HNF 462 1st Edition Lecture 29Outline of Last LectureI. Chromium Absorption and MetabolismII. Chromium FunctionsIII. Chromium Deficiency/ToxicityIV. Sources of FluorideV. Fluoride Digestion, Absorption, Transport, Storage, and ExcretionVI. Functions and Deficiency of FluorideVII. AI and Toxicity of FluorideOutline of Current LectureI. HistoryII. CaffeineIII. Chemical NameIV. Factors Affecting Caffeine MetabolismV. FunctionsVI. Physiological EffectsVII. Effects on the Neural System and BehaviorVIII. Interaction with Macronutrients’ MetabolismIX. ExerciseX. Caffeine is not CoffeeXI. Interaction with MineralsCurrent Lecture: Coffee1. Historya. Ethiopia: legend of Kaldi the goat herderb. Arabian Peninsula: coffee is cultivated and traded; public coffee houses (social place)c. Popular in Europe in early 1600sThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.d. Popular in America in mid-1600s2. Caffeinea. Most widely consumed drugsi. Coffee 75%ii. Tea 15%b. Absorbed rapidly in small intestinec. Metabolized in liveri. Little gets metabolized when first encounters liverii. Metabolized by hepatic enzymes; half-life is 4-5 hours1. Metabolized by demethylationd. Distributed to tissues in 45 minutes3. Chemical name: Trimethylxanthinea. Metabolic Productsi. Paraxanthine (most predominant), ii. Theobromine and theophylline (longer half-life than paraxanthine)4. Factors Affecting Caffeine Metabolisma. Pregnancy increase half-lifei. At 17 weeks, half-life is 10 hrsb. Cigarette smoking decreases half-lifei. Doubles the metabolic rateii. Chemicals in cigarette smoke are metabolized by same enzymes, so enzyme concentrations are higher in the bodyc. Drugs5. Functiona. Mimics the naturally occurring enzymes in the bodyi. Phosphodiesterases: degrade cAMP1. Inhibits enzyme to prolong half-life of cAMPii. Antagonize adenosine receptors in brain1. Adenosine: neurotransmitter triggers sleepiness and reduced alertness2. Counteracts adenosine’s functions: make the brain less sleepy andmakes more alertiii. Binds to ryanodine receptor1. Increases intracellular Calcium levels6. Physiological Effectsa. Increased metabolic ratei. Mediated by sympathetic nervous systemii. Increased catecholamine level in bloodiii. Increased cAMP level in cellsb. Increased blood [NEFA]7. Effect on the Neural System and Behaviora. Increases activity and alertness in mammalsb. Learning behavior in invertebratesi. Honey bees have increased learning and memory outcomec. Affects memory and learning in mammalsd. Caffeine consumption is associated with protection against neurodegenerative diseases in humanse. Dosage is important: positive effects in low doses, but in high doses the effects are opposite 8. Interaction with Macronutrients’ Metabolisma. No major impact on blood glucose and insulinb. Most influence on fat metabolism: NEFA levels increasec. Protein metabolism not widely studied9. Exercisea. Prolongs endurance and delays fatiguei. Spares muscle glycogenii. Likely by increasing [NEFA]: muscles use fatty acids instead of glucose10. Caffeine is not Coffeea. Coffee has other chemicals (ex polyphenols)b. Other chemicals have own health benefits11. Interaction with Mineralsa. Coffee and tea inhibit non-heme iron absorptionb. Reports of inhibition of calcium absorption and increased calcium excretioni. Evidence on bone health is
View Full Document
Unlocking...