KNES 237 Midterm 2 Flashcards
Disordered eating
- restricting, purging, steroid use
- weight and shape preoccupation
- striving for perfection, fasting
- yo-yo dieting, excessive exercising
- compulsive exercising, laxative abuse
Eating disorder
Anorexia nervosa, bulimia nervosa, binge eating disorder
Eating disorders- Family
History of dieting/eating disorders
history of depression/anxiety/alcohol dependence
history of obesity
Eating disorder- Indidvidual
- female gender, genetics, premature birth, low self esteem, perfectionism, previous depression/anxiety, previous obesity, early puberty, diabetes, Crohn’s disease
Eating disorder= Possible triggers and maintaining factors
- puberty
- socio-cultural pressures
- family factors
- pressure to achieve
- behaviour of peers
- comments about weight
Clinical diagnosis of anorexia
refuse to maintain body weight at 85% of expected
intense fear of gaining weight
disturbance in body image
amenorrhea (absence of 3 consecutive menstrual
cycles)
restricting type or binge eating/purging type, restrict to very low intake of calories
Physical consequences of anorexia
- Anemia
- Low bone density
- Depression
- Amenorrhea – absence of menstruation
- Impaired immune response
- Sensitivity to cold
- Soft, thick facial hair, thinning scalp hair
- Low blood pressure
- Irregular slow heart rate, loss of muscle tissue
Features of anorexia
- Individuals with anorexia nervosa typically severely restrict their food intake and may exercise intensely
- Some turn to self-induced vomiting after eating
- Family members and friends often report high levels of anxiety
- People with anorexia are often “model students” or “ideal children,” but in their personal lives may experience low self-esteem, social isolation, and unhappiness
How common is anorexia
- Approximately 1% of young women and <0.1% of young men have anorexia nervosa
- Reported in girls as young as five and women through their forties
- It usually begins during adolescence
- People at risk tend to be overly concerned about weight and food, and many attempted weight loss/dieted early
Treatment for Anorexia
- There is no treatment that cures anorexia nervosa quickly
- The disorder takes a good deal of time and professional help to treat (often years). Ongoing therapy is important for continued recovery.
- Treating the disorder is difficult because few with anorexia believe their weight needs to be increased
Treatment programs for anorexia
- Treatment programs focus on:
– Normalizing eating and exercise behaviors
– Nutritional health and body weight
– Psychological counseling for self-esteem
– Attitudes about body weight and shape
– Antidepressant or other medications
– Family therapy - Complete success in 25-50% (depending on
the study) and partially successful in others
Clinical diagnosis of bulimia nervosa
Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:
Eating, in a discrete period of time (e.g., a 2 hour period), an amount of food that is definitely larger than what most people would eat during a similar period of time and under similar circumstances.
Lack of control over eating during the episode (e.g., a feeling that you cannot stop eating, or control what or how much you are eating).
Recurrent inappropriate compensatory behavior to prevent weight gain, such as self-induced vomiting, misuse of laxatives, diuretics, or other medications, fasting, or excessive exercise.
The binge eating and inappropriate compensatory behaviors both occur, on average, at least once a week for three months.
Self-evaluation is unduly influenced by body shape and weight.
Bulimia Nervosa
- Bulimia nervosa occurs in 1-3% of young women and 0.5% of young men.
- Bulimia nervosa often starts with voluntary dieting to lose weight and at some point voluntary control over the dieting is lost.
- People feel compelled to engage in binge eating and vomiting
- The behaviors become cyclic, food binges are followed by guilt and/or depression, purging, and dieting
- Once a food binge starts, it is hard to stop
Features of bulimia nervosa
- Unlike those with anorexia nervosa, people with bulimia usually are not underweight or emaciated
- They tend to be normal weight or overweight
- Bulimia nervosa is common among athletes
Causes of bulimia nervosa
Exact cause not known with certainty
* Depression
* Feast-famine cycles: fasts and restrained eating
(purposeful restriction in food to control weight) may cause feelings of deprivation that trigger binge
* Abnormal mechanisms controlling food intake
A way for a person with bulimia to feel more in control over their lives
treatment for bulimia nervosa
- Nutrition and counseling to break feast/famine cycles
- Eating regular meals
- Psychological counseling to improve self-esteem and attitudes toward body weight and shape
- Antidepressants may be useful
- Full recovery of women is higher than for anorexia
- Most women with bulimia achieve partial recovery
- 1/3 relapse to bingeing and purging within seven years
Binge-eating disorder
- Likely to be overweight or obese, one third being male
- Individuals eat several thousand calories’ worth of food during a solitary binge (within 2 hrs), feel a lack of control over the binges, and experience distress or depression after the binges
occur - do not vomit, use laxatives, fast or exercise excessively in an attempt to control weight gain= no compensatory behaviour(s)
- Must have binges once a week over six months to be diagnosed
Binge-eating disorder: episodes
- Binge eating episodes associated with 3 (or more) of the following:
1. Eating much more rapidly than normal
2. Eating until uncomfortably full
