The strongest risk factors for developing dementia or Parkinson's disease are not solely genetic, but genetics can play a significant role. However, if there is a genetic predisposition, the situation changes. 

Hello, I am Professor Kim Yoon-jung from the Department of Neurology at Yongin Severance Hospital. I primarily treat patients with dementia, Parkinson's disease, and other difficult degenerative brain disorders. Many caregivers of patients with dementia or Parkinson's disease worry about the possibility of genetic inheritance. I will discuss whether dementia and Parkinson's disease are hereditary and provide some lifestyle guidelines to help prevent such degenerative brain diseases.

Human genetic information is contained in DNA, which consists of about 20,000 genes. These genes hold all the basic information about how our bodies are formed and how they function normally. However, when there are mutations in these genes...

Genes can malfunction, which can later lead to diseases. This is how you can understand it. The development of treatments is focused on diseases caused by dementia or Parkinson's disease. Research is being conducted around genes, and many genes related to degenerative brain diseases have been identified so far. The answers to this question can be both yes and no. The strongest risk factor for developing dementia or Parkinson's disease is age, which may lead one to think it is unrelated to genetics. However, in the case of dementia, about 5% of cases are familial, and for Parkinson's disease, approximately 10 to 15% have a family history. This fact suggests that there may be a genetic cause. Genes that cause familial diseases are referred to as disease-causing genes or pathogenic genes. In reality, patients with these pathogenic genes are very rare, and such cases are sometimes classified as rare diseases.

Recently, a risk factor gene has been discovered in patients who develop degenerative brain diseases without any family history. Individuals with this risk factor gene have about a fivefold increased probability of developing these conditions compared to those without genetic mutations in the risk factor. In some patients, genetic testing can predict the onset or progression of degenerative brain diseases. Among the causative genes, the APOE gene test is quite common. This genetic test provides important information that can predict the course of the disease. For example, in patients with mild cognitive impairment who have memory problems, if they possess the APOE ε4 genotype, there is a very high likelihood that they will eventually progress to Alzheimer's dementia. Conversely, patients with the APOE ε2 genotype have a protective effect against dementia, resulting in a lower probability of developing Alzheimer's disease.

In the case of Parkinson's disease, having the PARK2 gene can lead to developing the disease at a very young age. However, the progression of the disease is quite mild, and even if one has the disease for a long time, it does not necessarily progress to dementia. Deciding which genes to test is a highly specialized area, so it is advisable to consult with the attending physician. On the other hand, I can clearly state who should consider genetic testing. Patients with a family history of degenerative brain disorders, as well as those who develop symptoms at a relatively young age, should discuss the possibility of genetic testing with their physician. In this context, the age threshold for young is considered to be 65 years for dementia and 50 years for Parkinson's disease. There are also some individuals who are currently healthy but are concerned about their risk and wish to undergo genetic testing as a precaution.

However, this part has many considerations, so it is advisable to make a decision after consulting with the four members of the committee. Currently, degenerative brain wrinkles are not a curable disease. However, by understanding which genes cause degenerative brain diseases, we can develop drugs that can more effectively slow down or treat the disease. In the future, it is expected that treatments for degenerative brain diseases will be precisely tailored based on the genetic variations of the patient. Currently, many promising drug candidates have emerged from animal experiments, and it is anticipated that effective treatment technologies based on genetic information will be developed and applied in clinical settings. However, actual medication for patients can only occur after sufficient clinical trials on efficacy and side effects have been conducted. So far, preventing dementia or Parkinson's disease through lifestyle modifications is the best approach.

The best practices for preventing dementia include three things you should actively do, three things you should avoid, and three things you must take care of. You should engage in exercise, maintain a healthy diet, and do activities that require mental effort, such as reading, journaling, and studying. On the other hand, you should avoid alcohol, smoking, and any exercises that could lead to brain injury. Additionally, it is important to regularly undergo health check-ups to manage conditions like high cholesterol, high blood sugar, and high blood pressure. Socializing with others and participating in hobbies, as well as early screenings for dementia, are also essential.

If I had to pick the most important lifestyle habit for preventing Parkinson's disease, it would be exercise. A Mediterranean diet is recommended for preventing Parkinson's disease, which includes daily consumption of vegetables, fruits, beans, and whole grains. It is also advised to include fish, seafood, and poultry in your diet. I encourage everyone to shake off their worries about genetics.

I wish for you to prevent degenerative brain diseases through healthy lifestyle habits. Thank you.

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