Cholesterol is essential for cell membranes, steroid hormones, and vitamin D, but high LDL cholesterol contributes to atherosclerosis and raises heart attack and stroke risk. Saturated and trans fats - not dietary cholesterol alone - are the main dietary drivers of LDL for most people. Lower risk through a heart-healthy eating pattern, exercise, weight control, and, when needed, medications prescribed by a clinician.

What cholesterol does

Cholesterol is a waxy, fat-like molecule the body makes and needs. The liver produces most cholesterol, and cells use it to build membranes, make steroid hormones (including estrogen and testosterone), synthesize vitamin D, and form bile acids that help digest dietary fat.

Good vs. bad: HDL and LDL

Cholesterol travels in the bloodstream inside lipoprotein particles. Low-density lipoprotein (LDL) tends to deliver cholesterol to tissues and can deposit it in artery walls, contributing to atherosclerosis (plaque build-up). High-density lipoprotein (HDL) helps remove excess cholesterol from arteries and returns it to the liver for disposal. Higher HDL and lower LDL levels are associated with lower cardiovascular risk.

What raises blood cholesterol

Dietary choices matter, but context matters too. Foods high in saturated fat - such as fatty cuts of red meat, butter, full-fat dairy, and many fried and processed foods - tend to raise LDL cholesterol. Trans fats (largely removed from the US supply but still present in some imported and specialty foods) raise LDL and lower HDL.

Many animal foods contain cholesterol (eggs, shellfish, organ meats). For most people, dietary cholesterol has less effect on blood LDL than saturated and trans fats do, but very high intake can matter in some individuals.

Historically, public guidance recommended limiting dietary cholesterol to about 300 mg per day; more recent dietary guidance has shifted to focus on overall healthy eating patterns and reducing saturated fat rather than a single numeric cholesterol limit.

Health risks

When LDL-driven plaque narrows and hardens arteries, blood flow to the heart or brain can drop, raising the risk of heart attack and stroke. Stroke remains a leading cause of long-term adult disability and a major cause of death. 1

How to lower high cholesterol

Start with lifestyle changes: choose a diet rich in vegetables, fruits, whole grains, legumes, nuts, and fish. Replace saturated fats with unsaturated fats (olive oil, canola, avocados) and avoid trans fats. Maintain a healthy weight, get regular aerobic activity, limit alcohol, and stop smoking.

If lifestyle changes do not sufficiently lower LDL, clinicians commonly add medications such as statins or other lipid-lowering drugs to reduce cardiovascular risk. Your clinician will recommend a treatment plan based on your overall risk profile, including age, blood pressure, smoking, and existing cardiovascular disease.

Practical food tips

  • Favor lean proteins (poultry without skin, fish, legumes) over fatty red meats.
  • Choose low-fat or nonfat dairy when desired.
  • Limit fried foods, processed meats, and high-sugar baked goods.
  • Use cooking oils high in unsaturated fats rather than butter.
Talk with your healthcare provider about when to check your cholesterol and the LDL target appropriate for you.
  1. Confirm current US dietary guideline status on a numeric daily cholesterol limit (historical 300 mg/day vs current guidance).
  2. Verify the current ranking of stroke among causes of death in the United States.

FAQs about What Causes High Cholesterol

Is all cholesterol bad?
No. The body needs cholesterol for hormones, cell membranes, and vitamin D. The problem is high levels of LDL cholesterol, which can build up in arteries.
Do eggs and seafood raise my cholesterol?
Eggs and many seafoods contain cholesterol, but for most people they have a smaller effect on blood LDL than foods high in saturated or trans fats. Moderation and overall dietary pattern are key.
What dietary changes lower LDL cholesterol?
Reduce saturated and trans fats, eat more fruits, vegetables, whole grains, legumes, nuts, and fatty fish, replace butter with vegetable oils, and cut back on processed and fried foods.
When should I consider medication?
If lifestyle changes don't bring LDL down enough or if your overall cardiovascular risk is high, a clinician may recommend statins or other lipid-lowering drugs based on your individual risk profile.
How often should I check my cholesterol?
Your clinician will advise based on age, risk factors, and prior results, but adults commonly have fasting or nonfasting lipid panels every 4-6 years if low risk, and more often if on treatment or at higher risk.