You’re never too late to protect your brain from cognitive decline, according to a recent study published in the journal Molecular Nutrition and Food Research. New data offers a better understanding of the physiological factors related to the effect of diet on cognition as we age.

Led by Mireia Urpí-Sardá, adjunct lecturer and member of the Biomarkers and Nutritional & Food Metabolomics research group of the Faculty of Pharmacy and Food Sciences, the Institute for Nutrition and Food Safety (INSA-UB), the Food and Nutrition Torribera Campus of the University of Barcelona, and the CIBER on Frailty and Healthy Ageing (CIBERFES), the study was conducted over twelve years with 840 subjects over the age of 65.

The subjects were 65% women in the Bourdeaux and Dijon regions of France and were part of the Joint Programming Initiative "A Healthy Diet for a Healthy Life" (JPI HDHL).

Nutritious diet and cognition

Cristina Andrés-Lacueva, UB professor and head of the CIBERFES group states, "Within the framework of the study, a dietary metabolomic index has been designed -- based on biomarkers obtained from the participants' serum -- on the food groups that form part of the Mediterranean diet. Once this index is known, its association with cognitive impairment is evaluated."

Baseline levels of saturated and unsaturated fatty acids, gut microbiota-derived polyphenol metabolites and other serum phytochemicals that show individual bioavailability were chosen as biomarkers in this research.

Some of these factors have been seen as marks of exposure to the main food groups in a Mediterranean diet in addition to being seen as the reason for the health benefits of the Mediterranean diet pattern.

From the start of the study, the metabolome or set of metabolites -- related to food and created from gut microbiota activity -- was evaluated through a large-scale quantitative metabolomic analysis from the serum of the subjects without dementia.

Five neuropsychological tests were used to evaluate cognitive impairment over twelve years. The study indicates a protective association between the score of the Mediterranean diet based on serum biomarkers and a decline in cognition in older people.

Biomarkers to study the benefits of the diet

“The use of dietary pattern indices based on food-intake biomarkers is a step forward towards the use of more accurate and objective dietary assessment methodologies that take into account important factors such as bioavailability.", states Mercè Pallàs, professor at the UB Neurosciences Institute (UBneuro.

Expert Alba Tor-Roca, first author of the study and CIBERFES researcher at the UB, notes that "we found that adherence to Mediterranean diet assessed by a panel of dietary biomarkers is inversely associated with long-term cognitive decline in older people. These results support the use of these indicators in long-term follow-up assessments to observe the health benefits associated with the Mediterranean diet or other dietary patterns and therefore, guide personalized counseling at older ages."

The research was a collaboration with teams from the Department of Genetics, Microbiology, and Statistics of the Faculty of Biology and the Department of Pharmacology, Toxicology and Therapeutic Chemistry of the Faculty of Pharmacy and Food Sciences of the UB. Teams from the University of Bordeaux and the INRAE centre at Clermont-Ferrand University (France), King's College London (United Kingdom), the University of Amsterdam (the Netherlands), and the Parcelsus Medical University in Salzburg (Austria) have also participated.

Below are top foods and tips to protect cognition:

·         Eat more leafy green vegetables- kale, spinach, broccoli and other green leafy vegetables contain antioxidants to aid in the prevention of dementia. 2

·         Include blueberries in your diet. Blueberries are a source of anthocyanin, an antioxidant linked with the reduction of cognitive decline as part of the MIND diet. 3

·         Aim for two servings of fatty fish weekly. Omega-3-fatty acids in fish help reduce neuroinflammation that’s associated with cognitive decline. 4

·         Reduce red meat and processed meat. Both have been associated with an increased risk of dementia in a large UK study. 5

·         Beans or lentils-plant-based proteins are lower in fat and provide soluble fiber to help reduce cholesterol, a risk factor for cognitive decline.

·         Stay active. While WHO suggests 150 minutes of regular exercise weekly, older adults can still protect their memories with lower bouts of activity. 7

·         Maintain social contacts. Observational studies suggest that individuals who are socially active in mid-life and later life have a 30 to 50% less risk of cognitive decline. 8

·         Drink alcohol in moderation. Small amounts of alcohol may be protective against cognitive decline in individuals over 60. The key is moderation. 9

Lisa Andrews, MEd, RD, LD

References:

