Vegetable lecithins, natural ingredients of nutritional interest

Vegetable lecithins are mixtures of natural lipids composed of more than 50% of a specific form called phospholipid. Lecithins are commonly used by the food industry in the foodstuffs on our shelves for their emulsifying and thickening properties. Their presence in food products is mentioned on the label as E322, even though they are natural molecules.

Soy lecithins are currently the most widely used. In the current context of sustainable food, lecithins from rapeseed and sunflower are interesting alternatives to be explored.

Phospholipids in our body

Phospholipids are naturally present in our bodies as major components of biological membranes. They are involved in a large number of physiological processes. Due to their composition, plant lecithins are important sources of these phospholipids.

In recent years, phospholipids, particularly those of marine origin, have been the subject of growing interest due to their ability to increase the bioavailability and incorporation of fatty acids from our diet into certain target tissues such as the brain, liver or muscle.

Some vegetable lecithins, such as those from rapeseed and soya, offer an additional advantage because of their high alpha-linolenic acid (ALA) content, a precursor of omega-3 fatty acids.

The health benefits of plant lecithins: promising results

In the framework of the UMT ACTIA BALI "Biodisponibilité Alimentation Lipides Intestin¹ITERG and the DO-IT team of the CarMeN² laboratory have evaluated the health effects associated with certain plant lecithins.

The joint investigations showed that vegetable lecithins are ingredients with diverse and complex lipid profiles and biochemical properties.

For the first time, our work has shown that for an equivalent intake of ALA, the addition of rapeseed lecithin to rapeseed oil increases the intestinal absorption of ALA. This beneficial effect of rapeseed lecithin is only significant at so-called supplementation doses (i.e. for an intake of lecithin greater than 10% of total lipids, 30% in the case of this study), which are much higher than those found in food, which are generally between 1 and 3%.³.

We also compared the impact of rapeseed lecithin vs. soy lecithin (both ALA-rich plant lecithins) on metabolic health, as an ingredient (≤ 10% of total fat) in a normolipid diet⁴. This approach showed that at nutritional doses, both lecithins do not induce changes in lipid metabolism. At the same time, this study demonstrated a little-known impact of plant lecithins on the intestinal microbiota: rapeseed and soy lecithins increased the faecal abundance of a bacterial group described as being anti-inflammatory. Rapeseed lecithin is also thought to have a specific effect on the metabolism of bile salts (involved in the digestion of dietary fats), as its consumption promotes the elimination of these compounds, the accumulation of which can be toxic to our health. These data show that, in the short term, the use of vegetable lecithins as an ingredient in a balanced diet could have beneficial effects on the intestinal microbiota, unlike certain synthetic emulsifiers which have been described as being able to modify the composition of the microbiota in a way that could promote intestinal inflammation.

In summary

Together, these data offer encouraging initial results for the use of vegetable lecithins as natural emulsifiers in foods.

Due to their phospholipid content, lecithins can modulate lipid metabolism and exert liporegulatory, anti-inflammatory and anti-oxidant effects. In this respect, they could play a preventive role in metabolic disorders (such as obesity) and cardiovascular disorders. However, it is necessary to make a clear distinction between their role as a nutraceutical supplement (intake of more than 10% of total lipids) and their use as an ingredient (intake of less than or equal to 10% of total lipids) in different types of food^5,6.

These data, related to the study of the metabolic impact of plant lecithins, were obtained within the framework of a CIFRE-funded thesis, as well as with the support of ITERG, the Nouvelle Aquitaine Region, the ERDF and Terres Univia (Interprofessional association for plant oils and proteins).

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¹https://www.actia-asso.eu/projets/bali/

The joint technological unit (UMT) is a partnership tool between a technical institute and a public research unit, set up and supported by the Ministry of Agri-food, under the coordination of the ACTIA (Technical Coordination Association for the Agri-food Industry).

^2UMRINRAE1397 - INSERM U1060 / Université-Lyon1 - Cardiovascular Metabolism Diabetology and Nutrition Research Laboratory (CarMeN), Team 1 "Diet and food matrix in Obesity and metabolic diseases: role of Intestinal tract and innovative Therapeutics (DO-IT)

^3Robertet al, The Journal of Nutrition, 2020. doi: 10.1093/jn/nxaa244.

^4Robertet al, Molecular Nutrition and Food Research. 2021. doi: 10.1002/mnfr.202001068.

^5Robertet al, Biochemistry. 2020. doi: 10.1016/j.biochi.2019.11.017.

^6Robertet al, Cahiers de Nutrition et Diététique, 2021. doi: 10.1016/j.cnd.2021.06.002.