Lesser-known risk factors for Alzheimer’s disease

Some risk factors for Alzheimer’s are well known^1,2

A lot of the most common risk factors for Alzheimer’s are probably familiar to you, but there are some little-known things that may also increase your chances of developing Alzheimer’s. Learning about these factors can help you have a better overall picture of what may cause the disease.

Learn about lesser-known risk factors for Alzheimer’s^3-11

• Education level – Experts say that, in general, people with higher levels of education have a lower risk of developing Alzheimer’s. However, higher levels of education do not protect people from cognitive decline once memory loss begins. Once a person’s memory starts to get worse, it’s probably going to get worse at the same rate, regardless of the person’s education
• Diabetes – Many experts have studied the relationship between Alzheimer’s and diabetes, but there is still much that is unknown about the connection. What is pretty well understood is that people with type 2 diabetes are at higher risk for eventually developing Alzheimer’s disease. One reason for this link may be the way diabetes affects the brain’s ability to turn glucose (a type of sugar) into fuel
• Heavy smoking – Smoking is a well-known risk factor for cancer and heart disease, and it can also lead to an increased chance of developing Alzheimer's. A study found that people (aged 50-60 years) who smoked at least two packs a day were more likely to be diagnosed with Alzheimer’s later in life. Other people in the study who quit smoking or smoked less than half a pack per day were less likely to develop the disease
• Depression – Depression is common in people who already have Alzheimer’s, and a new study found that it can also increase the risk of developing the disease. People who had depression earlier in life were significantly more likely to be diagnosed with Alzheimer’s later in life. If the depression occurred before the age of 60, they were almost 4 times more likely to develop Alzheimer’s
• Cancer – This is actually the opposite of what you might think. Experts found that cancer survivors can have a lower risk of eventually being diagnosed with Alzheimer’s. Depending on the type of cancer, it can be a 9% to 51% decrease in risk. Receiving chemotherapy, a common treatment for cancer, was also associated with a lower risk of developing Alzheimer’s. More studies need to be done to determine the exact nature of the relationship between cancer and Alzheimer’s
• Hygiene – This is another risk factor that is the opposite of what you might think. A recent study found that people in countries that have better hygiene are at higher risk of developing Alzheimer’s. This study adds Alzheimer’s to a long list of other diseases that are connected to the “hygiene hypothesis.” The hygiene hypothesis is a theory that states people – including many in developed countries like the United States – who are exposed to fewer bacteria, viruses, and microorganisms have worse immune systems and are at greater risk for developing certain diseases
• Breast-feeding – A recent study showed that women without a family history of dementia who breast-feed their children may have a lower risk of developing Alzheimer’s. A possible reason for this connection may be that breast-feeding restores insulin tolerance, which is reduced during pregnancy. Insulin resistance is common in people with Alzheimer’s. While the results of the study are interesting, more research needs to be done to determine if breast-feeding truly lowers Alzheimer’s risk

Learn more about risk factors for Alzheimer’s.