Nutrition

Question 1

What are the ramification of living longer?

Answer 1

• we are now living longer but the prevalence of neurodegenerative diseases is increasing. This put a strain on the NHS. There is difference between life span and health span. If health span is low quality of life is low.

Question 2

who is Robert Katzman?

Answer 2

• he was one of the first clinicians to identify cognitive reserve. He found in group of elderly people with an average age 85.5 years there was inconsistency between biological measures of alzheimer’s and clinical symptoms. The research was done post mortem and he noted some individuals had extensive pathologies but these people had no symptoms e.g no memory decline. This pattern was in the brains that were heavier and had more neurones compared to the control group. This research enter cognitive reserve into the literature.

Question 3

what is cognitive reserve?

Answer 3

the capacity of the brain to sustain the effects of disease without manifesting clinical symptoms.

Question 4

what factors can increase cognitive reserve ?

Answer 4

• mental stimulation
  -active life style
• social stimulation
• cognitive remediation
  -physical activity

Question 5

what factors reduce cognitive reserve ?

Answer 5

-poor education
-mood disturbances
-poor nutrition
-alcohol/ drug abuse
poor health

Question 6

what is one of the strongest predictors of late onset dementia ? (research)

Answer 6

-mental ability in childhood. eg IQ
-Starret (2000) - a Scottish study that tracked intelligence in individuals between 11 and 77 years
- late onset dementia could be independently predicted by low childhood mental ability
-This research tell us that anything that can improve cognitive development has the potential to prevent cognitive decline e.g before birth and in childhood
-START YOUNG

Question 7

How can nutritions reduce dementia? (brain shrinkage )

Answer 7

-as we age our brain shrinks
-its starts from about 20 onwards
-way before an clinical symptom’s manifest they brain can be change which can indicate dementia e.g 40 years
-this knowledge lets us know that anything we can do to reduce brain atrophy has the potential to prevent cognitive decline.
-on average you lose 5-10% of brain weight between 20 to 90 years of age
- with Alzheimer’s and dementia you lose a substantial amount of neurones, in serve cases of alzheimer’s someone can lose 20% of the brain weight
- realistically reversing these changes is no going happen, therefore research should be focused on slowing the process or reducing the impact
-nutrtions can increase plasticity of neurones but not to a great degree

Question 8

what are the 3 different way diet can alter the aging brain?

Answer 8

1. diet in critical period of brain development can alter aging
2. short -term optimal function, using existing capacity to the full
   - slowing developing of the diseases in the brain

Question 9

what are the methological challenges to research the aging brain in relation to nutrition?

Answer 9

• this research relies of retrospective recall .e.g food food diaries or questionaires, you don’t actually get nutitions biomarkers. Therefore you are relying on a person memory to tell you what they ate instead empirical evidence.
• this research ideally occurs over a lifespan, its hard to do nutrition interventions with large control trails to determine cause and effect. therefore is it only correlations design research. Other factors eg economical factors or do they smoke ?
  -intervention trails are more likely to happen in animals but its hard to generalise these findings to humans
  -reverse causality - we know nutrition can alter cognitions however cognitions can alter diet e.g impulsively, and the question becomes what is causing what? directional issues
  -most effects on the brain come from nutrition deficiency however its completely unethical to create nutrition deficiency in humans. You could look at a population that is natural defiance however there are endless variables you don’t have control over compared to a controlled trail.

Question 10

what is oxidative stress?

Answer 10

-aging can be caused by oxidative stress.
- alzheimers is caused by a loss of neurones, oxidative stress can do this.
-Our brains are so metabolically active and relies on oxidative phosphorylation
-anything that is exposed to high levels of oxygen and metabolism is subject to oxidative stress.e.g then fruit is left in oxygen and goes gross because it gradually decades

Question 11

what is the free radical theory of aging ?

Answer 11

-aging is caused by cumulative oxidative damage to cells by are radicals produced during aerobic respirations
-the brain is a highly metabolic organ (lots of aerobic respiration) that relies on oxidative phosphorylation to produce energy
- this consequently produces free radicals which are reactive oxygen species (ROS) and reactive nitrogen species (RNS), these cause damage to cells.

Question 12

what is the problem with free Radicals?

Answer 12

-a molecule has electrons, and electrons like to be in pairs, then they are in pairs they are stable and unreactive
-free radicals are molecules that have unpaired electrons, so they are highly reactive, they go around tearing to other molecules to gain an electron so its paired up. This is damaging other cells.
-antioxidant have a beneficial effect as it can dominate an electron to a free radical so its stabilises
- if we consume enough antioxidant in our diet to deal with the free radicals it could help slow down the aging process

Question 13

what is the link between oxidative stress and inflammation?

