Info on coffee from Dr. Mercola:
It appears that drinking coffee may interfere with your body's ability to keep homocysteine and cholesterol levels in check, most likely by inhibiting the action of the vitamins folate, B12 or B6. Coffee has been previously associated with increased risk of stroke and rheumatoid arthritis. Studies have also shown that caffeine in coffee can raise blood pressure and levels of stress hormones, and if consumed in large quantities it can lead to heart palpitations, jitters and nervousness.
Pregnant women should NEVER drink coffee. Caffeine is a stimulant drug that easily passes through the placenta to the developing fetus and is also transferred through breast milk.
During pregnancy and in infants the half-life of caffeine is increased, which means that it will stay in your body, and your infant's body, longer. Moreover, fetuses have no ability to detoxify caffeine.
Research suggests that drinking more than 300 mg of coffee daily, or the equivalent of two to three 8-ounce cups, may increase the risk of miscarriage, birth defects such as cleft palate and low birth weight, although as I mentioned above I don't believe that ANY amount coffee is safe for pregnant women.
Even with moderate caffeine intake, when the woman experiences no effects, studies have found changes in both the mother's and the fetal heart rate and blood pressure. Preliminary studies also suggest that drinking four cups of coffee or more per day may put the infant at an increased risk of sudden infant death syndrome (SIDS). Caffeine may also make it more difficult for women to maintain necessary levels of iron and calcium, which are especially important during pregnancy.
It also appears that coffee consumption is associated with increased estrogen levels, which means an increased risk of breast and endometrial cancer.
Coffee also has the issue of pesticide contamination, which is particularly harmful during pregnancy. You can read more about this issue below.
Coffee is usually not grown in the United States and we therefore have no control over how many pesticides are sprayed on coffee crops. As such, coffee is a heavily sprayed crop, so drinking coffee is likely to expose you to a dose of pesticides with each cup.
Pesticides have been associated with a number of health problems such as:
Prostate cancer and other cancers
If you choose to drink coffee, drinking organic coffee might reduce or eliminate the exposure to toxic herbicides, pesticides and fertilizers. The only drawback is that the countries where coffee is produced probably have less control and monitoring for compliance to organic practices along with pesticide use. Another plus of organic coffee is that you will also be helping to protect the health of the people working in the coffee fields, as you will be helping to reduce their exposure to toxins as well.
Avoid Coffee if You Have High Blood Pressure, Insomnia or Anxiety
Since coffee is a stimulant it will only worsen the symptoms of insomnia and anxiety and should definitely be avoided. People with panic or anxiety disorders may find that they are especially sensitive to caffeine and may find that even a small amount of the stimulant exacerbates their symptoms. Similarly, the caffeine will linger in your body for hours after you drink it, so it may keep you up at night even if you drink it long before bedtime.
For those with high blood pressure, a general rule is that the more caffeine you drink in a day, the higher your blood pressure will be. So if you are already at the higher end of the scales, drinking coffee will only increase your blood pressure further.
[Coffee can contribute to adrenal fatigue.]