The value of lipids in the prevention of age-related cognitive and visual disorders
With the constant increase in the number of senior citizens in our society and the prevalence of age-related pathologies, the ageing of the population has been a major public health issue since the early 2000s. Diet is an environmental factor to which the individual is exposed during his or her life and on which it is possible to act to contribute to delaying the appearance of memory and visual deficits linked to ageing.
In the specific case of lipids, the public authorities have recently reiterated the importance of their consumption, and in particular omega-3 fatty acids, in people over 65 years of age in order to prevent the appearance of cognitive and ocular disorders during the ageingprocess.
What about lipids in the prevention of cognitive disorders?
In this context, ITERG has participated alongside academic partners in various projects on the theme of "lipids and the brain", within the framework of the UMT ACTIA[3 ] "Lipid nutrition and cerebral ageing"[4 ] (2006-2011) and "Nutrition, lipid nutrients and the brain (ALICE)"[5 ] (2011-2016), the objective of which was to identify the nature and quantity of lipids to be included in the diet in order to prevent brain ageing.
It has thus been shown in preclinical models (i) that an inadequate intake of omega-3 fatty acids induces neurobiological alterations in young people similar to those described in the elderly, associated with an increased risk of cognitive decline or dementia during the course of ageing; (ii) the value of joint supplementation with omega-3 fatty acids and vitamin A to preserve memory, which is impaired during ageing; (iii) the beneficial role of omega-3 fatty acids in the regulation of cerebral inflammation.
ITERG and its partners have confirmed these data in humans with a nutritional study aimed at evaluating the impact of an ingredient formula enriched with omega-3 fatty acids and vitamin A on the improvement of memory capacity and well-being in healthy elderly subjects (NutriMémo project) (results in the process of publication).
All these data have been confirmed by epidemiological data collected on large cohorts of elderly subjects (EVA, 3-Cities), which argue in favour of the consumption of omega-3 fatty acids and olive oil to prevent cognitive and memory decline,.
A similar picture emerges in terms of prevention of visual impairment
In the course of ageing, the lipid diet may also be a factor to be acted upon to prevent the appearance of certain visual acuity disorders, such as age-related maculopathy, which can evolve into macular degeneration (AMD).
ITERG has participated in various studies coordinated by the "Lifelong Exposures, Health and Aging" team of the Bordeaux Population Health research centre. The objective of these studies was to better characterise the role of lipid and fat-soluble nutrients, and their interactions, in the etiology of AMD. The PIMAVOSA study[13 ] showed a relationship between macular pigment density (present in the centre of the retina) and plasma concentrations of various nutrients, including long-chain omega-3 fatty acids, in healthy subjects, suggesting a synergistic action of these nutrients in macular pigment accumulation and protection against AMD. This work led to the LIMPIA nutritional intervention study, which demonstrated the beneficial impact of supplementation with long-chain omega-3 fatty acids and carotenoids in subjects with AMD parents. Finally, ITERG also took part in the BLISAR project aimed at better understanding the role of omega-3 fatty acids, cholesterol metabolism and their interactions in AMD (results in the process of publication).
All of this data therefore shows the essential role of lipids in our diet, via the consumption of oils rich in omega-3 fatty acids (rapeseed, walnuts), olive oil and fish, in the prevention of cerebral ageing.
[2 ] https://www.actia-asso.eu/umt-presentation/
 In collaboration with the Nutrition and Neuroscience Unit U2N (EA 2975, Universities Bordeaux 1 and 2).
 In collaboration with the Laboratory of Nutrition and Integrated Neurobiology NutriNeuro (UMR1286 INRA, University of Bordeaux).
 Buaud et al., 2007; doi: 10.1051/ocl.2007.0117 ׀ Buaud et al., 2010; doi: 10.1017/S0007114509993886 ׀ Létondor et al., 2014; doi: 10.1017/S0007114514002529 ׀ Létondor et al., 2016; doi: 10.3389/fnagi.2016.00103 ׀ Rey et al., 2016; doi: 10.1016/j.bbi.2015.12.013 ׀ Rey et al., 2018; doi: 10.1016/j.plefa.2018.04.003 ׀ Rey et al., 2019; doi: 10.1016/j.bbi.2018.07.025.
[9 ] https://epidemiologie-france.aviesan.fr/epidemiologie-france/fiches/cohorte-des-3-cites/fre-fr
 Heude et al, 2003; doi: 10.1093/ajcn/77.4.803 ׀ Berr et al., 2009; doi: 10.1159/000253483. https://anr.fr/Projet-ANR-06-PNRA-0005
[12 ] https://www.bordeaux-population-health.center/les-equipes/expositions-vie-entiere-sante-vieillissement-leha/
 Delyfer et al., 2012; doi: 10.1167/iovs.11-8721.
 Merle et al., 2017; doi: 10.1111/aos.13408.