3. Eating large amounts when not physically hungry
4. Eating alone because of feeling embarrassed by quantity of food being consumed
5. Feeling disgusted with self, depressed or guilty
Binge-eating disorder: percents
- 9-30% of people in weight-control programs and 30-90% of individuals with obesity have binge-eating disorder
- Condition is far less common (2 to 5%) in the general population
Binge-eating disorder: emotions
- Stress, depression, anger, anxiety, and other negative emotions prompt episodes
- Binge eating disorder may be related to genetic mutation that impairs normal eating behavior
– MC4R gene mutation in 5% of individuals with the disorder
Binge-eating treatment
- Treatment focuses on disordered eating and underlying psychological issues
- Persons will be asked to record food intake and note feelings, circumstances, and thoughts related to each eating event
– Information identifies circumstances that prompt binge eating and alternative behaviors to prevent it
Pica (craving for non-food substances)
- the word pica comes from the latin word for magpie, a bird known for its unusual eating habits
- purified starch (amylophagia)
- ice cubes (pagophagia) – one case study 10 kg
- clay or dirt (geophagia)
- Largely found in children and pregnant women
- Direct or indirect cause or symptom of iron
deficiency anemia
Eating disorder resourses
- Information and services for eating disorders are available
- Services delivered by health care teams specializing and experienced
- Primary care physician, dietitian, or nurse practitioner is good start to the process
Types of carbohydrates
Simple and complex
Simple carbohydrates
- Monosaccharides and disaccharides
- few are made by animals; most are plant sourced
- Health risk: rapidly absorbed into blood stream, increased insulin resistance and inflammation
Monosaccharides
- Glucose (blood sugar or dextrose), Fructose (fruit sugar), Galactose
- Most abundant and nutritionally relevant is glucose
- Only monosaccharides are absorbed into bloodstream
Disaccharides
- Two monosaccharides joined by a covalent bond
- Sucrose, maltose and lactose
Sucrose
- cane sugar, beet sugar
- is the most widely used natural sweetener
- glucose + fructose
Maltose
- formed from the partial breakdown of starch and is often used in malt beverages (e.g., beer= barley is malted, maltose is formed, bacteria ferment the maltose and make alcohol)
- glucose + glucose
Lactose
- is “milk sugar”, one of the only animal sugars besides glucose
- Glucose + galactose
Complex carbohydrates
Oligosaccharides and Polysaccharides
Oligosaccharides
- Short chains of monosaccharides joined by bonds that cannot be broken by human enzymes (i.e. they are a fiber source)
- Fructans and galacto-oligosaccharides
- Garlic, onions, wheat, artichokes, beans, lentils, chickpeas, inulin
- most ~ 3 monosaccharide units
Polysaccharides
- Long chains of monosaccharides joined by bonds (some digestible and some
not) - Include glycogen, starch, and cellulose
- Potato, rice, pasta, corn, cereal, bread, apple peel, seeds, nuts
- up to 1000’s of units
primary nutritional polysaccharides:
Starch: energy storage in plants (digestible)
Glycogen: energy storage in animals (digestible)
Cellulose: provides structure in plants( non-digestible)
- Starch and glycogen are digestible = glucose polymers bonded with α glycosidic bonds that CAN be broken down by enzymes
- Cellulose is non-digestible = connected via β glycosidic bonds that can NOT be broken down by human enzymes
Fiber in the intestine
- Fiber is important to our health because of what happens to it in the colon.
- COLON: Bacterial enzymes can break down fiber to form short chain fatty acids and gas as a byproduct.
- Fiber feeds our gut microbiota.
Microbiota symbiosis
- high fiber whole natural foods
- gut microbiota pyramid
Microbiote dysbiosis
- Processed foods low fibre
- chronic disease pyramid
Look for whole grain foods
- In a grain of wheat, the outer bran layer is a rich
source of dietary fiber - The germ contains protein, unsaturated fats, thiamin, niacin, riboflavin, iron, and other nutrients
- The bran and germ are removed in the refining
process (i.e. making white flour) - The endosperm primarily contains starch, the
storage form of glucose in plants = white flour
Soluble fiber
- benefits health in several ways
- Slows down glucose absorption, thereby lowering peak blood levels of glucose
- reduces fat and cholesterol absorption
- Found in oats, barley, fruit pulp, peas, beans, citrus fruits, strawberries and psyllium
- Lower calories than digestible carbohydrates (1-2 kcal/g typical)
Insoluble fiber
- Insoluble fiber is good because it benefits health in several ways
Moves bulk through gut, controls gut pH, removes toxic waste, prevents constipation - Found in vegetables, wheat bran, whole grains, flax seed, popcorn, corn bran, seeds, nuts, apple peel
Macronutrient effects on blood glucose
How does the body manage glucose:
1. Blood glucose rises when you eat.
2. High blood glucose stimulates pancreas to release insulin.
3. Insulin stimulates uptake of glucose into cells and storage as glycogen in liver and muscle. It
also helps convert excess glucose into fat stores.
4. As body cells use glucose, blood levels decline.
5. Low blood glucose stimulates pancreas to release glucagon.
6. Glucagon stimulates liver cells to break down glycogen and release glucose into blood.
7. Blood glucose begins to rise
Added sugars
- Major sources of simple sugars in most diets are added during processing of food
- Labels contain information on total sugars per serving but do not distinguish between naturally occurring and added sugars yet.
