Triglycerides are the main form of fat stored in the body. They come from our diet, from meat, oils and dairy, and some are made by the liver. Like cholesterol, triglycerides are a type of lipid (fat-like substance) needed by the body to work properly.
Triglycerides are produced by the digestion of fats from your food. Some also come from carbohydrates. When you eat, any excess calories not needed for energy are stored as triglycerides in your body’s fat cells. They are released later when energy is required between meals, to allow you to undertake your daily activities.
Why are triglycerides important?
The level of triglycerides in your body is a good indicator of health. High levels of triglycerides (known to doctors as hypertriglyceridaemia) are associated with an increased risk of heart disease, stroke, diabetes, fatty liver disease and metabolic syndrome (a condition that increases your risk of cardiovascular disease and is associated with high blood pressure and abnormal fasting blood sugar levels).
Triglycerides are associated with atherosclerosis – the build-up of fatty material (plaque) in the lining of your arteries, which can lead to coronary heart disease (which causes angina and heart attack) and stroke.
Unfortunately, high triglyceride measurements often go hand in hand with low levels of HDL-cholesterol – the so-called ‘good’ cholesterol, and this increases a person's risk of cardiovascular disease.
Very high levels of triglycerides (above 10 mmol/L) are associated with a risk of an attack of acute pancreatitis – sudden onset of inflammation of the pancreas that is very painful and sometimes fatal.
In Australia, doctors recommend you start having regular cholesterol tests at age 45. When you have a blood cholesterol test, your triglyceride levels are usually measured as well. Having high cholesterol and/or high triglycerides does not cause any symptoms, so routine blood tests are the best way to monitor your triglycerides.
Triglycerides give an indication of the level of fat in your bloodstream. The levels of triglycerides are higher for a few hours after meals, which is why triglyceride tests are usually done as fasting blood tests. The level of triglyceride in your blood test is also influenced by the recent intake of fat in your diet and consumption of alcohol.
When you are being tested for triglyceride levels you are usually asked to have no food or drinks (other than water) for about 10 to 12 hours before the test. Also, some doctors advise that you don’t have any alcohol for 24 hours before testing. Many people have their blood test in the morning after fasting overnight.
What’s the target level for triglycerides?
For Australians who are being treated for high cholesterol, the target level of triglycerides in the blood should be less than 2.0 mmol/L.
For other Australians, the level of triglycerides that is considered acceptable is not looked at in isolation, but based on a person’s overall risk of cardiovascular disease, which takes into account other factors. But generally, the target is less than 2.0 mmol/L.
Causes of high triglycerides
For most people, high triglycerides are due to eating too much food, especially food high in fat and high GI carbohydrates, drinking alcohol and being overweight or obese.
People with diabetes may also have trouble keeping their triglycerides within normal limits, as higher blood sugar levels make it more difficult for the body to absorb fat from the bloodstream. That’s another reason to keep your blood sugar controlled, if you have diabetes.
A very small number of people may have a genetic condition, such as lipoprotein lipase deficiency, that is responsible for their high triglycerides. This causes difficulty in clearing triglycerides from the bloodstream after a fatty meal.
Some medicines are also known to raise triglycerides; these include corticosteroids, beta-blockers and oestrogens.
Lowering your triglyceride levels
Many Australians, especially those carrying too much weight around their waist, have raised triglyceride levels.
As high triglyceride levels may mean an increased risk of future heart disease, especially in combination with low levels of ‘good’ cholesterol (HDL) and high levels of ‘bad’ low-density lipoprotein (LDL) cholesterol, it is important that you keep your triglycerides below the recommended levels.
There are some lifestyle changes that can help lower your triglycerides. Your doctor may recommend a 12-week trial of lifestyle measures, such as those below, to see if your triglyceride levels improve, before considering treatment with medicines.
- Losing weight if you are overweight – even modest weight loss can result in a worthwhile reduction in triglycerides.
- Limiting carbohydrates in your diet. Diets high in carbohydrates, particularly simple sugars, increase triglycerides, so avoid sweets, fruit juice, pastries, biscuits and desserts. Also try to substitute wholegrain versions of rice and pasta for white rice and pasta.
- Choosing polyunsaturated or monounsaturated fats (sources include mackerel, salmon and tuna; olive, canola and sunflower oils; and nuts, seeds and avocado) instead of saturated fats (sources include red meat and poultry, butter, cream, cheese and baked goods). Unsaturated fats such as omega-3s (such as found in salmon, mackerel and sardines) lower triglycerides, whereas saturated fat and trans fats increase triglycerides.
- Reducing alcohol intake – even small amounts of alcohol intake can raise triglyceride levels.
- Increasing physical activity — aim for at least 30 minutes of physical activity such as a brisk walk on most days, but at least 5 days.
Some medicines for other conditions can raise triglyceride levels — if this is the case, your doctor may suggest an alternative.
If you have diabetes, high blood sugar can lead to higher triglycerides – as the increased glucose can make it harder for the body to absorb fat, so good blood sugar control is important.
Treatment for high triglycerides
Treatment for high triglycerides depends on whether you also have abnormal cholesterol levels and which type of lipids are raised.
Medicines used in Australia for the treatment of raised triglycerides include:
- fenofibrate (brand name Fenofibrate RBX, Lipidil)
- gemfibrozil (for example, Ausgem, Lipigem, Lopid)
- fish oil may also be prescribed, either on its own or in conjunction with other medicines
- nicotinic acid is a form of vitamin B; however, it should be used to lower triglyceride levels only under a doctor’s supervision, as side effects are possible.
If you have raised ‘bad’ cholesterol (LDL cholesterol) as well as high triglycerides, you may be prescribed medicines called statins. Statins, such as atorvastatin, pravastatin and rosuvastatin, lower LDL-cholesterol and triglycerides. You may also need another medicine in addition to the statin.
Talk to your doctor to find out the best treatment for you if you have high triglycerides.