Lecithin is a common dietary supplement often claimed to lower cholesterol, unblock blocked breast ducts, and help cognitive function and liver health. In evidence-based medicine, does the use of lecithin really work? Are there any side effects and contraindications? See the internal report for details
What is lecithin?
The origin of lecithin is a complex phospholipid mixture (commonly found in animal and plant tissues) that was first isolated from egg yolk by a French chemist (Theodore Gobley) in 1846.
The main components include: choline, fatty acids, glycerol, glycolipids, phosphoric acid, triglycerides and phospholipids, of which phospholipids are the key structural and functional components of all animal and plant cell membranes, including: phosphatidylserine (phosphatidylserine), phospholipids Phosphatidylcholin, phosphatidylinositol, etc.
Because lecithin has an emulsifying effect (capable of binding water and fat), it is widely used in food processing, such as ice cream, infant formula, bread, margarine chocolate and other foods, and also as an antioxidant and flavor protectant
Soybean (soybean) is by far the most common ingredient used to make lecithin supplements, although milk, canola, sunflower, and corn are also sometimes used.
What are the proven benefits (benefits) of lecithin?
1. Lecithin Benefits Nonalcoholic Fatty Liver Disease
Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases, which is characterized by the accumulation of liver fat exceeding 5% of the liver weight, and more than 30% of the world’s population suffers from NAFLD .
There is no consensus on the drug treatment of NAFLD/NASH. Drugs that directly reduce oxidative stress and lipid accumulation, such as thiazolidinediones, metformin, lipid-lowering agents, and antioxidants, can improve clinical manifestations of diseases.
A prospective pilot study (prospective pilot study, 3 months in 30 patients with non-alcoholic fatty liver disease) pointed out that oral administration of phosphatidylcholine capsules (300 mg, 2 capsules each time, 3 times a day) can reduce Decreased alanine aminotransferase (ALT) (up to 59.6%) and aspartate aminotransferase (AST) (up to 75.4%), and increased glutathione peroxidase (GPX) related to antioxidant defense , superoxide dismutase (SOD). Note 1
*Conclusion: For non-alcoholic fatty liver disease, oral lecithin (phosphatidylcholine) may bring positive help, but limited by the small sample size, more large-scale studies with strict design are still needed for further verification.
2. Lecithin Benefits Ulcerative Colitis
Ulcerative colitis is a chronic inflammation of the colonic mucosa, extending from the rectum to the cecum, depending on the individual case. The disease has an unknown cause and is characterized by recurring uncontrolled inflammation of the colon. Symptoms include: frequent diarrhea, urgent bowel movements, rectal bleeding, and fatigue.
The prevalence rate in Western countries is 0.02% to 0.23%, and the cost of patient treatment has exceeded that of asthma, hypertension and chronic obstructive pulmonary disease.
Some studies have found that phosphatidylcholine in lecithin is an important protective component of colonic mucus, but if the content is too low, it will easily reduce the hydrophobic barrier function of intestinal mucus, allowing colonic bacteria to pass through the intestinal mucus barrier. The resulting immune response thus leads to inflammation and ulceration. Note 1
A literature meta-analysis (Meta-analysis, including 3 randomized controlled trials, involving 160 patients with ulcerative colitis) pointed out that lecithin sustained-release preparations (containing 30% phosphatidylcholine) can improve remission rates, clinical and Endoscopic findings, as well as histological activity and quality of life. Note 2
*Conclusion: For ulcerative colitis, oral lecithin sustained-release formulation may bring positive help, but limited by the small number of samples, more research is still needed for further verification.
3. Lecithin Benefits Liver Failure
Progression of liver disease can lead to a variety of physiological disturbances, possibly leading to hepatic failure and the need for intensive care. The underlying pathology may be acute, acute-on-chronic, or chronic.
Liver failure can present with a variety of clinical signs and symptoms that require prompt attention. Liver failure affects the anabolic and metabolic activity of all organ systems, and supportive care and specific therapy should be instituted to improve outcome and reduce recovery time.
