The damaging effects of cholesterol have long been thought of as targeting only your heart.

But a study from the University of California Davis says high levels of "good" cholesterol and low levels of "bad" cholesterol are correlated with lower levels of the amyloid plaque deposition in the brain, which is a hallmark of Alzheimer's disease.

This isn’t the first study on the topic, but it is the first one to examine the theory in humans. In 2010, researchers in Austria found that a chronic high cholesterol diet produces brain damage in rats that is similar to that of Alzheimer's disease.

“Unhealthy patterns of cholesterol could be directly causing the higher levels of amyloid known to contribute to Alzheimer's, in the same way that such patterns promote heart disease,” study leader Bruce Reed, a professor of neurology at the University of California Davis and associate director of its Alzheimer's Disease Center, said in a release.

The current recommendations for healthy levels of cholesterol are 60 mg/dL of HDL, or “good” cholesterol. That level is thought to be protective against heart disease. LDL, or “bad” cholesterol levels shouldn’t exceed 100 mg/dL to promote heart health.

Study co-author Charles DeCarli, also a professor of neurology at UC Davis and director of its Alzheimer's Disease Center, says the team’s findings are a "wake-up call" in that not only can people improve their chances of keeping their brains healthy later in life by controlling their blood pressure, but controlling cholesterol may have a similar effect.

According to the American Heart Association, the following lifestyle changes may help you reduce levels of "bad" cholesterol and maintain a healthy balance of overall cholesterol that’s good for your heart and your head:

Watch what you eat. A heart-healthy diet that’s low in saturated fats and sugar and high in vegetables, fruits, and lean meats or fish can help regulate cholesterol levels.

Get moving. Participate in at least 150 minutes a week moderate-intensity aerobic physical activity, and more than two days a week of muscle strengthening activities.

Kick butts. Avoid tobacco smoke, including second-hand smoke.

To learn more on this topic:
How Diabetes Affects Your Brain
Link Found Between Prediabetes and Alzheimer's
Treating High Cholesterol: A Heart-Healthy Diet