November 2, 2026, 3:13 am | Read time: 4 minutes
Many people fear cognitive decline in old age. However, research now presents a much more nuanced picture: Dementia is not always an inevitable consequence of aging. Those who recognize certain risk factors and take targeted action can do much to preserve their brain health for as long as possible.
The Brain Changes Throughout Life
With around 86 billion nerve cells, the brain is the most complex organ in the human body. It controls memories, language, movements, and our personality. At the same time, it continues to change throughout life.1
For a long time, dementia was considered an almost unavoidable accompaniment to aging. Today, scientists believe that the chances of living a long life with good cognitive health are significantly greater than previously thought.
What Lies Behind Dementia
Dementia describes the progressive loss of cognitive abilities. It affects memory, orientation, language, and judgment, among other things. The most common form is Alzheimer’s disease.2
In Alzheimer’s, certain proteins, known as amyloid and tau proteins, accumulate in the brain. As a result, nerve cells gradually die off. This process often begins many years before the first visible symptoms appear. “We can detect the biological signs of dementia in the blood up to 15, 20 years in advance,” says Prof. Emrah Düzel, director of the Institute for Cognitive Neurology and Dementia Research in Magdeburg.
These Risk Factors Can Be Influenced
According to calculations by the renowned Lancet Commission, 45 percent of all dementia cases can be linked to 14 risk factors that individuals can at least partially influence.3
These include high blood pressure, diabetes, obesity, smoking, lack of exercise, depression, hearing loss, social isolation (loneliness), excessive alcohol consumption, and air pollution. Reducing or treating these factors can lower the risk of developing dementia later.
How Important Are Genes?
Genetic factors do play a role, but they are not solely decisive. According to Prof. Düzel, even all known genetic risk factors explain only a relatively small part of the Alzheimer’s risk.
People with a family history can also take active measures. This is especially important for carriers of the so-called ApoE4 gene. According to Prof. Düzel, they should “pay special attention to cholesterol levels, diet, and exercise.”
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What Research Recommends for Prevention
A key role is played by the consistent treatment of medical risk factors. These include blood pressure, blood lipid levels, blood sugar, and untreated hearing problems. It is equally important to avoid smoking and excessive alcohol consumption. Healthy lifestyle habits can help maintain brain performance for as long as possible.
Prof. Düzel recommends “two hours of moderate activity a week,” meaning exercise that leaves you slightly out of breath. Additionally, he considers strength training indispensable: “Not only is cardiovascular activity important, but it’s equally crucial that we engage in physical strength training and build muscle mass.”
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Why New Environments Challenge the Brain
If you want to train your brain, you don’t necessarily have to solve Sudoku puzzles or fill out crosswords daily. According to Prof. Düzel, there’s a more effective alternative: exploring new places and unfamiliar environments. “Trying to find your way in a new environment is the best thing you can do,” says the expert. Navigating unfamiliar situations challenges various brain regions simultaneously and can actively train cognitive abilities.
The 3 Most Important Factors for a Healthy Brain
If Prof. Düzel could only name three measures to significantly reduce the risk of dementia, his choice would be clear: “Exercise, social contacts, meaning avoiding social isolation–and optimism,” he explains.
With this, the dementia researcher names three factors that everyone can actively promote, regardless of age. According to current research, they are among the most important building blocks for a long, mentally healthy life.