Answer 13

• when free radicals cause damage to healthy cells our immune system gets activated causes a low grade inflammatory response. This increases systemic inflammation in the body potentially in the nervous system as well.
  -The issue is chronic inflammation cells and immune cell products free radicals so inflammation causes oxidate stress again, its a vicious cycle
  -we want a diet to break this cycle

Question 14

what is the definition of inflammation?

Answer 14

-a biological responce to harmful stimuli e.g bacteria or damaged cells
-involves immune cells and vasculature
-there are 2 types of inflammation: acute which is sudden onset and has a short duration e.g hours or days. And chronic which is gradual and long durations days to years. (can happen from diabetes)

Question 15

how has genetic studies linked inflammation and AZ?

Answer 15

• its been found that over 60% of genetic risk of AZ is from microgila which is the brains immune cells.
  -we don’t know if the brain immune response is causes AZ or the immune system is activated by AZ pathology and the damage to cells

Question 16

what evidence do we have for the role of immune function in Aging az and dementia ??

Answer 16

Observational research has shown elevated levels of inflammatory proteins in blood and cerebral spinal fluid in people with az and dementia ( cant determine cause and effect)
- post-mortem studies have shown that people that had dementia and az had microglial activation in the brain ( brain immune protein) - however can go back to the argument that was it activate because of az pathologies, or was az cause by it?
-Pharmaco-epiemological studies- shown people who were on inflammatory for a long time for a different medical reason had less of a chance of developing dementia or az - however the results can be disappointment because the clinical traits are too short.

Question 17

what did walker et al (2017) find?

Answer 17

• they had 133 participants and found over 24 years that people who had elevated inflammation markers in the blood had small brain volume and worse memory. Issue is it was measure inflammatory in the blood stream not the central nervous system which would be better but we don’t have the technology for that.

Question 18

what is vitamin c ?

Answer 18

• an antioxidant ( could reduce oxidative stress reducing the brain aging).
• in citrus fruit, peppers, tomatos
• its a water-soluble so you need it everyday because its passed out by urine (fat-soluble can stay in the body in the fat)
  -it protects proteins,lipids, carbohydrates and nucleic acid for damage from from free radicals

Question 19

what was the Rotterdam study? (2000)

Answer 19

-they found people consuming the most vitamin c had low odds of developing az.
- people taking lots of vitamin e had 40% reduction in their chance of getting az.

Question 20

what is vitamin e?

Answer 20

• an antioxidant ( could reduce oxidative stress reducing the brain aging).
• its a collective name for 8 fat -soluble vitamins
  -nuts olives,greens, leafy veg
  -the brain is a fatty organ so its very susceptible the oxidative stress e.g damage from free radicals . Vitamin e is a good anti-oxidant prectector for the brain .

Question 21

what is beta-carotene?

Answer 21

• basically in anything you eat that is orange / red/yellow
  -its fat soluble that converts to vitamin A when its consumed
• can make you more tanned- in tanning tablets
• dont take in high dosage being linked to cancer if you are a smoker.

Question 22

what is selenium ?

Answer 22

• its a antioxidant and a mineral
  -there is a high concentration of it in the brain
  -its a co-factor in an enzyme that helps protect against oxidative damage
  -a major source of selenium is found in soil, but in the UK some areas have lots of selenium in the soil and some doesn’t. Where there is a selenium deficiency in the UK, there is more case of dementia ( we get selenium in the body by eating food grown in the grown)
• its worth noting we eat food ship from all over therefore hard to record how much selenium we get.
• study found that people with az had less selenium in their red blood cells then the control

Question 23

what ae polyphenols?

Answer 23

-red wine, fruit and veg, tea, cocoa, blueberries
-there is about 8000 polyphernol compounds.
- some are really strong anti-oxidants
-often called super food

Question 24

what is the study that shown the effect of blueberries (polyphernol) on sptail working memory?

Answer 24

-Williams et al (2008) - had young rats and older rats in a maze to get food over 12 weeks.
- they gave some of the old rats blueberries
-after 3 week of eating blueberries the old rats were performing all as good as the youngest rats and better than the old rats with no blueberries
the blueberries were increasing the performance of the rats in the maze, increasing memory

Question 25

what happened in humans trials of blueberry supplements?

Answer 25

Kent et al 2020 - multiple studies conducted in children. young adults, older people with either no cognitive impairment or cognitive impairment 8 out of 12 studies reported better cognition and 1 out of 5 reported better mood - the studies did have varied designs e.g dosage, so difficult to compare the studies

Question 26

is there a link between chocolate ( polyphernol )and cognition's?

Answer 26

- there is a correlation between which countries eat the most chocolate and which country has had to most nobel prize winners. (only correlational) - however a control trial where people had cocoa supplements found the more cocoa the better verbal fluency and quicker reaction times over 8 weeks - issue - more recent trail with more participants over 3 years found cocoa had no benefit to cognition. Was called the cosmos -mind trial

Question 27

what is the link between red wine and cognitions?

