Fats are largely misunderstood and avoided in many diets. However, lecithin is a naturally occurring, healthy fat that may have myriad health benefits. Read on to discover what foods contain lecithin and how it affects the human body.
What Is Lecithin?
Lecithin is a naturally occurring fat found in many plant and animal sources [1, 2].
Lecithin is a term for a group of yellow-pigmented fatty substances. Lecithins generally contain groups of phospholipids, which are key structural and functional components of cell membranes in all animals and plants [3].
Lecithin maintains and stabilizes fat in many food products. They also provide texture to many foods and increase their shelf life. Lecithin has the ability to bind water and fat sources, making it a common additive to many desserts, chocolates, salad dressings, meat products, and cooking oils [4, 5, 6].
Popular lecithins include soy lecithin and sunflower lecithin.
Soy Lecithin
Soy lecithin is extracted from soybeans.
It is composed of free fatty acids and small amounts of proteins and carbohydrates. The main component in soy lecithin is phosphatidylcholine, which comprises between 20% to 80% of the total fat amount [7].
Components
Active components in lecithin include [8]:
- Glycerophosphate
- Sodium oleate
- Choline
- Phosphatidylinositol
Phosphatidylcholine, the main fat found in lecithin, is a source of choline, an important nutrient that is critical for 4 main purposes in the human body [9]:
- Cell membrane structure and signaling
- Synthesis of the important neurotransmitter acetylcholine, which is required for brain and muscle function [10]
- Helps the process that controls the activation and blockage of genes (uses methyl groups to mark DNA)
- Fat transportation and keeping the fats circulating in your bloodstream in balance
Choline is also very important in breaking down homocysteine [10].
Phosphatidylcholine and the Choline Pathway
Mechanism of Action
Lecithin contains fatty acids that can activate gene-regulating receptors (peroxisome proliferator-activated receptors). Once activated, these receptors play a major role in energy balance and metabolic function [11, 12].
Peroxisome proliferator-activated receptors exist in many types of tissues such as in the heart, liver, muscle, fat, and intestine. These tissues rely on receptor activation for the promotion of fatty acid, ketone bodies, and glucose metabolism. Ketone bodies are used by the body as a source of energy [13, 14].
Natural Lecithin Sources
Lecithin is a common food additive but is also found in many natural sources.
Some vegetarian sources include [15, 16, 17]:
- Milk
- Yogurt
- Cheese
- Egg (yolk)
- Brussels sprouts
- Broccoli
- Legumes
- Soybeans
- Vegetable oil
- Cauliflower
- Nuts
Most animal sources generally provide a larger source of lecithin and choline. Some of the best animal sources include [15, 16, 17]:
- Fish
- Chicken liver
- Chicken kidney
- Pork
- Beef Liver
Potential Health Benefits of Lecithin
Regulations set manufacturing standards for lecithin supplements but don’t guarantee that they’re safe or effective. Speak with your doctor before using lecithin supplements, and discuss better-studied alternatives to meet your goals.
Insufficient Evidence For
Lecithin is a frequent food additive, but supplements have not been approved by the FDA for medical use due to a lack of solid clinical research. In fact, despite a relatively large body of research, lecithin has not been found to be effective for any medical purpose. The potential benefits we discuss in this section should be considered speculative at best; more research is required to confirm or refute any and all of them.
1) Cholesterol
Chronic high cholesterol leads to many heart-related complications such as heart attacks.
In one study of 30 patients, participants with high cholesterol levels took 500 mg of soy lecithin daily for 2 months. After 2 months, total cholesterol levels and bad (LDL) cholesterol levels were reduced by 42% and 56%, respectively [18].
Soy lecithin increased liver production of good (HDL) cholesterol in a 4-week study of 65 patients. Good cholesterol helps remove other forms of cholesterol from the body, and higher levels protect against heart attack and stroke [19].
Larger and more robust clinical trials are required to investigate whether lecithin can really lower cholesterol.
2) Mental Illness
Lecithin contains a phospholipid called phosphatidylinositol, a natural compound that may be effective against panic disorder [20].
In a study of 6 mania patients, 5 of them experienced better mental health with consumption of pure lecithin [21].
A meta-analysis of lecithin reported that it was worth investigating further as complementary therapy for bipolar disorder [22].
Again, larger and more powerful human trials will be required to confirm or refute these benefits. There is currently not enough evidence to recommend lecithin to improve mental health; talk to your doctor about better-studied strategies with more research behind them.
3) Liver Health
Cholestatic liver disease is the slowing of bile flow due to damaged or inflamed bile ducts. Mice experienced less liver damage when on soybean lecithin supplemented diet [23].
Individuals with choline deficiency are more susceptible to liver damage and liver failure. Choline in lecithin is first broken down in the liver, where it helps to absorb fats [24].
The effect of lecithin on the human liver has not yet been studied; research on this potential benefit has thus far been limited to animals.
4) Stress Response
Lecithin may improve the body’s resilience to stress. A study of 80 men and women divided into 4 groups of 20 individuals. Before exposure to a stress test, participants were given either 400, 600, or 800 mg of soy lecithin plus phosphatidylserine (another phospholipid that is commonly present in lecithin) or placebo for 3 weeks [25].
Interestingly, only the 400 mg group showed a decreased stress response to the stress test compared to the placebo [25].
These results will need to be repeated in larger and more robust human trials.
5) Colitis
The lecithin derivative phosphatidylcholine makes up over 70% of the total fats found in the mucus layer covering the inner surface of the intestine. This layer serves as a protective barrier that helps maintain the digestive tract from bacteria [26].
