Chapter 8: Alcohol Alcohol The character of alcohol Ethanol; the alcohol in beer, wine, spirits Properties No digestion Rapid absorption by simple diffusion Rate.
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Transcript Chapter 8: Alcohol Alcohol The character of alcohol Ethanol; the alcohol in beer, wine, spirits Properties No digestion Rapid absorption by simple diffusion Rate.
Chapter 8: Alcohol
Alcohol
The character of alcohol
Ethanol; the alcohol in beer, wine, spirits
Properties
No digestion
Rapid absorption by simple diffusion
Rate high in duodenum
No cellular receptors required
5% leaves body in form of sweat, urine, or breath
95% remains in the body until oxidation
Metabolized or chemically changed in liver
Is alcohol a nutrient?
Provides
energy; 7 kcal/gram
No other nutritive value
Empty calories
No vitamins, minerals, fat, or protein
Lack nutrient density
Alcohol: Production
Malting
Fermentation: glucose converted to
pyruvate
CHO---Maltose---Glucose ----Pyruvate -Acetaldehyde ------Ethanol
Ethanol processed in a variety of ways
to alcohol
Alcohol Absorption
Alcohol Metabolism
Small amounts
metabolized by
Alcohol
dehydrogenase
(ADH)
Liver
enzyme
Metabolizing large amounts of alcohol
Overwhelm ADH, cannot keep up
Uses microsomal ethanol-oxidizing system (MEOS) a back-up
system in liver
MEOS used by liver to metabolize drugs
Increase alcohol metabolism and tolerance
Pathway reduces body’s ability to detoxify drugs
Increase potential for drug overdose
Liver damage will hamper other metabolic pathways
Removing alcohol from circulation
Liver metabolism limited
Blood alcohol level falls slowly
microsomal ethanol-oxidizing
Catalase
Found in the liver peroxisomes
Minor pathway for alcohol metabolism
Catalase
H2O2
Ethanol
H2O
Acetaldehyde
Fate of Acetyl-CoA (from alcohol
metabolism)
More like a fat than a CHO
Acetyl-CoA
X
CO2 + H2O
Fatty Acid
Glucose
Factors affecting Alcohol Metabolism
Gender
Women: smaller body size, less total body water; less ADH
activity in stomach (only 10% metabolized in stomach); more
serious effects of chronic alcohol abuse;
More alcohol in blood liver cirrhosis is high
Women are more likely to develop cirrhosis
Males
High activity of ADH in stomach cells (Metabolize ~30% of
alcohol in stomach)
Higher amount of body water
Age; race; size; food; physical condition; alcohol content
Benefits of Moderate Alcohol
Intake (Table 8-3 )
1 drink a day for men, < 1 drink for women or 1 5oz
glass of wine
Beer – no benefits
Red Wine
Phytochemicals called polyphenols from grape skins
during processing
Lower risk of CVD
Lower risk of Ischemic stroke: lack of blood to brain
Effects of Alcohol
Alcohol cannot be stored and has priority in
metabolism
Metabolized by the liver
Damages protein in cell membranes as it enters
into cells
Liver cells-mostly affected
May cause Cirrhosis of the liver
Effects of Alcohol:
Cirrhosis
Fatty infiltration of the liver
Increased synthesis of fat from accelerated
acetyl-CoA production
Enlarged fatty deposits choke off nutrient and O2
supply to liver cells
Engorged liver cells burst and die
Scar tissue forms- process called cirrhosis
50% chance of death within 4 years
Is the second leading cause for a liver transplant
Alcohol and the Liver
Normal Liver Fatty Liver
Cirrhotic Liver
Liver Damage
Build-up of acetaldehyde can be toxic
Free radicals from alcohol metabolism
destroy cell membranes & DNA:
Alcohol
inhibits body’s natural defenses
against free radicals
Advanced stages of liver damage are not
reversible
Alcohol Abuse
3rd leading cause of death
Combined with tobacco, increases the risk of
esophageal and oral cancer
Risk for CVD
Liver cirrhosis, damages cell membranes esp liver cells
Fatty liver
suicides
fetal damage
obesity
Some forms of cancer
osteoporosis,
brain damage,
impotence, sleep disturbance, etc.
