Coffee is one of the most widely consumed beverages in the world. It is estimated that more than two-thirds of North Americans consume coffee every day. Coffee and tea have become part of our social life. How many times a week do we ask our family, friends, or colleagues whether they want to grab a cup of coffee? In addition, people use coffee to increase wakefulness in the mornings and help increase productivity.
Health Benefits
There are multiple noted benefits of coffee. When comparing people that consumed up to 4 cups of coffee with those who don’t drink coffee there was a 29% reduction in all-cause mortality, 15% reduction in cardiovascular disease, and 29% reduction in type 2 diabetes (source). The benefits are likely from caffeine and the polyphenols found in coffee.
Tea also contains polyphenols that can provide health benefits.
Coffee - how do you like your brew?
Caffeine
While coffee is the number one source of caffeine for adults, there are several other food items that are also significant sources (table below). Adolescents consume most of their caffeine in the form of soft drinks (NHANES 2011-2012 Overview, n.d.).
Tea typically contains slightly less caffeine than coffee. For example, a cup of black tea has about 40 mg and a cup of green tea has 30 mg. Herbal tea typically have 0 mg. Decaffeinated coffee still contains polyphenols.
*Note that the caffeine content and serving size may vary from store to store and between brands.
Source: McLellan et al., 2016.
Over the years there have been several concerns raised on the health risks of coffee and caffeine. However, recent data suggests that drinking about 3 cups of coffee or about 400 mg does not present as a health risk. As noted above, 3 to 4 cups of coffee a day has shown to be associated with reduced risk of diseases including Parkinson’s disease, heart disease, Type 2 diabetes, gallstones, depression, suicide, cirrhosis, liver cancer, melanoma and prostate cancer. To date there is no evidence that caffeine is associated with an increased risk of cancer.
On note is that caffeine is metabolized by an enzyme called CYP 1A2. The function, or how quickly CYP 1A2 clears caffeine from the body, does vary by individual. For those who slowly metabolize caffeine, there may be an increased risk of cardiovascular disease (source)
There are however some harmful effects of coffee, and some other findings that should be considered. In pregnant women, a high consumption has been found to be associated with a low birth weight, preterm birth (source), and pregnancy loss (source). There was also an association between coffee consumption risk of bone fracture for women but not for men. It is therefore important to have a discussion with your physician and/or dietitian to discuss your risk for such conditions.
Additionally, one of the major side effects of coffee and caffeine consumption is its effect on sleep. Caffeine intake can not only delay the time you go to bed, but it can also decrease your quality of sleep (source). If you’re having sleep problems, you may want to consider reducing caffeine intake in later afternoon/evenings.
Some considerations of caffeine intake and chronic diseases
Caffeine and Cardiovascular Disease
If you have never had coffee before, caffeine intake will raise the levels of the hormone epinephrine in your body leading to a short term increase in blood pressure. You can, however, develop a tolerance to this change within a week!
This is even true for patients suffering from hypertension. Furthermore, caffeine intake has been shown to not be associated with an increased risk of hypertension.
Long term coffee consumption has also been correlated with reduced incidence of coronary artery disease, which can lead to heart attack, stroke, or death from cardiovascular causes.
Effect on weight management and Type 2 Diabetes
Coffee has long been known to suppress appetite. Some studies have shown that caffeine increases energy expenditure by inducing the body to produce more heat. However, clinical trials with coffee consumption have shown little effect on body fat (source).
Individuals should be mindful of the amount of cream and sugar they consume with coffee. Coffee itself does not have much impact, but these ingredients can add additional calories, sugar, and fat while providing little nutrient benefit.
Caffeine does affect insulin sensitivity in the short term, but drinking caffeinated coffee or other beverages for up to 6 months has not been found to affect insulin resistance in adults (source).
Though more evidence is required before we start to consider recommending coffee/caffeine to prevent disease, we do know it can be part of a healthy diet. Currently, adults are recommended to not exceed limits of 400 mg of caffeine per day, and pregnant or lactating women are recommended a maximum of 200 mg day of caffeine. The source of caffeine is also an important consideration. Foods and beverages that also contain a high amount of sugar and fat, such as specialty coffee drinks, energy drinks and soda, should be consumed less often. If you have questions about your caffeine intake or are looking for some guidance about how much caffeine is appropriate for you, speak to your clinician.
It can be hard keeping up with the recommendations, guidelines and how much total caffeine you had a in day. The RxFood platform takes the guesswork out of estimating your caffeine intake. Contact your physician to get access.