Ahhh, coffee. That morning anytime pick-me-up, that warms us, comforts us, brings friends together and gives us a boost of energy – or does it? You may have heard coffee is good for you, or the opposite, that is bad for you. Maybe you’ve heard a little of both. So, what’s the truth? And should you indulge? If so, how much and is there too much? Today we will grind out the answers to those questions.
Probably the biggest thing to address about coffee is the obvious – caffeine. 93% of Americans drink caffeinated beverages and 75% of those people drink them daily. Is caffeine good or bad? How much is OK and what does it really do? First, caffeine is a naturally occurring compound that is found in more than 60 plants including coffee, tea, and cocoa that, once absorbed by the body, help us speed up messages between our brain and the rest of our body by blocking adenosine. Adenosine is a messenger that tells our body we have expended enough energy and that it’s time to rest (not coincidentally, the body decides that by measuring how much (adenosine triphosphate, or ATP we have used). With the adenosine blocked, we don’t get the “rest” signal, so we feel energized. But we don’t necessarily have the fuel to keep us going, so later our bodies will signal us to eat more to make sure that the fuel keeps up with energy output. Caffeine is an appetite suppressant though, so getting a hunger signal to help us refuel and be able to keep going doesn’t happen until later. So, knowing what caffeine is doing, what are its pros and cons? Well, it’s thought to protect the liver from cirrhosis and other liver diseases. Studies also show reduced risk of type two diabetes associated with it and another study shows a 3% drop in risk of arrhythmia for every cup of coffee consumed. Caffeine also reduces the risk of Parkinson’s and is used to treat migraines.
Now some downfalls: Anxiety. The jittery, wired, stressed out, or bouncing-off-the-walls stereotypes from having too much coffee or caffeine may be exaggerated, but a study did show that consuming more than 400 mg of caffeine (about 4 cups), is associated with an increase in anxiety for many people. Consuming less than 100 mg had no effect on anxiety levels. Sleep. While many people claim that coffee doesn’t interfere with their sleep, some of those same people will say that they have to have their morning coffee to get going, so there is some connection with having coffee and not being sleepy. Keep in mind too, that caffeine has a half-life of four to six hours, so that cup of coffee with dessert during a night out could be affecting you when you get home a few hours later. (In other words if you drink a cup of coffee with 100 mg of caffeine at 6:00 PM, you still have 50mg in your blood at 10:0 PM). Decaf isn’t always much better – some brands still have as much as 25% of the original caffeine – sometimes as much as 30 mg in a small cup. Finally, Withdrawals. While the FDA and the DSM V do not classify caffeine as an addictive drug, it’s well documented that people who use caffeine regularly do experience withdrawal symptoms when stopping suddenly. Things like headache, fatigue, mood swings, and difficulty concentrating. It varies by person and by how much you consume on a regular basis but it’s worth keeping in mind.
The next things to talk about regarding coffee are our physical health. First up, Blood pressure and arterial function. Both are closely related as far as coffee goes, but the two are still quite separate regarding coffee’s effects on them. About 10 years ago a study showed that within 30 minutes of drinking a cup of regular coffee, there was a significant drop in the arteries’ ability to dilate; whereas a cup of decaf had no effect. That was the first study to show a negative effect of arterial function caused by a caffeinated beverage. That’s likely because something else in the coffee, possibly combined with the caffeine, is messing with arterial function. Coffee contains roughly 1000 compounds other than caffeine and it’s likely that some of them are stripped out during the decaffeination process. Blood pressure on the other hand seems to be largely unaffected by coffee and caffeine, which is good news for people who need to watch the blood pressure. Additionally, the antioxidants and phytonutrients in coffee (known as chlorogenic acids) have been shown (in pill form) to significantly lower systolic diastolic blood pressure. More on chlorogenic acids and antioxidants later.
What about Blood sugar and weight loss? It has been known since at least 2015 that even a single cup of coffee can affect our blood sugar response – even with black coffee there can be a slight increase on our blood sugar. But what’s still unknown is if that increase is clinically significant. What is known though is that (black) coffee does not increase the risk of type two diabetes and there was no difference in risk associated with light or dark roast. But as far as weight loss, there was a difference between light and dark roast. In a controlled study where participants were randomized to drink two cups of either light roast or dark roast coffee every day for a month, researchers noted that overweight participants who drank the dark roast, lost an average of six pounds over the one-month study. Normal weight participants did not experience any weight loss, regardless of if their two cups were light roast or dark, and overweight participants who drank light roast did not see any statistically significant weight loss. Certainly, more data is needed but a good dark roast could fit into someone’s diet if they were planning to lose weight.
