Nutrition and Behaviour: Lecture Note Bundle

Nutrition and Behaviour

6th February 2017

Lecture 1: Introduction

Overview of the module:

Food Allergy and Food Intolerance

Feingold diet

Additives

Food intolerance and mental illness

Food intolerance and hyperactivity

Perinatal Diet

Brain development

Breast feeding

Essential Fatty Acids

Brain development

Depression

Dementia

Ageing

Anti-oxidants

Mediterranean diet

Fat

Homocysteine

Vitamin/Mineral Supplements

Intelligence

Aggression

Obesity

Satiety/Satiation

Portion size

Calorie reduction

Walter de la Mere: It’s a very odd thing, As odd as can be, That whatever Miss T eats, Turns into Miss T  You are what you eat!

The body is an amalgamation of what is eaten.

The structure of your body and brain are made from building blocks supplied by the diet. The fuel to run your brain comes from food. The release of energy requires mechanisms dependant on food.

Nutrients

A nutrient is a chemical substance in food that helps maintain the body.

Some provide the body with energy.

All nutrients help to build cells and tissues, regulate bodily processes such as breathing.

No single food supplies all the nutrients the body needs to function.

Nutrients are often divided into two groups: Macro and Micro. The differentiation is made between those that are needed in large quantities (macro) in order to cover its energy requirements, and others which are also required but a much smaller quantity of them is needed (micro).

Protein

A macro-nutrient that can be divided into two types: Protein and Peptides (smaller proteins) which are both essential to the cell.

Two major functions:

Enzymes that catalyze biological reactions

Structural

Proteins and peptides are made up of chains of amino-acids. Unlike fat and starch, the human body does not store excess amino-acids for later use and so they must be within food intake every day.

The body differentiates between essential amino-acids and non-essential.

Essential  Cannot be synthesized by the organism and therefore, must be supplied by the diet. There are eight amino-acids that are regarded as essential for humans: Phenylalanine, Valine, Threonine, Tryptophan, Isoleucine, Methionine, Leucine, Lysine.

Non-essential  If it is not within diet then the body is able to produce the amino-acid through metabolism and conversion of other compounds. NOTE: Although name suggests not of importance, it means it is not essential to have it within the diet not that it is not essential for functioning.

Phenylalanine precursor for Tyrosine, Tryptophan for Serotonin (tryptophan -> 5-Hydroxy-tryptophan -> 5-Hydroxy-trptamine which is serotonin), Tyrosine for Dopamine, NA, A.

Levels of Protein Structure:

Primary Structure  The linear arrangement of amino acids in a protein and the location of covalent linkages such as disulfide bonds between amino acids.

Secondary Structure  Areas of folding or coiling within a protein; examples include alpha helix and beta pleated sheets, which are stabilised by hydrogen bonding.

Tertiary Structure  The final three-dimensional structure of a protein, which results from a large number of non covalent interactions between multiple amino acids.

Quaternary Structure  Some proteins will reach this structural level, for example haemoglobin. This is the binding of multiple polypeptides into a single, larger protein.

Enzymes are proteins. Active site of a particular shape in which only specific substrates can bind to, making an enzyme-substrate complex. The enzyme will then alter the activity of the substrate.

Carbohydrates

All carbohydrates consist of the following molecules:

Mono-saccharide  Contains one saccharide molecule. The basic units of carbohydrates. Usually colourless, water-soluble, crystalline, some have a sweet taste. Examples include glucose, fructose and galactose. The basic blocks of disaccharides and polysaccharides by combining to form them.

Di-saccharide  Contains two saccharide molecules

Poly-saccharide  Contains many, more than two, saccharide molecules. Polysaccharides can be one of two types, they can be a single, unbranched strand (e.g. amylase) or can be branched (e.g. amylopectin)(both are examples of starch). Starch is a storage form of energy and if required, the bonds can be broken in order to release glucose. Release of glucose into blood stream is much more rapid with branched molecules. Some polysaccharides are digestible whereas others like cellulose.

