Having blood triglyceride levels above 150 mg/dL (1.7 mmol/L) puts you at increased risk for a heart attack, stroke, or heart valve disease, even if your blood cholesterol levels are normal (Eur Heart J, Dec 2021;42(47):4791-4806). About 10 percent of North Americans suffer from high triglyceride levels. High triglycerides are often found in people who:
• are diabetic, obese or alcoholic,
• have high blood pressure,
• have liver damage,
• have pancreatic disease,
• have kidney disease,
• have low thyroid function,
• have genetic disorders of fat metabolism,
• take beta-blockers, birth control pills, estrogen, diuretics or drugs that suppress a person’s immunity
You can lower high blood triglyceride levels with lifestyle changes including diet and exercise, and with established prescription treatments such as fibrates, omega-3 fatty acid preparations, and various biological agents (Eur Heart J, 2020;41(1):99-109c).
What Causes High Triglyceride Levels?
When blood sugar levels rise too high after meals, sugar is converted to a type of fat called triglycerides, so high blood triglyceride levels are usually caused by a high rise in blood sugar after meals and usually mean that a person is already diabetic or pre-diabetic (J Clin Endocrinol Metab, Oct 2011;96(10):E1596–E1605). High rises in blood sugar after meals cause sugar to stick to the outer membranes of every type of cell in your body and eventually destroy these cells. Sugar can stick to:
• brain cells, to cause dementia
• nerve cells, to cause pain or loss of feeling
• matrix cells of bones, to weaken bones and cause osteoporosis
• the DNA of cells, which can cause the uncontrolled growth that is cancer
• the inner lining of arteries, to form plaques
• plaques that have already formed, causing them to break off, leading to a heart attack or stroke
This is why diabetes has so many devastating side effects.
Normal fasting blood sugar is below 100, but a normal fasting blood sugar does not rule out diabetes because having a high blood sugar after meals usually happens earlier than having a high fasting blood sugar. You suffer cell damage even if your blood sugar levels are normal when you fast, but rise too high only after you eat. Many studies show that having a blood sugar greater than 140 one hour after eating a meal causes cell damage and indicates that you are already pre-diabetic or diabetic (Atherosclerosis, 2016 Nov 17;256:15-20). A high rise in blood sugar after a meal causes your liver to convert the extra sugar to fatty triglycerides and a triglyceride level >150 usually means that your blood sugar is also too high.
How High Triglycerides Cause a Fatty Liver
When you have high triglycerides, you use up your good HDL cholesterol because it tries to protect you by carrying triglycerides from your bloodstream into your liver. This is the most common cause of a low HDL (below 40). Your HDL has helped you by clearing excess triglycerides from your bloodstream, but the excess fat collects in your liver to eventually form a fatty liver.
Your body tries to protect you from high rises in blood sugar after meals that causes cell damage. Your pancreas releases insulin that lowers blood sugar levels by driving sugar from your bloodstream into your liver. However, if your liver is full of fat, it cannot accept the sugar and the liver then releases even more sugar from its cells to drive blood sugar levels even higher.
How to Predict High Risk for Diabetes
You are at high risk for diabetes if your:
• triglycerides are higher than 150,
• blood sugar is higher than 140 one hour after eating a meal,
• good HDL cholesterol is lower than 40.
A sonogram of your liver can be used to show whether you have excess fat stored there (“fatty liver“).
Triglycerides Can Also Lead Directly to Heart Attacks
Having high blood triglycerides also puts a person at increased risk for a heart attack because triglycerides can penetrate the inner lining of arteries to start plaques forming in them (Arterioscler Thromb, Nov 1994;14(11):1767-74). Once that has happened, the high triglycerides are associated with inflammation that causes plaques to break off and form clots (Circa Res, 2014;114:214–26) that cause heart attacks (Mymensingh Med J, Jul 2004;13(2):185-7).
Other Reasons for High Triglycerides
The ACC document covers the many other medical conditions associated with high triglycerides, such as poorly controlled diabetes, chronic kidney disease, rheumatoid arthritis or low thyroid function. Many medications can also raise triglycerides; check with your health care provider or pharmacist.
Dietary Treatment for High Triglycerides
• Eat lots of vegetables, but limit starchy root vegetables such as potatoes and sweet potatoes
• Eat lots of legumes (beans, lentils, chickpeas, soybeans, peanuts) and nuts
• Eat whole (unground) grains and restrict refined grains (bakery products, pasta, white rice and so forth)
• Restrict mammal meat and processed meats.
• Eat seafood twice a week or more
• Avoid sugar-sweetened and artificially sweetened beverages
• Avoid sugar-added foods
• Restrict salt
• Restrict alcohol
If your fasting blood triglyceride levels are greater than 150, you are likely to be pre-diabetic or diabetic and susceptible to cell damage from high blood sugar levels. If you have a big belly and small buttocks, the odds are that you are already diabetic. Check with your doctor immediately and go on a lifestyle program to cure diabetes and prevent heart attacks.
Gabe Mirkin, M.D., is a sports medicine doctor and fitness guru. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin has run more than 40 marathons and is now a serious tandem bike rider with his wife, Diana. His website is http://drmirkin.com/. Click to read Gabe’s full bio.