Lecture 7: Alcohol And Metabolism Flashcards Preview

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Flashcards in Lecture 7: Alcohol And Metabolism Deck (39):
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Alcohols and hydroxyl

- all alcohols have one or more hydroxyl (-OH) groups
- glycerol is the alcohol used to make triglycerides
- ethanol is the alcohol in beer, wine, and distilled liquor
• 2 carbon skeleton

1

The history of alcohil in diet

- consumed for thousands of years
- used for centuries
• medical treatment
• anesthetic
• safe beverage source (compare to unclean water)
- created by fermentationof grains, cereals, fruits
- strong cultural roots
- strictly prohibited in some religion

2

Alcohol nutrition

- 7 Calories per gram
- ethanol provides no essential nutrients to human health
- some alcoholic beverages, such as beer, contain small amounts of B vits, biotin, magnesium, selenium, and phosphorus
- the "french paradox" = high fat diet + red wine

3

Recommended intake

- consume alcohol in moderation
•two drinks per day for men
• one drink per day for wonen
• one drink = 1.5 oz distilled spirits, 4-5 oz wine, 10 oz wine cooler or 12 oz beer

- no alcohol consumption during pregnancy due to risk of fetal alcohol symdrome

4

Benefits of moderate alcohol consumption

- reduce stress
- enhance sociability and self confidence
- among the elderly: stimulate appetite => improve dietary intake
- reduce cardiovascular risks
• increase HDL (good cholestrol)
• decrease LDL (bad cholesterol)
• may blunt platelet aggregation; risk if clot forming
• wines contain flavonoids, including the potent anyioxidant resveratrol, which may protect heart health

5

Resveratrol

phytochemical, involved in plant immune response

Source of resveratrol in foods:
- grape skins
- red wine
- peanuts
- cocoa powder
- baking and dark chocolate
- japanese knotweed

In animals studies, Resveratol showed anti inflammatory and anti cancer effects, lowers blood sugar glucose after meals, promote cardiovascular health, and prolongs life span in invertebrates

6

Risks of moderate alcohol consumption

- may increase risk of breast cancer among some women
- may increase blood pressure
- may increase calorie intake and weight
- dangerous if consumed with certain medications, including OTC drugs

7

Alcohol absorption

- absorbed in the stomach and small intestine
- transported to the liver for metabolism
- excess released into the bloodstream and distributed to all tissues
- liver is the major organ for alcohol metabolism
- liver can only metabolize alcohol 1 drink per hour so then there would be very little released into the blood

8

Rate of absorbtion depend on...

- amount and speed of alcohol consumption
- presence or absence of food in the stomach
- gender (women have less body mass and less ADH in stomach)
- health status
- age
- genetics

9

Alcohol Oxidation in the Liver

-Liver metabolizes about one alcoholic drink per hour
CH3-CH2-OH ADH CH3-CHO ALDH CH3-COO-
ethanol ---> acetaldehyde ---> acetate
<---

-If drinking more than this amount, excess is released back into the bloodstream
-The more alcohol in the bloodstream, the higher the blood alcohol content (BAC)
*.08 is the legal BAC limit

10

GENETIC VARIATION IN ALCOHOL METABOLISM

- Certain Asian populations have normal levels of ADH, but low levels of ALDH which causes a toxic build up of acetaldehyde
-This causes flushed face, nausea and headache
- Acetaldehyde is very toxic in the body


11

ALCOHOL METABOLISM – MICROSOMAL ETHANOL OXIDIZING SYSTEM (MEOS)

-The liver MEOS system commonly breaks down and detoxifies medications and toxins.
-The body will metabolize alcohol FIRST, so drugs build up in the system to toxic levels.
-This can be fatal.
-This is why it is dangerous to combine alcohol and drugs.

12

WHAT IS ALCOHOL ABUSE?