Does coffee effect Cholesterol? It’s been known for quite some time that non-filtered coffee (i.e. French press, boiled, or Turkish, as well as using a metal basket in place of a paper filter) can raise LDL cholesterol levels (the ‘bad’ kind). This is because of fatty substances in the oils of coffee, known as Cafestol. Cafestol is responsible for the oil in roasted coffee beans and is linked to high LDL cholesterol levels, because it suppresses LDL receptor activity and reduces the breakdown of LDL cholesterol. Studies have shown significant increases in LDL number after just two weeks of drinking non-filtered coffee. The numbers are returned to normal shortly after switching back to paper filtered coffee. Researchers had thought that the reason was that the paper filter trapped the cafestol, but when they tested the filters they found it wasn’t the case. It turns out, that the fine particles of coffee not stopped by the other filters are what carry the cafestol and the paper filters do stop the smaller particles. Another study showed that 3 cups a day of filtered coffee raised total cholesterol, but the rise in LDL was not statistically significant, and, again, stopping the drinking of coffee returned the cholesterol levels to normal. Additional studies found that cafestol levels were highest in light roasts, so dark roast would seem to be better for your cholesterol, or stick to paper filters, which remove about 98% of the cafestol. If your cholesterol is a concern, you should certainly consider your coffee choice including roast type and method of brewing - and even consider stopping for a month or two to see what/how you drink your coffee is having any effect.
Now some more good stuff: Remember the antioxidants and polyphenol phytonutrients (chlorogenic acids) that I mentioned? With more than 1000 different compounds, luck would have it that many of them are good for us. Antioxidants and their relatives fight free radicals, which can contribute to aging, cancer, and other diseases. We want lots of antioxidants to help in that fight. Unfortunately, a study that tested more than 100 different coffees found that levels of chlorogenic acids varied by 30 times across the different types. The results may have been a little skewed however because Starbucks had 10 times less chlorogenic acid than the other coffees tested. It’s also widely accepted that darker roast contains fewer of the beneficial compounds than the lighter roasts, even from the same batch of beans. Dark roasting may wipe out as much as 90% of the antioxidant benefits of coffee, but when measuring blood levels of antioxidants, research showed no difference between medium roast and medium light roast. There was, however, a difference if there was dairy in the coffee. Casein (one of the major proteins in milk), blocks people’s bodies from absorbing antioxidants (in various foods, not just coffee) by binding to them. So for maximum antioxidant benefits, switch to soy or almond milk, which don’t have casein.
Bad chemicals, heartburn and bathroom breaks: One of the negative things people always try to say about coffee is that it’s a diuretic (meaning that it takes water away from you). Diuretic just means increases urinary output. It is true that caffeine is mild diuretic, but a 300 mg dose (three average cups of coffee) will cause about four extra ounces of urine output. So most of the urine from when you drink coffee is from the water in it. Now for heartburn: Sometimes coffee is associated with symptoms of stomach discomfort and acid reflux. Researchers studied the effects of different types of coffee on stomach acid and found that dark roasts suppress the secretion of stomach acids (it took longer for stomach pH to return to normal after drinking a cup of dark roast). With medium roast coffee, they returned to normal pH is three times faster than with dark roast. So dark roast may have some antacid effect, at least compared to light roast. Interestingly, there was no difference between medium light and medium dark roasts, and “low acid” coffee reportedly had no effect on heartburn or reflux symptoms when compared with “regular” coffee. And finally, the bad chemicals: The images of Colombians carefully handpicking beans into woven baskets that you see on TV commercials are a lie. Coffee manufactures want you to believe those images and feel like you’re getting a special handcrafted coffee that has been loved and nurtured. Don’t believe it - Coffee is a very large scale, commercial farming industry generating billions of dollars per year and those corporations will do whatever it takes to increase and protect their crops – like use tons of pesticides and fertilizers. Fortunately, dark roasting eliminates about 99.8% of pesticides and about 90% of a fungal contaminant called ochratoxin that is a potent kidney toxin. Unfortunately, dark roasting generally leaves behind about four times more benzopyrene (a byproduct of the roasting process), which is suspected to be a DNA damaging and carcinogenic. Don’t worry too much about it in your coffee, though, as a single cup contains fractions of a nanogram. In comparison, a single serving of a grilled chicken would have 1000 times as much.
So, regular or decaf; light roast or dark; black or light (with almond or soy, of course), drink up but do it in moderation and buy organic and natural processes when you can. If you think coffee or caffeine could possibly be contributing to any health concerns you have, take a break from it and see how you feel or what your numbers do.
To your health!
Doug & Robin
Written By: Doug Davis CHC