Ahhh, coffee. That warm cup of joe in the morning is what millions of people around the world depend on to start their day. For many it might just be for the caffeine; for others like me, who really love it, we would drink it in the morning either way. We treat ourselves to a nice, hot, smooth cup and enjoy our vice even if it’s bad for you. Or… is it?

In a complete flip from the past, recent studies have demonstrated that coffee has enormous potential health benefits. Some of the most interesting findings include:

1.Death
Several studies have come out in recent years that suggest an association between coffee consumption and a lower risk of death. In one cohort study, more than 500,000 individuals from 10 countries were followed over a mean period of 16.4 years. Compared to nondrinkers, men who drank the most coffee had a 12% lower risk of death (OR 0.88; 95% CI 0.82-0.95, P<0.001) and women had a 7% lower risk of death (OR 0.93; CI 0.87-0.98, P=0.009). The authors noted that coffee drinking habits were only assessed once and reverse causality might have affected the findings; however, the large numbers enrolled in the trial and exclusion of those who died within 8 years after the start of the trial certainly strengthen the findings.

In another trial, 185,000 individuals who identified as African American, Latino, Native Hawaiian, white, or Japanese American, and aged 45-75, were followed over a period of 16.2 years. Coffee was associated with a lower risk of death even after adjusting for confounders. The association was found for both decaffeinated and caffeinated coffee, as well as anywhere from 1 cup per day to 4 cups per day.1,2
 
2.Diabetes
A group from the Nurses Health Study had a combined follow-up for individuals of 1,663,319 years and found that those who drank coffee had a lower risk of developing diabetes. Out of those who did drink coffee, those who decreased their coffee intake by more than 1 cup per day increased their risk for developing diabetes by 17%. They investigated tea drinking but found no association. Diet was reassessed every four years using a questionnaire.3

3.Chronic Kidney Disease (CKD)
Because the caffeine in coffee can transiently increase blood pressure, there have been concerns, at time, with CKD or heart patients drinking non-decaffeinated coffee. However, one group followed more than 2,300 patients with CKD and coffee drinking was associated with a decrease in mortality in that group, independent of many potential confounders (eGFR, smoking status, race, income, hypertension, BMI, and others). Those who drank the most coffee had a 24% lower risk of death compared to nondrinkers. While the confidence intervals in all the quartiles were wide and the lower 2 quartiles crossed 1, this study at least demonstrates that coffee is safe in this population and that it might actually be beneficial. It would be interesting to see a similar design with a larger number of people to see if that same association holds true.4
 
4.Colon cancer
In one of the strongest associations of any of these trials, a group studied the association between coffee consumption and colorectal cancer among 5,145 cases and 4,097 controls. Coffee was associated with a 26% overall lower risk of developing colorectal cancer. Among the highest group of consumption (>2.5 servings per day), coffee was associated with a 54% lower risk (OR 0.46; 95% CI 0.39-0.54, P<0.001). Coffee data was collected using a validated questionnaire and the researchers controlled for race. The findings held true for both colon and rectal cancers.5


In fact, it is difficult to think of medications that hold this much promise to prevent disease. So how to enjoy that cup? There are a few things (in terms of health anyway) to consider: drink it black and don’t drink it scalding hot. Sugar is associated with numerous health problems and could be ruining the benefits you are receiving, while WHO’s International Agency for Research on Cancer issued a statement in 2016 that there is some limited evidence consuming drinks hotter than 200 degrees Fahrenheit might increase the risk for esophageal cancer.6 Really enjoy it, rather than just pounding it like you’d just as soon be drinking a 5-hour energy—this is a good time to practice those mindfulness exercise you added to your New Years’ resolutions.

The key to enjoying coffee black is to buy good coffee. You can balance out the cost by only making the amount you are going to drink. (I’ve always found it interesting that people will buy really cheap coffee to save money but then make 12 cups of it and throw half of it away at the end of the day.) On special occasions or if you really want to treat yourself, I would suggest trying the coffees from the Big Island of Hawaii. Kailua-Kona (or just Kona for short) has the most famous, but the coffee grown on the Big Island’s southeastern region of Ka’u is outstanding and a full equal to Kona. In fact Rusty’s Hawaiian, grown in Ka’u, has placed in the top ten in the world in cupping competition.

If you want more caffeine, you should be buying a lighter roast since roasting removes the caffeine from the bean. I really like the fullness of a French Press, and in fact paper filters remove some of the compounds responsible for providing flavor. It is also impossible to control water temperature, meaning the beans can get burned in the brewing process and make the coffee bitter.

There have been some concerns that coffee might be bad for you, but these are based on limited evidence or taken out of context. For example, there is an ongoing court battle in California about whether or not coffee should be labeled a carcinogen due to trace amounts of acrylamide; however, that is based on acrylamide alone and on animal studies, and drinking coffee is very different from drinking large amounts of acrylamide. There have also been some concerns because cafestol, a compound removed by paper filters but not with other methods (French press, Turkish coffee, etc), increases cholesterol; again though, based on current evidence, the presence of this compound does not appear to negatively affect outcomes. Unfortunately, these concerns might lead some to stop enjoying coffee while reaping the health benefits. In other words—drink up!7,8
 

References
  1. Gunter M, Murphy N, Cross A, et al. Coffee drinking and mortality in 10 European countries: a multinational cohort study. Annals of Internal Medicine. http://annals.org/aim/article-abstract/2643435/coffee-drinking-mortality-10-european-countries-multinational-cohort-study. Published August 15, 1017. Accessed April 2, 2018.
  2. Park SY, Freedman N, Haiman C. Association of coffee consumption with total and cause-specific mortality among non-white populations. Annals of Internal Medicine. http://annals.org/aim/article-abstract/2643433/association-coffee-consumption-total-cause-specific-mortality-among-nonwhite-populations. Published August 15, 2017. Accessed April 2, 2018.
  3. Bhupathiraju S, Pan A, Manson J, et al. Changes in coffee intake and subsequent risk of type 2 diabetes: three large cohorts of men and women.  Diabetologiahttps://link.springer.com/article/10.1007/s00125-014-3235-7. Accessed April 2, 2018.
  4. Regular coffee consumption may aid chronic kidney disease. MPR. www.empr.com/news/caffeine-ckd-chronic-kidney-disease-non-dialysis/article/705459/. http://cebp.aacrjournals.org/content/25/4/634.long. Published November 3, 20178. Accessed April 2, 2018.
  5. Schmit S, Rennert H, Rennert G, Gruber S. Coffee consumption and risk of colorectal cancer. Cancer Epidemiol Biomarkers Prev. 2016 Apr; 25(4): 634–639. http://cebp.aacrjournals.org/content/25/4/634.long Accessed April 2, 2018.
  6. IARC monographs evaluate drinking coffee, mate, and very hot beverages. International Agency for Research on Cancer. www.iarc.fr/en/media-centre/pr/2016/pdfs/pr244_E.pdf. Published June 15, 2016. Accessed April 2, 2018.
  7. Fact check: Calif. Judge rules coffee should come with a cancer warning, but should it? NPR. www.npr.org/sections/thetwo-way/2018/03/30/598348764/fact-check-calif-judge-rules-coffee-must-come-with-a-cancer-warning-but-should-it. Published March 30, 2018. Accessed April 2, 2018.
  8. How coffee raises cholesterol. Science Daily. https://www.sciencedaily.com/releases/2007/06/070614162223.htm. Published June 15, 2007. Accessed April 2, 2018.