Recently coffee has been very trendy in the media, and this is not without good reason. The final verdict came as the jury proudly announced some major benefits of drinking coffee, specifically 3 cups per day. This verdict came in the form of a giant meta-analysis which was published in the BMJ, a widely respected peer-reviewed medical journal.
What were the findings? Here is the positive part of it…
All cause mortality was reduced in both males and females between people who drank coffee and those who didn’t. There was no dose-dependant ratio (more coffee does NOT equal lower mortality), though the greatest effect was seen in the sweet spot of 3 cups of coffee per day.
Coffee drinkers have a 19% lower chance of mortality from cardiovascular disease than people who don’t drink coffee. These diseases include heart attack, stroke, of congenital heart failure for example. The risks of mortality from stroke specifically were reduced 30% in coffee drinkers. People who drank more than 3 cups of coffee did not see many adverse effects in this area, though the benefits were slightly lower. Again, 3 cups appeared to be the sweet spot for reducing mortality from cardiovascular disease.
Incidence of cancer was lower in those who drank more rather than less coffee, and also lower in those who drank coffee in comparison with those who didn’t. However, in individuals who already had cancer mortality rates were slightly increased in the group who drank large amounts of coffee. This was true as studied for all types of cancer in one large group, along with individual groups of cancer. There was an exception however, and this was increased chances of cancer in the urinary tract, like the bladder for example was associated with large amounts of coffee intake.
The risk of diabetes type II was decreased by a whopping 30% in a group that drank coffee in comparison to the group that didn’t. There was a linear association here too, meaning that as people drank more coffee the incidence of diabetes continued to shrink. This was true up until 6 cups of coffee, after which the benefit decreased.
Lastly, coffee drinkers had lower incidence of Parkinson disease, Alzheimer’s along with depression.
Now for some of the downsides…
One of the downsides were the findings in respect to cholesterol and fats profile. LDL levels (bad cholesterol) were slightly elevated, and HDL (good cholesterol) levels were slightly lowered in the individuals who drank more coffee in comparison with those who didn’t. The amount was not very significant, however this finding is important to note anyway.
Women who drank coffee were at higher risks for fractures than women who didn’t. This risk factor was not true for men however, in fact the opposite was true.
Pregnant women on the other hand have reason to keep away from drinking too much coffee. Women who drank more coffee were at risk to give birth prematurely, higher risk for low birth weights, along with pregnancy loss. There were also higher risks of childhood leukemia in those children born to women who consumed large amounts of coffee during birth.
What about a cup of coffee before we go to sleep?
Caffeine in general, and coffee in particular has a tendency to raise cortisol levels in our body. Cortisol is a hormone synthesised in our adrenals, which is responsible for our stress response. One of the ways that it does this, is by countering the effect of another hormone, called insulin. Insulin encourages our blood sugars to be absorbed by the cells in our body, but cortisol works to keep our blood sugar high, leaving us with optimal potential energy to deal with the stress. However, excess cortisol can be detrimental to our health. Excess cortisol in our body can suppress our immune system, leaving us vulnerable to infections and other diseases as well. In addition, excess cortisol can overwhelm one of the parts of our brain called the hippocampus, causing atrophy and impairing our memory.
Although healthy amounts of coffee can have positive effects on our health, as stated above, we have to make sure that we drink responsibly. Yes, I’m still talking about coffee. An interesting study found that drinking coffee up until 6 hours before going to sleep can make the quality and quantity of our sleep much worse. Now let’s tie all of this together.
Another study performed on students at Dartmouth found that sleep deprivation also increases cortisol levels in our body by up to 45%! So you first drink coffee before going to sleep, increasing your cortisol levels, then you don’t sleep well, increasing them even more. These increased cortisol levels mess with your circadian rhythm, bothering your natural sleep cycles and then you find yourself in a downwards spiral of cortisol making you stressed, depriving you of a good sleep, and threatening your health.
What’s the bottom line?
Please drink coffee responsibly, unless you are a pregnant woman. Give yourself a caffeine curfew no later than 16:00 in the afternoon, and stick to it.