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Caffeine: A positive addition to a healthy lifestyle? Ross Grant PhD Australasian Research Institute.

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Presentation on theme: "Caffeine: A positive addition to a healthy lifestyle? Ross Grant PhD Australasian Research Institute."— Presentation transcript:

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2 Caffeine: A positive addition to a healthy lifestyle? Ross Grant PhD Australasian Research Institute

3 “ Coffee-drinking is used for social engagement, leisure, enhancement of work performance and well-being.” “Unlike other [functional foods]….the wide use of coffee-drinking impacts a broad demographic (from children to elderly), with a wide spectrum of health benefits. Dorea J.G. etal. Br J Nutr (2005), 93:

4 “Tea acts as a stimulant and, to a certain extent, produces intoxication. The action of coffee and many other popular drinks is similar. The first effect is exhilarating. The nerves of the stomach are excited; these convey irritation to the brain, and this in turn is aroused to impart increased action to the heart and short-lived energy to the entire system. Fatigue is forgotten; the strength seems to be increased. The intellect is aroused, the imagination becomes more vivid. “Because of these results, many suppose that their tea or coffee is doing them great good. But this is a mistake. Tea and coffee do not nourish the system. “The continued use of these nerve irritants is followed by headache, wakefulness, palpitation of the heart, indigestion, trembling, and many other evils; for they wear away the life forces. Tired nerves need rest and quiet instead of stimulation”. Ministry of Healing p326

5 Caffeine Use by Age and Sex Australia & New Zealand SDA 2001

6 The issue: In recent times the ingestion of tea and coffee has become a topic of debate within the Adventist community.

7 The issue: Is the introduction of caffeine into the SDA diet a beneficial adjunct to an already well-balanced lifestyle?

8 Background: origins and sources of caffeine Molecular structure of caffeine identified by German chemist Runge in 1918

9 Background: origins and sources of caffeine Coffee drinking in the middle east is traceable to the 15 th century Sufi monks drank coffee to stay awake during prayers (Yemen, Arabia) By 1510 coffee was widely used in all levels of Arab society from Cairo to Mecca

10 Background: origins and sources of caffeine Tea was consumed in China from at least the 6 th century AD Olmec’s (ancient American civilization) may have used cacao pods for making chocolate drinks from 400BC Carbonated beverages containing caffeine were introduced by Coco-Cola in 1866 in Atlanta Georgia, USA.

11 Common dietary sources of caffeine Food/BeverageCaffeine content Instant coffee (1 tsp)60-80 mg/250 mL Percolated coffee mg/250 mL Instant decaffeinated2 mg/250 mL cup Tea10-50 mg/250 mL Tea decaffeinated1 mg/250 mL cup Coca-Cola36-50 mg/375 mL Milk Chocolate20 mg/100g* bar Energy Drinks (R.Bull) 80 mg/250mL can Table 1: Caffeine content of selected foods (source: ANZFA caffeine report, 2001 and Choice Magazine online (Sept, 2001)). *An average sized Mars bar weighs 80g

12 Common dietary sources of caffeine Guarana Guarana is a woody climbing plant that is native to the Amazon basin Guarana seeds contain more than 4% caffeine by weight, in comparison with coffee beans which may contain up to 2.2% by weight depending on the variety

13 Absorption of Caffeine into the body Caffeine is metabolized in the liver by CYP1A2 and is converted into the three products paraxanthine, theobromine and theophylline each of these have physiological effects on the body. Peak caffeine blood levels reached in minutes typical half-life of between 4-6 hours Once caffeine is absorbed, it is able to enter all body tissues and easily crosses the blood-brain, placental and blood-testicular barriers

14 Action of Caffeine on the body PHARMACOLOGICAL REVIEWS Vol. 51, No

15 Action of Caffeine on the body Principle action of caffeine is thought to be through blocking adenosine receptors on nerve tissue. Serotonin Caffeine

16 Function of Adenosine receptors Adenosine levels are raised whenever there is an increase in the amount of energy (ATP) consumption compared to energy (ATP) synthesis. Activation of adenosine receptors in various tissues allow the body to modulate cellular activity in response to decreasing energy (ATP) levels.

