Lecture 11-14: nutrition for the ageing brain Flashcards
Total brain volume decreases upon ageing (from age of 30, each decade = 2-3% reduction in brain weight) in both grey + white matter
True/false
true. Mostly prefrontal cortex & hippocampus
- Volume decrease partly due to ..
Changes in neurons:
- neuronal size
- no of synapses
- loss of myelin sheets
What two things also happen with an ageing brain?
White matter hyperintensities
Neurotransmitters
- Change in two ways: altered production & receptors (decline or upregulated)
- Dopamine and serotonin most affected by ageing, alongside profound changes in acetylcholine (Ach) production.
Protein aggregation happens upon ageing. This is always via differnt mechanisms
true/false
true
What are sirtuins?
Class of NAD+-dependent signalling proteins involved in metabolic regulation (they can silence genes)
- Sensors amounts of energy, day light, stress ~ cellular distress
- Promote cell survival and health
- Play a critical part in ageing/longevity = neurodegeneration
Inflammageing leads to activation of X in the brain
microglia
When we age, there is always more activation of microglia. What do they do?
They support the neurons and form myelin around the neurons. They also serve a immunological function.
When we age, there is more production of pro-inflammatory, instead of anti-inflammatory cytokines (inflammageing)
In brain: this leads to more
reactivation of the microglias (=marker)
X = Collective term of all degenerated protein/lipid/nucleic molecules, damaged bc of anchored sugar molecules
AGEs: Advanced Glycation End products
By what reaction are AGEs formed?
maillard reaction (sugar attaching to protein. Hours/days) in your body – long lived, irreversibly formed.
AGEs bind to receptors (RAGEs) (also in brain). This increases
an inflammatory response
What two types of intelligence are there
Fluid (novel-processing), Crystallized (Learned – knowledge)
What happens to these types of intelligences upon ageing?
crystallized: increases
Fluid: decreases
What is ‘successful’brain ageing?
Successful: ‘brain reserve’ (structure: you were born with a particular size. Changes up to 18, also education plays a role here) + ‘cognitive reserve’ (relate to circuitry in brain: ways to get jobs done, synaptic connections)
X explains the difference in neuropathology upon ageing
High vs low brain reserve (you were born with a particular size)
What other dementias are there besides alzheimers?
vascular dementia
lewy body dementia
frontotemporal dementia
other
MCI = mild cognitive impairment
Another form of cognitive impairmnet: effect can maybe be reversed. What is it called?
SCD = Subjective clinical decline.
It is possible that some persons with the same amount of protein aggregates develop alzheimer’s and some don’t.
true/false
true
symptoms of MCI?
cognitive changes of concern to individual and family
one or more cognitive domains impaired significantly
preserved activities of daily living
Normal ageing = Neuronal loss only in X.
Few tangles is normal/not normal
hippocampus
Normal
Alzheimers disease is characterized by
Protein aggregation:
= amyloid-beta & tau
Formation of plaques & tangles
Neuronal death
Taking out amyloid-beta will decrease disease symptoms
true/false
false
Risk factors for abnormal brain ageing + %s?
Non-modifiable risk factors (60%)
- Genes
- Age
Modifiable risk factors (40%)
- Dietary components -> indirect
Alcohol intake, Obesity, Diabetes, Hypertension
Lifestyle-related factors (18-20%)
- Not a one-on-one relationship (more sports = maybe change in diet)
What is an important genetic risk factor for AD? What is it?
ApoE: Apolipoprotein E
Plays a role in the transport of fat & cholesterol in brain
Three variants of ApoE?
- e2: protective (epsilon)
- e3: neutral
- e4: increases (+29%) wit one allele
Why is e4 allele increasing the risk of alzheimers?
e4: shift towards use of omega-3-fatty acids as brain fuel
exact mechanism unknown
Q: “AGEs (advanced glycation end product) are irreversibly formed. Which statements below about “AGEs” are true?
A: (1) AGEs are formed via the Maillard reaction
(2) They can be formed both endogenously and exogenously
(3)AGEs are not harmful
(4) AGEs are in fact the covalent attachment of a sugar to a protein
1, 2, 4
Q: “When does age-related cognitive decline begin?”
A: “From the age of 20-30”
B-vitamins: B6, B12 + folate, why are they important in healthy brain ageing?
They regulate the homocysteine metabolism.
B6 is needed to convert homocysteine into cysteine.
B12+folate also play a role.
Homocysteine = risk factor alzheimers disease. > One of metabolites (cysteine) destroys neurons (in rats).
In what food sources can you find B6, B12, folate?
B6: wholegrains, nuts, seeds, animal products
B12: animal products (liver), dairy (fortified)
Folate: Leafy veg, animal products
What are possible explanations for mixed results of vit B +cognitive decline in RCT’s ?
- Study population (baseline level, cognitive state)
- Beneficial (interactive) effects of B-vitamins on other nutrients (omega-3-fatty acids: when levels are too low, vit D does not work. So, a lot of interactive effects)
What nutrients are needed to make serotonine?
- B6, B3, zinc, folate, magnesium (tryptophan
-> 5HTP) - B6, C, zinc, folate, magnesium (5HTP-> serotonine)
What nutrients are needed to make dopamine/noradrenaline?
- B6, folate, iron (Tyrosine -> L-dopa)
- B6, magnesium (L-dopa-> dopamine)
- C, copper (dopamine ->noradrenaline)
What nutrients are needed for high amount of anti-oxidants?
carotenoids/vit C/vit E/trace elements/flavonoids/polyphenols
Vit d + brain = unclear proof, only observational. What are the guidelines?
women 50-69: 10 microgr/day + women and men with medium skin tone
20 microgr/day for men and women 70 or older
What form of vit D is measured in the blood?
Calcidiol
In kidneys, calcidiol is transformed into..
calcitriol (25(OH)D3): active metabolite binding to receptors
Q: “Which statement is false?”
A: (1) B-vitamins are necessary for homocysteine metabolism, the latter which is considered a risk measure in plasma for dementia
(2) An optimal omega-3-status is necessary in order for vit-B supplements to work properly
(3) B-vitamins are not important as cofactors for neurotransmitter synthesis (eg serotonin/dopamine)
(3) B-vitamins are not important as cofactors for neurotransmitter synthesis (eg serotonin/dopamine)
Q: “Which of these statements is true?”
A: (1) “Vit D needs to be supplemented (10 microgr/day) to older aults from the age of 70 onwards, irrespective of gender, including individuals with a medium skin tone
(2) Vit D needs to be supplemented to all women between 60-69 (10 mirogr) and to both men and women from the age of 70 onwards (20 microgr) all of this includes men with medium skin tone, living far away from the equator
(3) Vit D needs to be supplemented to males from the age of 60 onwards, only in Caucasian individuals
(2) Vit D needs to be supplemented to all women between 60-69 (10 mirogr) and to both men and women from the age of 70 onwards (20 microgr) all of this includes men with medium skin tone, living far away from the equator
