It may seem like common sense, but new science is finally showing that what’s good for your body is also good for your brain. Things like exercise, eating well, and keeping bodyfat in check all appear to be good things for your mind. In fact, they may even reduce the buildup of the proteins related to forgetfulness.

And while there are lots of things that are good for your brain, researchers have identified other factors that appear to be bad.

A few of them are expected (genetics for example). Others are a bit more surprising. Here are 7 that you need to be aware of.

Air Pollution

New research shows that women who live in areas with high pollution levels consisting mostly of fine particulate matter (small particles that can be inhaled) have a 92% higher likelihood of developing forgetfulness than those living in climates with cleaner air.

Women who had the APOE4 gene (a genetic variation that increases the risk for forgetfulness) showed the strongest predisposition. And according to the study’s authors, if this trend holds true for the general population, air pollution may in fact be responsible for up to 21% of all forgetfulness cases.

Poor Sleep

Sleep is a lot more important for brain health than once thought. Lack of sleep can lead to brain fog the following day, but clinical studies also show that difficulty sleeping may have a cumulative effect on the brain and may be linked to the buildup of forgetfulness-related brain proteins.

Scientists believe that with exercise it’s possible to loosen the amyloid plaques in the brain, but good, healthy sleep is necessary to actually rid the body of them. “Sleep is absolutely essential for taking out the garbage and keeping your brain healthy over time,” says Dr. Isaacson.

Difficulty Smelling

The ability for someone to recognize familiar smells may be a good indication as to whether they may develop forgetfulness.

A recent clinical study published in the Annals of Neurology discovered that volunteers who had difficulty identifying certain smells like menthol, clove, strawberry, and lemon seemed to be at an increased risk of forgetfulness.

According to Dr. Isaacson, “When someone can’t distinguish between different smells, it may absolutely be a signal that forgetfulness disease is brewing,” (It can also be an early sign of Parkinson’s disease and other neurological problems, he continued.)

According to brain health experts, something as inexpensive, simple and easy to implement like a scratch-and-sniff test could be a great way to screen people early on.

Your Eating Habits

According to Dr. Isaacson one of the best and easiest ways to reduce your risk of forgetfulness is to simply eat an early dinner and not eat again until the next morning.

He says, “fasting for a minimum of 12 hours, as well as eating fewer calories overall, may be a way to promote brain health as we age.”

By restricting calories overnight, you trigger your body to release ketones.

“It helps you fuel the brain with something that’s not only more efficient from an energy-burning standpoint, but that may have an anti-aging effect as well”, he continued.

Previous Concussions

For people with a predisposition to forgetfulness due to family history, any type of head trauma can accelerate the brain changes and cognitive decline associated with the disease.

A recent study in the journal Brain, showed that young to middle-aged adults who’ve had at least one concussion and had a genetic predisposition to forgetfulness had less grey matter in key areas of the brain associated with forgetfulness, compared to a control group.

They also had each participant perform a recall test where they performed worse than the control group. These findings suggest that the trauma may play a key role in memory function.

Researchers are hoping to use these findings in efforts to identify people at an earlier age who are at risk for forgetfulness.

Loneliness

According to a study published in JAMA Psychiatry, senior citizens who were classified as being lonely were 7.5 times more likely to develop amyloid protein clusters.

While the connection is clear experts are still not sure which comes first—if the symptoms of forgetfulness cause people to feel lonely and left out, or if feeling lonely actually contributes to the development of forgetfulness—their suspicions are that they may both be true.

High Blood Pressure

A recent study published in the journal regarding forgetfulness appears to be counterintuitive. Their findings suggest that when hypertension begins in old-age it appears to reduce forgetfulness symptoms.

Dr. Isaacson explains, “As we get more frail, having a reserve of blood pressure may actually be protective.”

While these findings are interesting, researchers caution that high blood pressure in young and middle-aged adults can actually increase the risk of forgetfulness in later life.

"Knowing your numbers when it comes to blood pressure, cholesterol, and body mass index—and talking with your doctor about how you can optimize those numbers—is still one of the most important things you can do," says Dr. Isaacson.