Recommendation: Drink up to 24oz of coffee per day if you like it and are in good health. If you’ve been diagnosed with heart, adrenal, or circulatory problems don’t drink it daily without letting your doctor know. It was very easy for me to find a lot of research suggesting moderate daily coffee is either ok or beneficial. It was a little difficult to find research showing coffee was likely harmful, especially to healthy people. Genes appear to play a significant role when we drink over 16oz (about 240mg of caffeine) daily.
Slow Your Roast, It’s Not That Simple…
Before we get too excited let’s think about what happens when we drink it. It makes most of us feel really different, almost immediately. Based on your genes and tolerance you’ve developed this could last for hours. This means it’s making your body do something it didn’t really feel like doing before you drank it. To me, this is a logical reason to not drink it every day. Trust the body to function naturally–feed it well and let it be. If something is wrong, seek medical advice before treating yourself with chemicals like caffeine. Its Alzheimer’s-reducing phytochemicals are found in other food sources you should be eating as part of a balanced diet anyway (dark chocolate + red wine = win). We know caffeine stimulates the adrenal gland to produce hormones. While I couldn’t find a study proving that moderate daily coffee consumption wears out healthy adrenal glands over time, I’m gonna play it safe and keep it to about 20oz/day tops.
Café-at Emptor
A latté the research doesn’t take into account whether the subjects are drinking espresso vs filtered vs boiled Turkish coffee. Also, the older studies definitely neglected to control for smoking, mold toxins, and other recently discovered risk factors. (Look up “Bulletproof Coffee” for info on moldy beans!) Not to mention, there’s evidence that caffeine affects people very differently based on age. Those are a few reasons why trusting a single study’s accuracy is not good enough. However, it’s unlikely that so many different populations would exhibit these similar results in lieu of some true effect–good or bad.
But There Are Likely Benefits, Based On These Grounds
Despite uncertainty, research provided tons of useful info about coffee. Most importantly, mutants with a ‘slow’ caffeine metabolism genotype get the short end of the stick. They have a higher risk of heart issues when they drink more than 16oz/day. You’re probably in that group if an afternoon coffee affects your sleep that night. The ‘fast’ genotype can drink coffee at 1pm and feel normal a few hours later. They also enjoyed a lower risk of non-fatal M.I. in that study from Costa Rica. ((Coffee, CYP1A2 Genotype, and Risk of Myocardial Infarction)) Another study reviewed 5 studies (total n=140,220) from 1966-2011 and found a reduced risk of heart failure when Nordic people consumed 3-35oz coffee daily, with the biggest benefit around 15oz/day. ((Habitual Coffee Consumption and Risk of Heart Failure: A Dose-Response Meta-Analysis)) A different study suggests glucose absorption is delayed with coffee (even decaf) consumption, which is great news for those trying to control glucose and insulin spikes. ((Coffee acutely modifies gastrointestinal hormone secretion and glucose tolerance in humans: glycemic effects of chlorogenic acid and caffeine)) #Foreshadowing… Nerds also supported previous evidence of coffee’s neuro-protective effects by preventing buildup of ROS and inhibiting apoptosis via a specific pathway. ((Attenuation of oxidative neuronal cell death by coffee phenolic phytochemicals)) Again, even decaf was effective because it retains the phytochemicals (especially Chlorogenic Acid). This supported a Canadian study of 4,615 seniors which associated a significantly lower risk of Alzheimer’s with moderate daily coffee (also NSAID use, moderate wine, and exercise). ((Risk Factors for Alzheimer’s Disease: A Prospective Analysis from the Canadian Study of Health and Aging)) The other study I found suggested a significant rise in blood pressure associated with caffeine alone. Combining data from 16 studies (n=1010; 1966-2003) 410mg caffeine (not in coffee) raised systolic 4.16mmHg, diastolic 2.41. However, when the caffeine came from coffee alone (about 24oz/day) the effects were significantly reduced. ((Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of randomized controlled trials))
The verdict: Based on the collection of current info, coffee can be part of a healthy diet.