1.    Alba Tor‐Roca, Alex Sánchez‐Pla, Aniko Korosi, Mercè Pallàs, Paul J. Lucassen, Pol Castellano‐Escuder, Ludwig Aigner, Raúl González‐Domínguez, Claudine Manach, Francisco Carmona, Esteban Vegas, Catherine Helmer, Catherine Feart, Sophie Lefèvre‐Arbogast, Jeanne Neuffer, Hyunah Lee, Sandrine Thuret, Cristina Andres‐Lacueva, Cécilia Samieri, Mireia Urpi‐Sarda. A Mediterranean Diet‐Based Metabolomic Score and Cognitive Decline in Older Adults: A Case–Control Analysis Nested within the Three‐City Cohort Study. Molecular Nutrition & Food Research, 2023; DOI: 10.1002/mnfr.202300271

2.    Agarwal P, Leurgans SE, Agrawal S, Aggarwal NT, Cherian LJ, James BD, Dhana K, Barnes LL, Bennett DA, Schneider JA. Association of Mediterranean-DASH Intervention for Neurodegenerative Delay and Mediterranean Diets With Alzheimer Disease Pathology. Neurology. 2023 May 30;100(22):e2259-e2268. doi: 10.1212/WNL.0000000000207176. Epub 2023 Mar 8. PMID: 36889921; PMCID: PMC10259273.

3.    Liu X, Morris MC, Dhana K, Ventrelle J, Johnson K, Bishop L, Hollings CS, Boulin A, Laranjo N, Stubbs BJ, Reilly X, Carey VJ, Wang Y, Furtado JD, Marcovina SM, Tangney C, Aggarwal NT, Arfanakis K, Sacks FM, Barnes LL. Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) study: Rationale, design and baseline characteristics of a randomized control trial of the MIND diet on cognitive decline. Contemp Clin Trials. 2021 Mar;102:106270. doi: 10.1016/j.cct.2021.106270. Epub 2021 Jan 9. PMID: 33434704; PMCID: PMC8042655.

4.    Saleh RNM, Minihane AM. Fish, n-3 fatty acids, cognition and dementia risk: not just a fishy tale. Proc Nutr Soc. 2022 Mar;81(1):27-40. doi: 10.1017/S0029665121003700. Epub 2021 Oct 11. PMID: 34632980.

5.    Zhang H, Greenwood DC, Risch HA, Bunce D, Hardie LJ, Cade JE. Meat consumption and risk of incident dementia: cohort study of 493,888 UK Biobank participants. Am J Clin Nutr. 2021 Jul 1;114(1):175-184. doi: 10.1093/ajcn/nqab028. PMID: 33748832; PMCID: PMC8246598.

6.    Kishida R, Yamagishi K, Maruyama K, Okada C, Tanaka M, Ikeda A, Hayama-Terada M, Shimizu Y, Muraki I, Umesawa M, Imano H, Brunner EJ, Sankai T, Okada T, Kitamura A, Kiyama M, Iso H. Dietary intake of beans and risk of disabling dementia: The Circulatory Risk in Communities Study (CIRCS). Eur J Clin Nutr. 2023 Jan;77(1):65-70. doi: 10.1038/s41430-022-01188-1. Epub 2022 Aug 11. PMID: 35953593.

7.    Gallardo-Gómez D, Del Pozo-Cruz J, Noetel M, Álvarez-Barbosa F, Alfonso-Rosa RM, Del Pozo Cruz B. Optimal dose and type of exercise to improve cognitive function in older adults: A systematic review and bayesian model-based network meta-analysis of RCTs. Ageing Res Rev. 2022 Apr;76:101591. doi: 10.1016/j.arr.2022.101591. Epub 2022 Feb 17. PMID: 35182742.

8.    Sommerlad A, Kivimäki M, Larson EB, Röhr S, Shirai K, Singh-Manoux A, Livingston G. Social participation and risk of developing dementia. Nat Aging. 2023 May;3(5):532-545. doi: 10.1038/s43587-023-00387-0. Epub 2023 May 18. PMID: 37202513.

9.    Mewton L, Visontay R, Hoy N, Lipnicki DM, Sunderland M, Lipton RB, Guerchet M, Ritchie K, Najar J, Scarmeas N, Kim KW, Riedel Heller S, van Boxtel M, Jacobsen E, Brodaty H, Anstey KJ, Haan M, Scazufca M, Lobo E, Sachdev PS; Collaborators from the Cohort Studies of Memory in an International Consortium (COSMIC). The relationship between alcohol use and dementia in adults aged more than 60 years: a combined analysis of prospective, individual-participant data from 15 international studies. Addiction. 2023 Mar;118(3):412-424. doi: 10.1111/add.16035. Epub 2022 Sep 4. PMID: 35993434; PMCID: PMC9898084.