Answer 27

-25/31 animal studies found a cognitive benifical effect of wine - no significant effect on human trials why the difference ? dosage is difference, hard to translate between animals and humans - animals trails have way more control, eg can control an animals diet completely. -

Question 28

what is homecysteine ?

Answer 28

-an amino acid considered a risk factor in several diseases including neurological diseases. - there are two ways body can reduce the amount of homocycsteine it has in the body, it can be changed to methinine or cysteine but to do this the body need vitamin B12 B6 and folate more homoccysteine more likely to get dementia

Question 29

where is B6, B12 and folate from?

Answer 29

-b12 - fish, red meat, eggs -older people can struggle yto absorb b12 so have to have injections - lack of b12 links to high levels of homocysteine folate is another b vitamin, found is plants, nuts, avocados b6-banana, chicken

Question 30

how did smith et al (2010) measure the effect of b vitamins on the brain?

Answer 30

- examine the effect of b vitamin on cognitive decline and memory and brain stricture/volume - went on for 2 years with participants over 70 with mild cognitive impairment -randomly assigned daily dosages -it was found that b vitamins lowers homocystiene with slowed the rate of brain atrophy -similar study showed b vitamins reduced memory decline -alternative found vitamins did not reduce cognitive decline - being low does increase homocysteine however taking extra might not help much future- more of a deficiency problem

Question 31

what is one reason there is inconsistent research about nutrition effect the brain? (single vs patterns )

Answer 31

- research usually looks at a single nutrient but this is not actually how we consume nutrients, we eat multiple nutrients at a time - we should consider dietary patterns as a whole instead of single nutrients because its ver complex - when we take supplements we are taking what sciences has figure out what is in foods that is good for us -however when we eat we dont know everything goes on post meal because of the lack of technology - because of these studies single supplementd might not be as beneficial as studying whole diet patterns

Question 32

what is the Mediterranean diet ?

Answer 32

-low in meat, high in olive oil veg,fruit, fish -moderate in diary and wine - linked to multiple health benefits - linked to have low mild cognitive impairment compared to western diets

Question 33

what is the western diet? america and UK

Answer 33

- high in fats, sugars, processed meat and potato -moderate in dairy, eggs, fish -low in fruit and veg, wholegrain

Question 34

what is the predimed study ?

Answer 34

-7447 participants in Spain where they controlled the peoples whole diet. - 3 groups, Mediterranean diet with extra virgin olive oil, another was Mediterranean diet more nuts, and a control which wad low fat diet people were on these diets for 6.5 years both MD groups had better cognitions

Question 35

how do nutrition interaction to effect wellbeing ?

Answer 35

-it was found the b vitamins was better at preventing brain shrinkage in people with high level of omega 3 - shows they work together and studying them individually might not be get

Question 36

how is saturated fatty acids linked to cognitive decline?

Answer 36

- unsaturated fats have double bonds but saturated fatty acids don't. -unsaturated fats are better and found in nuts, oils and avocados -saturate fats are bad and in butter and cake - one cause of dementia is vascular, not enough oxygenated blood can get the the brain because of blood clots - people with higher blood pressure are more likey to get dementia - saturated fatty acids could be cause vascular dementia

Question 37

what is trans fats?

Answer 37

-its when a unsaturated fat becomes a saturated fat because its heated and pumped with hydrogen -done to make stuff solid at room temperature, easier for baked goods -trans fat can increase bad cholesterol and lowers good cholesterol and the the chance of az -trans fat also linked to shrinking brain volume

Question 38

what is a ketogenic diet ?

Answer 38

- it limits your carbs - you eat high fats and small protein and small carbs other way to increase ketosis - prolonged fasting - ninety mins of intense exercise -you can take ketones - and median fat chains There are 3 types of ketone the bodie produces during the breakdown of fatty acid - acetoacetate (from the break down of fatty acid ) -beta-hydroxybutyric acid (BHB) (formed from acetoaceate) -acetone

Question 39

why do we need ketones ?

Answer 39

- so in general the fatty acids in our diet our quite large and cant not pass through the blood brain barrier however ketones can get passed the blood brain barrier - ketones are made in the liver and are in the bloodstream and go to the brain - the brain coverts the ketones back to a form they can enter the TCA cycle and then become ATP (body energy currency ) - modern research has shown small fatty acids can get through the brain blood barrier (tiny) - our brain runs on glucose however when ketones are increased the brain can use them for energy -its been found that ketone preserves cognitive function when hypoglycaemia is increased with a clamp

Question 40

What was seen my Ketone in a PET scan

Answer 40

- usually a substances (tracker ) is injected into the body and attaches to glucose and you can use that tacker in the brain with a PET scan - a tacker was created to attach to ketones so you can see ketone in the brain - participants would fast and carbs were limited, and the ketones replaced all metabolic function in the brain that would of been glucose ( under extreme circumstances) - there was more ketones in the blood with more days of fasting and the more the brain use ketones as energy - - even when we have a normal amount of glucose in the body and ketones are injured into the bloodstream, ketone takes up some metoblic proccesses in the brain from glucose - this means ketone up take in the brain isnt't driven by hypoglycaemia , if we have enough ketones and enough glucose, our brain will use them equally for energy - however most the time we don't have ketones so our brain uses glucose - to achieve ketosis you need a high fat diet and low carb, this means you will have more ketones

Question 41

how does ketones link to dementia ?

