A German experiment from November 2008 discovered that caffeine appears to play a role in endothelial repair. Other investigations have reported that, if anything, regular coffee use tends to reduce risk markers relating to endothelial health (E-selectin) and systemic inflammation (C-reactive protein) which have both been associated with cardiovascular disease. The research that demonstrates positive effects for both caffeinated and decaffeinated coffee could possibly be explained by other health promoting phytochemicals such as kahweol which is found in all forms of coffee.A recent examination by the Center for American Indian Health Research at the University of Oklahoma looked for a correlation between coffee use and type-2 diabetes in a group of 1,141 men and women. The study volunteers were followed for an average of 7.6 years. Their ages ranged from 45-74 years old. The participants who drank the largest amount of coffee (a whopping 12 cups or more) demonstrated a 67% reduced risk of developing diabetes during the follow-up period. The authors of the investigation concluded that “a high level of coffee consumption was associated with a reduced risk of deterioration of glucose metabolism”.
Daily consumption of caffeine in coffee, tea or soft drinks increases blood sugar levels for people with type 2 diabetes and may undermine efforts to control their disease, say scientists at Duke University Medical Center...The findings, appearing in the February issue of Diabetes Care, add more weight to a growing body of research suggesting that eliminating caffeine from the diet might be a good way to manage blood sugar levels.
Daily use of coffee results in the secretion of more cortisol which increases the production of lactate. Studies so far suggest that high level of cortisol shrivel the division of the brain that is responsible for memory. High volume of this hormone affects your immune system and decreases your body’s power to resist infections. If you take more than 3 cups of coffee daily then it will result in the depletion of your adrenals. If the adrenal gland is over stimulated, it may result in fatigue, insomnia, weight gain, depression and a weakened immune system. Usually, caffeine stays in people’s system for about eight to thirty hours. The presence of caffeine in the system leads to the release of more glucose in to the blood stream followed by a stern fall in blood sugar. Coffee also provides more stress on your kidneys.
From everything I've read about adrenal fatigue and the adrenals, the two biggest drainers are excess sugar consumption and excess stress. Now, yes coffee is a stress, and the body does recognize all the stress the same (doesn't matter whether you're being chased by a lion, or you just got a divorce).
The fastest way to burn out the adrenals through stress is the emotional/mental stress. Because that can go on forever, or at-least long periods of time and in unlimited amounts.
With coffee, a certain amount of cortisol is released with the normal half-life. But with emotional/mental stress, you can consistently release large amounts of stress.
So if you really want to avoid adrenal fatigue, head in the direction of a positive mind-set, and get the sugar under control.
In its natural environment, coffee most often grows in the shade. However, most cultivated coffee is produced on full-sun,monocropping plantations, as are most commercial crops, to maximize production per unit of land. This practice is, however, detrimental to the natural environment, since the natural habitats which existed prior to the establishment of the plantations are destroyed, and all non-Coffea flora and fauna are suppressed - often with chemical pesticides and herbicides.... In addition, shade-grown coffee is considered by some to be of higher quality than sun-grown varieties, as the cherries produced by the Coffea plants in the shade are not as large as commercial varieties; some believe this smaller cherry concentrates the flavors of the cherry into the seed (bean) itself.
Keep that in mind if you are a coffee drinker.