A preliminary randomized controlled trial in patients with fulminant and subacute liver failure indicated that lecithin treatment (at a dose of 350 mg, 3 times a day for 6 to 8 weeks) had a faster recovery from brain lesions and a lower mortality rate. Note 1
*Conclusion: Lecithin therapy may bring positive help to some patients with liver failure, but limited by the small sample size, more research is still needed for further verification.
4. Lecithin Benefits Dementia and Cognitive Impairment
Dementia is an umbrella term used to describe a clinical syndrome of progressive cognitive decline, but its subtypes are classified according to the cause of dementia, such as: Alzheimer’s disease, vascular Dementia, Lewy body dementia, and frontotemporal dementia.
Clinical manifestations of dementia vary from individual to individual, and the cognitive deficits it causes can manifest as memory loss, communication and language impairment, agnosia (inability to recognize objects), apraxia (inability to perform previously learned tasks), and impaired executive functioning. loss (reasoning, judgment, and planning).
A Cochrane database of systematic reviews (comprising 12 randomized trials related to Alzheimer’s disease, Parkinson’s disease, and subjective memory problems) noted. Note 1
Lecithin supplementation did not have any clear clinical benefit for Alzheimer’s or Parkinson’s disease compared to placebo, but may help with subjective memory problems.
*Conclusion: So far, lecithin supplementation has not significantly helped dementia and cognitive function, and more large-scale studies are needed for further verification.
5. Lecithin can benefit the development of mental disorders
Schizophrenia is considered a neurodevelopmental brain disorder caused by early genetic and environmental risk factors including: maternal malnutrition, depression, anxiety, infection, and smoking, and is characterized by two classes of symptoms: positive and feminine.
Positive symptoms include hallucinations, delusions, disorganized thinking and speaking patterns, and abnormal motor behavior, and negative symptoms include blunted or flat affect, lack of motivation, absent or diminished speech patterns, diminished interest in social interactions, and anhedonia.
A double-blind, placebo-controlled trial (subject to 49 children) showed that offspring whose mothers were supplemented with lecithin (Phosphatidylcholine) during pregnancy showed fewer attention problems and less social withdrawal on behavioral assessments. Note 2
The magnitude of this improvement was comparable to similar deficits seen at this age in people with schizophrenia.
The underlying mechanism is related to lecithin increasing the activation of α7-nicotinic acetylcholine receptors, which in turn changes the development of behavioral problems in young children.
*Conclusion: Oral lecithin during pregnancy may reduce offspring-related psychiatric behavior problems, but the results still need to be further verified by more large-scale studies.
6. Lecithin is good for hypercholesterolemia
Cholesterol is a biomolecule critical to the structure and function of mammalian cell membranes and the synthesis of hormones and vitamins.
Hypercholesterolemia is a state of abnormal blood lipid levels. Secondary dyslipidemias are the most common, accounting for about 80%. The remaining causes are primary dyslipidemia caused by abnormal lipoprotein metabolism genes.
Although the relationship between cholesterol rise and cardiovascular disease has become the focus, risk factors such as smoking, high blood pressure and diabetes may also lead to the occurrence of atherosclerosis.
A double-blind controlled study (2 months, 30 patients with hypercholesterolemia) pointed out that compared with placebo, oral lecithin capsules (daily dose 500 mg) can significantly reduce total cholesterol (Total cholesterol) and low Density lipoprotein cholesterol concentration (LDL). Note 1
The underlying mechanism may be related to reduced intestinal cholesterol absorption or increased bile acid secretion.
*Conclusion: Oral lecithin may help improve hypercholesterolemia.
7. Lecithin Relieves Menopausal Symptoms in Women
The transition to menopause, or perimenopause, is associated with profound reproductive and hormonal changes. The typical symptom is hot flashes (also known as vasomotor symptoms), most women have this symptom, about 1/3 of women have moderate to severe problems.
Other symptoms, such as joint pain and stiffness, fatigue, difficulty concentrating, poor sleep, irritability, and depression, are quite common in middle-aged women
A randomized, double-blind, placebo-controlled study (8 weeks in 86 women aged 40 to 60) found that supplementation with high doses of soy lecithin improved vitality scores (as measured by POMS Brief, a simplified version of the Mood State Scale) , diastolic blood pressure and cardio-ankle vascular index (cardio-ankle vascular index). Note 2
*Conclusion: Lecithin may have a positive effect on improving some women’s menopausal symptoms (such as fatigue).
