson’s disease, multiple sclerosis and HIV, can cause cognitive disorders.

III. Oxidizing stress and cognitive disorders: relationship

Oxidative stress occurs when an imbalance between the production of free radicals and the ability of the body to neutralize them using antioxidants leads to damage to cells and tissues. The brain is especially vulnerable to oxidative stress due to a high level of oxygen consumption, a relatively low level of antioxidants and the abundance of lipids subject to peroxide oxidation.

In the context of cognitive disorders, oxidative stress plays an important role in damage to neurons, impaired synaptic function and the formation of amyloid plaques and neurofibrillar balls characteristic of Alzheimer’s disease.

• Damage to neurons: Free radicals damage DNA, proteins and lipids in neurons, which leads to a violation of their function and death.
• Synaptic dysfunction: Oxidative stress disrupts the transmission of signals between neurons in synapses, which leads to a decrease in cognitive abilities.
• The formation of amyloid plaques and neurofibrillar balls: Oxidative stress contributes to the aggregation of beta-amyloid and hyperphosporlation of tau-white, key components of amyloid plaques and neurofibrillar balls, respectively, which are pathological signs of Alzheimer’s disease.
• Inflammation: Oxidative stress triggers inflammatory processes in the brain that exacerbate neurons damage and cognitive disorders.

IV. Antioxidant properties of vitamin E and brain protection

Vitamin E is a powerful antioxidant that neutralizes free radicals and protects cells from oxidative stress. Its lipophilic properties allow him to integrate into cell membranes and protect lipids from peroxidation peroxidation. In addition, vitamin E interacts with other antioxidants such as vitamin C and glutathione, enhancing their protective function.

In the brain, vitamin E plays an important role in protecting neurons from oxidative damage, maintaining the integrity of cell membranes and modulations of neurotransmission.

• Protection of cell membranes: Vitamin E protects lipids in cell membranes of neurons from peroxidation peroxidation, preserving their structure and function.
• Neutralization of free radicals: Vitamin E neutralizes free radicals that form as a result of metabolic processes and exposure to environmental factors, preventing neurons damage.
• Maintaining neurotransmissance: Vitamin E can modulate neurotransmission, improving the transmission of signals between neurons and cognitive functions.
• Anti -inflammatory action: Vitamin E has anti -inflammatory properties and can reduce inflammation in the brain, protecting neurons from damage.
• Improving blood supply to the brain: Some studies show that vitamin E can improve blood supply to the brain, providing neurons with oxygen and nutrients.

V. Epidemiological studies: vitamin E and risk of cognitive impairment

Numerous epidemiological studies studied the relationship between vitamin E consumption and the risk of developing cognitive disorders, including Alzheimer’s disease and dementia. The results of these studies are ambiguous, but some of them indicate the potential protective role of vitamin E.

• Research with the participation of older people: Some studies have shown that in older people with a higher level of vitamin E in blood plasma or with a higher consumption of vitamin E with food, the risk of cognitive disorders, including Alzheimer’s disease, is lower.
• Research of the type-control type: Studies of the type-control type, in which people with Alzheimer’s disease with a control group without a disease are compared, showed that people with Alzheimer’s disease often have a lower level of vitamin E in blood plasma.
• Longitudinal research: Longitudinal studies that track people over a long period of time showed that higher consumption of vitamin E with food can be associated with a slower decrease in cognitive functions with age.

However, it is important to note that not all epidemiological studies showed a positive relationship between vitamin E and cognitive functions. Some studies did not reveal a significant connection, while others showed that high doses of vitamin E can be associated with an increased risk of adverse outcomes.

VI. Clinical trials: vitamin E and cognitive functions

Clinical trials in which vitamin E is prescribed to people with cognitive impairments or the risk of their development have also given ambiguous results.

• Studies with the participation of people with Alzheimer’s disease: Some clinical trials showed that high doses of vitamin E (for example, 2000 IU per day) can slow down the progression of Alzheimer’s disease in people with a moderate degree of disease. However, other studies have not confirmed these results.
• Research with the participation of people with LKN: Some studies have shown that vitamin E can improve cognitive functions in people with LKN, especially in combination with other antioxidants. However, additional studies are needed to confirm these results.
• Prevention research: Several studies studied the influence of vitamin E on the prevention of cognitive impairment in healthy elderly people. The results of these studies were ambiguous, and some of them showed that vitamin E did not have a significant effect on cognitive functions, while others showed that it could have a small protective effect.

