Obesity, depression, and high blood pressure all have negative health ramifications — but a new study has revealed these conditions may also increase your risk of developing Alzheimer’s disease

Researchers from the University of California, San Francisco studied the similarities between Alzheimer’s patients in order to flag risk factors so others can lower their chances of disease. The findings, published in the Journal of Neurology, Neurosurgery & Psychiatry, reveal the top risk factors that are responsible for two-thirds of the world’s Alzheimer’s cases. The research team analyzed more than 300 studies that focused on Alzheimer’s disease-specific risk factors and narrowed it down to the nine they believed to be the most common:

  1. Obesity
  2. Carotid Artery Narrowing
  3. Low Education
  4. Depression
  5. High Blood Pressure
  6. Frailty
  7. Smoking Habits
  8. High Levels of Homocysteine (amino acids)
  9. Type 2 Diabetes (in Asian populations only)

Researchers also discovered that the best way to protect the brain was to follow a healthy diet like the Mediterranean diet, which is rich in fatty fish (full of omega-3s), vegetables, and whole grains. What's more is certain vitamins and hormones designed to reduce high blood pressure can help lower the risk of developing Alzheimer’s, too. 

This new medical discovery should shed some light onto the underlying causes of Alzheimer’s, and eventually help researchers determine why these specific risk factors make people more susceptible to disease.

It was 1906 when Dr. Alois Alzheimer first noticed abnormal clumps of tissue and tangled fibers in the brain of a woman who died of an unusual mental illness. Her symptoms, like Alzheimer’s patients today, included memory loss, language problems, and unpredictable behavior, according to the National Institute on Aging. Since then, doctors haven’t discovered a cure for the irreversible, progressive brain disorder that is known to destroy memory, thinking skills, and the ability to carry out simple tasks. In most people, symptoms first appear in their mid-60s.

According to the National Institutes of Health, Alzheimer’s disease is the sixth leading cause of death in the United States, with more than five million Americans currently diagnosed. Unless doctors and researchers figure out how to treat or prevent the disease, the number of cases will continue to grow significantly.

Source: Yu JT, Xu W, and Tan L, et al. Meta-analysis of modifiable risk factors for Alzheimer’s disease. Journal of Neurology, Neurosurgery & Psychiatry. 2015.