Consuming dietary fiber may reduce the risk of dementia in older adults more prone to Alzheimer's. The evidence emerges from a study conducted in Italy, on a community of people housed in social and health residences. (1)
The beneficial function of dietary fibers
Consumption of fruits, vegetables, whole grains and other sources of dietary fiber is unanimously recognized as beneficial to health. Dietary guidelines indicate an optimal dietary fiber intake of 30-35 g/day for men and 25-32 g/day for women in adults. (2)
The intake of dietary fiber, along with other nutrients, was also associated with improved brain integrity, such as higher total brain volume and lower white matter hyperintensity volume in older adults without dementia, the study authors note.
The impact of dietary fiber on cognitive function could be mediated by its influence on the gut microbiota. Dietary fiber intake shapes the composition and/or functionality of the gut microbiota, increasing the production of fermentative end products, such as short-chain fatty acids (SCFA). These metabolites have shown the potential to modulate brain function through the 'microbiota-gut-brain' axis.
Dietary fibers against Alzheimer's
Il the team. international group of researchers (US, Spanish and Italian) on these premises evaluated the relationship between dietary fiber intake and the incidence of cognitive decline in a prospective study on elderly residents in the community, the Invecchiare in Chianti study, the aging in the Chianti area (InCHIANTI).
A systematic review affected 848 over-65 (56% females), with an average age of 71 years. For 15 years, every three years, the researchers looked at their diet, cognitive conditions and other health parameters.
The result
In the 15 years In general, a correlation between fiber consumption and cognitive decline did not emerge from observation.
In the elderly with the APOE4 gene (associated with an above-average Alzheimer's risk), however, it emerged that a daily consumption of 5 grams of dietary fiber is markedly associated with a 30% lower risk of cognitive decline.
The APOE4 gene
The APOE4 gene is recognized as an indicator of the risk of dementia, which however must be reconciled with lifestyle, the diet it's the age. The fear of relatives of people with Alzheimer's of contracting the same pathology has fueled a business of unreliable predictive analytics.
In the scientific field, however, new reliable and non-invasive diagnostic methods are on the way. The first study on the subject is Italian. In the Interceptor project, preparatory to the application of the new diagnostics, 400 people at risk are enrolled to predict the conversion of mild cognitive decline into Alzheimer's dementia. (3)
The project it is promoted and supported by the Ministry of Health and Aifa, the Italian Medicines Agency, in collaboration with the Istituto Superiore di Sanità and Aima, the Italian Association for Alzheimer's Disease. The Agostino Gemelli IRCCS University Hospital Foundation coordinates and participates together with a network of 20 Italian neurological structures.
Marta Strinati
Footnotes
(1) Andrea Unión-Caballero, Tomás Meroño, Cristina Andrés-Lacueva, Nicole Hidalgo-Liberona, Montserrat Rabassa, Stefania Bandinelli, Luigi Ferrucci, Massimiliano Fedecostante, Raúl Zamora-Ros, Antonio Cherubini. Apolipoprotein E gene variants shape the association between dietary fiber intake and cognitive decline risk in community-dwelling older adults. Age and Aging, Volume 52, Issue 1, January 2023, afac329, https://doi.org/10.1093/ageing/afac329
(2) Dario Dongo, Carlotta Suardi. Whole grain and fiber, long healthy life. GIFT (Great Italian Food Trade). 25.1.19
(3) The Interceptor project is described in the official site https://www.interceptorproject.com/
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".
