Nutrition, neurogenesis and the ageing brain

D R S O P H I E M I Q U E L : S E N I O R P R I N C I PA L S C I E N T I S T, M A R S I N C D R J O N D AY: D I R E C TO R , C E R E B R U S A S S O C I AT E S

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Overview

• The ageing population and cognitive health

• Nutritional intervention, cognitive benefits and neurogenesis

• Activities and outcomes

• Summary

The ageing population

By Fobos92 (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)] via Wikimedia Commons

+80 +77.5 +75 +72.5 +70 +67.5 +65 +60 +55 +50 +45 +40 -40

Age demographics

1950 2050 2010 2100

World population: The world in 2100 https://www.economist.com/blogs/dailychart/2011/05/world_population via @TheEconomist

The population pyramid is changing

Growing number of people with dementia

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Low- & Middle-income High-income

WHO, 2012

A global grand-challenge

• Between 2015 and 2030 the number of people aged 60 years or over is predicted to grow by 56% from 901 million to 1.4 billion

• All nations will need to spend more on healthcare to treat and manage dementia and other age-related cognitive-diseases

• By 2050, increases in the ageing population will present significant economic and social challenges, and the burden for healthcare systems will become enormous

• The current cost of dementia alone is $818 billion worldwide. By 2030, it is expected to reach $2 trillion.

United Nations, D.o.E.a.S.A., Population Division, World Population Ageing 2015. 2015: New York. p. 164. Alzheimer's Disease International, World Alzheimer Report 2015: The global impact of dementia - an analysis of prevalance , incidence, cost and trends. 2015, Alzheimer's Disease International: London. p. 87.

A global response is required

It is becoming widely accepted that lifestyle changes are the best protection against dementia, creating a massive opportunity for nutritional products (Wesnes).

Lexical cluster analysis. Terms: cognitive+decline+diet. Database: PubMed

Nutritional interventions, cognitive benefits and

neurogenesis

Ageing

• Ageing is a highly complex process marked by succeeding events that promote alterations in the normal functioning of an individual organism over time and that include many common chronic neurodegenerative diseases

• The mechanisms controlling the neuronal degeneration which cause these diseases (and normal brain ageing) remain elusive

Designed by kjpargeter / Freepik

Nutrition and cognitive decline (1)

• Cognitive function declines from early adulthood onwards, even in healthy individuals free from disease

• This decline starts in the twenties, affects many dimensions of cognitive function, is large in magnitude, and occurs in all individuals

• The rate and severity of cognitive decline during normal ageing can be attenuated through:

• Improved nutrition

• Appropriate dietary supplementation

• Increased physical exercise

• Performance of mental exercises

Intervention

Adult hippocampal neurogenesis

Cognition

Nutrition and cognitive decline (2)

• Research in healthy individuals or at the early stage of cognitive decline has demonstrated the beneficial impact of nutrition on cognitive functions:

• Polyphenols and polyphenol-rich diets

• Flavonoids

• Vitamins

• Long-chain ω-3 Poly-unsaturated fatty acids (EPA & DHA)

• Calorie restriction

• Ketogenic diets

Intervention

Adult hippocampal neurogenesis

Cognition

Neurogenesis and healthy cognitive ageing

• The prefrontal cortex and hippocampal formation are influenced by ageing and are thought to contribute to age-related cognitive decline

• Human and animal studies have found that the most consistent age-related changes occur within the dentate gyrus (DG)

• Neurogenesis in the DG persists into adulthood and is linked with cognition and mood. However, neurogenesis declines with normal ageing

• Determining the extent to which neurogenesis in the DG can be modulated by lifestyle and diet is, therefore, an attractive focus of research

Gazzaley, Cooney, Rissman & D’Esposito. Nat. Neurosci. 8, 1298–1300 (2005) Small, Stern, Tang, & Mayeux. Neurology 52, 1392–1396 (1999) Morrison & Baxter. Nat. Rev. Neurosci. 13, 240–250 (2012) Brickman. Nat. Neurosci. 17, 1798–1803 (2014) Erikson et al. Nat. Med. 11, 1313 - 1317 (1998) Zainuddin & Thuret. Br Med Bull 103, 89-114 (2012)

Mastication, nutrition and healthy cognitive ageing

• Factors such as exercise and diet enhance adult hippocampal neurogenesis

• Experimental studies using animals have found that impaired masticatory function results in:

• Physical changes: decreased proliferation of neural stem cells in the hippocampus

• Behavioural changes: decreased learning and memory ability

• In humans, tooth loss and masticatory difficulty are positively correlated with having greater odds of cognitive impairment

Neuroprotection

• Research currently focusses on interventions in lifestyle, diet, obesity, and the intake of nutrients, micronutrients and dietary components such as the phytochemicals

• One family of phytochemicals that is of interest is the flavanoids as they are able to interact with the cellular and molecular architecture of the brain

• A body of emerging evidence suggests that flavanoids, phenolics, and carotenoids confer a range of effects that may support health and improve quality of life

Spencer, Vauzour & Rendeiro. Arch. Biochem. Biophys. 492, 1–9 (2009) Brickman. Nat. Neurosci. 17, 1798–1803 (2014) Created by Dragana_Gordic - Freepik.com

Activities and outcomes

ILSI Europe: Nutrition and Mental Performance Task Force

Through its workshops, ILSI Europe enables renowned experts to discuss and debate…

1. The potential for maintaining cognitive function via dietary interventions (2014)

2. The mechanisms and timeframes of brain ageing (2016)

3. The question of when neuroprotection via nutrition can begin (2018)

ILSI Europe: Nutrition and Mental Performance Task Force

Themes of the 1st workshop:

• Setting the stage of nutrition for ageing brains

• Mechanisms of ageing and neuroprotection via nutrients

• Individual variation in maintaining brain health

• Cognition and diet

• Methodological challenges – finding solutions

ILSI Europe: Nutrition and Mental Performance Task Force

Themes of the 2nd workshop:

• Mechanisms of ageing and impact of nutrients

• New avenues in cognitive ageing and nutrition

• Challenges in investigating the role of nutrition on cognitive performance

• Multi-component and multi-domain interventions

• Relevance to public health

ILSI Europe: Nutrition and Mental Performance Task Force

Themes of the 3rd workshop:

• Impact of nutrition on brain functions using neuroimaging technologies

• Microbiome and immune status: Impact on brain function

• Biomarkers of food intake and cognitive health

• Sleep deprivation: effects on diet and cognitive performance

• New methodologies applied to dementia and how nutrition could play a role

Summary

Can we eat our way to healthy cognitive ageing?

• Age- and diet-induced effects on brain function are facilitated by changes in the levels of circulating factors

• Dietary interventions that tip the balance of factors towards a rejuvenating milieu are potentially effective means to promote healthy ageing by enhancing stem cell function and neurogenesis

• Further studies, especially in humans, are warranted to ascertain whether mastication could be used as a potential health intervention to slowdown cognitive decline in the ageing population or delay the onset of diseases such as dementia

Thank you for your attention

D R S O P H I E M I Q U E L : S O P H I E . M I Q U E L @ E F F E M . C O M D R J O N D AY: J O N @ C E R E B R U S .O R G

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