Coffee Subject

In some cases, the solids themselves are subjected to extraction by a solvent. For example, in one process used to decaffeinate coffee, the coffee beans are mixed with activated charcoal and a high-pressure stream of supercritical carbon dioxide (carbon dioxide at high pressure and above its critical temperature) is passed over them at approximately 90°C. A supercritical solvent is a highly mobile fluid with a very low viscosity. The carbon dioxide removes the soluble caffeine preferentially without extracting the flavoring agents and evaporates without leaving a harmful residue. 

One of the major advantages seen in this method is the relatively low temperature, 500°F, to which the coffee is exposed. An earlier version of these roasters brought out in 1935 subjects the beans to a temperature of 850°F. 

Stadler, R. H., Fay, L. B., Antioxidative reactions of caffeine formation of 8-oxocaffeine (1,3,7-trimethyluric acid) in coffee subjected to oxidative stress, J. Agric. Food Chem., 43(5), 1332, 1995. (CA122 289398f)... 

A variety of factors differentiating tolerance studies could have contributed to the observed discrepancy. Lower doses are less likely to lead to tolerance than higher doses or will do so less rapidly. The habitual coffee drinkers in some studies may have had different levels or durations of consumption. In the cases of acute dosing, caffeine consumed by subjects outside the laboratory on the day of the experiment may have varied. This is particularly true when some investigators request in advance that subjects abstain from caffeine prior to the experiment, while others do not. Differences in age, gender, and arousal-relevant personality dimensions,... 

Battig, K., and Buzzi, R., Effect of coffee on the speed of subject paced information processing. Neuropsychobiology 16, 12, 1986. 

Several European investigations have compared the effects of boiled vs. filtered coffee on serum cholesterol. In a study with 101 Dutch men and women17who typically consumed an average of 5.6 cups/day of filtered coffee, investigators assigned subjects randomly to drink 4 to 6 cups/day... 

Their second study19 examined differences between boiled coffee and paper-filtered coffee for four weeks each with a two-week washout period in between treatment periods in 28 women and 13 men, 23 to 61 years old, with an average baseline total cholesterol of 5.5 mmol/L (210 mg/dL). Subjects were instructed to continue to drink their habitual amount of daily coffee, which ranged from 2 to 14 cups, with either boiled or drip coffee. With boiled coffee, both total cholesterol and LDL-C levels were significantly higher (0.32 mmol/L [12 mg/dL]) while HDL-C levels were modestly lower (0.07 mmol/L [3 mg/dL]). 

Forde et al.20 used a more complex study design to examine the effect of boiled coffee vs. paper-filtered coffee vs. coffee abstinence. The investigation involved 33 men with elevated baseline serum cholesterol levels (average 8.7 mmol/L [335 mg/dL]) who apparently were habitual boiled coffee drinkers (implied but not stated). The 10-week study was divided into two 5-week periods. Subjects were assigned to one of four groups (1) continuation of habitual consumption (control), (2) abstinence from coffee for the full 10 weeks, (3) abstinence from coffee for the first 5-weeks, followed by 5 weeks of paper-filtered coffee consumption, and (4) abstinence from coffee for the first 5 weeks, followed by 5 weeks of boiled coffee consumption. 

In 1990, Vatten et al.51 in Norway subsequently reviewed data on breast cancer risk from a cohort of 14,593 women with 152 cases of breast cancer during a follow up of 12 years on subjects who were between 35 and 51 years old at the beginning of the study and between 46 and 63 years at the end. They reported no overall statistically significant correlation between breast cancer and coffee consumption, but when body mass index was taken into account, lean women who consumed >5 cups per day had a lower risk than women who drank two cups or less. In obese women, however, there was a positive correlation between coffee intake and breast cancer. In a 1993 study, though, Folsom and associates52 failed to find an association between caffeine and postmenopausal breast cancer in 34,388 women in the Iowa Women s Health Study, with a median caffeine intake of 212 mg/day in women who developed breast cancer and 201 mg/day for women who did not and in Denmark, Ewertz53 studied... 

Increasing lifetime caffeinated coffee intake significantly inversely associated with bone mineral at hip and spine in subjects who did not report drinking at least one glass of milk a day between 20-50 years of age. 

Caffeine did not have adverse effect in subjects with adequate calcium intakes near or above 800 mg/d, although daily caffeine intake a2-3 servings of brewed coffee may accelerate bone loss from the spine and total body in women with a low calcium intake. 

Coffee Use. Table V focuses on the relationship of coffee use to the same six causes of death considered on previous tables. Approximately 70% of the Adventists in this study use no coffee. However, 17% drink two or more cups of coffee per day and 10% limit their intake to one cup per day. The "no coffee" category includes 362 subjects who report occasional coffee use (less than one cup per day). They were combined with subjects who indicated their coffee use as "0" cups per day. All subjects in the occasional use category took the effort to write a note to this effect on their questionnaire. We suspect many more subjects who really belong in the occasional use category simply recorded their use as "0" cups per day because it approximates their use closer than "1 cup per day". 

Figure 1. Age-standardized relative risk of fatal coronary disease among California Adventist males age 35-69 divided by meat and coffee use, 1960-80. The number of deaths is indicated at the base of each bar. The probability that chance alone accounts for the differential in risk between the indicated group and subjects who use no meat or coffee is less than 0.001.

The most important item to keep in mind when interpreting this data is that all the relationships mentioned are merely associations between a disease outcome and some personal characteristic which is common to a high proportion of subjects who experience the disease. Even if statistical testing has essentially ruled out chance phenomenon as a likely explanation for these observed associations, there is still the very real possibility that the associations are indirect and, thus, not directly relevant to the cause of the disease. For example, it is likely that Adventists who use meat and/or coffee may have many other characteristics which are different from subjects who abstain from these products. One or more of these characteristics may be the important factor which actually accounts for the association between meat and a specific cause of death. Yet, such a factor may not have been measured or taken into account during the data analysis. 

We suspect that the magnitude of most of the associations noted between meat or coffee and specific fatal diseases are somewhat underestimated because Adventists may tend to underreport the amount of meat or coffee they use. If a substantial number of subjects actually use more meat and coffee than they reported on the Initial questionnaire, it would tend to make it harder to find the real associations, and the observed associations would tend to be weaker. Furthermore, we may have missed associations because subjects changed their habits during the 21-year follow-up period. All observed associations are based on meat and coffee use at the time subjects completed the baseline questionnaire (1960). Subsequent changes in these habits would tend to reduce or eliminate the possibility of finding disease associations with these habits. Failure to find associations, or detection of weak associations, could also result from the fact that our study population contains relatively few subjects who are very heavy users of meat or coffee, while it contains an abundance of subjects who have no exposure to these items. 

The coffee trees in the world are subject to a large number of diseases (2-4, 8, 73, 92) lists range up to 60 and more, and yet the disease possibilities do not always disturb plantation owners. Occasionally, as where the leaf rust attacks, or where koleroga (black rot) is serious, growers are on the lookout for diseases and are anxious about their future. There are local places where diseases are apparently more benign than in others, and this tends to dull the worry about disease losses in a country. 

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