Answer 41

- in PET scan of people with dementia is shown a reduction in glucose up take however this was unsurprising as we know the neurones are dying, therefore they do not need as many glucose - however it was also see that in conditions where you are predisposed to dementia, they also had a reduction in glucose metabolism, even before there was any structural differences, therefore the reduction may not be due to the neurones dying - this lead to the suggestions that dementia could be a type of diabetes - its being suggested that these energy deficits happen before the develpment of dementia and are not a cause of dementia - this is also specific to glucose and not ketones

Question 42

what is the evidence that ketones may reduce cognitive impairment in people with dementia ?

Answer 42

- 23 older adults were studied who all had mild cognitive impairment, they either had a high carb or low carb diet for 6 weeks -the low carb diet saw improved verbal memory performance - the memory change wasn't correlated with the change in calories, insulin or weight, it correlated with the amount of ketones in the blood evalutions- indirect measure, only correlational - really low carb diets are extremely hard to do constantly

Question 43

what are medium chain triglycerides ?

Answer 43

they are small chains of fatty acids which makes them a lot easier to be absorbed by the blood stream and can be converted into ketones well - you can buy these as supplements to get ketones in your bloodstream instead of going on a ketogenic diet - when we get old the glucose we uptake in the brain reduces - when people are having medium chain triglycerides supplements it increases ketone uptake by the brain, this is closing the brain energy gap we get as we get older - this allows people to function better and their memory is improved

Question 44

who is patient TP ?

Answer 44

- he was male with early onset dementia - he went looking for answers and got in contact with doctors and started taking triglycerides for 20 months - he had regular tests - on the az cognitive test he did see an improvement (however fairly easy) - at the times his ketones levels were the highest, his cognitive performance was better evalution - case studies are hard because its only 1 individual, cant generalise - no cause and effect - can over interpret findings

Question 45

what was the BENEFIC trial?

Answer 45

- it looked at supplementing tyiglycerides over a period of time in people with mild cognitive impairment - one group had it and one had placebo with long chains of fatty acids - they found that tyrglycerides increased levels of ketones, and the brain up took more ketones - they looked a memory, attention, processing speed and language ability - memory and language did improve - however there is a large standard deviation in the results, there could be outliers bringing up to results cognitive outcome correlated with the amount of ketones in blood

Question 46

What is the importance of water to the body?

Answer 46

-essential for survival -maintains cell structures and helps cell processes - important in food digestions and waste removal ( e.g water is in our saliva and stomach acid) - nutrient transport- water brings the nutrients to the right areas of the body - hydrated body do this more efficiently -sleep - prevention of chronic illness/ disease 80% of brain mass is water sodium in water- helps nerve impulses, muscle contraction and maintaining water balance. Sodium is key in the ostmotic flow of water

Question 47

What is body water regulation?

Answer 47

-how we get it in and out of the body - drinking water is 80% of how we get water and our diet is 20% -it leaves the body via urine, faecal matter, perspiring, breathing and vomiting

Question 48

what is the regulation of thirst??

Answer 48

- when we have more sodium then water in the balance the osmotic pressure outside the cell is increase - the neurons inside the cell pick up on this change and push water outside the cell to try and dilute the sodium - this means there is a lack of water in the cell -the cell neurons detect that there is not enough water in the cell and signal the hypothalamus, the hypothalamus signals the posterior pituitary to release AVP -AVP signals the kidneys to preserve water and causes thirst sensation - the brain monitors swallowing and stomach fluid so it know when to signal to us to stop drinking water - RAAS system - what can also happen is when we are low on water our blood volume also decreases. Then our blood pressure decreases, this reduces the efficiency of our body circulation system which is critical for oxygen and nutrients to move around your body - this decreases cell function -our body picks up on this and releases AVP andangiotensinogen - this causes our atries to constrict so there is less space for the blood to flow which increases blood pressure, also triggers thirst and causes kidneys to save water

Question 49

what are other factors that influence our water intake ?

Answer 49

age- changes in renal activity and the thirst response alter drinking behaviour - taste- preference other beverages - health beliefs - individuals may have different motivation factors

Question 50

how many people are dehydrated and why?

Answer 50

- over a third of people in the UK are not drinking enough water, over half of children are dehydrated -rodger et al (2021) - found participants drank when thirsty but sometimes suppressed the the urge to drink water due to situational factors like work -found few participants saw drinking water as a goal despite knowing the benefits - more research needed

Question 51

what is the definition of cellular hydration and cellular dehydration ?