17 Distribution of Adenosine receptors in the body Brain Fat tissue Pancreas MuscleHeart Lung Stomach Liver human-body.jpg Lymphocytes

18 Action of Caffeine on the body Receptor subtype HEARTCNSKIDNEYOTHER A1 Heart rhythm Decrease heart rate & force of atrial contraction & responsiveness to adrenaline Wakefulness- decrease in electrical excitability and inhibition of excitatory amino acid (EAA) release AntidiuresisAnti-lipolytic insulin enhancer Anti hypertensive Wound healing Hair growth A2A Regulates blood vessel tone- dilation of the coronary arteries supplying blood to heart and muscle Anti-inflammatory – increases cerebral blood flow Wound healing Anti – aggregation of platelets Increases gastric mucosal blood flow (ethanol)

19 The widespread prevalence of caffeine- sensitive (adenosine) receptors in the body suggests the likelihood of multi- organ involvement following caffeine consumption. Action of Caffeine on the body

20 Immediate effects of Caffeine Positive: Caffeine can increase serotonin and dopamine release in the brain; somewhat mimicking the effect caused by antidepressants. (Casas, 2004) Elevated Mood; including increased; Feeling of wellbeing Alertness Energy Sociability

21 Immediate effects of Caffeine Positive: Studies indicate that: Caffeine decreases reaction times and improves vigilance, sustained attention and selective attention (Smith, 2004). Tasks requiring speed are more sensitive to caffeine’s benefits than tasks involving intellectual power (Snel, 2004). NOTE: Caffeine seems to have either no effect or a negative effect on memory (Smith, 2004).

22 Immediate effects of Caffeine Negative: Studies indicate that: Higher doses of caffeine produce: Anxiety Jitteriness Upset stomach (Juliano and Griffiths, 2004)

23 Immediate effects of Caffeine Negative: Studies indicate that: caffeine can exaggerate the body’s response to stress by increasing heart rate and blood pressure (Lane et al., 2002) It is possible that caffeine alone may induce an adrenocortical stress response during rest and in the absence of explicit stressful challenge (al'Absi and Lovallo, 2004)

24 Longer-term effects of Caffeine Negative: cardiovascular James (2004) suggests that population studies of BP indicate that caffeine use could account for: 14% of premature deaths due to coronary heart disease, and 20% due to stroke.

25 Longer-term effects of Caffeine Negative: cardiovascular A prospective study of 1971 middle-aged men, showed that heavy coffee consumption (814 mL or more/day), increased the risk of acute myocardial infarction or coronary death by up to 75% compared to non- coffee drinkers (Happonen et al., 2004). Caffeine has been shown to, dose dependently, increase serum homocysteine levels (Verhof et al., 2002, Panagiotakos et al., 2004) Increased serum cholesterol and urinary excretion of 8-hydroxy-2-deoxguanosine in rats (Sakamoto et al., 2005)

26 Longer-term effects of Caffeine Negative: osteoporosis Basic science experiments show that caffeine increases calcium excretion in the urine In a prospective study of ~ women followed for 6.5 years a weak association of highest caffeine intake (>6 cups daily) was observed with osteoporosis (Hansen et al., 2000).

27 Longer-term effects of Caffeine Negative: Urinary A high caffeine intake (>400 mg/d) was associated with urinary urge incontinence in a study of almost 260 women (overall risk, 2.4%; 95% CI, ), Note: This is similar to the likelihood of urinary stress incontinence of a vaginal delivery compared with caesarean delivery (2.4%; 95% CI, ) (Arya et al., 2000; Rortveit et al., 2003; Holroyd- Leduc and Straus, 2004).

28 Longer-term effects of Caffeine Negative: Brain Headache Caffeine is considered a modest risk factor in chronic daily headache, (Gadoth and Hering- Hanit, 2005). Caffeine withdrawal headache, (beginning 1 to 2 days following cessation of regular caffeine use), can last up to a week (van Dusseldorp and Katan, 1990). Caffeine may disrupt sleep or aggravate mood, both of which may exacerbate headache (van Dusseldorp and Katan, 1990).

29 Longer-term effects of Caffeine Negative: Behavioural Dependence Caffeine exhibits physical dependence in up to 30% of consumers (Griffiths and Chausmer, 2000) Some caffeine users may also demonstrate clinical dependence (Strain et al., 1994). Withdrawal symptoms (start 12-24hr–last 2-9 days) Headache, fatigue, depressed mood, irritability, nausea, vomiting muscle pain/stiffness

30 Longer-term effects of Caffeine Negative: Behavioural Sleep Sleep is one of the physiological functions most sensitive to the effect of caffeine in humans 200mg caffeine will: Prolong sleep latency Increase initial light sleep Decrease later deep sleep Increase shifts between sleep stages Decrease in subjective sleep quality Increased time taken to reach REM sleep

31 Longer-term effects of Caffeine Negative: Brain Can precipitate the onset and/or exacerbation symptoms of anxiety disorders, including panic disorder and obsessive-compulsive disorder, (Smith, 2004). Caffeine can interfere with the action of medication used to treat anxiety disorders and depression (Greden et al., 1981; Jefferson, 1988). Long term caffeine use affects serotonin metabolism in the brain of rats: implications for depression (Haider etal 1998, Haleem etal 1995)

32 Longer-term effects of Caffeine Negative: pregnancy/foetus Caffeine is cleared at a slower rate from the pregnant woman and foetus (t 1/2 18hrs) Caffeine readily crosses the placenta into the foetus Metabolising enzymes not present in foetus or placenta (Grosso and Bracken, 2005). Foetus therefore exposed to caffeine and its metabolites for a prolonged periods of intra- uterine life.

