Caffeine for the Sustainment of Mental Task Performance Formulations for Military Operations (2001) / Chapter Skim
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4 Safety of Caffeine Usage
4 Safety of Caffeine Usage
Pages 47-60
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From page 47... ...
In 1980 the Food and Drug Administration (FDA) proposed to delete the use of caffeine as an added food ingredient from the GRAS list, to declare that no prior sanction exists for the food use of caffeine, and to list caffeine as a food 47
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From page 48... ...
Based on comments submitted to the agency in response to the proposal published in the Federal Register of October 1980, the FDA proposed to codify a prior sanction for the use of added caffeine in nonalcoholic carbonated beverages. Thus, the agency was proposing to use a provision of the Food, Drug and Cosmetic Act that exempts from the definition of a food additive any substance used in accordance with an approval granted prior to the Food Additives Amendment of 1958.
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From page 49... ...
These diterpenes are extracted by hot water but are retained by paper filters, thus explaining why filtered coffee has no effect on serum cholesterol, while boiled coffees such as Scandinavian cafetiere and Turkish coffees do. Several approaches have been utilized to investigate the possible relationship between caffeine intake and brood pressure.
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From page 50... ...
However, the odds ratio from the 15 cohort studies was not statistically significant. A study of 10,359 men and women in the Scottish Heart Health Study showed a significantly higher prevalence of coronary heart disease in subjects who were nonusers of coffee than in those who drank varying amounts of coffee (Brown et al., 1993~.
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From page 51... ...
compared to women who did not consume regular coffee. Despite numerous studies attempting to show a relationship between caffeine and serum lipoproteins, blood pressure, cardiac arrhythmias, and risk of coronary heart disease, results have failed to show a consistent adverse effect of ingestion of moderate amounts of caffeine.
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From page 52... ...
More recent animal studies, using lower doses of caffeine, have indicated that preconceptual exposure of rats to caffeine reduced fertility due to effects on implantation rather than fertilization rate and was associated with lower birthweight and lower neonatal and prepubertal growth rates (Pollard et al., 1999~. Other studies by these same authors have indicated that in rats, caffeine administration during pregnancy is also associated with increased fetal mortality, impaired sexual differentiation, and reduced maturation of neuronal mechanisms controlling respiration and parturition.
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From page 53... ...
One approach to obtaining an objective assessment of caffeine intake and exposure is to use biomarkers such as serum paraxanthine levels. A recent, wellcontrolled study of 487 women with spontaneous abortions and 2,087 normal controls, in which caffeine exposure was quantitated objectively by sent paraxanthine levels, showed that the mean serum paraxanthine concentration was significantly higher in women who had spontaneous abortions than in controls (752 versus 583 ng/mL)
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From page 54... ...
In a prospective study of a large number of women aged 34-59 years, a positive relation was observed between caffeine intake and risk of hip but not forearm fracture (Hernandez-Avila et al., 1991~. In contrast to these findings, more recent studies have failed to show a detrimental effect of caffeine on total bone mineral gain in three groups of teenage women with mean daily intakes of caffeine ranging from 14 to 77 mg (Lloyd et al., 1998)
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From page 55... ...
No effect was observed on bone loss in postmenopausal women whose habitual dietary caffeine intake ranged from 0 to 1,400 mg/day (Lloyd et al., 1997) or on bone mineral density in older men (Glynn et al., 1995~.
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From page 56... ...
Total body water as measured by bioelectrical impedance decreased by 2.7 percent, and sodium and potassium excretion increased by 66 and 28 percent, respectively. Caffeine use during prolonged operations in hot environments increases the risk of dehydration because such operations involve large sweat losses and/or inadequate fluid and electrolyte intake.
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From page 57... ...
Stress may include physical stress (exercise—see Chapter 3) , physiological stress (heat stress see Chapter 3, infection, sleep deprivation)
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From page 58... ...
(1998) found that administration of a combination of caffeine and ephedrine slightly increased systolic blood pressure during exercise, and addition of yohimbine to this combination increased diastolic pressure and heart rate during rest and increased cardiac work load during exercise.
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From page 59... ...
SUMMARY Caffeine is approved as a food additive with provisional status by the FDA, thus indicating that the agency concludes there is no evidence of a human health hazard arising from consumption of caffeine added to foods and cola beverages. However, controversy continues with respect to caffeine's role in cardiovascular disease, negative reproductive outcomes, physical dependency and withdrawal, and excessive intake.
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