Study Published in Nature Digital Medicine Shows Potential of Machine Learning and Augmented Reality-based Digital Biomarkers in Alzheimer’s Detection

Top Alzheimer's Disease Risk Factors

March 14, 2023Neelem Sheikh

Researchers and neurologists currently believe that Alzheimer’s disease is not caused by a single factor but rather is multifactorial. Alzheimer’s disease is caused by a combination of factors, including age, genetics, environment, and lifestyle. Together, these factors are believed to cause beta-amyloid plaques and neurofibrillary tangles to build up in various brain regions, ultimately resulting in the death of neurons and progressive neurocognitive decline.

For healthcare providers, providing education about Alzheimer’s disease risk factors is a crucial step in promoting brain health awareness and enabling patients to take charge of their brain health. This article will provide an overview of established risk factors for Alzheimer’s disease and all-cause dementia.

Alzheimer’s Disease Risk Factors

With the growing awareness surrounding the importance of Alzheimer’s disease prevention and early detection, research efforts continue to grow our understanding of the factors involved in the development of Alzheimer’s. Although it is unclear what triggers the pathological changes in the brain, researchers have discovered several factors that may increase the risk of developing Alzheimer’s disease.

The top Alzheimer’s disease risk factors are advancing age, genetics, and family history, with advancing age being the greatest risk factor. According to the Alzheimer’s Association, after age 65, the risk of Alzheimer’s disease doubles every five years. Although Alzheimer’s is generally associated with older adults, it can also develop in individuals under the age of 65 (early-onset Alzheimer’s disease).

Researchers have also discovered several genetic risk factors for Alzheimer’s disease. Both risk and deterministic genes have been found for Alzheimer’s disease. 

Alzheimer’s Disease Risk Genes

Genetic variants on the APOE gene on chromosome 19 have been found to increase the risk of developing Alzheimer’s disease. APOE comes in several forms, or alleles: APOE2, APOE3, and APOE4. Individuals inherit two APOE alleles, one from each biological parent. 


APOE2 is associated with a decreased risk of developing Alzheimer's disease, APOE4 is associated with an increased risk, and APOE3 is not believed to influence risk.

Alzheimer’s Disease Deterministic Genes

Although Alzheimer’s caused by deterministic genes is estimated to account for less than 1% of all Alzheimer’s cases, several deterministic genes have been linked to early-onset Alzheimer’s.


This includes amyloid precursor protein (APP) on chromosome 21, presenilin 1 (PSEN1) on chromosome 14, and presenilin 2 (PSEN2) on chromosome 1.

Having a family history of Alzheimer’s disease is also a known Alzheimer’s disease risk factor. Although family history is influenced in part by genetics, it’s also influenced by lifestyle and environment, as families often have similar lifestyles and environments. Individuals who have a parent or sibling living with Alzheimer’s disease are at an increased risk of developing Alzheimer’s.

Alzheimer’s Disease-Related Dementia Risk Factors

Many neurological diseases, including Alzheimer’s disease, cause dementia. Alzheimer’s disease is the most common cause of dementia, accounting for approximately 60% to 80% of all dementia cases. With this in mind, it’s not only important to educate patients on the risk factors for Alzheimer’s disease itself but also the risk factors for all-cause dementia—especially considering many of these factors are modifiable.

The most recent report of the Lancet Commission on dementia prevention, intervention, and care suggests there are 12 potentially modifiable risk factors for all-cause dementia. In their life-course model of dementia prevention, they categorize risk factors by three stages of life: early life, midlife, and later life. They estimate that modifying these risk factors may prevent or delay up to 40% of dementia cases.

Early Life Risk Factors (age <45 years)

  • Lower educational attainment

Midlife Risk Factors (age 45 to 65 years)

  • Hearing loss

  • Traumatic brain injury

  • High blood pressure

  • Alcohol consumption (>21 units/week)

  • Obesity (body mass index ≥ 30)

Later Life Risk Factors (age >65 years)

  • Smoking

  • Depression

  • Social isolation

  • Physical inactivity

  • Diabetes

  • Air pollution 

*Note: Some of the above factors are not always entirely modifiable. For example, where you grow up and the level of education you can attain may not be modifiable. Similarly, genetic factors are at play for hypertension and diabetes, meaning these risk factors are not always modifiable.

The Lancet’s life-course model speaks for itself—it’s never too early or too late for patients to start prioritizing their brain health by making meaningful changes. Educating patients on Alzheimer’s disease risk factors provides them with the tools they need to support their brain health and reduce their risk of dementia.

Altoida’s mission is to accelerate and improve drug development, neurological disease research, and patient care. To learn more about our precision neurology platform and app-based medical device, contact us today.

Contact Us Today