With origins in Ethiopia, coffee is now grown all around the world. Coffee lays claim to a $40 billion industry in the US. That’s a single food item! More than 50% of the US population drinks at least one 8 ounce coffee each day. Many people have several cups each day, but do they drink too much? Are they becoming dependent upon coffee? Are they immune to its acute effects? Should they care if they are?
As we all know, most coffee drinkers do so to get a little pep in their step in the morning. Caffeine that is in the coffee is very well studied and comes with numerous benefits. Unfortunately (in this case), the body is extremely adaptive. We can become immune to the stimulatory effects elicited by caffeine, to the point where we need more and more coffee to get enough caffeine to wake us.
This effect is known as desensitization. And it happens with a wide range of things: cocaine, methamphetamine, and other illicit drugs; insulin (eventually becoming type II diabetes);and penicillin to name a few. While desensitization is never welcome, it is a sign that you should back away from coffee for a couple of days to a week an allow. It can even be an indicator of an even more serious issue; adrenal fatigue.
However great the acute stimulatory effects of coffee are the other chronic health benefits are much greater! Few know that coffee can be considered a superfood itself, on par with spinach, kale, and many other antioxidant, vitamins, and mineral rich foods.
Caffeine is much more than just a stimulant; it’s a cognitive enhancer, a metabolic booster, a gastrointestinal motivator (morning poop?), acts as an anti-inflammatory, improves fat burning, and improves athletic performance (1-8)! That’s JUST caffeine. Coffee also has a bunch of other bountiful compounds such as chlorogenic acid (nothing to do with chlorine!), various diterpenes, and several micronutrients(9).
While there are numerous healthful compounds in coffee, it can be hard to isolate which effects are explicitly attributed to each compound in the coffee matrix. This is in large part because most compounds behave or are absorbed/metabolized differently depending on what else is ingested at the same time. A similar effect is seen in fruit; the fructose in fruit is not considered nearly as detrimental compared to pure fructose because of the vitamins, minerals, fiber, and water that come along with the fructose in the fruit. Instead of focusing on the individual components, we’ll look at the whole of coffee and its potential positive and negative effects.
If you suffer from postprandial bloat (after eating bloat) from undigested foods, then you might be able to benefit from the gastric acid promoting effects of coffee (30). A cup of coffee has been compared to a 1,000 calorie meal in terms of how much it stimulates the gastrointestinal system to push food through. Despite that, it has been shown that coffee consumption does slow gastric emptying, this could be attributed to a higher (more basic) pH since coffee isn’t nearly as acidic as the stomach, which does slow the breakdown of food. This sound contradictory, and it is, in part. Increased gastric acid improves the breakdown of food. Increased gastric emptying literally corresponds to how quickly food is pushed through the intestines. Food that has not been broken down can pass through the intestines. On the other hand, food that is entirely broken down can remain in the intestines if gastric emptying is next to nothing. Neither is good and we want a balance between the two so we can vacate our bowels and still gets the essential nutrients from the foods we eat.
Diabetes is one of the fastest growing, and most expensive, ailments in the modern world. Coffee might have something to say about that, when a better overall nutritional approach is also adopted. Numerous studies have shown an inverse relationship between moderate coffee consumption and the development of type II diabetes mellitus! The largest studies (of more 120,000 people) showed that those who consumed 5 cups of coffee per day were correlated with a 54% lower risk of developing type II diabetes compared to those who drank no coffee (10). A more aggressive Finnish study showed that a whopping 10 cups of coffee each day led to a 79% lower incidence of type II diabetes (11)! I must say, that this is a LOT. Too much for most people because of the risk of hypertension and anxiety at such extremes. From the larger study, it was also found that only increasing caffeine produced a more modest inverse effect with the development of type II diabetes and decaffeinated coffee has even lesser effects; another example of the benefits of the entire matrix of coffee, not any one particular component.
There are numerous proposed mechanism as to WHY coffee reduces incidence of type II diabetes. A few are as a follows… Lowered glucose absorption in the intestines from chlorogenic acid and other phenolic, antioxidant compounds (12). Enhanced uptake of magnesium (13,14). Increased activity, energy expenditure, and subsequent weight loss (11,15,16).
Yet another disease affecting more and more people each year is Parkinson’s Disease. Again, coffee consumption has been correlated with reduced risk and later onset of Parkinson’s Disease (17). A study of 8,000 plus Japanese-Americans revealed that those who did NOT drink coffee were three to five times more likely to develop Parkinson’s in contrast to drinking three to four cups each day over a 10 year period (18). Unfortunately, there have been very mixed outcomes for postmenopausal women on estrogen replacement therapy (19). This has been attributed to the inhibitory effects of estrogen on a specific hepatic enzyme (CYP1A2) responsible for caffeine metabolism (20).
Possibly even more intriguing is the relationship between coffee and hepatocellular carcinoma (liver cancer). A large Japanese study in excess of 90,000 men and women over the 10 years revealed a inverse correlation between coffee consumption and liver cancer; more coffee, less incidence of liver cancer (21). Researchers found that 5 or more cups of coffee a day reduced risk by 76% over those who did not drink any coffee (22). These results are, in large part, attributed to two diterpenes found in coffee and coffee oil; cafestol and kahweol. These two have demonstrated increases in liver enzyme levels (AST and ALT) (23). This is generally NOT a good thing. However, they have also shown to promote effective enzyme activity along with increases in hepatic glutathione and decreased DNA alterations resulting from carcinogens (in animals) (24,25). These showings are powerful in reducing abnormal liver functions.
With all of the benefits of coffee, there are also things to be weary of. A major complaint from coffee drinkers is acid reflux. It is acidic and does promote gastric acid production; both down and up stream. Be careful not to consume so much that it tends to come back up! Coffee has also been shown to inhibit iron and zinc absorption to a significant degree (26,27). In addition, caffeine is a potent vasoconstrictor, leading to increased blood pressure (hypertension) (28). However, a contrast function of caffeine is diuresis which is often used as a mode to reduce blood pressure (29). Next it should be noted that everyone has different sensitivity to all foods and chemicals, including coffee and caffeine. As a result, you should assess your own tolerance of caffeine and coffee. Perhaps you can consume 5 or more cups and feel great, but others might consume the same amount and be brought to the edge of an anxiety attack with sky high blood pressure. We are all different!
If you love coffee, then this review may be your best friend to encourage you to drink a bit more without worry. If you don’t, then you’ve now been made aware of what you could be missing out on. Either way, coffee won’t kill you nor make you immortal. It might be able to improve your quality of life to a point by reducing risk of type II diabetes and liver cancer, improving your cognition and athletic performance, and even reduce total body inflammation while improving digestion because of the phenolics, plant-based compounds within these magical Ethiopian beans. Of course, the quality of your coffee is important, like the quality of your food, so do your due diligence and treat coffee with the respect it deserves and get some of the good stuff. In addition to coffee and caffeine, you can also benefit from the wonders of cocoa powder! These are small additions to your lifestyle that could very well enhance your total sense of well-being and quality of life. That said, there is no cure all above and beyond proper, well-balanced nutrition and exercise on a regular basis. Coffee may be beneficial, but it won’t counteract a lifestyle of poor eating decisions.
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