An enduring, vexing question that occurs to everyone who has a friend or family member afflicted with Alzheimer’s is ‘Is Alzheimer’s Inherited?’. Alzheimer’s disease, which got its name in 1906 from a German doctor, Alois Alzheimer, who identified it, is a fearful infirmity that afflicts persons primarily over 65-years-old. Dr. Alzheimer studied a 51-year-old woman afflicted with deep dementia. He noticed changes in personality, loss of memory and difficulty in managing space around her and time. After she died four years after the study’s start, Dr. Alzheimer found it was possible to detect degeneration of certain areas of her brain.
Although Alzheimer’s is the most common type of dementia for elderly people worldwide, not all dementia cases are related to Alzheimer’s disease. Research shows that between 50% and 70% of dementia cases among seniors is actually Alzheimer’s disease, characterized by progressive deterioration of mental and physical functions.
About 36 million persons are afflicted globally
More than 35.6 million persons worldwide are afflicted with Alzheimer’s. By 2050, the rate of growth in the number of people afflicted by it is expected to rise by 10 million persons annually. The World Alzheimer Report says that in 2015 there were 46.8 million with Alzheimer’s disease worldwide, with 58% of them living in poor areas.
Alzheimer’s disease is not infectious or contagious, but the compelling question is whether it is inherited. A first important thing to note is that there are two recognized types of Alzheimer’s disease:
• When the symptoms appear in old age (late onset Alzheimer’s)
• When the symptoms appear at a young age (early onset Alzheimer’s) (Early onset Alzheimer’s affects a few families and is inherited.)
The most common signs of Alzheimer’s disease are:
Changes in personality,
Difficulty in recognizing people, places and objects,
Difficulty in performing common tasks, such as cooking, wash, talking, walking or dressing,
Difficulty in remembering directions and finding the way home,
Misplacing and losing things,
Difficulty in interacting with others,
Changes in sense of humor.
Alzheimer’s has broad impact on mind and body
Gradually, people afflicted with Alzheimer’s lose competence and power in their brain and body. They encounter difficulty in working and maintaining relationships and friendships.
According to the National Institute of Health, persons with Alzheimer’s can survive for eight to 10 years after the first symptoms appear.
Life with a person afflicted by Alzheimer’s is difficult but can be eased by certain steps, such as speaking loudly, repeating things or questions and using simple sentences.
Alzheimer’s destroys the body and brain and is caused by destruction of neurons, which makes the brain unable to pass information to other neurons. Alzheimer’s is associated with plaque and tangles in the brain, which affects memory, thinking and movement. The destroyed neurons die. Gradually, the whole brain is affected by this progressive destruction. Often the first symptoms are confused with normal aging. Examination of brain tissue is required to confirm the diagnosis.
No present cure for and no known causes of Alzheimer’s
For now, there is no way to stop or reverse the disease.
The exact causes of Alzheimer’s disease are unknown, but it is known that genes play an important role. What are genes and how do they work? Genes are the basic block of our DNA and each one brings special information. The configuration of the genes establishes each person’s unique DNA. All persons are born with 46 chromosomes in pairs of 23 each. Scientists have shown that the genes numbered 1, 14, 19 and 21 are linked to Alzheimer’s disease. However, that does not answer the main question, “Is Alzheimer’s Disease Inherited?”. The answer is elusive.
Most scientists say Alzheimer’s is not inherited, but some Alzheimer’s cases are caused by a mutation of these genes passed by parent to child. Mutation of specific genes increases the risk of Alzheimer’s. For example, Chromosome 21 is responsible for Down’s syndrome, and scientists have shown that persons with Down’s syndrome have a greater risk of developing Alzheimer’s. It is not clear why.
Is Alzheimer’s Inherited? Scientists say Alzheimer’s not inherited in 99% of cases
It is important to note that in the 99% of cases, Alzheimer’s is not inherited. Having a certain set of genes can increase the risk of Alzheimer’s in the remaining one percent. Under one theory, it can be inherited through the maternal line. Some scientists, such as Dr. Lisa Marconi, say persons whose mothers had Alzheimer’s with a high level of amyloid protein have a greater risk of being affected compared to others with a paternal instance of Alzheimer’s or with families with no Alzheimer’s history. The small number of inherited cases, however, usually appear in early onset than those who show no signs of inherited Alzheimer’s. The age range for early onset Alzheimer’s is between 30 and 60 years old.