Answer 51

cellular hydration- when electrolytes and fluids travel through the cell membrane into the intracellular fluid (ICF) - helps maintain homeostasis -cellular dehydration - when you lose or use more fluid then you are taking in. Fluid travels from the (ICF) to the extracellular fluid (ECF) in response to osmotic pressure -dehydration levels indicated by % of body mass lost (BML) -symptoms of dehydration are dry mouth, fatigue, headaches

Question 52

what is studied in psychology relating to hydration and dehydration?

Answer 52

- cognitive functions and mood state -cognitive function : attention, language, memory mood state: happiness, sandiness, tension - look at cognitive function by objective tests like speed and accuracy tasks, and neuroimaging -look at mood state with subjective scales and questionnaires

Question 53

what did Ganio et al (2011) find out about the effects of mild dehydration?

Answer 53

-25 males, cross-over design, mix of exercise and placebo capsules, everyone was in each condition -dehydration = 1.59% BML ( less than 2 %) - found dehydration worsened visual working memory and visual vigilance. it also increase anxiety, tension and fatigue. - a similar study ( armstrong et al, 2012) was done with females with slightly less dehydration 1.36% BML - dehydration increased fatigue, mood disturbance, task differently and decreased concentration. However most aspects of cognitive performance wasn't affected, it effect mood more. -there was slight difference between the female and the male participants because different levels of dehydration have minor different effects - these two studies had the same methods but males cognition were effected and women were not, might be a gender difference ? - both these studies demonstrate that small levels of dehydration have an impact on cognitive function and mood

Question 54

what did benton et al (2016) find out about water supplements and mild dehydration?

Answer 54

-101 undergraduate students were subject to 30 degrees temps for 4 hours to cause dehydration less that 1 % BML - random controlled trials where participants got to have a drink of water or not -participants had to do a number of cognitive test at a number of intervals - they were weighed throughout the experiment as well - the study looked at the change of participants perform in the cognitive tests, so the study was not effected by individual difference -the working memory and attention was worse in people who lost more body mass and had no water - for the first time it was shown that consuming water at a BML 1% was beneficial. -people who had water had their anxiety, depression reduced and energy up

Question 55

what did cousins et al (2019) find out about water supplements and mild dehydration?

Answer 55

- 164 undergraduates, 4 hours in 30 degree heat, less than 1% BML - some had water, so did not, so had placebo and some had electrolyte - those who had no water had the greatest mood decline e.g anxiety -those with water had better attention -demonstrated that BML less that 1% has disruption on psychological function Limitation - heat exposure - its used to speed up dehydration however exposure to heat acts as a stressor on the body. Stress causes cortisol to be released and this results on poor attention and memory -only studies been done in young adults, missing research on children and older adults. Children need a larger amount of water and older adults can come dehydrated more frequently. - there is evidence that people have responded to the placebo color of water, therefore this might have an effect.

Question 56

what did edmonds et al (2017) find out about water?

Answer 56

- 96 adults -3 groups, no water, 25 ml water, and 300 ml water - water decreased sensation of thirst -improved attention and memory -this shows water improves cognitive function

Question 57

What is the evulation of Ganio et al (2011) and armstrong et al (2012) ?

Answer 57

- they both did the same thing but ganio used males and armstrong used females. - they did the same things but used different tests - there are little variations in the results which is important because they used the same methods. - there shouldn't be different results if the same methods were used. - individual difference - placebo effect -diuretics - exercise could cause internal stress changing someone physiological state or it could have the opposite effect and the exercise increases positive mood. - the hydration measure- questions if urine is helpful in tell us about long term hydration, its only helpful in short term.

Question 58

-what is a plausible mechanism of why dehydration effects our cognition and mood?

Answer 58

=edmonds et al suggests that due to the variation in brain regions and the attentional laod require for task maybe affected differently by hydration status

Question 59

what study did young et al (2019) do relating to dehydration and psychological functions?

Answer 59

- the aim was to see whether cardiovascular and autonomic changes may explain changes in psychological functions of minor levels of dehydration study 1 -had 12 male participants exposured to 30 degree heat for 4 hours, half had water, the others did not. fMRI scans were done while participants did a cognitive test and mood test study 2 - 56 participants both males and female were in 30 degree heat for 4 hours, some had water and some did not. Did a mood test and a heart rate variability test. -study 1 had 0.59% BML and study 2 had 0.55% BML - study 1 found dyhration of 0.6%

Question 60

what study did young et al (2019) do relating to dehydration and psychological functions?