- ‘Added sugars’ add calories without adding nutrients
The bad side of sugar
We need sugar to survive, but…
- Tooth decay
- Empty calories (calories without nutrients)
- Often mixed with fats in sweets
- Limit sweet and sticky foods; replace them with vegetables and fruits
- Overall quality of diet decreases when sugar intake increase
Sugar alternatives
- Alcohol sugars (~2.6 kcal/g)
Xylitol
Mannitol
Sorbitol - Used in chewing gum and other candies and foods
- Can be used to mask the unpleasant aftertaste of some artificial sweeteners
- Are not well absorbed in the gut; large amounts can cause diarrhea
Stevia
- Herbal Alternatives: Stevia (GRAS – generally recognized as safe - status)
- Initial studies with crude whole leave extracts of stevia = reproductive, renal and cardiovascular toxicity
- Purified stevioside preparations show no toxic effects
- In 2012 Health Canada approved its use in foods
Artificial sweeteners
Aspartame, sucralose, Acesulfame K, saccharin
Aspartame
A dipeptide (2 amino acids = aspartic acid + phenylalanine)
Digestion releases methanol (10%), aspartic acid (40%) and phenylalanine (50%)
Methanol converted to formaldehyde and then formic acid
200 times sweeter than sucrose (sugar)
Products containing it bear a “contains phenylalanine” label for people with PKU (phenylketonuria)
“Nutrasweet” & “Equal”
Acceptable daily intake 40 mg/kg BW
Not compatible with high temperatures (> 30ºC)
Sucralose
- Made from sugar = chlorinated sugar
- 600x sweeter than sugar
- Safe when heated
- “Splenda”
Acesulfame K
- Often used in combination with other artificial sweeteners
- Stable at high temperatures
Saccharin
Discovered in 1879 by accident by chemist working on coal tar derivatives
- 300x sweeter than sucrose
- Banned in Canada in 1977 due to bladder cancer fears, returned to market once it was discovered the mechanism by which it caused
cancer in rats is not present in humans.
maternal artificial sweetener consumption during pregnancy
- Reduced insulin sensitivity
- Altered mesolimbic reward pathway in the brain
(promotes food seeking behavior) - Altered gut microbiota composition and function
- Offspring had 25% higher fat mass at 3 weeks of age
Sugar and Tooth decay
A. Mechanism
B. Promoters of tooth decay
C. Protective foods
D. Fluoride and dental health
A. Mechanism
- sugar is sole food for bacteria -> produce acid
- bacteria form sticky white plaque
- acid is produced by bacteria for 20 min after
sugar is eaten
B. Promoters of tooth decay
- increased frequency of sticky foods
- acidic beverages
- excessive cleaning/polishing of teeth
- nursing bottle syndrome
C. Protective foods
- cheese (increases ph of plaque- decrease acidity)
- protein (with calcium it strengthens enamel
- low calorie sweeteners such as orbital, mannitol, xylitol (stimulate saliva)
D. Fluoride and dental health
- promote remineralization of eroded enamel
- water, toothpastes, dental rinses
- excess leads to fluorosis or “mottled” enamel during tooth development
- cosmetic condition that can only form in children less then or equal to 8 years when permanent teeth are developing
Fluoride in drinking water
2011 City of Calgary voted to remove fluoride from water supply
2016 study compared rates of tooth decay in grade 2 children from Calgary (removed fluoride) and Edmonton (kept fluoride)
Compared 2004/2005 and 2013/2014 data
Both cities had high rates of tooth decay but was increasing more rapidly in Calgary
2021 study shows gap is widening: “Of the approximately 2,600 Grade 2 students in each city who took part in the study, 55.1% of
Edmonton participants had one or more cavities in their baby teeth. In comparison, the number was 64.8% of Calgary children.”
November 2021 City of Calgary voted to reintroduce fluoride into water supply (set to start by September 2024)
Gestational diabetes
Only during pregnancy
Type 1 (insulin- dependent) Diabetes
- typically diagnosed before 40, abruptly
- treatment is with insulin, diet and exercise
Type 2 (non-insulin dependent) diabetes
- lifestyle related
- treatment is weight reduction
Diabetic symptoms
Poorly controlled, untreated diabetes produces:
Blurred vision
Frequent urination
Weight loss
Increased susceptibility to infection
Slow healing sores
Extreme hunger and thirst- cells being stared from glucose
Diabetes: health consequences
Long term, diabetes may cause:
Heart disease and stroke
Kidney damage (nephropathy)
Blindness (retinopathy)
Nerve damage (neuropathy)
Loss of limbs due to poor circulation
Alzheimer’s disease
Insulin
Insulin is a pancreatic hormone
Reduces blood glucose
Facilitates passage of glucose into cells(T2D)
Low/no insulin (T1D) starves cells
Cells can also starve if cell membranes become insulin- resistant (T2D)
Gestational diabetes
- 5 to 6% of women develop gestational diabetes
- Indigenous and Black, women with obesity, women over 35 years, and women with low physical activity have greater risk
- Women with gestational diabetes are insulin resistant
- Control blood glucose levels with an individualized diet and exercise plan
Gestational diabetes 2
- Infants of women with diabetes may have increased body fat at birth & have blood glucose control problems after delivery
At greater risk for diabetes later in life
6 to 20% will have a physical abnormality that may threaten survival or a high quality of life
e.g. cleft palate, club foot, heart defects - some women require daily insulin injections for blood glucose control
Gestational diabetes after pregnancy
Gestational diabetes disappears after delivery
But type 2 diabetes may appear later in life in the mom
Exercise, maintenance of normal weight, and a healthy diet reduce the risk that diabetes will return
Type 1 diabetes
Type 1 diabetes results from a deficiency of insulin
Accounts for about 5-10% of all diabetes and is increasing yearly (2x as high as children in ’80s)
Diagnosis of type 1 peaks around the ages of 11 to 12 years and usually occurs before age 40
Autoimmune disease that destroys pancreatic beta-cells that produces insulin
Breastfeeding for first four months may protect infants against type 1 diabetes
Environmental factors are more important than genetics in type 1 diabetes
Candidates have included: early exposure to cow’s milk proteins; vitamin D deficiency; early exposure to gluten; certain viruses (rubella, rotavirus, mumps, cytomegalovirus, enteroviruses); gut microbiota
Immune-mediated diseases and microbiota
- Finland highest rate of type 1 diabetes in the world.