The monosaccharides glucose and fructose form sucrose (table sugar), a disaccharide. The disaccharide lactose is formed from D-galactose and D-glucose.

Glycogen is the main form of bodily carbohydrate storage. When intake of food, glycogen is stored in the liver.

Important role in storing glucose when blood levels are too high and releases glucose by being broken down when levels are too low. It is a highly branched molecule made up of glucose monomers.

Carbohydrates release energy slowly.

Associations: (hypoglycaemia is the deficiency of glucose in the bloodstream)

Hypoglycaemia and memory: Sommerfield et al. (2003): Examined the effects of acute insulin-induced hypoglycaemia on short term, delayed and working memory in individuals with type-1 diabetes. Found that all of the memory systems examined were impaired by acute hypoglycaemia, particularly working memory and delayed memory.

Hypoglycaemia and mood: Gold et al. (1995): Investigated the effects of hypoglycaemia on mood in healthy, non-diabetic participants. Found increase in tense arousal, decline in energetic arousal, and state called tense tiredness for at least 30 minutes.

Carbohydrate and mood: Thayer (1987): Simple carbohydrates provided a temporary elevation in energy levels. Lieberman et al. (1986): Decline in depression. Gitlin and  Fairbanks (1987): Depressed individuals increase their preference for carbohydrates, particularly sweets, during a depressive episode.

Fats

Chains of carbon atoms with hydrogen attached.

Two main types of fatty acids:

Saturated  Found in animal products such as milk, cheese, butter, and oils such as coconut and palm. They are the biggest dietary cause of high LDL levels. All bonds between the carbon atom chains are single bonds and so molecule is straight.

Unsaturated  Found in rapeseed, sunflower and corn oil. Helps to lower cholesterol if used in the place of saturated fats. Have ‘kinks’ in the chain of carbons as the result of the presence of double bonds.

There is a third type of fat:

Trans fats  Formed when a vegetable oil hardens through a process called hydrogenation in which hydrogen is blown through the oil in the presence of a catalyst. Raises LDL cholesterol (so bad). Found in fried foods, commercially baked foods, processed foods and margarine.

LDL  Low-density lipoprotein. They transfer lipids (including cholesterol) around the body allowing for fats to be available and taken up by the cells. Drive atherosclerosis:

Endothelium becomes damaged (e.g. due to high blood pressure or cigarette smoke).

Damage causes inflammatory response, white blood cells move into artery wall, cholesterol accumulates from blood.

Atheroma deposit builds up.

Calcium salts and fibrous tissue build up at site, forming hard plaque, reducing artery elasticity and it narrows.

Easily blocked by a blood cell which can result in a myocardial infarction or stroke depending on location.

HDL  high density are deemed as the good cholesterol because they remove lipid molecules from macrophages in the wall of the arteries and transport to the liver for breakdown.

Although lipids, fats, cholesterol are all deemed as ‘bad’, 60% of the dry weight of the brain is fat of which a quarter is cholesterol. Cholesterol is an essential part of sex hormones, vitamin D and steroid hormones from the cortex of the adrenal gland. If you do not have an intake of cholesterol then the body will produce it, so it must be required for some functions.

There are two families of essential fatty acids (polyunsaturated fatty acids):

Omega-3  20% of the brain is DHA which is an omega-3 fatty acid. Essential and so body cannot produce it, must be taken in from diet. Found in fish like salmon, mackerel, tuna, walnuts.  Evidence in the general population does not support beneficial role for omega-3 in preventing cardiovascular but Casula et al. (2013) conducted a meta analysis and found that it can be protective against cardiac death, sudden death, and myocardial infarction in people who have a history of cardiovascular disease.

Omega-6  Corn oil, sunflower oil, nuts and seeds. Family of pro-inflammatory and anti-inflammatory fatty acids.

Effects of essential fatty acids:

Influences brain development: McNamara and Carlson (2006): Review of literature into the role of omega-3 fatty acids in brain development and function: potential implications for the pathogenesis and prevention of psychopathology.