Answer 60

- the aim was to see whether cardiovascular and autonomic changes may explain changes in psychological functions of minor levels of dehydration study 1 -had 12 male participants exposured to 30 degree heat for 4 hours, half had water, the others did not. fMRI scans were done while participants did a cognitive test and mood test study 2 - 56 participants both males and female were in 30 degree heat for 4 hours, some had water and some did not. Did a mood test and a heart rate variability test. -study 1 had 0.59% BML and study 2 had 0.55% BML - study 1 found dehydration of 0.6% influenced blood flow to the neural systems therefore there was negative impact on dehydration on brain activity -study 2 found- dehydration influence heart rate which mediated the effect of hydration on mood. -dehydration even at small levels changes autonomic activities and brain function - the research is important because it highlighted the mechanisms effected by minor dehydration : brain function, cardiovascular function, autonomic function, mood - this mechanism could link -limitation - all young adults, cant see the change in older people - can see the link between changing brain activity and anxiety and cognitive difficulty but its not causational design, what do not know what is effecting what!

Question 61

hydration in older adults ?

Answer 61

- they are more susceptible to dehydration - in part its due to a change in thirst response and renal activity - they drink a lot less - lots of dehydration research is based on children and adults, there is very little research on the psychological effects of dehydration on older people

Question 62

what is suhr et al (2004) find out about hydration in older people ?

Answer 62

- 28 old adults fasted before data collection - no food or water - half of them resumed their normal diet and fluid intake plus 16 ounces of water - then they did cognitive tests - those who fasted had a decline in memory, attention and psychomotor processing - those with extra water had a positive effect on their memory, attention and psychomotor processing ( mental acclivity) limitation - could of been lack of food

Question 63

what is the vascular endotheluim mechanism idea of why dehydration effects cognition?

Answer 63

-our endothelium is in the lining of our arteries and is essential in controlling blow flow -endothelium function is a good indicator for vascular health and cognitive performance - endothelium function declines with aging and so does cognitions -things like diet and exercise that reduce ef - poor ef has been linked to poor cognitions and dehydration has been linked to poor Ef ef= ethdothelium function

Question 64

what is cortisol and oxytocin?

Answer 64

- cortisol is a stress hormone, its released in response to stress - oxytocin is released in the brain and can regulate emotional responses and prosocial behavior and positive communication. Its a neurohormone with a positive effect

Question 65

what Kruase et al (2011) study which attempt to support the watering hole hypothesis?

Answer 65

krause et al (2011) - can hydration state control stress responsivness and social behaviour - hydration state links to neurohormones in relation to maintaining homeostasis - bit these neurohormones relate to stress and anxiety -Oxycontin is an anti stress hormone - it looks at whether when im sodium levels increase due to dehydration, does this internal stressor cause us to repsonce different to external stressors there is two types of stress, physical stressors (real) and psychogenic stressors (perceived) - both signal the paraventricular nucleus (PVN) of the hypothalamus - when the PVN is activated, it might influence behavior -psychological stressors increase cortisol release -both psychical and psychological stress changes both internal and external behaviour, our hydromineral balance changes which changes us internal (we want to drink) and external (mood -anxious) - he is arging that both the internal and external changes may be linked The study its self -group 1 - rat where injected with 2 different levels of sodium (changing their hydromineral balance e.g causes dehydration ) and their renin activity, cortisol, oxytocin, and AVP was measure group 2 - rats had different levels of sodium and placed in a plastic restrain (physical stressor) and the measures where taken group 3- rats had different levels of sodium and releases of a social environment with unfamiliar rats (psychological stressor ) - social interaction tested Findings - rats with high sodium had internal stressors and low sodium the rats did not - the rats who had higher sodium had lower levels of cortisol when restrained -renin relates the stress hormones and the rats with high sodium had lower levels of renin rats with more sodium released less adrenal corticopic hormone ( ACTH) this is and icator of cortisol - the rats with high sodium had higher levels of oxytocin (anti stress hormone ) - so more sodium reduced the release of renin, ACTH and cortisol (all stress hormones ) and increased oxytocin ( antistress hormone ) also rats with high sodium spent more time interacting with unfamiliar rats which means it increase prosocial behaviour - when the rats where experiencing internal stressors it improved the repsonce to external stressors, arguing they may be linked -when experiencing an internal stress response, it limited the anxiety response

Question 66

what is the watering hole hypothesis ?

Question 67

what are carbohydrates?

Answer 67

There are apart of the three main macronutrients humans need (carbs, protein and fat). Its our main energy source. -brain runs on carbohydrates - includes sugars, starches and fibres - monosacchardries is a single sugar unit -glucose - two sugar units is disaccharides and multiple are polysacchrides. -simple carbohydrates are monosacchrides and disaccharides, they are either sugars that occur naturally (healthier) or refined sugars (in processed foods) -they have a lack of nutriental benfit -complex carbhydrates are polysaccharides e.g fiber and starch moni - fruit di- candy poly-bread

Question 68

what is fiber?

Answer 68

its a polysaccharide (carb) that is non-digestible that help maintain regularity, it can manipulate how quickly other foods is digested and keep a healthy tract. It also reduces the carbohydrates absorption rate (GL)

Question 69

what do carbs do for our body?

