In last week’s blog I discussed: The great debates about Fat, Salt, Chocolate, what is too much OR TOO LITTLE? It appears that coffee may also have different and surprising effects at various levels of consumption. Below I cherry pick from an article by Jacob Schor ND, FABNO in Natural Medicine Journal.
Dr. Schor reviewed a study conducted with 63,257 Chinese participants, aged 45 to 74 years over a period of 9.5 years. The researchers controlled for “height, weight, lifetime tobacco use, current physical activity, sleep duration, and medical history” so that they could focus on intake of coffee (and tea). Oddly, they noticed that high blood pressure was more common among participants who were female, those who had never smoked, those who were more physically active and those who did not drink alcohol. It was less surprising that hypertension was more common among those who were older, had less education and ranked higher on the body mass index.
Since coffee tends to rev us up, it would not come as a surprise to most people that it could increase blood pressure. Doctors know coffee affects several factors such as the sympathetic nervous system, the adrenals, kidneys, the energy system and it signals blood vessels to constrict. In the study, drinking less than one cup of coffee a day was not associated with hypertension. Drinking one to three cups of coffee per day (at 237 mL, nearly 8 ounce cups) was linked to increased blood pressure.
But, here is where it gets pretty interesting. Drinking more than three cups a day seemed to lower blood pressure. How is that possible? Well, it appears that there are other constituents of coffee that have effects that counters those of caffeine. For example, coffee contains potassium which relaxes blood vessels and promotes the creation of nitric oxide. Five cups of coffee can deliver about ¼ the daily need for potassium. Coffee also contains Chlorogenic acid (a polyphenol) which tends to lower blood pressure. At higher intake amounts, the other components of coffee seem to tilt the balance to the benefit side.
Higher coffee intake also seems to lower the risk of liver disease. I found that information in another analysis of data from that same study.
What is the takeaway from all this? Should we work to drink 4 or more cups of coffee a day? (If so, hopefully, organically grown and not as sugary coffee drinks.) Personally, I don’t think that is the best answer. There are other, more nutritious, sources of potassium. Think acorn squash, avocado, beans, sweet potato, spinach, potato, Swiss chard, raisins, prunes, tomato, and as I’m sure you already know, banana. Those foods as well as spices, fruits, vegetables, red wine, olive oil and cocoa provide the benefits of polyphenols and antioxidants that are in coffee.
If your blood pressure stays in what your doctor says is the normal range, maybe that means whatever amount of coffee you are drinking is okay.