major functions of water in the body

• carries nutrients and waste products throughout the body
• maintains the structure of large molecules such as proteins and glycogen
• participates in metabolic reactions
• serves as the solvent for minerals, vitamins, amino acids, glucose, and many other small molecules so that they can participate in metabolic activities
• acts as a lubricant and cushions joints and inside the eyes, the spinal cord, and, in pregnancy, the amniotic sac surrounding the fetus in the womb
• aids in the regulation of normal body temperature, as the evaporation of sweat from the skin removes excess heat from the body
• maintains blood volume

water balance

• the accounting of water inflows, outflows, and storage changes within a system over time

major water sources (water in)

• fluids (2000 ml - 8 cups)
• water content in food (500 ml - 2 cups)
• water produced from metabolism (300 ml - 1.25 cups)

beverages (550 - 1500 mL)

foods (700 - 1000 mL)

metabolism (200 - 300 mL)

total: 1450 - 2800 mL

body's major routes of water loss (water out)

insensible losses

• skin perspiration (750 ml - 3 cups)
• lung respiration (300 ml - 1.25 cups)
• feces (100 ml - 0.4 cup)

sensible losses

• urine (1650 ml - 6.75 cups)

kidneys (urine) (500 - 1400 mL)

skin (sweat) (450 - 900 mL)

lungs (breath) (350 mL)

GI tract (feces) (150 mL)

total: 1450 - 2800

moderate alcohol consumption for men

• less than or equal to 2 drinks (per day)

moderate alcohol consumption for women

• less than or equal to one drink (per day)

one drink when referring to an alcoholic beverage

½ oz pure ethanol

• 5 oz of wine
• 10 oz of wine cooler
• 12 oz of beer
• 1 ½ oz of liquor (80 proof whisky, scotch, rum, or vodka)

several factors that affect the body's ability to metabolize alcohol

• rate of stomach emptying
• intake of certain drugs
• type of beverage consumed

rate of stomach emptying affect on alcohol metabolization

• alcohol needs no digestion, quickly absorbed across the walls of an empty stomach, reaching the brain within a few minutes
• when stomach is full of food – alcohol has less chance of touching the walls and diffusing through → influence on the brain is slightly delayed
• carbohydrate snacks slow alcohol absorption, high-fat snacks slow peristalsis, keeping alcohol in the stomach longer

alcohol metabolization: women vs men

• women produce less alcohol dehydrogenase enzyme in the stomach → more alcohol reaches the intestine for absorption into the blood stream
• absorb more alcohol than men of the same size drink, more likely to become intoxicated on alcohol than men

type of alcohol consumed, effect on alcohol metabolization

• certain drinks have higher alcohol content than others
• different beverages influence gastric emptying and absorption rate
• carbonated drinks increase gastric pressure, speed gastric emptying (higher and earlier peak BAC)
• higher alcohol content / hard alcohol (higher concentration of ethanol, slower initial absorption but progresses quickly once in small intestine)
• diluted alcohol (reducing gastric irritation, speed up gastric emptying) – faster absorption than undiluted spirits
• sugary drinks – can slow the absorption of alcohol

potential health benefits associated with moderate consumption

• reduces blood clotting
• increases HDL
• reduces inflammation (CRP)
• improved insulin sensitivity
• lower dementia / Alzheimer's disease risk

polyphenols

• red wine, dark beer
• antioxidant effect

detrimental effects of alcohol when consumed in excess

• dehydration, loss of important minerals
• malnutrition (diet quality declines as alcohol consumption increases)
• displacing other important nutrients
• arthritis
• bone loss
• cancer
• fetal alcohol syndrome
• heart disease
• hyperglycemia
• hypoglycemia
• infertility
• kidney disease
• liver disease
• lung disease
• nerve disorders
• obesity
• psychological disturbances (depression, anxiety, insomnia)

MEOS (Microsomal Ethanol-Oxidizing System)

• enzyme system that metabolizes both alcohol and several other types of drugs
• handles about ⅕ of the total alcohol a person consumes
• high blood concentrations, repeated exposures to alcohol – alcohol stimulates synthesis of enzymes in the MEOS
• results in more efficient alcohol metabolism and tolerance to its effects
• drinking and using drugs at the same time – alcohol is prioritized for metabolism, drug more slowly (drug effect builds up, greatly amplified result)

Cirrhosis

• advanced liver disease in which liver cells turn orange, die, and harden, permanently losing their function (often associated with alcoholism)
• fatty infiltration of the liver (most advanced stage)
• 2nd leading cause for liver transplant
• 50% chance of death within four years

Wernicke-Korsakoff Syndrome

• a neurological disorder typically associated with chronic alcoholism and caused by a deficiency of the B vitamin thiamin (also called alcohol-related dementia)
• syndrome characterized by paralysis of eye muscles, poor muscle coordination, impaired memory, and damaged nerves

macronutrients

• required in gram quantities
• structure - polymer
• some are essential
• provide calories

carbs, lipids, protein

micronutrients

• required in mg quantities
• structure - individual molecule
• all are essential
• provide no calories

vitamins and minerals

fat-soluble vitamins

dissolve in fat or organic solvents

• vitamin A
• vitamin D
• vitamin E
• vitamin K

how solubility affects absorption: fat-soluble vitamins

• must first enter the lymph and then enter the blood

how solubility affects transport: fat-soluble vitamins

• require transport proteins to move around

how solubility affects storage: fat-soluble vitamins

• held in fatty tissues and the liver until needed

how solubility affects excretion: fat-soluble vitamins

• remain in fat storage sites in the body rather than being excreted
• more likely to reach toxic levels when consumed in excess

water-soluble vitamins

dissolve in water

• found in the watery compartments of food
• B vitamins
• vitamin C