Lecithin is a lipid molecule, which refers to a substance that is insoluble in water. It is a component of human cells, has a major role in cell communication and nutrient absorption, and plays a role in brain function. Lecithin has become a commonly used dietary supplement due to its many proposed benefits, including heart health, brain health, weight loss, and relief from joint pain, among others. With the increased use of lecithin supplements, several unpleasant lecithin side effects have been reported, including gastrointestinal problems, rashes, and weight gain.
There are many sources of lecithin in nature, including soybeans, eggs, and certain types of beans and nuts. Because the majority of lecithin supplements are made from soy products, lecithin is often referred to as soy lecithin. Lecithin supplementation has become quite popular, and lecithin is often added to protein drinks or health food bars. It can also be consumed as a tablet. In addition, it is also commonly added to many different foods to increase shelf life, increase thickness in products like margarine, or to prevent food stickiness during cooking or frying.
Lecithin appears to be generally safe for most people, and side effects are unusual in people consuming less than about 30 g per day. At higher levels, lecithin side effects have been reported, most commonly nausea, vomiting, or diarrhea. These higher levels are usually from supplementing with lecithin and would be almost impossible to reach when consuming a normal diet or from using food products that have been treated with lecithin.
Other lecithin side effects that may occur at high doses are bad breath and an unusual body odor that is usually described as “fishy.” Sudden weight gain is sometimes reported. On the other hand, some people may experience loss of appetite and sudden weight loss.
Less commonly, some people may experience a sudden drop in blood pressure if they take too much lecithin. A drop in blood pressure can be experienced as dizziness, sudden mental confusion, or actual fainting. This side effect is usually associated with very high lecithin intake or it may occur in someone whose blood pressure is already quite low.
Lecithin side effects may also result from an allergic reaction. This happens when the body perceives lecithin as a foreign pathogen and produces antibodies to attack it. An allergic reaction can be relatively mild and might involve sneezing, runny nose and eyes, or an itchy rash. More severely, this allergic reaction might result in a serious condition that necessitates medical attention, such as the throat closing, trouble swallowing, difficulty breathing, and anaphylactic shock.