Though keeping your low-density lipoproteins or LDL cholesterol levels low is advisable in view of the health risks of its higher levels, very low or extremely low levels also carry risks.

Extremely low LDL cholesterol levels mean LDL levels below 40 mg/dL. However, the risk of cardiovascular events, which is very high with high LDL levels, diminishes at these low levels.

However, such too-low values are associated with certain other risks such as cancer and hemorrhagic stroke, which I have outlined below along with the possible causes, required diet changes, and treatment options.

When you are born, your LDL cholesterol levels are at around 40 mg/dL. But, as you grow the average healthy levels rise and as an adult, your LDL values should be below or around 100 mg/dL.

To know where you stand, compare your results with the standards described in this post on the normal and undesirable cholesterol levels in children, adults, and the elderly.

Experts set a new guideline in 2004 for people with the highest risk of cardiovascular disease. According to this guideline, such high-risk people should ideally have an LDL cholesterol level of 70 mg/dl.

The experts described this as a therapeutic option, indicating that it is one of the options that can reduce the risk of heart disease considerably.

What do very low LDL levels mean?

There is no consensus on how to define very low LDL cholesterol, but LDL cholesterol levels are considered to be low when they are significantly below the normal levels of 100 mg/dL.

However, very low LDL cholesterol levels can be defined as levels below 40 milligrams per deciliter of blood. When cholesterol levels fall too low, you are exposed to risks of developing certain conditions.

Dangers of very low LDL cholesterol blood levels

Though not so common, extremely low cholesterol in patients with no history of taking cholesterol-lowering drugs is associated with certain health concerns, which, however, still carry some ambiguity. Although the risks of these complications are rare, they deserve mention and are explained below:

  • Cancer risk. Studies carried out on patients with very low LDL cholesterol in the blood and who are not on cholesterol-lowering drugs suggest that such patients have 15 times the risk of developing cancer. However, whatever studies are conducted only suggest and there is definite evidence to confirm the same.
  • Hemorrhagic stroke. Epidemiological studies have confirmed an increased risk of intracranial hemorrhage in patients with low cholesterol in both men and women and more so in older people..
  • Depression and anxiety. Studies have shown that patients with acute depression showing suicidal behavior displayed low levels of total cholesterol and LDL cholesterol. According to one study published in the Journal of Psychiatric Research, individuals with low total cholesterol levels and depression were 7 times more likely to die prematurely from unnatural causes such as suicide and accidents
  • Nervous system dysfunction. CNS cholesterol makes up almost 25% of the body’s total unesterified cholesterol and most of it is found in the myelin sheath that covers the core of the nerve fiber. LDL cholesterol helps the nerves to communicate with each other through electric signals. Low levels of LDL disturb this sequence and lead to nervous dysfunction.
  • Immune system dysfunction. Your immune system requires cholesterol to function properly. Various studies conducted have shown the following connection between cholesterol and our immune system.
    • There were significantly fewer circulating white blood cells in people with low cholesterol. This suggests a less efficient immune system. because as you know the WBCs form the core of our immune system.
    • According to an Israel study, individuals with LDL cholesterol less than 70 mg/dL are five times more likely to develop sepsis.
    • Low cholesterol increases the risk of respiratory tract infections. The risk was stronger among men and in older people.
    • The bottom line is that low LDL cholesterol increases our risk of infections of all types and from all sources whether you’re a man or a woman, young or old. The lower the levels of LDL, the higher climbs the risk.
  • Preterm birth or a baby with low weight. In a study, published in the October 2007 issue of the Journal of Pediatrics, nearly 13% of the women with very low cholesterol gave birth prematurely. The researchers also found that white women were more at risk and that almost 21% of white women with very low cholesterol levels had preterm deliveries. On average, the preterm babies of mothers with low cholesterol weighed five ounces less than babies delivered full-term to mothers with moderate cholesterol.
  • Increased risk of Parkinson’s disease. According to the Honolulu-Asia Aging Study, low LDL cholesterol is associated with an increased risk of Parkinson’s disease. The association was more noticeable in men aged 71 to 75 years.

Causes of very low LDL levels

Extremely low levels don’t just come about due to cholesterol-lowering drugs. There can be other causes as well. There are four major causes why your LDL levels can fall too low.

  1. Iatrogenic, meaning due to cholesterol-lowering drugs such as statins. 
  2. Reduced production of LDL due to
    • Liver disease
    • Malabsorption such as celiac disease, where there is poor absorption from the gastrointestinal tract
    • Malnutrition, inadequate intake of nutrition.
  3. Increased clearance of LDL due to hyperthyroidism or an overactive thyroid gland causes cholesterol levels to drop to abnormally low levels.
  4. Inherited: Low LDL Syndrome
    • In Abetalipoproteinemia (ABL) virtually no LDL cholesterol is present
    • In familial hypobetalipoproteinemia (FHBL) the LDL cholesterol levels are extremely low.

Very low LDL cholesterol clinical assessment

  • Acanthocytosis is a condition characterized by abnormally shaped or crenated red blood cells called  acanthocytes
  • Malabsorption of fats and fat-soluble vitamins such as A, D, E, and K leads to a deficiency of these vitamins in the body.
  • Diarrhea and steatorrhea are characterized by foul-smelling, pale, and bulky stools.
  • Hepatomegaly – enlarged liver
  • Neurological involvement due to demyelination of the nerves
  • Myositis – inflammation of the muscles
  • Degeneration of the retina of the eyes

How is very low LDL cholesterol treated?

The first concern is to raise the LDL from +/- 40 mg/dL and bring it to at least around +/- 70 to 80 mg/dL. This will reduce the risk of complications.

Early treatment in neonates can prevent the further progression of neurological problems as well as the degeneration of the retina.

Vitamin E in the dose of 100 mg/body weight will set right the low vitamin E levels in the body tissues. Plasma levels of tocopherol, however, may still be below normal. Tocopherols are a member of the vitamin E family naturally present in vegetable oils, nuts, fish, and leafy green vegetables.

Dietary fat is restricted to control steatorrhea. Deficiency of vitamins A, D, and K is treated with replacement therapy.

Infants and children who are identified with genetic disorders such as homozygous FHBL or ABL require prompt treatment with very high doses of vitamin E. Heterogeneous patients require Vitamin E in modest doses

Adults may develop complications, which are treated according to their merits and demerits.

Dietary management consists of restricting intake of long-chain fatty acids to 15 g per day. This will improve the complications due to fat malabsorption.

Very large doses of oral vitamin E at 100-300 mg/kg/day are given in homozygotes to avoid neurological problems. This will raise the tissue levels of vitamin E.

Heterogeneous adult patients require Vitamin E in modest doses

Vitamin A (10,000-25,000 IU/d) supplementation is given in cases where there is vitamin K depletion.