Statins are widely prescribed drugs that are effective at lowering LDL (“bad”) cholesterol. The medications interfere with an enzyme that helps the liver make cholesterol.

LDL cholesterol can form plaques on the inside walls of your arteries. These plaques, which can also include fatty substances and waste material from cells, can narrow blood vessels. Sometimes plaques build up so much that they block the flow of blood. This can lead to a heart attack or stroke. Plaques can also rupture. A large chunk that breaks free can form a clot that blocks blood flow in the artery.

Like any medication, there are potential risks, benefits, and complications with statins. A much-studied subject is whether statins increase or decrease the risk of cancer. Unfortunately, there isn’t a clear-cut answer. It does appear that statins may increase the risk of certain types of cancers. Some groups of people may also have an increased risk of cancer when taking statins.

Managing Cholesterol: Statins vs. Diet and Exercise

Statins and Cancer

In a 2008 article in Current Oncology, researchers point to studies that show a strong association between statin use and higher cancer risks in:

  • the elderly
  • people with breast cancer
  • people with prostate cancer

Statins may also be associated with tumor progression in people with bladder cancer.

These researchers believe that the connection between statins and cancer may be linked to T cells. T cells, or Tregs, are white blood cells that help fight off infection. They can also be helpful in attacking some types of cancer. Because statins lead to a constant increase in T cells, the body’s other tumor fighting immune responses may be weakened over time.

In a 2015 letter to the editor published in Journal of Clinical Oncology, researchers reviewed past medical studies of statins, cholesterol levels, and cancer. The writers suggested that LDL cholesterol, while potentially harmful to blood vessels, may be beneficial in the way it binds to microorganisms. LDL could make some microorganisms inactive. This may help prevent certain kinds of cancer, including colon cancer.

Studies have yet to prove that statins may actually cause cancer. Many of these studies found a strong association between long term statin therapy and higher rates of cancer. Those who need to take statin drugs may have other risk factors for cancer, or the drug may increase the risk. This subject will continue to be studied, especially as more and more people take statins for cardiovascular health.

Possible Anti-Cancer Benefits

Many researchers believe statin therapy may raise the risk of developing cancer or worsen existing cancer. Other studies, though, suggest that the cholesterol-lowering drugs may actually offer some cancer protection.

A 2015 study in JAMA Oncology found that statin use during androgen deprivation therapy, a treatment for prostate cancer, might help manage the cancer. A separate study, presented at the 2015 American Society of Clinical Oncology, suggests that postmenopausal women who take statins may decrease their odds of cancer mortality. Further, research published in the Journal of the National Cancer Institute found that statin use might help lower the risk of liver cancer, especially among individuals who have liver disease or diabetes.

Talk to Your Doctor

It can be confusing when studies produce a mix of results. That’s why it is important to speak with your doctor. Your doctor can help you determine if the benefits outweigh the possible risks for your situation.

The connection between statins and breast cancer risk does appear to be stronger than with other cancers. If you’re at high risk for breast cancer, particularly if there’s a family history of the disease, you may want to think twice about statin therapy.

Weight loss, regular exercise, and a low cholesterol diet may help reduce your LDL levels naturally. Your genetic makeup has a big impact on your cholesterol levels, so even a heart-healthy diet may not make a big enough difference in your LDL numbers. Fortunately, a new group of drugs called PCSK9 inhibitors are showing promise as an effective alternative to statins without some of the other side effects related to statins. These drugs may be available in a few years.

PCSK9 Inhibitors: What You Need to Know

To better understand how statins may affect your heart disease and cancer risks, talk with your doctor. You may benefit from getting a second opinion. And be sure to investigate the lifestyle choices you can make that may help bring down your LDL levels without any medication.