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Flashcards in Caffeine Deck (13)
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1
Q

About what percentage of people regularly drink tea or coffee?

A

80-90%

2
Q

What is the average adult daily intake of caffeine?

A

200-400mg

3
Q

How is caffeine consumed in children?

A

Through chocolate and soft drinks.

4
Q

How is caffeine absorbed and how long does it take?

A

Through the gastrointestinal tract, over about 30-60mins.

5
Q

What is the plasma half-life of caffeine?

A

Around 4 hours, but people’s concentration in blood plasma tends to rise over the day - top ups.

6
Q

What is caffeine converted to in the liver?

A

Metabolites.

7
Q

How is caffeine excreted?

A

95% in urine, 2-5% in faeces, the rest through saliva.

8
Q

What are the behavioural effects of caffeine?

A

Arousal.
- Smith et al (1999) found that low-intermediate doses have a variety of positive subjective effects when taken after 24hrs abstinence.

9
Q

What is meant by the effect of caffeine being biphasic?

A

At low doses it’s a stimulant that increases locomotor activity, but at high doses it does the opposite.

10
Q

What did Rogers and Dernoncourt (1998) suggest about the positive effects of caffeine after abstinence?

A

That they might be an alleviation of withdrawal symptoms.

11
Q

What did Griffiths and Mumford (1995) find about caffeine tolerance?

A

That people develop tolerance to the subjective effects of caffeine, e.g. heavy drinkers can consume coffee before bed.

12
Q

What did Griffiths et al (1990) find about withdrawal symptoms in caffeine drinkers?

A

That it occurs even in people who only drink one cup a day.

13
Q

What are the health effects of chronic caffeine consumption?

A
  • High BP
  • Risk of coronary heart disease
  • Low infant birth weight.