Penn State Department of Family and Community Medicine, Penn State College of Medicine, Hershey (Dr. Malone); Torrance Memorial Physician Network, Calif (Dr. Tsai) malm0001@hotmail.com
The authors reported no potential conflict of interest relevant to this article.
Type 2 diabetes . A 2009 prospective cohort study, which included 40,011 participants followed for more than 10 years, found that drinking at least 3 cups of coffee or tea was associated with a lowered risk of type 2 diabetes. 46 A 2009 systematic review of 20 cohort studies showed that high intakes of coffee, decaffeinated coffee, and tea are associated with a reduced risk of diabetes. 47
A meta-analysis of 12 studies involving 832,956 participants found an inverse relationship between cutaneous melanoma and coffee consumption.
Melanoma. A meta-analysis of 12 studies involving 832,956 participants demonstrated an inverse relationship between cutaneous melanoma and coffee consumption. 47 The risk of melanoma decreased by 3% and 4% for one cup/day of total coffee and caffeinated coffee consumption, respectively. Furthermore, a 2016 meta-analysis found that caffeinated coffee may have greater chemopreventive effects against melanoma than decaffeinated coffee. 48
Adverse effects
Despite the many potential benefits of coffee, caffeine is a potent drug that should be used with caution. 49 People with underlying heart problems should avoid caffeine due to concern that it may cause palpitations from tachycardia. It may worsen anxiety problems or depression. Coffee may increase the production of stomach acids, which can worsen acid reflux or stomach ulcers.
Regular coffee intake is associated with a lower risk of mortality, reduced CV events, and a reduction in liver disease progression.
Caffeine is a potent diuretic and may decrease absorption of calcium and cause OA. Caffeine may cause dependence and withdrawal symptoms. Some of the symptoms of withdrawal include drowsiness, headaches, irritability, nausea, and vomiting. It may disrupt sleeping patterns by causing jitters and sleeplessness. 49 Additionally, large amounts of caffeine may cause overdose and death.
The bottom line
Regular coffee intake is associated with a lower risk of mortality, reduced cardiovascular events, and a reduction in liver disease progression. Coffee may also have some utility for improving cognitive function and reducing the risk of type 2 diabetes. Caffeinated coffee should be limited to no more than 32 oz per day, due to the risk of insomnia, palpitations, anxiety, and gastritis.
Chocolate/cocoa
Overview
Few natural products have been claimed to successfully treat as many disorders as chocolate. The modern concept of chocolate as food has overshadowed its traditional medicinal use, although recent trials have looked at evidence for some of its traditional uses. Chocolateis processed from the pod of the cacao plant. The earliest evidence for its medical use is in Mayan civilizations, and for most of its approximately 4000-year history, chocolate was consumed as a bitter drink referred to as the “drink of the Gods.” The traditional drink was mixed with water, vanilla, honey, chili peppers, and other spices. Important components in chocolate include flavonoids (antioxidants), cocoa butter, caffeine, theobromine, and phenylethylamine.
Chocolate has stimulating, anti-inflammatory, neuroprotective, and cardioprotective effects, and improves the bioavailability of nitric oxide, which can improve blood pressure and platelet function. 50 Epicatechin (an antioxidant) in cocoa is primarily responsible for its favorable impact on vascular endothelium via its effect on both acute and chronic upregulation of nitric oxide production. Other cardiovascular effects are mediated by the anti-inflammatory effects of cocoa polyphenols, and modulated through the activity of NF-kappaB. 51
