Coffee is among the most popular beverages in America, with some people consuming upwards of 6-10 cups a day.
Such a high level of coffee consumption is clearly unhealthy from a clinical perspective. But most Americans do not consume that much coffee, instead averaging 1-3 cups of coffee a day.
This article is intended to flesh out the research and help individuals make an informed decision about coffee consumption.
Coffee’s Physiological Effects
Most people choose to consume coffee for the caffeine, seeking increased alertness, attention, and cognitive function. There is little debate that caffeine leads to these outcomes. Within 30-60 minutes of consuming coffee, peak levels are reached causing increased blood pressure, dopamine, adrenalin, noradrenalin, and cortisone levels. After days of regular coffee use, however, tolerance develops and these changes are no longer as drastic as with the first cup. This effect is similar to that experienced with pharmaceutical antidepressant use – the body adjusts the levels of catecholamines (dopamine, adrenalin, noradrenalin) and cortisone normally produced in anticipation of the surge that will happen once the coffee is consumed. The consumer often experiences this tolerance as fatigue and morning grumpiness, because these chemicals are closely related to our circadian rhythm and our ability to feel awake in the morning.
In certain susceptible populations coffee consumption can lead to panic attacks and frank psychosis due to the high levels of catecholamines. It is clear that if these symptoms arise both coffee and caffeine consumption should be eliminated. For others the short-term effects of coffee are more subtle. Because the metabolism of coffee may take anywhere from 2-12 hours, with an average of 4-6 hours, many people may experience insomnia or difficultly staying asleep due to morning coffee consumption. In the average person, 15% of the caffeine consumed is broken down every hour.
This metabolism appears to be accelerated for smokers, which may evoke the classic combination of increased coffee and cigarette use together. In fact, when smokers do eventually quit smoking their metabolism quickly shifts back to prior levels and they may notice the initial catecholamine surges again from coffee consumption. People with liver disease will have the reverse affect, and metabolize coffee more slowly than the rest of the population. Pregnant women should also take note since coffee easily passes through the placenta and breast milk; these women should avoid large amounts of caffeine due to reports of it causing low birth weight. Currently, research shows that the daily level should be below 400mg for pregnant or breastfeeding women, but many doctors recommend strict avoidance when possible.
The Cons of Coffee
Because coffee acutely (i.e. quickly) increases the levels of circulating catecholamines, including dopamine, it quickly becomes an addictive substance. Over time the body adjusts the amount of circulating catecholamines in anticipation of the influx that coffee will bring. This often leads people to increase their coffee consumption, seeking that original high they once obtained. In the clinic, I have observed that most regular coffee consumers report that they are not “morning people” until they have their cup of coffee. For this reason I do not recommend regular coffee consumption, especially first thing in the morning. When people stop consuming coffee first thing in the morning, they quickly report higher energy in the morning as well as enhanced mood.
Coffee also is known to affect the distal colon, leading to increased motility and defecation. Due to the increased motility, nutrients may not be absorbed as effectively, leading to less nutritional availability. Additionally, coffee loosens the lower esophageal sphincter, the ‘valve’ between the stomach and esophagus, and increases stomach acid production. Both of these effects lead to increased incidence of acid reflux, or GERD, and stomach ulcers.
The Health Benefits of Coffee
Since coffee not only contains caffeine, but also other compounds, it is a difficult substance to research. Other compounds found in coffee include phenol chlorogenic acid (an antioxidant), potassium, magnesium, niacin (vitamin B1), kahweol, and cafestol.
Early research suggests that coffee, not caffeine, may lower the incidence of diabetes, Parkinson’s, symptomatic gallstones, and Alzheimer’s disease. The mechanisms responsible for these outcomes have not been identified, but solid research supports the claims with respect to the reduction in Parkinson’s and Alzheimer’s disease.
Undoubtedly coffee has been shown to increase cognitive performance, alertness and attention and improves these factors even in the event of sleep deprivation. Nothing, however, improves cognitive performance as effectively as a good night’s sleep, so don’t use coffee as a regular substitute.
Finally, although acutely we see a rise in blood pressure (i.e. don’t drink coffee right before going to the doctor’s office), research does not support the claim that coffee will cause long term hypertension. Current research suggests that individuals with high blood pressure are not likely to see it increase because of coffee consumption alone.
Also noteworthy is that this research does not discuss the cultural and ritual benefits of coffee consumption, which may provide their own beneficial role in many people’s daily lives.
The decision of whether or not to drink coffee rests with the individual. In the past I have recommended that patients avoid large amounts of coffee simply due to diuresis (increased urination) and subsequent dehydration, but current research has disproved this long-standing theory. What my research has shown is that low to moderate coffee consumption may be benefital in reducing the incidence of Parkinson’s, Alzheimer’s, symptomatic gallstones, and type 2 diabetes; but these benefits may come at a cost to some people. If you are experiencing insomnia, mood swings, acid reflux, fatigue, depression, gastrointestinal complaints, or chronic pain it may be benefital to remove coffee for a period of 2-3 weeks to see if your symptoms improve.
I personally choose not to consume coffee every day, particularly in the morning, because my energy is higher without habitually drinking coffee. I do, however, enjoy an occasional coffee, particularly a cafe americano, because I enjoy the flavor and the community aspect. My research demonstrates there are some psychological and health benefits to this sort of coffee consumption. In general, however, these benefits are not exclusive to coffee. Thus, if I were to experience any sleep, digestive, mental, or emotional disturbances I would stop drinking coffee altogether to make sure that my problem isn’t caused by something I was putting into my body. You can certainly get antioxidants, magnesium, and niacin from many other great foods; most of which won’t make you dependent or groggy in the morning.
As always, empower yourself with information and make informed decisions. You have the power to only control a few things in life, one of them is what you put in your body for nourishment. Choose wisely and enjoy.
– Dr. N
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