It is important to note that in most clinical trials, alpha-tocopherol was used, the most common form of vitamin E. However, studies show that other forms of vitamin E, such as tocotrienols, can have more pronounced neuroprotective properties.

VII. Vitamin E action mechanisms in the brain: molecular paths

The mechanisms with which vitamin E affects cognitive functions is multifaceted and include several molecular pathways.

• Antioxidant Protection: Vitamin E neutralizes free radicals and protects neurons from oxidative stress. It is built into cell membranes and prevents lipid peroxidation, maintaining the integrity of membranes and the function of neurons.
• Anti -inflammatory action: Vitamin E suppresses inflammatory processes in the brain, reducing the production of pro -inflammatory cytokines and other inflammation mediators. This helps to protect neurons from damage caused by inflammation.
• Gene expression regulation: Vitamin E can affect the expression of genes associated with cognitive functions, such as the genes involved in neurogenesis, synaptic plasticity and antioxidant protection.
• Modulation of neurotransmissions: Vitamin E can modulate neurotransmission, improving the transmission of signals between neurons. He can affect the release of neurotransmitters, such as acetylcholine and glutamate, and on the activity of neurotransmitter receptors.
• Improving blood supply to the brain: Vitamin E can improve the blood supply to the brain, expanding blood vessels and reducing the risk of blood clots. This provides neurons with oxygen and nutrients necessary for their normal function.
• Anti -amyloidogenic action: Some studies show that vitamin E can reduce the formation of amyloid plaques characteristic of Alzheimer’s disease. He can inhibit the aggregation of beta amyloid and contribute to its removal from the brain.
• The neuroprotective effect of tocotrienols: Tokotrienols, especially alpha-Tokotrienol, have unique neuroprotective properties. They can protect neurons from exteitotoxicity (damage caused by excessive stimulation of glutamate), stimulate neurogenesis and improve neurons survival.

VIII. The role of various forms of vitamin E (tocopherols and tocotrienols)

As mentioned earlier, vitamin E exists in eight different forms: four tocopherols and four tocotrienals. Each form has various biological activity and distribution in the body.

• Alfa-Tokoferol: This is the most common and most studied form of vitamin E. It is the main antioxidant in blood plasma and plays an important role in protecting cell membranes from oxidative stress. Alpha-tocopherol also participates in the modulation of immune function and regulation of genes expression.
• Other Tokoferols (beta, gamma, delta): These tocopherols also have antioxidant activity, but are less effectively held in the body than alpha-tocopherol.
• Tokotrienols (alpha, beta, gamma, delta): Tokotrienols have unique neuroprotective properties that can exceed the properties of tocopherols. They have a higher antioxidant activity in some systems and can protect neurons from exteitotoxicity, stimulate neurogenesis and improve neurons survival. Alpha-Tokotrienol is especially well studied in the context of neuroprotection.

Some studies show that tocotrienols can be more effective in protecting against cognitive impairment than tocopherols. However, additional studies are needed to confirm these results and determine the optimal dose and form of vitamin E for the prevention of cognitive impairment.

IX. Sources of vitamin E in food

Vitamin E is contained in various foods, both plant and animal origin.

• Vegetable oils: Vegetable oils, such as sunflower, safflore, soy, corn and wheat germ oil, are good sources of vitamin E. Wheat germs contain a particularly high amount of vitamin E.
• Nuts and seeds: Nuts and seeds, such as almonds, hazelnuts, peanuts, sunflower seeds and pumpkin, are also good sources of vitamin E.
• Green sheet vegetables: Green leaf vegetables, such as spinach, broccoli and manhold, contain vitamin E, although in smaller quantities than vegetable oils and nuts.
• Fruits: Some fruits, such as avocado, mango and kiwi, contain vitamin E.
• Enriched products: Some products, such as cereals and margarine, are enriched with vitamin E.

It is important to eat a variety of foods to provide sufficient consumption of vitamin E of different sources.