-Excessive alcohol consumption (occasional or chronic)
-Binge drinking – consuming ≥4 alcoholic drinks on one occasion (within 3-5 h period)
-Alcoholism – chronic dependence on alcohol

13

EXCESSIVE ALCOHOL INTAKE: YOUTH

-Binge drinking: consuming 4+ drinks in one occasion
-Causes neurotoxicity in the frontal cortex (decision making) and the hippocampus (memory) due to excessive release of glutamate after drinking is over
-Alcohol consumption is the number one cause of death among those under 21 years of age

14

THE TRUTH ABOUT SOBERING UP

-What does NOT help to speed up alcohol breakdown?
*Walk around
*Coffee or Caffeine
*Supplements
-What does help?
*Only consume one drink per hour
*Drink water before and after
-ADH build up is what cause a hangover
-Drinking water after a hangover will help a lot! You get a headache from the dehydration

15

HANGOVERS

-Build up of acetaldehyde causes vomiting, nausea
-Loss of glucose from liver storage causes weakness
-Dehydration and electrolyte imbalance (loss of potassium and sodium through increased urine production) from the body and brain causes headache, fatigue and nausea
*Frequent urination due to suppression of Vasopressin (Antidiuretic Hormone)
- the only cure is water

16

CHRONIC ALCOHOL ABUSE: MALNUTRITION

-Primary malnutrition: alcohol intake displaces food intake leading to deficiencies of protein, vitamin and minerals due to inadequate intake of these nutrients
-Secondary malnutrition: alcohol intake inhibits the proper digestion, absorption, transport, activation and/or retention of nutrients consumed in the diet

17

FETAL ALCOHOL SYNDROME

-Alcohol is a known teratogen
-Alcohol crosses the placenta and enters the fetal bloodstream
-Immature fetal liver cannot metabolize alcohol
-Results in dose-dependent birth defects
-Binge/heavy drinking in first trimester typically results in Fetal Alcohol Syndrome (FAS) and may result in Sudden Infant Death (SID)

18

FETAL ALCOHOL SYNDROME SYMPTOMS

-Intrauterine growth retardation
-Facial abnormalities
-Heart defects
-Slow growth after birth
-High infant mortality rate
-Lasting emotional, behavioral,
social, learning and
developmental problems throughout life

19

B Vitamins: Energy Metabolism

-Vitamin B1: Thiamin
-Vitamin B2: Riboflavin
-Vitamin B3: Niacin
-Vitamin B6
-Pantothenic acid
-Biotin

20

B Vitamins: Cell regeneration and red blood cell synthesis

-Folate
-Vitamin B12

21

B VITAMINS IN FOOD

-When foods are processed, we often lose some of the nutrition, including B vitamins
-In the US, B vitamins are added back into foods by means of enrichment
-Enriched grains are a large source of B vitamins in the US diet

22

VITAMIN B1: THIAMIN

-First discovered B-complex vitamin
-Function: Part of the coenzyme thiamin pyrophosphate (TPP) involved in carbohydrate and branched-chain amino acid metabolism, and biosynthesis of acetylcholine and GABA neurotransmitters
-Food Sources: Pork, enriched grains, sweet potato
*One cup of Total Cereal meets daily needs

23

VITAMIN B1: THIAMIN (Deficiency)

Deficiency: Beriberi
-Causes muscle wasting and peripheral nerve damage (neuropathy).
-Widespread in China when rice was highly processed and refined and not enriched with B vitamins
-Alcoholics are at risk for Beriberi as well
*Thiamin intake is probably low in the diet
*Thiamin need is increased in order to metabolize alcohol
*Alcohol consumption decreases thiamin absorption
- no known toxicity of overdosing

24

VITAMIN B2: RIBOFLAVIN

-Function: Coenzyme for flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)
-Involved in the electron transport chain during energy metabolism of carbohydrates, fats and protein
-Function: Part of coenzyme required by glutathione peroxidase, an antioxidant

25

VITAMIN B2: RIBOFLAVIN (continue)

-Food Sources = eggs, meats, dairy products, broccoli, enriched grains
-Characteristics: Heat stable, but sensitive to light
-Must package milk in opaque containers to protect riboflavin from sunlight
-Deficiency: Ariboflavinosis
*Sore throat, dry & scaly lips, purple
tongue, irritated skin, impaired vitamin B6 and
niacin metabolism
-No known toxicity

26

VITAMIN B3: NIACIN

-Function: form coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) which are required for oxidation-reduction reactions involved in catabolism
-Function: coenzyme in DNA replication and repair
-A limited amount of niacin can be synthesized from the amino acid tryptophan

27

VITAMIN B3: NIACIN (continue)