33 Longer-term effects of Caffeine Negative: pregnancy/foetus Conflicting reports - foetal development Increased caffeine use may cause spontaneous abortion A decrease in intervillous placental blood flow has been documented after maternal ingestion of just 200 mg of caffeine (Kirkinen et al., 1983). May effect foetal oxygenation and nutrition (Ghidini, 1996) After reviewing several animal studies, Nakamoto (2004) suggests that caffeine may affect neurodevelopment; further human studies required

34 Longer-term effects of Caffeine Negative: Child Insufficient research precludes a definite conclusion as to whether caffeine consumption during pregnancy leads to mood disorders in children. However, cortisol, which is increased by caffeine, may influence the foetal hypothalamic-pituitary-adrenal axis which controls the stress response Prenatal stress has been linked to interference in neuron development in the serotonergic system in late gestation (Linnet et al., 2003; Lovallo et al., 2005).

35 Longer-term effects of Caffeine Negative: Adolescence Significantly higher anxiety scores were observed in caffeine dependent year-olds (13.7 ± 7.7) compared with the non-dependent group (7.5 ± 5.9) (Bernstein et al., 2002). It would be useful to study more about how much caffeine children consume, and how this may affect them as adolescents are currently exposed to the opportunity to consume large amounts of caffeine due to the introduction of energy drinks, and frequenting of coffee lounges.

36 Longer-term effects of Caffeine Positive: Diabetes Coffee drinkers in the highest category (≥6 or ≥7 cups/day) showed a relative risk of (4-6 cups/day) had a relative risk of 0.72 compared with the lowest category (0 or ≥2 cups/day). Two reasons were suggested for the apparent protective effect of caffeine against diabetes: 1. Coffee contributes antioxidants to the diet (Pulido et al., 2003; Svilaas et al., 2004). 2. Caffeine ingestion can acutely reduce glucose storage (Greer et al., 2001). However, authors don’t recommend increasing coffee consumption as other health effects should first be considered (van Dam and Hu, 2005). ed

37 Longer-term effects of Caffeine Positive: Gallstones Leitzmann et al., ( 1999) reported that 4 cups of coffee per day showed a relative risk of gallstone formation of 0.55, This indicates a 45% reduction in the risk of forming gallstones in moderately heavy coffee drinkers. Colon Cancer Case-control studies seem to indicate a lower risk of colon cancer associated with coffee drinking, but cohort study results are less clear (Tavani and La Vecchia, 2004).

38 Longer-term effects of Caffeine Positive: Parkinson’s disease A 5-fold lower risk of developing PD was observed in those who drank over 4 medium cups of coffee per day. This protection was not seen in decaffeinated coffee (Xu et al., 2005). Animal experiments also show that caffeine directly protects against the death of neurons in Parkinson’s disease (Xu et al., 2005).

39 CONCLUSIONS Almost 2000 research papers have been published that included caffeine as a research variable in the title in the last 10 years Almost universal use of caffeine throughout the world have made well controlled studies difficult

40 CONCLUSIONS Caffeine is a drug that blocks activation of a specific nerve receptor system Benefits observed include reduced risk of Parkinson’s disease, type 2 diabetes, colon cancer and gallstones These are offset by negative biological effects; physical dependence, exacerbation of anxiety increased blood pressure & cardiac fatality risk osteoporosis, urge incontinence, potential harm to the foetus. The collection of negative effects impact on the quality of life in the community.

41 CONCLUSIONS A lifestyle with moderate energy intake, exercise and a diet high in fruit and vegetables would not appear to benefit from the inclusion of caffeine; but would rather result in the addition of unnecessary negative physiological stressors.

42 “Tea acts as a stimulant and, to a certain extent, produces intoxication. The action of coffee and many other popular drinks is similar. The first effect is exhilarating. The nerves of the stomach are excited; these convey irritation to the brain, and this in turn is aroused to impart increased action to the heart and short-lived energy to the entire system. Fatigue is forgotten; the strength seems to be increased. The intellect is aroused, the imagination becomes more vivid. “Because of these results, many suppose that their tea or coffee is doing them great good. But this is a mistake. Tea and coffee do not nourish the system. “The continued use of these nerve irritants is followed by headache, wakefulness, palpitation of the heart, indigestion, trembling, and many other evils; for they wear away the life forces. Tired nerves need rest and quiet instead of stimulation”. Ministry of Healing p326


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