Answer 69

- it provides us with enough energy to move around and provides energy for our neurones to fire and our brain to function - when we are low on carbs we have to rely of proteins as a secondary source of energy - if you are really low on carbs you can draw on your own body tissue for proteins for energy as our muscles are primarily protein -carbs are also used to break down fat, if you have low carbs you struggle to do this - for carbs to be used fro energy they must be in the from of glucose. This means disacchrides and polysaccrides must be broken down into monsacchardies -its turned to glucose in the liver -if your body has an excess of glucose your body will try to store it as glycogen and it many connections of glucose. It can be stored in muscles, liver and a small amount in the brain (its a back up supply) - when our blood sugar drops we use the glycogen stored to steady our blood-glucose level .

Question 70

how is glucose metabolised ? (maintain homostasis)

Answer 70

- some of the hormones involved might effect the changes blood glucose has on the brain - when we have high blood glucose level our beta -cells release insulin and insulin simulate cells to take up glucose and store it, then glucose it brought back down to a normal level - when we haven't eaten and our blood glucose level is low our alpha cell release glucagon which stimulates the production of glucose -glucagon can also make us hungry -its the balance between insulin and glucagon which keeps our glucose levels steady ( both comes from pancreas)

Question 71

insulin and glucose related to body parts

Answer 71

- insulin and glucagon is released from the pancreas and control blood glucose level - liver stored glucose -muscles can take and store glucose when insulin is present. more muscle more glucose can be stored fat cells can take up glucose when insulin is present, fat cells use glucose to make more fat. - the brain for the most part doesn't need insulin to take up glucose and glucose is the more fuel for the brain -

Question 72

what happens when you are hypoglycmaemic ?

Answer 72

- you have very low blood glucose levels!! -the body response by releasing glucagon as normal but also releases adrenaline (epinephrine) which increase blood glucose triggering the stores of glucose in the muscles and liver

Question 73

why do we rely on blood glucose levels for glucose to the brain?

Answer 73

- the brain can only store a really small amount of glucose compared to our muscles and liver - glucose has to cross the blood brain barrier by glucose transporters which are called GLUT, GLUT 1 and 3 don't rely on insulin, they are passive transports (concentration gradient) , ( doesn't need insulin the stimulate the cells to allow glucose up take ). GLUT 4 does dependent on insulin. - so for the most part our brain doesn't need insulin - the blood brain barrier to to keep stuff out of the brain we don't want -astrocytes are small areas in the brain we can store small amount of glucose - our brain demands high levels of energy and we require a continuous level of glucose

Question 74

how did our thinking about glucose in the brain change in 2001?

Answer 74

- original it was thought that if we had enough glucose in the body then enough glucose could cross the brain blood barrier and our brain was getting enough energy. Because our muscles and liver stores glucose we didn't think it was majorly impacted by the food we eat. -In 2001 a study was done with animals looking a brain glucose levels and memory tasks. - rats did a maze task varying in difficulty - the rats who had an infusion of glucose 30 mins before the task did significantly better than the rats who didn't - when the task was easy the glucose seemed to have no effect, but when it was hard, it did . - the rats with no treatment or the placebo had a decrease in glucose in the brain during the task, the glucose infusion rats didn't have the glucose in the brain decrease -glucose in the brain drops more dramatically when the cognitive task in harder - this research and similar others confirmed that brain glucose levels effects cognitive function especially under high cognitive demand -this means it is biologically plausible that blood glucose could effect psychological function - this got scientists thinking about the carbohydrates we consume may be effecting our cognitive function

Question 75

What is a hyperinsulemic clamp?

Answer 75

-it infuses insulin into the bloodstream (which gets the cells to take glucose) so glucose level increase in the bloodstream - this clamp also you to control insulin in the body therefore control glucose in the body to see what varying levels do to brain function. - a study used this clamp to make individuals hypoglycemic and put them in a PET scan. Compare to people with normal levels of glucose the people in a hypoglycemic state had reduced brain activation. Neurones where firing less officially. - this is the gold standard research however requires high levels of medical supervision and equipment therefore unrealistic that most studies can use this method and has small sample group

Question 76

what levels of glucose do you want in the blood ?

Answer 76

Mmol/L - less than 10 our body tries to get rid of glucose in urine (too much) - 3 to 10 - brain well protected - less than 3 - cognitive problems 2.2 or less- hypolgycaemic reaction, surge of adrenaline

Question 77

what is the oral glucose tolerance test?

Answer 77

- its medical testy for diabetes or reactive hypoglycaemia - you have an empty stomach and drink 75g of glucose, this effects people in different ways, no everyone ends up with the same glucose blood levels like you would with the clamp -lot of individual difference shown - people with diabetes has their insulin not working the way it should, therfore the liver and muscles don't take up the glucose and the glucose in the bloodstream stays high people with hypoglycaemic produce to much insulin and then have a lack of glucose in the bloodstream rapidly

Question 78

what is spontaneuous hypoglycaemia ?