8. Lecithin Benefits for Bipolar Disorder
Bipolar disorder is a chronic relapsing disorder characterized by recurrent episodes of mania or depression, usually in adolescence or early adulthood.
Patients experience depressive episodes, characterized by low mood and associated symptoms (such as loss of joy and decreased energy), and manic episodes, characterized by excited or irritable moods, or both, and associated symptoms and energy Increased and decreased need for sleep or hypomania.
A case-control study of a boy with hypomania and a DGKH gene showed that supplementation with lecithin (phosphatidylcholine) in addition to medical treatment relieved symptoms of hypomania and insomnia. Note 3
*Conclusion: For patients with DGKH susceptibility genes for bipolar disorder, lecithin supplementation may bring positive help, but more trials are still needed to confirm its clinical benefits.
9. Lecithin Improves Breast Duct Blockage
With all the amazing benefits that come with breastfeeding, it also comes with some challenges, namely blocked (or blocked) milk ducts and mastitis.
Blocked Milk Ducts are a common breastfeeding problem that occurs when the milk is not fully drained from the breast, or when there is too much pressure inside the breast. It may feel like a tender lump in the breast, which can be painful and uncomfortable for new moms.
Lecithin is often mentioned in the treatment of partial blocked ducts, and is thought to reduce the viscosity of milk to prevent blocked ducts (by increasing the proportion of polyunsaturated fatty acids in milk).
The recommended dosage is about 3600-4800 mg of lecithin per day, or 1 capsule each time (1200 mg, 3-4 times a day).
*Conclusion: So far, although lecithin has been used to improve breast duct obstruction, there is no scientific research to evaluate whether the treatment is effective.
Are there any side effects of lecithin?
Lecithin is very safe for most people, but possible side effects that have been reported include: diarrhea, excessive sweating, vomiting, nausea, abdominal pain, or a feeling of fullness.
Safety precautions (7 points of taboos)
- It may induce allergic reactions (lecithin is usually extracted from soybeans, egg yolks, sunflower seeds or rapeseeds, so it may contain residual protein from the original extract. This means that people who are allergic to soybeans, rapeseeds, eggs or sunflower seeds may also have an allergic reaction to lecithin, symptoms include: rash, trouble breathing, swelling of the face, lips, tongue, or throat.)
- Metabolites of lecithin: choline is converted into trimethylamine oxide (TMAO) in the gut, and higher TMAO levels are associated with an increased risk of major cardiovascular adverse events. Note 4
- Lecithin is involved in lipogenesis and hepatic lipid accumulation, and if excessive, it may be related to obesity and hepatic steatosis. Note 5
- Do not use it in combination with anticholinergic drugs (Anticholinergic drugs) , which may affect the efficacy of the drug. The related drug names are: atropine (atropine), scopolamine (scopolamine), antihistamines (antihistamines), antidepressants (antidepressants).
- Do not use it in combination with acetylcholinesterase inhibitors (acetylcholinesterase inhibitors) , which may increase drug side effects. Related drug names are: donepezil (donepezil), tacrine (tacrine), rivastigmine (rivastigmine) , galantamine (galantamine).
- Do not use in combination with glaucoma and xerosis drugs: pilocarpine, which may increase the chance of side effects.
- Lecithin may increase platelet adhesionNote 6, thereby reducing the effectiveness of blood thinners such as aspirin, please pay attention if you take related anticoagulant drugs.
How to eat lecithin (how much is the dosage)?
There is no established optimal recommended dose of lecithin. The dose most commonly used in studies is approximately 0.5 g to 2 g daily.
But you should always follow the recommended dosage provided on the product, or consult your doctor or pharmacist to determine a safe dosage.
Note 1: https://pubmed.ncbi.nlm.nih.gov/11273253/
Note 2: https://www.ncbi.nlm.nih.gov/pubmed/29310653
Note 3: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4476977/
Note 4: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3701945/
Note 5: https://www.ncbi.nlm.nih.gov/pubmed/19288019
Note 6: https://www.ncbi.nlm.nih.gov/pubmed/10595648