- in different regions around 8 times lower incidence
- share similar genes but different hygiene/microbial exposure
- Estonia, once lower, is catching up with Finland
managing type 1 diabetes
- Insulin
Injections
Pump
Islet transplant - Diet
- Exercise
Type 2 Diabetes
- Occurs in individuals with overweight or obesity and a sedentary lifestyle
- Most common in people over 40 – but increasingly seen in young children
- Increasingly common in children and adolescents
- Strong genetic component
Diabetes
Type 2
- Runs in families (Black, Hispanic, Indigenous and Asian); associated with ”apple” obesity
- Individuals with type 2 diabetes are insulin-resistant
- Type 2 diabetes can be managed with diet & exercise - most of the time
- If not, there are 8 different classes of diabetes medications that can be prescribed to manage diabetes
- act on different parts and affect different pathways in the body
Prediabetes and insulin resistance
Elevated fasting blood glucose levels below the cut- off point used to diagnose type 2 diabetes
20% of Canadian adults, and 314 million people
worldwide have prediabetes
Prediabetes is a major risk factor for type 2 diabetes
Insulin resistance
- Common risk factors for insulin resistance
Obesity
Low levels of physical activity
Genetics - When blood glucose levels become high, the pancreas secretes more insulin to keep glucose levels under control
- Pancreas becomes exhausted from over-work and insulin production slows or stops
- When fasting blood glucose levels reach 7 mmol/L or higher, type 2 diabetes has developed
Managing type 2 diabetes with diet and exercise
- Weight loss alone significantly improves blood glucose control
- Proper diets are crucial
Complex carbohydrates including whole-grain breads and cereals, and other high-fiber foods, vegetables, fruits, low-fat milk and meats, and
fish
Unsaturated fats
Regular meals and snacks
Protein at every meal (particularly bedtime)
Sugar intake and diabetes
High intakes of simple sugars do not directly cause diabetes – but can contribute to obesity
Sugar does not have to be eliminated from the diet of individuals with diabetes, but total carbs should be reduced
High-sugar diets increase blood triglyceride levels and the risk of heart disease in people with metabolic syndrome
Glycemic index
- Foods that elevate blood glucose require more insulin to move glucose into cells
- Foods that affect blood glucose are given a glycemic index value
Blood glucose elevation caused by 50 grams of a food, compared to the elevation caused by eating 50 grams of glucose - Low-glycemic index foods decrease triglyceride levels and insulin needs in type 2 diabetes
Glycemic index values
Sticky rice 86, yogurt 31, milk 25, hummus 6
- fruits have low glycemic index
- grains have medium glycemic index
- sugers, breads and processed food have high glycemic index
Alcohol is..
- a food because it is made from carbohydrate
- a drug because it modifies various body functions
Alcohol forms..
- Alcohol forms when yeast ferments sugars in different foods.
- Wine - sugar in grapes
- Beer - sugar in malted barley
- Cider - sugar in apples
- Vodka - sugar in potatoes
- At low dose, acts as stimulant (e.g. increase talkativeness)
- At high dose, depresses the central nervous system (e.g. drowsiness, respiratory depression)
Alcohol in beverages
- beer (4-6% alcohol) - 355 ml can
- wine (8-14% alcohol) ~ just over half a cup = 148 ml
- distilled liquor (many around 40%) = 44ml shot
Alcohol in body
- requires no digestion
- 10% absorbed directly across empty stomach wall
- reach brain in 1 minute
Positives for alcohol
1 (women) – 2 (men) standard drinks per day
Moderate consumption (may) protect from heart disease in men over 45 and women over 55
Increases high-density lipoprotein (HDL), the “good cholesterol”
May protect against Type 2 diabetes (in nondiabetics) and ischemic stroke (but not hemorrhagic)
Wine consumption was found to be cardioprotective but not beer. More recent
research, wine and beer but not spirits.
Red wine’s pigments act as an antioxidant and inhibit blood clot formation
Purple grape juice also works
May decrease the ability of LDL cholesterol to stick to plaques in the arteries
negatives of alcohol
- Heavy drinking, ~ 5 or more drinks/dau threatens drinkers health and those of others
- great cancer risk incrwases with increased alcohol consumption
- High blood pressure, stroke, heart attack, cirrhosis, throat and stomach cancer, breast and bladder cancer, vitamin and mineral deficiencies, fetal alcohol syndrome, accidents, drownings, violent behavior, etc…
Alcoholism
chronic and progressive disease
- the younger the age when alcohol is first consumed, generally the greater the chances of developing a drinking problem
Alcohol poisoning
Passing out
Semi-conscious
Cold, pale, or bluish skin
Vomiting while sleeping
Slow or irregular breathing
Seizures
Taking risks when you’ve been drinking can lead to:
getting hurt or even death—alcohol-related injury is the major cause of death in teens and young adults
sexual risk-taking—this includes unwanted sex, unplanned pregnancy, and sexually transmitted infections
suicide and self-harm—higher risk in teens and young adults who drink heavily or often
Fetal alcohol spectrum disorder (FASD)
- Children born to women who drink during pregnancy can develop fetal alcohol syndrome.