Answer 78

- harris (1924) people who produce to much insulin have their blood glucose levels drop -causes anxiety, shaking, sweating, irritable, headache, hunger

Question 79

what did Bolton (1973) found out about glucose and aggression ?

Answer 79

- he studied an Indian tribe known for being very aggressive and violent he had the tribe members friends and family rate how aggressive their were -and tested there blood glucose level - people with the highest levels of aggression had highest levels of hypoglycaemic curve (low blood glucose level) - simliar results came from research on offenders with intermittent explosive disorder. The most violent offenders had high insulin and low blood glucose

Question 80

What did Bushman et al () find out about low blood glucose levels ?

Answer 80

- over a poerid of 21 days 107 married couples had there glucose levels measure before bed - they were also given a voodoo doll that meant to reflect their partner - at the same time their glucose levels were measure partners could put pins in the voodoo doll, this was meant to reflect their inter martial aggression. - partners with the lowest blood glucose levels put the greatest number of pins into the voodoo doll. - this should suggested that low blood glucose levels could contribute to high intermartial aggression.

Question 81

evaluation of the research state low blood glucose levels effects brain function ?

Answer 81

- only correlational research, we don't know if it is the blood glucose level effecting behaviour. - we don't know how frequent people are experiencing low glucose levels but it might be more rarer than we think. Young and benton (2020) demonstrated that nearly everyone wont experience levels so low to effect brain function - all studies dont look at a long enough period of time, only look with a few hours

Question 82

what did young and Benton (2020) find out about the experience of hypoglycaemia ?

Answer 82

- they found that 18% of 150 older adults thought they regularly experienced hypoglycemia ( this was lower than expected ) - only 50% were accurate that their BG was lower than base line - only 2.0% had blood glucose less than 3.0 mmol/L - then they were given breakfast- all people the that had lower BG levels had them raised therefore non of them was experience such low low level where it could stat influencing brain function - so why do people think they are experiencing hypoglycemia ? - these patients experienced symptoms they believed linked to low BG e.g shakes, hard to concentrate. 30% experienced automatic symptoms and 51% reported neurological symptoms. - these symptoms are more linked to mental health issue and people are misinterpreting these as low BG.

Question 83

is raising blood glucose levels to high then normal beneficial ?

Answer 83

- there is about 30 years of research - participants fast, then have a glucose concentrated drink - then do cognitive tests - get their blood tested for glucose levels - it might be more beneficial in older people as younger people are already performing fairly optimally Benton (1987) 60 children aged 6 and 7 were given a drink with glucose or a placebo towards the end of a school day - then they had to perform a task that was going to causes them intense frustration - they wanted to see if the children who had glucose drink deal with the task more calmly - the child who had to glucose spent more time to concentrate on the task then showing signs of frustration - similar student done with undergraduate, they had a online game and then a confederate of the opposite sex came in and said 'mostly people can do better than that' . The people who had to glucose drink became less irritable. - there is not enough studies to be able to say that glucose reduces fatigue. Also all the evidence comes from when participants are given a physical or psychological task, ie they are put under pressure to perform, if they are not under pressure then glucose may not increase alertness. There is a lack of evidence from multiple scenarios rtrrr.

Question 84

what is the glycaemic index (GI)

Answer 84

- all carb foods can be given a GI number according to their effect on blood glucose levels - 50 g of glucose is given number of 100 -so a portion of test food that contains 50g of carbohydrates is compared to the effect of 50g of glucose - food that doesn;t spike blood glucose and is low absorbing has a low GI number

Question 85

how did benton et al (2007) look at glycaemic index effect on behaviour?

Answer 85

-they look at children behaviour in school children either had a high GI breakfast, median or low. - their behaviour was examined after 110-180 mins - they did a task causing frustration - children were less frustrated - with the task when they consumed a lower GI - their also did attention task - when the children had a breakfast with high GI they had more lapse in concentration - they also did a memory test - the high GI the poor memory - this is evidence that take in food with a lower GI will increase brain function for a long period of time. Its more consistent and stable in the blood, whereas when you have high GI your body tries to take it up quicker in the muscles and liver and therefore not in the blood to get to the brain. It a curve, it starts off really high but decreases rapidly. - other meta analyse found that GI had to impact of children cognitions - however maybe there arent being tested for long enough after the glucose intake - also when you are trying to change a meal to vary glucose but at the same time you are also varying the macronutrient, therefore this maybe causing an effect - limitation- don't take blood from kids so cant see their blood glucose levels

Question 86

so does blood glucose influence brain function?

Answer 86

- it may but the effect is small - only effects some people - different effect on children and adults - GI could effect brain function but hours later - many research design limitations

Question 87

who is patient TP ?