The only certain thing about the risk of Alzheimer’s is that age is the single most important risk factor. The most common gene associated with Alzheimer’s disease in elder persons is called apolipoprotein E (APOE). studies show this gene:
• APOE E2 seems to reduce the risk,
• APOE E4 seems to increase the possibility of Alzheimer’s disease,
• E3 seems to have no effect at all.
All persons take one gene from their mother and another from their father. If a person has two copies of APOE E4, the possibility of developing Alzheimer’s is greater than if two copies of APOE E2 are inherited. It is important that even in this case, it is not certain that persons with two copies of APOE E4 exhibit Alzheimer’s and people with two copies of APOE E2 do not.
Another study showed that in Nigeria there is no relationship between APOE E4 and late onset Alzheimer’s disease because APOE is one of many genes that contribute to the risk of developing Alzheimer’s. Instead, it is also important that having this pack of genes is not enough to exhibit Alzheimer’s symptoms because lifestyle, stress and food are also important.
Another gene involved in high risk of Alzheimer’s disease is the mutated TREM2 (an immune receptor found in brain microglia). The mutation of this gene could be responsible for increasing the risk of being afflicted by three to five times. Other genes suspected of being involved with Alzheimer’s is the ABCA7 which is linked to cholesterol. Blood tests detect if a person has one of these genes.
Evidence that ethnic, cultural and lifestyle factors play role
American scientists have put forward a theory that Alzheimer’s may be linked to certain ethnic groups. They showed that in a five-year study more than the half the Caucasians with Alzheimer’s disease died. However, 60% of Native Americans, Africans, Latin Americans and Asians survived. They concluded that genetic and cultural characteristics also play a role in Alzheimer’s disease. These observations, studies and theories agree on the following important things:
First, it is impossible to establish a single reason responsible for Alzheimer’s disease. It is more likely that other reasons are also risk factors, such as head injuries, depression, diabetes or hypertension, even if it is not known why.
Second, choosing our food and lifestyle correctly helps the brain remain active and strong.
The logical consequence of these studies is that everyone can be affected by Alzheimer’s as they grow older. It is difficult to prevent or avoid, but historical and personal circumstances can influence the likelihood of onset of the disease.
The second most commonly asked question is, “Is it possible to prevent or treat Alzheimer’s disease?”
As said above, it is not possible to treat Alzheimer’s disease but some habits and medicines can be useful in slowing its progression. Other behavior can increase the risk. Establishing good health habits and taking particular medicines or vitamins do not cure the disease but help reduce some symptoms. That is the first line of defense.
Good and bad habits to start or stop
List of some good habits that help prevent Alzheimer’s disease:
• Reduce intake of saturated fat,
• Make sure fruits and vegetables are in the daily diet,
• Take Vitamin E or B12, with your doctor’s advice,
• Avoid food supplements that are rich in iron and copper unless your doctor prescribes them,
• Do physical exercise each day to help the heart and brain,
• Ask a doctor about adding food supplements rich in Omega 3, Vitamin C and Selenium.
Some bad habits to avoid to decrease the risk of Alzheimer’s:
• Sleep well and avoid chronic sleep deprivation,
• Stop smoking,
• Avoid or reduce high stress.
FDA suggests two medications that impede Alzheimer’s growth
As for medications, the U.S. Food and Drug Administration has approved the following two types of medications that can help slow the progress of Alzheimer’s symptoms, even though they don’t stop or cure it:
• Cholinesterase inhibitors, such as Aricept, Razadyne and Exelon
• Memantine, as Namenda.
Both types are used to treat cognitive problems, such as memory loss, confusion and difficulties in thinking.
In summary, when we ask the question: “Is Alzheimer’s Inherited?”, we must remember that there is no strong evidence that family genes (except involving early onset Alzheimer’s), places where people live, ethnic group or employment are directly connected with Alzheimer’s disease. It has been observed that persons who continue using their brain facilities have less risk of being affected.
It is also true that those who participate in physical activity, take care of what they eat and drink, stay active socially and continue receiving cognitive stimulation may reduce the onset of Alzheimer’s disease during their later years.
In coming years, science may provide specific ways to treat Alzheimer’s. We can also hope new medicines will be found to prevent or stop progressive degeneration. Until now, the only suggestions that scientists and doctors provide is to understand family hereditary factors for early onset predictions of Alzheimer’s and in such cases to conduct regular checkups. Caring for one’s health and maintaining a healthy lifestyle can play a role in decreasing the Alzheimer’s disease risk and assuring a longer life and better quality of life in the golden years.