- Children with FASD experience impaired growth and mental development.
- May have distinct FASD associated facial features although this is only present in about 10% of individuals with FASD
FASD notes
4% of Canadians have FASD
2.5× more prevalent than autism spectrum disorder
~11% of Canadian mothers report consuming alcohol during pregnancy (3% report alcohol binges)
Mental health disorders are seen in >90% of
individuals with FASD, compared to 20% of general population (depression and anxiety most common)
There is no cure for FASD, but research shows that early intervention can improve a child’s development.
Alcohol intake and diet quality
- 7 calories/gram in pure alcohol
- For adults who drink, 3-9% of calories come from alcohol, and 50% of calories come from alcohol in heavy drinkers
- As alcohol consumption from alcohol-containing
beverages increases, the quality of the diet generally decreases - Empty calories – calories but no nutrients
How does the body handles alcohol?
- Alcohol is easily and rapidly absorbed in the stomach and small intestine
- Once in the body, alcohol remains in the blood and body tissue until it is broken down by the liver and used for energy or is converted into fat and stored
- Blood levels of alcohol build up as drinking continues
- Unlike carbohydrates (glycogen in liver and muscle) and fat (triglycerides in adipose tissue and liver), alcohol is NOT stored and remains in the body until eliminated
How does the body treat alcohol?
- treats alcohol as a toxin and begins elimination
immediately —- up to 10% eliminated directly without being metabolized - exhaled via lungs and the rest via sweat, saliva and urine - At least 90% of alcohol that enters body is eventually completely oxidized
- Because the stomach has alcohol dehydrogenase, a very small amount of alcohol is metabolized there but the majority remains the job of the liver
Sex differences- why women have lower alcohol tolerance?
- Stomach alcohol dehydrogenase begins breakdown (women have lower amounts of the enzyme – therefore less first pass metabolism and more alcohol can reach bloodstream)
- Alcohol is dispersed among body tissues but very little alcohol enters adipose tissue due to poor fat solubility. Women have more body fat and less body water – because alcohol is dispersed in body water, women reach higher
peak blood alcohol concentrations than men - Women also have lower blood volume
How the body handles alcohol, blood alcohol concentrations (BAC)
Determined by:
1. amount of alcohol consumed
2. presence or absence of food
3. rate of alcohol metabolism
Absorption of alcohol
- Blood alcohol levels increase more rapidly if the absorption rate is higher:
1. Drinking on an empty stomach speeds up alcohol absorption
2. The higher the concentration of alcohol in the beverage the faster the absorption (peak at about 20% alcohol)
3. Carbonated beverages tend to speed up absorption (champagne, sparkling wines, mixed with soft drinks, tonic mixers) - Absorption can be slowed down by:
1. Eating before or while drinking (slows down absorption of
alcohol into bloodstream)
2. Diluting drinks with water or fruit juice
Blood levels and effects
- A drink or two in an hour raises blood levels to 0.03% in a person of about 140 lbs (mild intoxication)
Impaired driving limit is 0.08% in most places
0.08 - 0.10%: impairment in all driving skills, coordination, balance & speech
0.13%: more severe slurred speech, double vision, dulled reflexes, unsteadiness, dangerously impaired decisions making, vomiting
>0.35%: loss of consciousness, alcohol poisoning, can cause death
Alcohol metabolism in the liver
- Liver can process about 1 drink per hour
- alcohol circulates in body until liver can process it
- therefore, consume no more than 1 drink per hour
- amount of alcohol dehydrogenase depends on genetics and how recently you’ve eaten ( alcohol metabolism higher in fed versus fasted state).
Alcohol damages the liver
- fatty liver- fat accumulates
- fibrosis- lever cells die and form scar tissue
- cirrhosis- damage least reversible
Alcohol and behaviour
- Depresses the behavioral inhibitory centers - The person becomes more talkative, more self-confident and less socially inhibited.
- Slows down the processing of information from the senses - The person has trouble seeing, hearing, smelling, touching and tasting; also, the threshold for pain is raised.
- Inhibits thought processes - The person does not use good judgment or think clearly.
