NUTR*4510 - Unit 5: Alcohol and Nutrition

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Questions and Answers

What percentage of individuals with alcohol use disorders are likely to experience pancreatitis?

70 - 80 %

50 - 60 % (correct)

30 - 40 %

10 - 20 %

What is a potential consequence of impaired lipid digestion due to pancreatitis?

Steatorrhea (correct)

Increased calcium levels

Improved absorption of fat soluble vitamins

Enhanced lipid metabolism

How does alcohol consumption specifically impact calcium status?

Leads to poor calcium status (correct)

Causes excessive calcium intake

Improves calcium absorption

Has no effect on calcium status

Which vitamin is especially affected by impaired lipid digestion?

Vitamin D Signup and view all the answers

What is a potential consequence of impaired protein digestion in individuals with alcohol use disorders?

Diarrhea Signup and view all the answers

What is the primary pathway for ethanol metabolism at low to moderate alcohol consumption levels?

Alcohol Dehydrogenase Signup and view all the answers

Which enzyme in the brain primarily metabolizes ethanol?

Catalase Signup and view all the answers

What factor influences the amount of ethanol processed through the pathways in the body?

Amount and pattern of exposure to alcohol Signup and view all the answers

Which pathway accounts for approximately 60% of ethanol metabolism in cases of high and chronic alcohol consumption?

CYP2E1 Signup and view all the answers

What is one potential consequence of ethanol metabolism involving ROS (Reactive Oxygen Species)?

Liver or brain damage Signup and view all the answers

Which of the following factors does NOT influence the risk of cellular damage due to ethanol exposure?

Type of alcohol consumed Signup and view all the answers

What role does Acetaldehyde Dehydrogenase (ALDH) play in ethanol metabolism?

Converts acetaldehyde to acetic acid Signup and view all the answers

What is a significant consequence of chronic alcohol consumption on the central nervous system (CNS)?

Altered and depressed CNS function Signup and view all the answers

What is the primary active agent in alcoholic beverages that affects the central nervous system?

Ethanol Signup and view all the answers

At what blood alcohol concentration level does impaired judgement and perception typically begin?

0.03 – 0.12 g/100 mL Signup and view all the answers

How is the majority of ethanol metabolized in the liver?

Alcohol dehydrogenase Signup and view all the answers

What is a significant consequence of chronic alcohol consumption due to the production of acetaldehyde?

Tissue inflammation and scarring Signup and view all the answers

What is the legal driving blood alcohol limit in many jurisdictions?

0.08 g/100 mL Signup and view all the answers

Which enzyme converts acetaldehyde to acetic acid in the liver?

Acetaldehyde dehydrogenase Signup and view all the answers

What type of effects does ethanol have on synaptic membranes?

Depresses central nervous system function Signup and view all the answers

Which process contributes primarily to the damage from acetaldehyde in tissues?

Reactive damage to DNA, proteins, and lipids Signup and view all the answers

What is one of the primary effects of ethanol on motility patterns in the small intestine?

Inhibition of the enteric nervous system's function Signup and view all the answers

How does ethanol consumption affect the absorption of nutrients in the small intestine?

It prevents digested products from circling around the villi. Signup and view all the answers

What consequence can result from the exfoliation of villi tips due to ethanol consumption?

Nutrient deficiencies and potential bleeding Signup and view all the answers

What is one of the effects of ethanol on pancreatic function?

Reduction in enzyme secretion for lipid digestion Signup and view all the answers

What happens to the villi as a result of chronic alcohol consumption?

Villi are shortened and may resemble stubs or nubs Signup and view all the answers

What is a potential effect of decreased cell turnover in the intestinal lining due to ethanol?

Increased susceptibility to infections Signup and view all the answers

What is one consequence of the decreased function of the small intestine caused by ethanol?

Malabsorption or nutrient deficiencies over time Signup and view all the answers

How does ethanol contribute to diarrhea according to its effects on the colon?

By decreasing transit time Signup and view all the answers

What role does retinyl esterase play in the context of alcohol consumption?

It increases the conversion of retinyl palmitate to retinol. Signup and view all the answers

What is the effect of chronic alcohol consumption on retinyl palmitate stores?

It causes retinyl palmitate stores to deplete. Signup and view all the answers

Which substance is primarily converted to retinoic acid after alcohol consumption?

Retinol Signup and view all the answers

What is the primary consequence of increased activity of CYP2E1 in ethanol metabolism?

Conversion of retinol to 4-hydroxy-retinol. Signup and view all the answers

What happens to the blood retinol levels upon acute alcohol consumption?

They are transiently increased. Signup and view all the answers

How does retinoic acid affect gene expression?

Promotes epithelial cell differentiation. Signup and view all the answers

What is the effect of acute alcohol consumption on vitamin A status assessment?

It misleadingly increases perceived vitamin A status. Signup and view all the answers

What happens to retinoic acid after its production from retinol?

It is rapidly degraded. Signup and view all the answers

What is the main storage form of vitamin A in the body?

Retinyl palmitate Signup and view all the answers

Which statement correctly describes a consequence of vitamin A deficiency?

Reduced night vision Signup and view all the answers

What enzyme is responsible for converting retinyl palmitate to retinol?

Retinyl esterase Signup and view all the answers

Where in the body is retinyl palmitate primarily stored?

Liver stellate cells Signup and view all the answers

How does the body maintain blood levels of retinol?

By releasing retinol from liver stores into the bloodstream Signup and view all the answers

What is the chylomicron remnant's role in vitamin A transport?

It delivers dietary vitamin A to the liver Signup and view all the answers

What is primarily measured to assess whole body vitamin A status?

Concentration of retinol-RBP-PA complex Signup and view all the answers

Which factor limits the early detection of vitamin A deficiency?

