Coffee is one of the most frequently consumed beverages on earth, yet there remain many questions regarding its effects on health.
More and more studies confirm the multiple benefits of drinking coffee.
Recent study published in Clinical Nutrition on 8/20/16 by Wu l, et al reviewed 9 prospective cohort studies and concluded that 1-2 cups of coffee prevent cognitive (mental) decline, preventing or slowing down the development of Alzheimers and other dementias and memory loss. There was no benefit shown in drinking less than 1 cup or more than 3 cups a day.
Coffee also was found beneficial in patients with depression, who drank between 68mg/day to 509 mg/day of caffeine (equivalent to 1-6 cups of american coffee) in the data from 330,677 participants from seven studies. (Wang L, et al. Coffee and caffeine consumption and depression: a meta-analysis of observational studies. Australian and New Zealand Journal of Psychiatry, 02/26/16)
What about the effect of coffee on the heart? Coffee can cause a short-term increase in blood pressure, but the consensus appears to be that it has a negligible role in promoting hypertension. A recent review found that the cumulative effect of coffee consumption on blood pressure was less than 1 mm Hg, and coffee did not promote hypertension. (Steffen M, at all.The effect of coffee consumption on blood pressure and the development of hypertension: a systematic review and meta-analysis. J Hypertens. 2012;30:2245-2254)
Coffee has more mixed effects on other important cardiovascular risk factors. A meta-analysis of 12 studies found that coffee increased serum levels of total cholesterol, low-density lipoprotein cholesterol, and triglycerides if you consume more than 3 cups per day. Moderate coffee consumption reduced the risk for heart failure, with a peak protective effect at 4 servings per day, but higher consumption can worsen heart failure. (Mostofsky E, et al.Habitual coffee consumption and risk of heart failure: a dose-response meta-analysis. Circ Heart Fail. 2012;5:401-405.)
A meta-analysis of 18 studies with over 400,000 participants in total found that coffee consumed daily was associated with a reduction in the risk for incident type 2 diabetes (adult onset). (Huxley R, et al. Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2 diabetes mellitus: a systematic review with meta-analysis. Arch Intern Med. 2009;169:2053-2063)
What about atrial fibrillation, arrhythmias, “skipped beats”, etc.? Coffee, tea, and chocolate consumption was not associated with an increased frequency of these ailments. Habitual caffeine consumption of less than 2-3 cups a day may actually reduce the risk. (Cheng M, Hu Z, Lu X, et al. Caffeine intake and atrial fibrillation incidence: Dose response meta-analysis of prospective cohort studies. Canadian J Cardiol 2014: DOI:10.1016/j.cjca.2013.12.026.)
A review of 9 cohort studies found that at least 4 cups of coffee per day reduced the risk for stroke by 17% compared with abstinence from coffee. (Zhang R et al. Coffee consumption and risk of stroke: a meta-analysis of cohort studies. Central European Journal of Medicine, 03/02/2012)
Other benefits include, but not limited to:
Decreased risk for liver cirrhosis and fibrosis, liver cancer
Reduced risk of skin cancer, like melanoma
Reduced risk of colorectal cancer, endometrial and oral cancers. (Hashibe m, et al. Coffee, tea, caffeine intake, and the risk cancer in the PLCO cohort. British Journal of Cancer, 08/21/15)
SO ENJOY YOUR CUP OF JOE, BUT NO MORE THAN 3 CUPS A DAY.