caffeine

Question 1

Caffeine proposed health benefits

Answer 1

T2D
CVD
wieght loss
perfomance improvement

Question 2

health canada caffeine limit

Answer 2

400mg/day

Question 3

coffee and redbull caffeine content

Answer 3

coffee - 80-200mg

redbull - 80mg (not variable)

Question 4

How coffee works

Answer 4

antagonist to adenosine receptors

• structurally similar
• bind adenosine receptors without activating them
• competitive inhibitor

brain, muscle, adipose tissue, gut

Question 5

Coffee, caffeine and T2D

Answer 5

acute
- caffeine and coffee decreases insulin sensitivity (increase T2D risk)

chronic

• coffee and decaf protective against T2D in dose dependent manner
• across all ethnic groups and drinking habits

OGTT (oral glucose tolerance test)

• caffeine = negative
• coffee = neutral
• decaf = positive

*potentially unrelated to caffeine

Question 6

Bioactive compound of interest in coffee

Answer 6

chlorogenic acid (CGA)

• main antioxident in coffee
• western culture >60% dietary antioxident from coffee (13% fruits and veges)
• hydrolyzed by colonic bacteria
• absorbed in large intestine
• individual differences due to microbiota diversity across individuals

Question 7

Coffee with high and low GI breakfast

Answer 7

Coffee raised glucose response of low GI food above decaf with high GI food
- lowers insulin sensitivty acutely

Question 8

Caffeine on blood pressure (CVD related)

Answer 8

acute
- coffee increases blood pressure

chronic

• prospective cohort, 9 years, healthy baseline
• slight reduction in relative risk

in T2D population

• prospective cohort, 20+ years
• large decrease in CVD mortality and total mortality

Question 9

Brewing methods of coffee on health

Answer 9

boiled coffee increased total cholesterol
filtered did not

• cafestol and kahweol content
  filtered out by paper

Question 10

Genetic effects on caffeine metabolism and related health problems

Answer 10

CYP1A2 codes liver enzyme that metabolizes caffeine

• wild type CYP1A2*1A fast metabolizer, low blood caffeine
• CYP1A*1F slow metabolizer (20% of population)

Preliminary data

• case controlled observational study
• increased risk of myocardial infarction

Question 11

Caffeine and weight loss

Answer 11

acute
- 300mg mean increase of 79kcal/day
long term
- observational prospective study
- no significant data
- 0.4 kg in 12 years