I wish I had clear and unambiguous advice for you when it comes to coffee.
As you will see, the data are mixed. After reviewing the following articles, you may get a sense that it is likely OK (I do,) if not abused. Coffee reminds me of alcohol. By now you must have been living on the Moon if you have not heard that alcohol is OK in moderation, that is, less than 12 oz of wine, 8 oz. of beer, and 2 oz. of hard liquor a day. Even elderly people may safely follow these recommendations (J. American Geriatric Society 2007;55:49.) In fact, consumed in moderation, alcohol reduces insulin resistance (J. Metabolism Clinical and Experimental 2005;54:306,) like coffee does (J. Metabolism Clinical and Experimental 2007;56:599.) Consequently, alcohol reduces the risk of heart problems by 38% (J. Family Practice News, April 1st, page 1.)
But, you will still hear about articles saying that coffee may worsen our risk of pre-diabetes (J. Annals Nutrition & Metabolism 2006;50:407.) Coffee also has been reported to increase insulin levels after a meal, but not the fasting levels of sugar. One researcher showed that sugar after meals may improve by 20 % if diabetics get off coffee altogether (J. Endocrinology Practice 2007;13:239.)
I feel the problem is drinking too much coffee, particularly if your liver does not detoxify it very well. Coffee in excess increases the risk of non fatal heart attacks, if the person has a slow CYP1A2 allele, or gene for detoxification, which impairs coffee metabolism in the liver (JAMA 2006;295:1135.)
Weak adrenal glands, perhaps from genetics, or too much trauma, emotional, and/or physical, also have a lot to say on how you handle coffee. People with a tendency to TOIL (Toxicity, oxidation, inflammation and less optimal mitochondrial function-see newsletter archive) in the cell membranes lining their esophagus, and stomach, may get symptoms of reflux, and even gastritis with too much coffee. I am one of them, so, I am forced to limit my coffee to one cup a day and with meals only. My dad woke up dead from a bleeding ulcer. I am afraid I inherited his poor tendency to molt the lining of my stomach, which is brand new every 36 hours.
Compounding the problem is the possibility of an addicting personality, which would make it very hard to stop at one or two cups a day, since caffeine has an addictive potential. Again, this is the same as alcohol. The American Medical Association recommends that you limit your alcohol intake to one, or two drinks a day, and don’t start drinking if you don’t drink now, since you don’t know how you will react when faced with the potential of developing an addiction. I would advice you to do the same with coffee. A moderate amount has been defined as less than 4 cups a day. This seems excessive to me, so, I limit myself to one cup a day, with meals, and never in the morning, or late at night.
Get yourself a cup of Joe, or not, and read the highlights of one of the best articles I have seen on coffee: “Is coffee a functional food?” (British J. Nutrition 2005;93:773.)
Coffee has a lot of antioxidants (flavonoids, phenolic compounds, theobromine, xanthine, nicotinic acid, trigonelline, quinolinic acid, tannic acid, pyrogallic acid, and hydroxycinnamic acids.) This is why it is the single most important source of antioxidants in the USA, which is really a reflection of how low the American diet is on fruits and veggies (Scranton University report, August 29th, 2005. Reuters News.) Coffee’s maximum antioxidant activity is found when it is roasted medium.
Other drinks have antioxidants, too. The most are found in green and black tea, then, in descending order, coffee, coca cola, red wine, carrot juice, apricot nectar, and white wine. Coke is on the list because they add teobromines, caffeine, and vitamins. Too bad they also add HFCS, artificial sweeteners, preservatives, colorings, and acid. More below.
- Unfiltered Italian coffee raises glutathione levels (the strongest antioxidant.)
- Coffee decreases the absorption of potassium, magnesium, and manganese
- On the average, the average caffeine content is 58-259 mg/serving
- Coffee is best decaffeinated through the supercritical CO2 method. Arabian coffee is 70% caffeine free. Ethopian Coffea arabica 94% caffeine free.
- Coffee decreases early morning drive sleepiness for about 30 minutes, following no sleep, and 2 hrs after sleep restriction.
- Coffee reduces breast cancer risk, except in obese women. It decreases liver cirrhosis, pancreatitis gall bladder stones, asthma, sugar levels after a meal, and it also decreases the risk of diabetes, and the risk of cardiovascular events.
- Coffee increases body temperature, energy expenditure, testosterone, potency and sexual activity in elderly women.
It improves mood, lowers risk of suicide, increases speed of processing information, and improves cognitive performance. Coffee induces better neurologic outcomes, ADD improvement, lower risk Parkinson’s disease, and Alzheimer’s disease. It also improves the dopamine system, so that it is useful in alcohol and drug addiction. Cappuccino may be used to treat the dry mouth seen with tricyclic antidepressants.
But, problems may be seen after 4 cups a day: withdrawal syndrome, short sleep, increase in blood pressure, increase inflammation, and lower infant birth weight
Coffee decreases the oxidation of LDL lipids, AJCN 2007;86:604
J. Archives Internal Medicine 2006;166:1190
Coffee reduces risk of cirrhosis, especially alcoholic cirrhosis
J. Diabetologia 2006;49:2618
Coffee reduces risk of mortality of heart disease in diabetics type II
J. Circulation 2006;13:2045
Coffee does not increase risk of heart disease]