Alcohol & Nutrients
Vitamin deficiencies
Alcohol interferes with vitamin metabolism
Folate, thiamin, vitamin B6, B12, C, vitamin A
Magnesium deficiency
Increase magnesium loss via the urine
Tetany—sharp contraction of muscles, twitches, cramps, seizures
Impaired CNS
Hallucinations
Zinc deficiency
Decreased absorption and increased excretion
Change in taste and smell, anorexia, trouble seeing at night, impaired wound
healing
Iron toxicity in liver, hasten cirrhosis, iron deficiency, due to GI
bleeding.
Alcohol & Nutrients
Polyneuropathy
A disease process that involves the peripheral nerves
Can culminate in muscle paralysis, loss of sensation in lower extremities if
untreated
Usually associated with deficiencies in thiamin (vit B)
Sideroblastic anemia
Anemia characterized by RBC containing an internal ring of iron; due to vitamin
B6 deficiency
Megaloblastic anemia
A form of anemia characterized by large, nucleated, immature red blood cells
that result from the inability of precursor cells to divide normally.
Due to folate deficiency
Alcohol & Nutrients
Fetal Alcohol Syndrome
Alcohol reaches the fetus
Deprive brain of oxygen and nutrients
~4 drinks a day or binge drinking while
pregnant
May cause
Mental retardation
Short attention span
Hyperactivity
Social and behavior problems
Abnormally small at birth
Small head circumference
Small, widely spaced eyes
Flat mid-face
Thin upper lip and jaw underdeveloped
Alcohol Blood Levels and Brain
Responses
Blood Level
Brain Response
0.05
0.10
0.15
0.20
0.30
0.35
0.50—0.60
Judgment impaired
Emotional control impaired
Muscle coordination, reflexes impaired
Vision impaired
Drunk, lacking control
In a stupor
Loss of consciousness, death
Other Problems of Alcohol
Drinking in the workplace
Operating motor vehicles and equipment
Sexually transmitted diseases
Unplanned pregnancy
Children of alcoholics are 4x more likely to become
alcoholics
Warn children of the consequences of alcohol
A low threshold to alcohol
Depression
Binge Drinking
Especially in college students
> 4 or more drinks in a row
Acute alcohol intoxication
Signs of alcohol poisoning
semiconsciousness or unconsciousness
slow respiration (<8 breathes per min. or more >8
seconds between breath)
cold, clammy, pale, or bluish skin
strong odor of alcohol
2005 Dietary Guidelines
Alcoholic Beverages
Those who choose to drink alcohol should do so sensibly
and in moderation
1 drink/day for women
2 drinks/day for men
Alcoholic beverages should not be consumed by
Those who cannot restrict intake
Women of child bearing age
Pregnant & lactating women
Children & adolescents
Those taking medications
Those with specific medical conditions
Those driving or operating a machine
Advice on page 273
U.S. Surgeon General’s office, the National
Academy of Science, USDA/DHHS do not
specifically recommend drinking alcohol
“Drink in moderation”
Avoid alcohol while pregnant
Diagnosis
Physiological dependence
Tolerance to the effect of alcohol
Evidence of alcohol-associated illnesses
Continued drinking in defiance of medical
and social advise
Depression and blackouts
C.A.G.E. Questionnaire
C: Have you ever felt you ought to cut down on
drinking?
A: Have people annoyed you by criticizing your
drinking?
G: Have you ever felt bad or guilty about your
drinking?
E: Have you ever had a drink the first thing in the
morning to steady your nerves or get rid of a
hangover (eye-opener)?