Colitis is a chronic inflammatory bowel disease that targets the inner lining of the colon with inflammation. In colitis, there is a significant reduction in phosphatidylcholine content in the protective mucus barrier allowing bacteria to easily cause inflammation [26].
Supplementation of phosphatidylcholine in a study of 60 colitis patients was able to restore the mucus barrier and decrease inflammation caused by colitis [27].
Animal & Cell Research (Lacking Evidence)
No clinical evidence supports the use of lecithin for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.
6) Immunity
In one study, diabetic rats given a daily supplement of soy lecithin had a 29% increase in white blood cell activity [28].
Meanwhile, non-diabetic rats had a 92% increase in overall white blood cells (T and B cells) [28].
This potential benefit has only been studied in animals; human trials will be required to confirm and repeat it.
7) Bile Salt Injury
The liver produces bile. The gallbladder stores it to digest dietary fats such as cholesterol. When bile levels are too high, bile salts can damage cells by digesting their fatty cell membrane. Lecithin may bind to and reduce bile salt levels, protecting cells from harm [29, 30].
This benefit is speculative and has not yet been investigated in human trials.
8) Absorption of Drugs and Supplements
Improving drug absorption is a contentious area of study.
Some drugs and supplements can have improved effects if more is absorbed into the body. However, some could become toxic if the body cannot properly distribute, break down, and eliminate a drug in larger amounts [31].
Lecithin may help transport fat-soluble drugs and nutrients across fat insoluble cell membranes. For example, supplements such as curcumin, Boswellia serrata, green tea, silymarin, and grape seed extract have all shown enhanced absorption when delivered with lecithin [32, 33].
Talk to your doctor before supplementing with lecithin to avoid any unexpected interactions with medications or supplements you are already taking.
Lecithin & Brain Health
Some people use lecithin to improve brain health, but studies on the subject have been mixed, contradictory, or negative. For example, a meta-analysis found that lecithin supplementation did not have a significant benefit to people with dementia; according to the authors, the evidence was not sufficient even to recommend a larger trial [34].
People who believe that lecithin improves brain health may base their beliefs in a handful of positive studies. In one such study, phosphatidylserine (from soy lecithin) blended with phosphatidic acid improved memory, mood, and thinking ability in a 3-month study of 72 elderly patients. This same mixture also showed improved daily function, mood, and general condition in a different 2-month study of 56 Alzheimer’s patients [35].
However, in a study of 51 subjects, using high doses of lecithin did not improve symptoms in dementia patients [36].
Cancer Research
In another study, researchers compared 3,101 previous breast cancer cases to 3,471 healthy subjects. Use of lecithin supplements was associated with reduced incidence of breast cancer [37].
Lecithin supplementation was also strongly associated with reduced incidence of breast cancer in postmenopausal women, but not premenopausal women [37].
These results are promising, but additional research will be required to determine whether lecithin can consistently decrease breast cancer risk.
Side Effects & Precautions
1) Allergies
Since soy lecithin comes from soybean oil, it contains soy proteins that can trigger soy allergies. However, blood from soybean-sensitive patients showed no reaction to soy lecithin. Soy lecithin presents a low risk for people with minor reactivity to soy [38].
Lecithin contains Immunoglobulin E (IgE) binding proteins. When these proteins bind to the immune system’s antibodies, the antibodies trigger an allergic response which can cause rapid inflammation and digestion discomfort. Those with a soy allergy should be cautious even with other lecithin based products [39, 40].
2) Blood Clotting
A 15-day study with 60 patients showed a daily dosage of soy lecithin increased blood cell clumping (platelet adhesion) in the blood. Blood platelets are responsible for sealing damaged blood vessels. However, increased activity of blood platelets is linked to heart disease [41, 42].
3) Infertility in Men
Soy products, including soy lecithin, contain the plant hormone phytoestrogen, which acts like the human hormone, estrogen [43].
Researchers took pregnant rats with male fetuses and added phytoestrogens to their diet. Later in their development, the male rats had a lower sperm count and hormone imbalances [44, 45].
4) Fat Build-up
Lecithin promoted fat production and storage in mouse cells. Human liver cells started to build up fat storage when introduced to lecithin [11].
Pregnancy
After pregnant mice had a soy lecithin-supplemented diet, their offspring later showed behavioral and biological defects, causing laziness and poor balance [46].
The choline in lecithin can also be a minor cause for concern during pregnancy. When choline reaches the large intestine, gut bacteria and the liver converts it into trimethylamine oxide (TMAO). High levels of trimethylamine oxide may increase the risk of heart disease [47, 48].
Drug Interactions
Lecithin was shown to increase platelet adhesion, which could reduce the effectiveness of blood thinners such as aspirin. Aspirin thins the blood by decreasing the clotting effect of platelets in the blood [41].
Limitations and Caveats
Many of the available lecithin studies only test animals, so some benefits may not be replicated in humans. More human trials are required; talk to a doctor before you use lecithin for its purported health benefits.
Supplementation
Dosage
There is no established safe and effective dosage for lecithin supplements. The most common dosages used in studies range from 0.5 to 2 g/ day [18, 49, 50].
The largest dose of lecithin used in a study ranged from 20 to 25 g/day [36].
Takeaway
Lecithin is a fatty compound rich in choline and other active components. It is most often extracted from soy, though many plant and animal fats contain lecithin.
Clinical studies indicate that lecithin supplementation may play a role in cholesterol, mental health, and liver health. Most other research has been limited to animals thus far.