Myth or truth… alcohol myths
“Walk around the block”- Muscle can’t metabolize alcohol, only liver time alone will do the job
“Cup of coffee”- Stimulant but doesn’t speed up metabolism of alcohol, wide-awake drunk
Alcohol interaction with other drugs
- Sleeping pills, antidepressants, and pain killers interact harmfully with alcohol
- Alcohol metabolism competes for detoxification system in liver and drug builds up
- Aspirin or ibuprofen: stomach ulcers & bleeding (irritate stomach lining as does alcohol)
- Acetominophen (“Tylenol”): liver damage
- Sedatives, narcotics: severe sedation
Red bull and vodka
- RED BULL is a stimulant (contains: caffeine, taurine, ginseng, guarana, sugar)
- taurine - can alter the locomotor stimulatory, sedating, and motivational effects of ethanol in a strongly dose-dependent manner
- ALCOHOL is a depressant…
- Red Bull can mask the effects of alcohol - you
feel less intoxicated while still experiencing alcohol-related impairments
Type 1 alcoholism
- occurs after the age of 25, and is generally environmental and genetic in origin (drink to relieve anxiety); affects men and women
Type 2 alcoholism
- Typically genetic and occurs with early exposure (teen years) (drink to induce euphoria); affects men more often
Binge drinking
- Binge drinking (≥5 drinks for males or ≥4 drinks for females in 1 occasion) has been reported by:
15% of 8th graders
26% of 10th graders
31% of 12th graders - Binge drinking cancels any health benefits from
moderate drinking and can cause social problems, injury and chronic health problems. When youth binge drink, they are much more likely to develop dependence on alcohol and to be injured or to injure others. Please seek help.
If you drink, drink safely
- Don’t drink and drive or operate machinery
- Designated drivers and cabs
- Don’t drink on an empty stomach
- Do not drink if you are pregnant or could become pregnant
Protein and amino acids
- Proteins are chains of amino acids
- The body cannot produce sufficient essential amino acids
- The body can produce non-essential amino acids
- If a cell is building a protein & cannot find a needed amino acid, synthesis stops
how many Essential amino acids are there?
9
How many non-essential amino acids are there?
11
Denaturation of proteins
*Can occur due to exposure to: heat, acids, bases, alcohol, heavy metals
Good:
- cooking denatures food proteins (e.g. egg white)
- stomach acid open’s protein structure for digestion
Bad:
- fever can denature body proteins
- heavy metals (mercury) can destroy body proteins
* produces toxic effects by protein precipitation, enzyme inhibition, and generalized corrosive action
Protein digestion in GI tract- stomach
- HCl denatures (unfolds) proteins & converts pepsinogen into pepsin
- Pepsin cleaves large polypeptides into smaller polypeptides
Protein digestion in the GI tract- small intestine
- Pancreatic proteases break polypeptides
into di- and tripeptides and some amino acids - Intestinal di- and tri-peptidases complete
the break down of peptides into amino acids - Once in the enterocyte, di- and tri-peptides
are broken down to free amino acids which
are absorbed into the blood stream
Protein function within our body
- Building materials (muscle, fetus, scar tissue, red blood cells, intestinal cells)
- Enzymes
- Hormones
- Fluid balance
- Transport (lipoproteins)
- Acid-base regulation (blood proteins buffer blood pH by picking up hydrogen ions)
- Antibodies
- Energy
Proteins can provide energy…
- 4 kcal/gram but unlike carbohydrate and fat, protein contains nitrogen (free nitrogen can be used for protein formation or if there is an excess, excreted as urea by kidney)
- Glucose stored as glycogen; fat stored as triglyceride but protein consumed in excess cannot be stored. There is no storage form of protein.
- Amino acids can be converted to glucose – fat can’t
Dietary protein
Digestibility
- animal proteins (>90%)
- legume protein (80%)
- grains and other plants (60-90%)
Protein quality
- EAA limit protein synthesis
Complete proteins
- Contains all the essential amino acid in amounts to sustain protein formation in the body
- Meat, fish, poultry, cheese, eggs, milk &
many soybean products (quinoa by some standards falls just short of the lysine needed to be classified as a complete provider of all essential amino acids)
Incomplete proteins
- Lack some of the essential amino acids
- Lower nutritional quality due to low levels of select EAA and presence of antinutritional factors, such as protease inhibitors that decrease protein digestibility.
Grains do not contain sufficient lysine.
Legumes do not contain enough methionine.
Complementary proteins
Grains and Legumes together
* All essential amino acids are present.
* Complete protein!
Positive nitrogen balance
- retain more than excrete
- growing child, pregnant women, person building muscle
Nitrogen equilibirum
Normal healthy individuals
Negative nitrogen balance
- lose more than take in
- trauma patient, astronaut
Protein sources
Chicken or beef (3 ounces) 21g
Egg 7g
1 cup milk 11g
1 serving yogurt (Greek) 6-10g (up to 23 g)
Lentils (1/2 cup) 8g
Peanut butter (1 Tbsp) 3g
Individual AA- not found naturally in foods
- can be contaminated
- interfere with absorption of other EAA
- excess consumption of methionine worsens the symptoms of schizophrenia, promotes hardening of the arteries, impairs fetal and infant development, and leads to nausea, vomiting, bad breath, and constipation
- in sports: glutamine & branched chain amino acids may have some performance benefits
Whey protein
- Milk protein = 20% whey + 80% casein
- immune enhancing properties
- low in fat and nutrient dense
- may improve body composition
Can eating extra protein make muscles grow larger?
False. Although sufficient protein intake is
necessary, extra strength training is what leads to
muscle growth — not extra protein intake.
Kwashiorkor: protein deficiency
- Children suffering from a severe form of protein
deficiency experience swelling in the arms, legs,
and stomach area; the swelling hides the
devastating wasting that is taking place within their bodies - Children often have the characteristic “moon face” (edema), swollen belly, and patchy dermatitis (from zinc deficiency)
Marasmus: protein and calorie deficiency
Lacking both protein and calories
Can you consume too much protein?
