While most people worry about high triglycerides, your levels are low. What does this mean? If triglycerides are harmful, can levels be too low? Read on to understand what low levels mean, what decreases them, and how they interact with HDL and LDL cholesterol values.
It is well known that high triglycerides are dangerous, but little is known about the influence of low levels on health. Studies suggest that in healthy people, low triglyceride levels are beneficial. Low triglycerides are also good for people with diabetes and might also be protective against heart attacks [1, 2].
One study even suggests that the lower a person’s triglycerides are, the less likely they will be to die from any cause. In this study, almost 14k people were followed for 24 years. The scientist found that levels below 89 mg/dL – that’s almost twice lower than the borderline-normal value of 150 mg/dL – were associated with a 41% lower risk of dying than high levels [3+]
So can your levels ever be too low to do any harm?
We still don’t have any definitive answers, but we can look for some clues.
In one study, people with heart failure and lower levels were more likely to die from heart complications. The levels associated with risk were around 120 mg/dL on average, while levels of 130-149 mg/dL were considered protective .
Upon further analysis, the researchers concluded that only women with heart failure and low triglycerides may be at an increased risk of dying. According to them, low triglyceride levels may point to more advanced stages of heart failure .
In another study, people with lung scarring (pulmonary fibrosis) had triglycerides under 57 mg/dL, which was about 60% lower than the values of healthy controls .
Similarly, people with autoimmune disease had 50-70% reduced triglyceride levels compared to healthy people in a different study. Researchers suggested that low triglyceride levels might actually be a marker of autoimmunity and an overactive immune response .
It’s important to note here that low triglycerides in all of these cases are not causing any of these conditions. They are the effect of these conditions. For example, in heart failure, low triglycerides may be due to liver damage (liver maker triglycerides) due to diminished oxygen supply or increased levels of inflammation.
There is no proof that low triglyceride levels are harmful in and of themselves.
There isn’t an official cutoff for low triglycerides. Most labs will consider any value below 150 mg/dL normal and values below 90 mg/dL as optimal.
If you are healthy and your values are lower than normal, you probably have nothing to worry about – on the contrary.
But based on the studies above, in certain conditions, levels that are 50-70% lower than the average healthy person’s might signal a more serious course of disease or higher levels of inflammation [4, 5, 6].
A study suggests that when blood triglycerides are lower than 100 mg/dL, LDL cholesterol levels are somewhat overestimated based on the formula labs use. That means your triglyceride levels are correct, but your LDL-C may be lower than what the results show. The lab may need to perform a different analysis to give you a precise LDL-C value if necessary [7, 8].
This combination is usually beneficial. It has been linked with reduced risk of heart attacks 
Studies have found that genetic variations in the LPL gene (rs1801177, rs118204057, rs268, rs301, rs326, rs10096633), responsible for low blood triglycerides were associated with decreased risk of all-cause death and lower risk for heart disease [12, 13].
In 80k Icelanders, a variant of the ASGR1 gene (del12 in intron 4) was associated with low blood triglycerides .
The Pima are Native Americans who live in what is now central and southern Arizona and parts of Mexico. They have enormously contributed to scientific advances through their willingness to participate in research .
The Pima were adapted to surviving in the desert, directing water, engaging in physical labor, growing vegetables, and eating a low-fat, high-carbohydrate diet. Once white settlers brought an abundance of fatty foods and a sedentary lifestyle to their communities, their prevalence of diabetes skyrocketed .
In a study from 1980, 15 obese Pima Indians had a reduced rate o VLDL-C (carriers of triglycerides) production and increased rate of triglyceride breakdown, compared to 10 obese whites .
This means that Pima Indians made fewer triglycerides and broke them down faster than the white subjects. Yet they were more obese, more prone to diabetes, and less prone to heart disease. They were adapted to a life of scarcity, one in which it was important to store energy well .
They were, however, not adapted to the modern lifestyle. These findings shaped the “thrifty gene” hypothesis: populations who have struggled with periods of limited resources and famine were more likely to survive if they were “metabolically thrifty” and stored calories efficiently. This gave them a genetic advantage, but in modern times, it puts people at risk of diabetes and obesity .
In 1,002 heart disease patients, metabolically healthier people had lower triglyceride levels after meals compared to people with an abnormal metabolic profile, regardless of their body fat .
In this study, metabolic health was evaluated using the following markers:
- Elevated blood pressure: systolic/diastolic blood pressure≥130/85 mmHg or using meds for high blood pressure
- Elevated triglyceride level: ≥150 mg/dL
- Low HDL-C level: <40 mg/dL in men or<50 mg/dL in women or using cholesterol-lowering medication
- High blood sugar: fasting glucose level≥100 mg/dL or using antidiabetic medication
- Insulin resistance: HOMA-IR >2.6
- Systemic inflammation: hs-CRP level≥3 mg/L
People who were considered metabolically healthy had a normal weight (BMI < 25) and <2 of abnormal markers above .
Remember, heart disease can lower triglycerides, not the other way around. Low triglyceride levels do not cause heart disease. They are just a marker of what’s going on in the body.
Low blood triglycerides were compared in lean and obese people with and without autoimmune disease. Low levels were associated with :
- Chronic thyroid disease
- Lupus-like syndrome
- Rheumatoid arthritis
- Skin disease (atopic dermatitis)
- Other autoimmune disorders
In these cases, again, low triglycerides are just one of the markers of what’s going on in the body (e.g. inflammation). Trying to artificially increase triglycerides will not prevent nor improve autoimmune conditions. You need to work with your doctor to address the underlying health issues.
If you are worried about your health, speak with your doctor. He will interpret your triglyceride levels based on your medical history, symptoms, and other test results.
Low triglyceride levels are usually beneficial. If you are healthy and your levels are relatively low, you have nothing to worry about. Studies found low levels were associated with reduced risk of heart disease and death from all causes.
Abnormally low triglyceride levels have been linked with worse outcomes in certain conditions, such as heart failure. They have also been linked to autoimmunity. Low triglyceride levels are, in these cases, probably due to underlying issues such as inflammation or impaired liver function.
Doctors consider any value below 150 mg/dL normal and under 90 mg/dL optimal.
Low triglycerides can slightly overestimate LDL cholesterol. High HDL cholesterol and low triglycerides are usually beneficial and lower the risk of heart attacks.
Genes, ethnicity, and metabolic health can also impact your triglyceride levels. When in doubt of what your results mean, talk to your doctor.