Lecithin: Benefits, Dosage, Contraindications

Cholesterol-lowering

Phospholipids exert a cholesterol-lowering effect. Thus, in patients suffering from hypercholesterolemia, soy lecithin supplementation significantly reduces plasma cholesterol levels. In hypercholesterolemic hamsters and rabbits, soy phospholipid supplementation increases HDL cholesterol levels and reduces the LDL/HDL ratio, a known risk factor for metabolic diseases. These effects are thought to be due to the fact that phospholipids can decrease the activity of microsomal HMG-CoA reductase (an enzyme involved in the cholesterol biosynthesis pathway) and the enterocyte absorption of cholesterol. They also increase the excretion of biliary cholesterol, lipid beta-oxidation, and plasma concentration of ApoA1 (Apolipoprotein A1 is the main protein component of antiatherogenic high-density lipoproteins HDL).

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Metabolic

A study conducted on rats demonstrated that rapeseed lecithin, rich in alpha-linolenic acid (ALA), when added without prior pre-emulsification, was able to induce a dose-dependent increase in the appearance of lipids and ALA in the lymph, which would be associated with an increase in the secretion and size of chylomicrons (lipid particles carrying triglycerides after digestion). Thus, vectorization of ALA in the form of phospholipids via lecithin from rapeseed would increase its bioavailability, compared to vectorization in the form of triglycerides in an oil. However, the study shows that the beneficial effect of rapeseed lecithin on lipid absorption becomes significant only at supplementation doses (30% of total lipids), much higher than those found in foods, which never exceed 10%. These data validate a dose-dependent effect of plant lecithins on lipid absorption. Independently of their dose, both lecithins induced changes in the intestinal microbiota in these mice, increasing the fecal abundance of Clostridium Leptum, a bacterial group described as anti-inflammatory. Rapeseed lecithin may additionally have a specific effect on bile acid metabolism by promoting bile acid elimination, whose accumulation can be toxic. Thus, these preclinical data demonstrate that the use of plant lecithins as an ingredient in a balanced diet does not induce any adverse effect on lipid metabolism. Soy and sunflower lecithins are among the only emulsifiers not to cause any major deleterious impact on the composition and pro-inflammatory potential of the intestinal microbiota.

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Hepatoprotective

Research results on animals suggest that lecithin may protect against alcohol-induced liver damage.a0 Moreover, the liver plays a central role in lipid metabolism and homeostasis. Several preclinical studies have demonstrated that replacing a fraction of dietary triglycerides with plant lecithins was associated with an improvement in the liver lipid profile with a reduction in hepatic triglycerides.

Neurological

Oral lecithin intake may increase serum choline levels, which is a precursor to acetylcholine. As a source of choline, lecithin was thought to help alleviate symptoms of cholinergic diseases such as Alzheimer's disease and tardive dyskinesia. However, oral lecithin intake does not appear to affect cholinergic neuronal function.

Anti-inflammatory

Supplementation with phosphatidylcholine resulted in a significant reduction in arthritis development in rats, potentially due to inhibition of the inflammatory response mediated by neutrophil leukocytes. Soy phosphatidylcholine can limit the inflammatory process in joints in a chronic mouse model of rheumatoid arthritis (collagen-induced arthritis) when administered during the onset of the disease. Pretreatment effectively prevented leukocyte adhesion to the endothelial layer and reduced inducible nitric oxide synthase (iNOS) expression, thereby reducing the degree of synovial angiogenesis. Therefore, lecithins could prove effective in reducing inflammatory reactions in arthritis and similar inflammatory processes.

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