Maintenance of retinol levels within a set range Signup and view all the answers

Study Notes

NUTR*4510 - Toxicology, Nutrition & Food - Unit 5: Alcohol and Nutritional Status

This unit examines alcohol's effects, particularly on nutritional status.
Alcohol absorption occurs rapidly due to its small size and both lipid and water solubility.
About 20% is absorbed in the stomach, 80% in the small intestine.
Ethanol is the parent compound and is not a metabolite.
Alcohol depresses central nervous system (CNS) function.
Alcohol consumption affects synaptic membrane function.
Alcohol promotes the release of adenosine, an inhibitory neurotransmitter.

Acute Alcohol Consumption

Blood alcohol levels (g/100 mL) correlate with clinical signs and symptoms.
0.01-0.05 g/100 mL: near normal behaviour
0.03-0.12 g/100 mL: mild euphoria, loss of inhibitions, some sensorimotor impairment (Legal driving limit is 0.08 g/100mL)
0.09-0.25 g/100 mL: impaired judgment, perception, memory, significant sensorimotor impairment
0.18-0.30 g/100 mL: confusion, staggering gait, impaired vision, exaggerated emotions
0.25-0.40 g/100 mL: stupor, vomiting
0.35-0.50 g/100 mL: coma, death

Chronic Alcohol Consumption

Long-term exposure to acetaldehyde and reactive oxygen species (ROS) damages tissues, primarily the liver.
This leads to intestinal damage, cirrhosis, pancreatitis, and oral and liver cancers.

Alcohol/Ethanol Metabolism (in the liver)

Moderate Consumption: (~80% via alcohol dehydrogenase, ~20% via CYP2E1).
- Ethanol is converted to acetaldehyde.
- Acetaldehyde is converted to acetic acid.
- Acetic acid is part of the TCA cycle.
High/Chronic Consumption: (~40% via alcohol dehydrogenase, ~60% via CYP2E1).
- Similar as above but with a higher proportion via CYP2E1.
- Results in increased ROS and damage to DNA, proteins, and lipids.

Alcohol/Ethanol Metabolism (in the Brain)

Catalase is the main enzyme in the brain (~60%)
CYP2E1 and ADH also play a role (about 20% each)
Ethanol is initially converted to acetaldehyde.
Acetaldehyde is further metabolized to acetic acid.
These metabolic processes alter and depress CNS function.

Global Distribution of Alcohol-Attributable Deaths

Liver cirrhosis and unintentional injuries are significant causes of death related to alcohol consumption globally.
Other contributing factors include cardiovascular diseases, diabetes, cancers and neuropsychiatric disorders

Hormesis (or Hormetic Effect)

Low doses of a stressor (e.g., xenobiotic) can produce a beneficial response.
At higher doses, there are negative/harmful outcomes.
A J-shaped curve illustrates the relationship between dose and effect, showing a hormetic zone.

Alcohol Dosing and Total Mortality in Men and Women

A meta-analysis of 34 prospective studies reveals a J-shaped relationship between alcohol intake and total mortality in both men and women.
Up to moderate intake (4 drinks per day in men, 2 in women) has an inverse relationship with mortality.
Higher doses contribute to increased mortality.

Comparison of Alcoholic Beverages ("drinks" or Servings)

Tables provide details of alcohol-content in different sizes of liquor.

Canada's Guidance on Alcohol and Health

Provides 2021 and 2023 recommendations for alcohol consumption in Canada.

Cancer Incidence and Mortality Attributable to Alcohol Consumption

Global data indicates a significant link between alcohol consumption and various cancers.
Cancer cases and deaths attributable to alcohol have increased between 2002 and 2012 and are most prevalent in various WHO regions.

Alcohol and Cancer

Ethanol alone is not a strong carcinogen, but it increases the carcinogenicity of other xenobiotics.
- Promotion of carcinogen absorption through dissolvation/solvent effect.
- Altering metabolism and tissue distribution of other xenobiotics, increasing the damage to cells.
- Causing cell injury (promoting cell division and proliferation, increasing the risk of mutations.)
- Inhibiting DNA repair.
- Altering the immune response to neoplasms.

Alcohol/Ethanol & Nutrient Deficiencies Favouring Carcinogenesis

Nutrient Intake:
- High alcohol consumption decreases nutrient intake and choices.
- Alcohol affects energy production which disrupts the metabolic rate and heat production.
- Alcohol leads to poor ethanol (and nutrient) absorption.
Food Choice:
- Moderate levels of ethanol can increase food intake.
- High levels can decrease food intake.
- High cost of alcohol can decrease budget for healthy foods
Nutrient Utilization/Metabolism:
- Affects small intestine motility and function affecting nutrient absorption
Effect on Pancreas:
- Disrupts enzymatic processes impacting lipid and protein digestion, absorption
Effect on Liver:
- Progressive disruption in the metabolism of nutrients, starting early with fatty liver and leading to ALD (alcohol-associated liver diseases).

Alcohol/Ethanol & Vitamin A Status

Dietary Vitamin A converts to retinyl palmitate, packaged, delivered to stellate cells and converted back to retinol (as needed).
Alcohol increases the conversion of retinyl palmitate.
Alcohol decreases retinyl palmitate.
Alcohol modifies/promotes retinol to retinoic acid to change gene expression patterns.
Depleted vitamin A impairs the ability to repair damaged small intestine.
Vitamin supplementation is not recommended as it has potential risks.

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Description

Explore the intricate relationship between alcohol consumption and nutritional status in this quiz. Understand how alcohol affects absorption, central nervous system functions, and blood alcohol levels. This unit is essential for grasping the implications of alcohol on health and nutrition.