Is dementia hereditary? Understanding your family’s risk

When a loved one is diagnosed with dementia, it’s natural to wonder if the condition might run in the family. Understanding the role genetics play in dementia can help you make informed decisions about your health and the health of your loved ones.

According to the World Health Organization, dementia affects over 55 million people worldwide, with nearly 10 million new cases diagnosed annually. A recent study found that more than 2 in 5 people (42%) over the age of 55 in the US will develop dementia in their later years.

Researchers continue to explore the genetic and environmental factors contributing to dementia risk, offering hope for early detection and intervention.

Here’s what you need to know about whether dementia is hereditary and what you can do to take care of your brain health as you age.

Dementia vs Alzheimer’s disease

“Dementia and Alzheimer’s disease are terms often used interchangeably, but they are not the same,” said Cindy D. Marshall, MD, neuropsychiatrist and medical director of the AT&T Memory Center at Baylor University Medical Center. “Understanding the difference is important for proper diagnosis and treatment.”

Let’s break down the key differences between dementia and Alzheimer’s:

• Dementia is an umbrella term for a decline in cognitive abilities that interferes with daily life. The symptoms of dementia can range from a decline in memory or thinking to personality or behavior changes.
• Alzheimer’s disease is the most common cause of dementia, affecting approximately 5 million people in America. While all Alzheimer’s cases are forms of dementia, not all dementia cases are Alzheimer’s.

Is dementia hereditary?

While most cases of dementia are not hereditary, lifestyle and genetics can both influence your risk. Certain types of dementia, including Alzheimer’s disease, frontotemporal dementia and Huntington’s disease, have a clearer genetic link than others.

The genetic influence depends on the type of dementia. For instance, in rare cases of familial Alzheimer’s disease, a mutation in specific genes can be passed down from parent to child. However, most dementia cases are “sporadic,” meaning they may occur without a known genetic cause.

Dr. Marshall emphasizes that genetic testing does not predict if or when you’ll develop dementia, as most cases involve a combination of genetic, lifestyle and environmental factors.

The role of family history in dementia risk

The likelihood of inheriting dementia varies based on the type and your family history. Having a family member with dementia can increase your risk, but it doesn’t mean you’re destined to develop it.

• Alzheimer’s disease: If you have a parent or sibling with Alzheimer’s, your risk is slightly higher, especially if multiple family members are affected.
  • Early-Onset Alzheimer’s: This rare form of Alzheimer’s (occurring before age 65) can sometimes be hereditary.
  • Late-Onset Alzheimer’s: The more common form of Alzheimer’s has a weaker genetic link
• Frontotemporal dementia (FTD): This form of dementia has a stronger hereditary component. About 40% of FTD cases are linked to genetic mutations.
• Vascular dementia: While genetics can influence conditions like high blood pressure and diabetes that increase vascular dementia risk, the condition itself is less directly tied to heredity.
• Lewy body dementia: While there is usually no strong hereditary component, a family history of Parkinson’s disease or Lewy body dementia can slightly elevate risk.
• Huntington’s Disease: This genetic disorder causes dementia and motor impairments in the later stages of the disease.

For other types of dementia, having a close relative with the condition can increase your risk slightly, but lifestyle factors play a significant role in determining your overall risk.

5 ways to reduce your risk of dementia

Even with a family history of dementia, it's possible to take proactive steps to reduce your risk of dementia, potentially delaying or preventing the onset of the disease.

"As the aging population grows, the overall number of people with dementia is expected to rise,” Dr. Marshall said. “However, it is never too late to start making healthier choices."

Here are five lifestyle tips that can help reduce your risk of developing dementia:

1. Embrace healthy habits: Regular exercise, eating a balanced diet and maintaining a healthy weight can protect brain health.
2. Manage chronic conditions: Control high blood pressure, diabetes and cholesterol to reduce risk.
3. Stay mentally active: Keep your mind sharp by participating in activities that stimulate your brain, like solving puzzles, reading or picking up new hobbies or skills.
4. Prioritize your mental health: Addressing depression, stress and sleep disorders can have long-term benefits for cognitive health.
5. Avoid smoking and excessive alcohol consumption: Both habits are linked to an increased risk of cognitive decline.

While genetics may play a role in the development of dementia, they are only part of the picture. By adopting a proactive approach to brain health, you can help reduce your risk and support overall well-being—regardless of your family history. If you want to discuss ways to reduce your individual risk of dementia, find a doctor near you.