These 9 Controllable Risks Account for Majority of Dementia Cases

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Researchers reviewed 323 studies involving more than 5000 people to evaluate dementia and the conditions that increase or decrease its risk. The good news? They found 9 modifiable conditions that increase the risk of dementia.

Why is that good? Modifiable means that we can generally impact these factors by our lifestyle, diet or with medications. So, while age, family history, and genetics are outside of our control, these other nine factors were strongly connected with an increased dementia risk- and they're ones we can typically do something about.

According to research, we can exert some control, take charge of our health and perhaps significantly decrease our dementia risk by addressing these 9 factors:

1. High Blood Pressure

High blood pressure has been correlated with an increased risk of dementia. Some research also concluded that people who treated their high blood pressure medically were not at an increased risk for dementia.

2. Obesity

A high body mass index (BMI), specifically in mid-life, has been associated multiple times with a higher risk of developing dementia. Interestingly, in late life, a few extra pounds seem to have a protective effect on the brain.

3. Depression

Research has shown that depression puts people at a higher dementia risk as they age. Some studies place that risk at as much as two to four times higher. Getting treatment for depression can improve your quality of life currently as well as possibly protect your brain in the future.

4. Low Education Levels​

Several studies have looked at education levels and the presence or absence of dementia. Researchers concluded that the amount of education matters. In general, the more schooling a person has, the less likely they are to develop dementia. This phenomenon may be related to the idea of cognitive reserve —the thought of storing up knowledge and cognitive abilities which help to compensate for potential losses later.

5. Carotid Atherosclerosis

Carotid atherosclerosis is a buildup of plaque which causes the two main arteries that bring blood to the brain to narrow. This makes it harder for adequate oxygen to travel to the brain, and it can increase the risk of stroke and vascular dementia.

Many studies have found that heart conditions increase the risk of dementia. Therefore, what you do for heart health can be considered beneficial for your brain as well.

6. Type 2 Diabetes

Type 2 diabetes has been correlated multiple times with an increased risk of dementia. In fact, some researchers have even nicknamed Alzheimer's as "Type 3 Diabetes" because of the connection between the two conditions. Interestingly, this study only found a significant risk for Asian populations.

Some research has also demonstrated that higher blood sugar levels even in people without diabetes is associated with a higher dementia risk.

7. Smoking

The researchers found that smoking significantly increased the risk of dementia. Clearly, there are many other health risks related to smoking as well, including lung cancer and COPD. Interestingly, other studies have concluded that even exposure to secondhand smoke was correlated with a higher risk of developing dementia.

8. Hyperhomocysteine (High Levels of Homocysteine)

Homocysteine is an amino acid that is naturally occurring in our bodies. Too much of it, however, can increase our risk for heart conditions, blood clots, stroke and- as specifically highlighted in this review of research- dementia. Some research has shown that you can decrease your level of homocysteine by eating a diet that contains more folic acid (found in leafy green vegetables, whole grains, beans and citrus fruits) and vitamin B supplementation.

9. Frailty

Frailty, a general condition where a person is weaker, less physically active, tired, slower and less resilient, was also found to be correlated with a higher dementia risk.

One possible explanation for this is that a frail person may be less likely to be physically active, socially interactive and mentally engaged, all of which have been connected to a lower risk of dementia.

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Xu W, Tan L, Wang H-F, et al. Meta-Analysis of Modifiable Risk Factors for Alzheimer’s Disease. Journal of Neurology, Neurosurgery & Psychiatry. August 2015:2015–310548.