Alzheimer's Disease (AD)
Introduction to Alzheimer’s Disease
In 1906, a German doctor peered into a microscope. He was looking at samples of brain tissue from a woman who had recently died. The patient was only in her 50s. For years she had suffered severe memory problems and other difficulties. What the doctor saw were unusual changes in the woman’s brain. The doctor’s name was Alois Alzheimer, and the disease he described now bears his name.
What is Alzheimer’s Disease?
Alzheimer’s (AHLZ-high-merz) is a disease of the brain that causes problems with memory, thinking and behaviour. It is not a normal part of aging.
What happens in Alzheimer’s Disease
The brain has 100 billion nerve cells (neurons). Each nerve cell connects to many others to form communication networks. In addition to nerve cells, the brain includes cells specialized to support and nourish other cells. Groups of nerve cells have special jobs. Some are involved in thinking, learning and memory. Others help us see, hear, smell and tell our muscles when to move.
In Alzheimer’s disease, brain cells start to deteriorate. The body attempts to stop this process by producing a protein called amyloid. However, amyloid deposits build up in the brain, leading to further deterioration. These deposits of amyloid are referred to as “plaques” and cause the brain cells to shrivel up and form “tangles”, which in turn lead to changes in the brain structure and cause the brain cells to die. The formation of plaques and tangles also prevents the production of some important brain chemicals, called neurotransmitters (eg: acetylcholine, which is important in memory function). Over time the loss of brain cells causes the brain to shrink.
Causes of Alzheimer’s Disease
While there is no known cause for Alzheimer’s disease, some research studies have indicated that the following factors may play an important role in the development of the condition:
- Genetic factors, such as the presence of, or changes to, certain genes
- Environmental factors, such as long-term exposure to some environmental solvents (eg: pesticides, glues and paints) or infection with certain viruses or bacteria
- Lifestyle factors, such as a lack of exercise, poor-quality sleep and a diet lacking fruit and vegetables.
Researchers now believe that a combination of these lifestyle, environmental and genetic risk factors trigger an abnormal biological process in the brain that, over decades, results in Alzheimer-type dementia. Identified risk factors for developing the condition include:
- Increasing age
- Down syndrome
- History of a head injury
- Risk factors for blood vessel disease such as smoking
- Family history of Alzheimer’s disease
- High blood pressure
- High cholesterol
- Insulin resistance.
There is some evidence of a slightly higher prevalence of Alzheimer’s disease in females than males, but this may reflect their longer life expectancy.
Stages of Alzheimer’s Disease
- Early-stage Alzheimer’s
In the early stage of Alzheimer’s, a person may function independently. He or she may still drive, work and be part of social activities. Despite this, the person may feel as if he or she is having memory lapses, such as forgetting familiar words or the location of everyday objects.
Common difficulties include:
- Problems coming up with the right word or name.
- Trouble remembering names when introduced to new people.
- Challenges performing tasks in social or work settings.
- Forgetting material that was just read.
- Losing or misplacing a valuable object.
- Increasing trouble with planning or organizing.
2. Middle-stage Alzheimer’s
Middle-stage Alzheimer’s is typically the longest stage and can last for many years. As the disease progresses, the person with Alzheimer’s will require a greater level of care
At this point, symptoms will be noticeable to others and may include
- Forgetfulness of events or about one’s own personal history.
- Feeling moody or withdrawn, especially in socially or mentally challenging situations.
- Being unable to recall their address or telephone number or the high school or college from which they graduated.
- Confusion about where they are or what day it is.
- The need for help choosing proper clothing for the season or the occasion.
- Trouble controlling bladder and bowels in some individuals.
- Changes in sleep patterns, such as sleeping during the day and becoming restless at night.
- An increased risk of wandering and becoming lost.
- Personality and behavioral changes, including suspiciousness and delusions or compulsive, repetitive behavior like hand wringing or tissue shredding.
3. Late-stage Alzheimer’s
In the final stage of the disease, individuals lose the ability to respond to their environment, carry on a conversation and, eventually, control movement. They may still say words or phrases, but communicating pain becomes difficult. As memory and cognitive skills worsen, significant personality changes may occur and extensive help with daily activities may be required.
At this stage, individuals may:
- Need round-the-clock assistance with daily activities and personal care.
- Lose awareness of recent experiences as well as of their surroundings.
- Experience changes in physical abilities, including the ability to walk, sit and, eventually, swallow.
- Have greater difficulty communicating.
- Become increasingly vulnerable to infections, especially pneumonia.
Treatment of Alzheimer’s Disease
As there is no known cure for Alzheimer’s disease, treatment focuses on managing symptoms and supporting the person and their family. This may include:
- Treating medical conditions that may contribute to confusion or physical decline eg: lung disease or anaemia
- Encouraging stimulating activities in order to encourage the person to continue their normal activities as much as possible
- Providing memory aids and memory triggers such as calendars and written reminders
- Encouraging social interaction to help prevent feelings of loneliness and depression
- Contacting support groups that may be able to offer family/caregivers assistance
- Encouraging regular routine to reduce confusion
Importance of Nutrition in Alzheimer’s Disease Care
Older people suffering from dementia are at increased risk of malnutrition due to various nutritional problems, and the question arises which interventions are effective in maintaining adequate nutritional intake and nutritional status in the course of the disease. It is of further interest whether supplementation of energy and/or specific nutrients is able to prevent further cognitive decline or even correct cognitive impairment, and in which situations artificial nutritional support is justified.
Many studies have suggested that the dietary omega-3 fatty acid, docosahexaenoic acid (DHA), also limited amyloid, oxidative damage and synaptic and cognitive deficits in a transgenic mouse model with Alzheimer’s. Both DHA and curcumin have favourable safety profiles, epidemiology and efficacy, and may exert general anti-aging benefits (anti-cancer and cardioprotective.)
Although the formation of new synapses is triggered by neuronal firing, the number of synapses that form can be modulated when three circulating nutrients, uridine, DHA, and choline are administered together. In Alzheimer’s disease (AD) the need for extra quantities of the three nutrients is enhanced, both because their basal plasma levels may be subnormal (reflecting impaired hepatic synthesis), and because especially high brain levels are needed for correcting the disease-related deficiencies in synaptic membrane and synapses. This is because cellular levels of the nutrients control the saturation of key enzymes in the synthesis of the phosphatides in synaptic membranes. One of the nutrients, uridine, also affects synaptogenesis by activating synapse synthetizing receptors (P2Y) in the brain.
Nutritional care and support should be an integral part of dementia management. In all stages of the disease, the decision for or against nutritional interventions should be made on an individual basis after carefully balancing expected benefit and potential burden, taking the (assumed) patient will and general prognosis into account.