X. Dosage and safety of vitamin E

The recommended daily vitamin E is 15 mg (22.4 IU) for adults. Most people get enough vitamin E with food. However, some people may need vitamin E additions, for example, people with fat absorption disorders or people who observe strict fat diets.

It is important not to exceed the upper permissible limit of vitamin E consumption, which is 1000 mg (1500 IU) per day. High doses of vitamin E can increase the risk of bleeding and other adverse outcomes.

Before taking the additives of vitamin E, it is recommended to consult a doctor, especially if you have any diseases or you take medications that deliver blood.

XI. Interaction of vitamin E with other nutrients

Vitamin E interacts with other nutrients, which can affect its effectiveness and safety.

• Vitamin C: Vitamin C is a water -soluble antioxidant that can regenerate vitamin E after it has neutralized a free radical. Joint consumption of vitamin E and vitamin C can enhance their antioxidant protection.
• Selenium: Selenium is a mineral that is a component of glutathioneperoxidase, an important antioxidant enzyme. Vitamin E and selenium act synergically in the protection of cells from oxidative stress.
• Omega-3 fatty acids: Omega-3 fatty acids are useful fats that have an anti-inflammatory effect. Vitamin E can protect omega-3 fatty acids from oxidation.
• Vitamin K: Vitamin E in high doses can affect blood coagulation and interact with vitamin K. People taking medications that thinning blood should be careful when taking vitamin E.

XII. Other lifestyle factors affecting cognitive functions

In addition to vitamin E, many other lifestyle factors affect cognitive functions.

• Healthy diet: A balanced diet rich in fruits, vegetables, whole grain products and healthy fats is important for maintaining brain health.
• Regular physical activity: Regular physical activity improves blood supply to the brain and promotes neurogenesis.
• Mental activity: Maintaining mental activity, for example, by reading, solving puzzles or studying new skills, can help maintain cognitive functions.
• Social activity: Maintaining social ties and participation in public life can reduce the risk of cognitive violations.
• Sufficient sleep: A sufficient sleep is necessary for the restoration and consolidation of memory.
• Stress management: Chronic stress can negatively affect cognitive functions. It is important to learn how to effectively manage stress.
• Refusal of smoking and moderate alcohol use: Smoking and excessive alcohol consumption increase the risk of cognitive impairment.
• Control of vascular risk factors: Control of high blood pressure, high level of cholesterol and diabetes can reduce the risk of vascular dementia and Alzheimer’s disease.

XIII. Future research areas

Despite significant progress in the study of the role of vitamin E in the prevention of cognitive impairment, additional studies are needed to obtain more clear and convincing data.

• Clinical trials using various forms of vitamin E: It is necessary to conduct clinical trials using various forms of vitamin E, including tocotrienols, to determine the most effective form and dose for the prevention of cognitive impairment.
• The study of vitamin E action mechanisms at the molecular level: A deeper study of vitamin E action mechanisms is necessary at the molecular level in order to better understand how it protects the brain from damage and improves cognitive functions.
• Research with people with various genetic profiles: It is necessary to conduct research with the participation of people with various genetic profiles in order to determine who can get the greatest benefits from taking vitamin E to prevent cognitive impairment.
• Studying the interaction of vitamin E with other nutrients and lifestyle factors: It is necessary to study the interaction of vitamin E with other nutrients and lifestyle factors in order to develop complex strategies for the prevention of cognitive impairment.
• Development of new methods for assessing the effectiveness of vitamin E: It is necessary to develop new methods for assessing the effectiveness of vitamin E in the prevention of cognitive impairment, such as biomarkers of oxidative stress and neuro.

XIV. Conclusions and prospects

Vitamin E plays an important role in protecting cells from oxidative stress and has potential neuroprotective properties. Epidemiological studies and clinical trials gave ambiguous results regarding its effectiveness in the prevention of cognitive impairment. However, some studies indicate the potential protective role of vitamin E, especially in slowing the progression of Alzheimer’s disease and improving cognitive functions in people with LKNs.

Additional studies are needed to determine the optimal form, dose and terms for taking vitamin E for the prevention of cognitive impairment, as well as to identify people who may be most beneficial from its use.

It is currently recommended to eat a variety of foods rich in vitamin E and lead a healthy lifestyle to maintain brain health and reduce the risk of cognitive impairment.