- Protein-rich foods are often high-fat foods (saturated) Excessive red meat linked to colon cancer
- Calcium : protein ratio —– good is 20 : 1 — actual 9 : 1 High protein intake increases Ca loss in the urine
- Dehydration, Burden the kidney to excrete excess nitrogen (requires water)
- In healthy individuals, the kidney generally adapts
- Exceptions: kidney disease or diabetes
Vegetarians
- Vegan: exclude all animal derived foods
- Lactovegetarian: include milk products
- Lacto-ovo-vegetarian: include milk & egg
- Partial vegetarian: excludes red meat
- Pesco-vegetarian: excludes poultry & red meat
Vegan diet health benefits
- Lower body weight
- Lower blood pressure
- Less heart disease
- Lower mortality from cancer especially colon
At-risk nutrients
- protein
- iron
- zinc
- calcium
- vitamin d
- Vitamin B12
Population at risk: pregnancy and lactation, infancy, childhood and adolescnce
at-risk: Protein
a) Complete protein: animal sources
b) Incomplete: plant protein
*Grains: not enough lysine
*Legumes: not enough methionine
Complementary Proteins:
Grains & Legumes
Milk & Grains
Milk & Legumes
At-risk:Iron
- iron in plant foods, legumes, dark green leafy
vegetables, iron-fortified cereals, whole grain
breads & cereals more poorly absorbed than
animal source iron - but vitamin C enhances absorption of non-heme (plant sources of iron)
At-risk: Zinc
- meat is rich source
- seafood also good source
- whole grains, nuts, legumes
- critical for immune function and growth
At-risk: Calcium
- calcium-fortified juices or soy milk
- other sources:
*calcium-set tofu
*some legumes (navy & white beans)
*almonds
*tahini and chia seeds
At-risk: Vitamin D
- vitamin D fortified milk
- exposure to sunlight (northern climates limited)
- supplement likely necessary
At-risk Vitamin B12
- only in animal foods
- fortified soy milk or breakfast cereals or supplement
Food allergy
- Symptoms of food allergies range from mild to serious
- They involve the immune system
- Typically, allergy begins when a person eats a food containing an allergen (typically a protein, but not always)
- Incidence is on the rise
Food allergy: immune system
- After one or more exposures, the person forms
antibodies to the allergen - Antibodies attach to various cells including the mucous membranes of the mouth and gut, the lungs, nose and eyes, etc.
- Upon re-exposure to the allergen, the allergen binds to the antibodies and triggers histamine release and other immune responses
- Reaction time is usually seconds to ~2 hrs
Vaccines for food allergy treatment
Injecting a gene-based vaccine may help patients tolerate peanuts by avoiding IgE-activated response.
Parasistes for food allergy treatment
Scientists are using proteins from helminth
parasites that block the activity of mast cells and other immune players to suppress allergies.
Oral tolerance for food allergy treatment
Eating tiny amounts of peanut protein to gradually retrain the immune system to tolerate allergens by avoiding IgE antibody-mediated response.
Top eight foods that cause allergies
- Nuts, eggs, wheat, milk, peanuts, seafood, soy, fish
Food allergy common in children
- Incidence of allergy is higher (6-8%) in children three years of age or less
- Children can grow out of cow’s milk, eggs and soy, but often don’t outgrow peanut, nut, fish or shellfish allergies
– Allergy appears before 3 yrs - 80% outgrow them
– Allergy appears after 3 yrs - 33% outgrow them - Incidence of documented allergy in adults is about 3% (20-30% of general public believe they have allergies)
Allergic reactions include:
- Skin eruptions, skin rash, hives 84%
- Upset stomach or intestinal tract, vomiting, cramps, nausea, diarrhea 52%
- Respiratory problems: congestion, runny nose, cough, wheezing, asthma 32%
- Anaphylactic shock. Rare
Anaphylactic shock- generalized, all-systems reaction
- low blood pressure
- respiratory and GI distress
- can be fatal
- most commonly eggs, wheat, milk, soy,
nuts, peanuts, seafood, fish - peanuts responsible for 62% of deaths and 30% because of tree nuts.
Skin tests
can be used to suggest allergies or rule them out but aren’t as good as eating the food.
Blood tests
can be used to look for antibodies to specific allergens. Not completely definitive since finding IgE doesn’t always mean someone is allergic
Food challenge
Medically supervised oral food challenge is the most definitive way to confirm food allergies
Diagnostic elimination diets
- Elimination diets are another key approach to determine food allergies and are usually used when there are chronic symptoms (e.g. dermatitis, not anaphylaxis)
- There are two parts to an elimination diet:
– The elimination (avoidance) phase
– The reintroduction (challenge) phase - Eliminate suspicious foods (typically for 1-2 weeks or until symptoms are gone). Keep a diary of foods/symptoms.
- Reintroduce suspicious foods, one at a time, and watch for symptoms (at least 3 days in between the addition of the next food)
Allergy treatments
- There are no reliable treatments for food allergies
– Research examining new approaches including giving small amounts of allergen to build tolerance - Most treatments carry the risk of allergic symptoms, so the best thing to do is to eliminate the food from your diet
- Many childhood allergies disappear by age 2 – 3
- Foods could be added later in life
Precautions for allergys
- People with food allergies have to be careful and should have a plan ready in case they develop a serious reaction
- They have to become students of food ingredient labels
- A preloaded syringe of epinephrine is essential for people who develop anaphylactic shock (EpiPen)
Why do we have more allergies today?