-Deficiency: Pellagra
*Dermatitis, diarrhea, dementia
-No known toxicity from food
-Food sources: meat, fish, poultry, enriched grains
*Niacin availability is higher in meats
-Excessive supplementation
may cause flushing and more
severe symptoms over time

28

PANTOTHENIC ACID (VITAMIN B5)

-Function: metabolized into two important coenzymes involved in metabolism
*Coenzyme A (CoA)
*Acyl carrier protein (ACP)
-Food sources: many foods, but high amounts in chicken, beef, egg yolk, potatoes, oat cereals, tomato products, whole grains and organ meats

29

VITAMIN B6: PYRIDOXINE COMPOUNDS

-Function: Coenzyme in 100+ enzymes involved in amino acid metabolism
*without B6, all amino acid are essential
-Function: Essential for gluconeogenesis, releasing glucose from glycogen and several steps in glucose metabolism
-Food Sources: meat, fish (tuna),
poultry, enriched grains,
starchy vegetables, bananas

30

VITAMIN B6: PYRIDOXINE COMPOUNDS (continue)

-Deficiency Symptoms: anemia, convulsions, depression, confusion, skin issues
*Typically affect the skin, blood and nervous system
-No known toxicity from food
-Excess supplementation can cause nerve and skin problems

31

BIOTIN (VITAMIN B7)

-Function: coenzyme in metabolism
and in creating fats and glucose
-Food sources: many foods
-Deficiency: rare, except in people who consume large numbers of raw egg whites over long periods of time: hair loss, dermatitis, conjunctivitis
*Albumin is a protein in the raw egg white that binds biotin with high affinity and prevents its absorption

32

B-VITAMINS REVIEW

-B-vitamins act as co-enzymes
-B-vitamins are essential for energy metabolism, but do not serve as energy source
-B-vitamins take part in synthesis of fatty acids and cholesterol, and gluconeogenesis
-B-vitamins are involved in metabolism of carbohydrates, fatty acids and amino acids
-Good sources of B-vitamins are: whole grains, cereals, meats, dairy products and some fruits and vegetables

33

IODINE: TRACE MINERAL

-Function: synthesis of thyroid hormone
*Regulate metabolic reactions associated with body temp, resting metabolic rate, macronutrient metabolism, reproduction and growth
-Food Sources: seafood, iodized salt

34

IODINE AND TYROID HORMONES

-Deficiency: goiter, hypothyroidism
-World Health Organization: “Iodine deficiency is the greatest single cause of preventable brain damage and mental retardation” in the world.
-Deficiency during pregnancy causes cretinism in baby
*Mental retardation, stunted growth, deafness, muteness
-Excess iodine: blocks the synthesis of
thyroid hormone; leads to goiter

35

MICRONUTRIENTS INVOLVED IN ENERGY METABOLISM (Choline)

-Choline (vitamin-like): important for metabolism, structural integrity of cell membranes, neurotransmission
-Deficiency: can cause fatty liver
-Toxicity: fishy body odor, vomiting, diarrhea, low blood pressure
-Sources: eggs, milk, meat, and many other foods
-Added to many foods as an emulsifier (lecitin)

36

MICRONUTRIENTS INVOLVED IN ENERGY METABOLISM (Chromium)

-Chromium (trace mineral): enhances ability of insulin to transport glucose to cells
-Deficiency: very rare, it was documented only in laboratory animals when chromium was removed from diet.
-Toxicity: under investigation, possible DNA damage when taken in high doses as a supplement
-Sources: many foods
-Controversy: can chromium supplements help loose body fat and increase muscle mass?

37

MICRONUTRIENTS INVOLVED IN ENERGY METABOLISM (Maganese)

-Manganese (trace mineral): many functions including roles in metabolism, synthesis of protein matrix in bones, component in antioxidant enzyme superoxide dismutase
-Sources: many foods
-Deficiency: very rare
-Toxicity: nervous system damage (occupational hazard in mines)

38

MICRONUTRIENTS INVOLVED IN ENERGY METABOLISM (sulfer)

-Sulfur (major mineral): component of thiamin and biotin; essential for metabolism, stabilizes protein shape, plays role in alcohol detoxification
-Sources: proteins from various foods
-No known deficiency
-No known toxicity