Reduces incidence of depression: (person from above^) Animal studies have found that reductions in the fatty acid are associated with increased anxiety, aggression, depression.

Decreases incidence of dementia: Cherubini et al. (2007): Found that dementia was associated with low plasma n-3 fatty acids. The possibility of higher intake being associated with lower risk of cognitive impairment should be further investigated.

Vitamins

Two types:

Fat soluble

Water soluble

Thiamine - Wernicke–Korsakoff syndrome (WKS) is the combined presence of Wernicke's encephalopathy (WE) and Korsakoff's syndrome. Cause is a deficiency in thiamine (B1), common cause of deficiency is alcoholism.

WE  Ocular disturbances, changes in mental state (confusion), unsteady stance and gait (ataxia).

K  Anterograde amnesia, variable presentation of retrograde amnesia, asphasia, agnosia, deficit in EFs.

Similar characteristics to case study HM who suffered from temporal lobe damage.

Butterworth et al. (1993): Results of this study demonstrate significant reductions of TPP-dependent enzymes (thiamine pyrophosphate) in autopsied samples from alcoholic patients with the clinical and neuropathologically confirmed diagnosis of Wernicke-Korsakoff Syndrome (WKS). Enzyme activities in brain samples from alcoholics without WKS were within normal limits. These findings provide evidence, for the first time, of a direct implication of TPP-related metabolic processes in the pathogenesis of WKS.

Minerals

Two types of minerals:

Major elements  More is needed of them compared to trace elements: calcium, iron, phosphorus, potassium, sulphur, chlorine, sodium, magnesium. Iron deficiency in infancy can cause permanent brain damage

Trace elements:

Essential trace elements

Non-essential trace elements

Iodine, copper, zinc, chromium etc. Chromium seems to facilitate uptake of glucose.

Most trace elements are supplied by a wide variety of foods, and the body is unlikely to be deficient in them.

Water

The average body is about 60-70% water.

The percentage may be 75% in infants.

Without water, depending on the temperature, you will die in 2-10 days.

Common view that dehydration disrupts the brains functioning.

Kempton et al. (2010): Found that dehydration following exercise led to a significantly stronger increase in blood-oxygen-level-dependent response during an executive function task suggesting greater activity is required for performance to be of the same degree.

The amount of water in food is a major factor in determining energy density.

Additives

Problem is often a poor diet rather than poor foods as a wide ranging diet is needed. It is the relative proportion of foods that is important.

Nutrition and Behaviour

6th / 8th February 2017

Lecture 2: Food Hypersensitivity and Food Intolerance

Hyperactivity and psychotic symptoms

Feingold

Benjamin F Feingold

Some develop intolerance to aspirin (acetylsalicylic acid)

Those sensitive to aspirin react to foods containing natural salicylates, similar substances.

Aspirin sensitive patients react to the yellow colouring tartrazine (E102)

Those sensitive to tartrazine react to aspirin

A yellow synthetic azo dye

Typical products include fizzy drinks, fruit squash, puddings, cakes, sauces, soups, sweets, jelly, ice cream, jams, honey products etc.

Aspirin and tartrazine produce either hives or a rash in those who respond to those compounds.

While ill he became aware of a marked increase in hyperactivity among children

Estimated half to 5 million children affected of which half taking Ritalin (used to treat ADHD and ADD).

25 years before when he was a paediatrician, hyperactivity was rare among children.

Noted that if the use of additives and the increase in hyperactivity was plotted, the lines were parallel.

The Feingold diet was then developed on the premise that salicylates may trigger hyperactivity.

In 1965, a woman in her early forties came with a swollen face and giant hives.

Placed on a diet avoiding artificial colours and flavours

Within 3 days her condition improved

Additionally, unknown to Feingold she had a long history of aggressive behaviour which also diminished.

Most herbs, spices, fruits and vegetables are within the category of high-salicylate foods.

Johnny’s Dietary Diary

Chocolate bar at 11:30am, very noticeable behaviour change at