- Hygiene hypothesis
- Unhealthy fats (low omega-3)
- Obesity (inflammatory state)
- Vitamin D deficiency (increased allergies in NA)
- Timing of exposure to foods (want to induce oral
tolerance) - Greater allergenicity when peanuts roasted
- Use of topical ointments or lotions containing
peanut oil in infants (bypasses oral route for
tolerance) - Use of soy formula (cross-reactivity to peanuts)
Food intolerances
- Involve the digestive system not the immune system
- Are typically dysfunctions where an enzyme is missing
- True intolerances produce predictable reaction(s)
- Triggers: constituents of certain foods, synthetic compounds, food contaminants, deficiencies
Food intolerances: Constituents of certain foods
- red wine and aged cheese
- Histamine in wine blamed for headaches
- Tyramine (aged cheese, soy sauce) linked to migraines in sensitive people
Food intolerances: Synthetic compounds added to foods
- Sulfites, food-colouring, MSG
- Sulfites are great antimicrobials but affect our tissues adversely too
- Although sulfites do not cause a true allergic reaction, sulfite- sensitive people may experience similar reactions as those with food allergies
- MSG (monosodium glutamate) is a flavor enhancer whose intolerance is linked to dizziness, sweating, flushing, rapid heartbeat and ringing in the ears.
food intolerances: food contaminants
- chemicals used in production, insect parts
Food intolerances: deficiencies
- In digestive enzymes (lactase)
Lactose Intolerance
*Lactase enzyme highest at birth
A. Symptoms
- bloating, abdominal discomfort, diarrhea, gas
B. Causes
- lactase declines with age
- intestinal villi damage from medicines, prolonged diarrhea, malnutrition
C. Prevalence
- >80% Southeast Asians to <10% Northern Europeans
Lactose intolerance Dietary changes:
- total elimination of milk products not necessary
- 1/2 cup usually tolerated
- increase intake gradually; take with other foods;
spread intake through day - yogurt & hard cheese better (Greek yogurt has less lactose than regular yogurt)
- as cheese ages less lactose (bacteria use it)
- Lactaid™ milk, tablets or enzyme drops
Saturated fats
- Solid, no points of unsaturation
- animal fats, butter, lard, coconut oil, palm kernel oil
Monounsaturated fats
- more liquid, one point of unsaturation
- Omega 9 fatty acids: olive oil, avocados, peanuts, almonds, canola
Polyunsaturated fats
- liquid, at least two points of unsaturation
- Omega 3 fatty acids:
eicosapentanoic acid- fish, shell fish
Docosahexanoic acid- fish, shellfish
alpha linolenic acid: flaxseed, soybean, walnut, rapeseed oils - Omega 6 fatty acids (caution)- corn oil safflower oil, sunflower oil
The fish oils: ‘long chain’ n-3
- Eicosapentaenoic acid (EPA)
- Docosahexaenoic acid (DHA)
- reduce heart disease risk
- reduce tendency for blood to clot
- Inuit have impaired blood clotting
- risk for uncontrolled bleeding & hemorrhagic stroke
- recommend fish 2x per week
Ratio of n-6 to n-3
- Ratio of n-6 to n-3 is important
- Functions of one are adversely modified by high
amounts of the other - People should consume n-6:n-3 at 4:1 or less
because high n-6 intake increases inflammation - Canadians n-6:n-3 ratio is over 9:1 === inflammation
– We need to increase intake of n-3 fatty acids
Hydrogenation
- Adding hydrogen to liquid unsaturated fats (oils) makes them more saturated and solid
- Shelf life, cooking properties, and taste improve
- Hydrogenation has two drawbacks:
– Hydrogenated vegetable oils have more saturated fat: - Corn oil contains 6%
- Corn margarine has 17%
– Hydrogenation changes structure of the unsaturated fatty acids - Converts some fats into trans fats
Trans fatty acids
- Trans fat comes from hydrogenated vegetable oils
- Trans fats raise blood cholesterol levels more than other types of fat and promote inflammation
- Increase LDL & lower HDL (worse than saturated fats)
- Not made by body & limited amount naturally in beef & dairy
- Increase the risk of heart disease, stroke, sudden death from heart disease, and type 2 diabetes.
Cholesterol
- Cholesterol is found only in animal products
- Tasteless, odorless, clear liquid
- Plants do not contain cholesterol because they can’t produce it and don’t need it
- Blood cholesterol reflects two sources
– Endogenous: 2/3 is produced by the liver
– Exogenous: 1/3 comes from the diet
Slide 28 Lecture 14
- Chylomicron transports dietary fats
- VLDL and LDL transports fat made by liver
Chylomicron
- transports fats
- delivers it to tissues that need it
- then returns to liver
HDL
- reverses process of cholesterol
- reverse transport (cholesterol to liver)
Liver
- can make its own triglycerides
- lipids made by liver are carried by VLDL (very low lipid protein)
LDL
- Derived from VLDL which carries fats and stick to lining vessels
- creates plaque
Percents for fats
Chylomicron = 80% triglyceride
VLDL = 50% triglyceride
LDL = 50% cholesterol
HDL = 50% protein
Total cholesterol and LDL ( low density lipoprotein)
- decrease intake of SAT (<10% of calories) &
trans fat (0 g/d) - decrease intake of cholesterol
- increase intake of fiber
- lose weight if necessary
