beyond CAFFEINE

Why Coffee Is Considered Good For Your Health

BY ROB SAINT LAURENT, M.ED

In 2018, the US was regarded as having the world’s most lucrative beauty and personal care market, worth nearly $90 billion. The lion’s share of that revenue is being made by a small group of multinational corporations that have dominated cosmetics manufacturing for roughly a century: Proctor & Gamble, L’Oréal, Unilever, Estee Lauder, Shiseido, and others.1 Hot or cold, sweetened or unsweetened, creamy or watery, humans have an affinity for their daily cup of joe. According to the National Coffee Association USA, we consume about 500 billion cups of coffee each year worldwide. In the US, as many as 63 percent of adults put down over 450 million cups of coffee daily. It’s an industry that shows no signs of slowing as new trends, like cold brew coffee (with a higher caffeine content), continues. As a dietary staple, it’s prudent to consider how coffee may affect our health since that’s probably not our first thought when reaching for that morning boost.

Cancer Controversy

Like its eggs and butter breakfast companions, not to mention alcohol, coffee has a history of debate.

Many may not realize or remember that in 1991, coffee was listed as a possible carcinogen by the World Health Organization’s International Agency for Research on Cancer (IARC). IARC based the decision on “limited evidence” that coffee may cause bladder cancer. Since then, the IARC has reversed its position, announcing in 2016 that coffee posed no cancer risk. They’ve concluded from over 500 epidemiological studies that coffee may actually have a protective effect against liver, colorectal, and uterine cancers.1,2

Illustrating the complexity of coffee, cancer concerns again arose in 2018. This time, a California judge ruled on behalf of the Council for Education and Research on Toxics, that a cancer warning label must be placed on coffee sold within the state because of high levels of acrylamide formed during roast- ing. The Food and Drug Administration (FDA) then stepped in and said the preponderance of evidence suggests otherwise. Said FDA Commissioner Scott Gottlieb, “Strong and consistent evidence shows that in healthy adults, moderate coffee consumption is not associated with an increased risk of major chronic diseases, such as cancer or premature death, and some evidence suggests that coffee consumption may decrease the risk of certain cancers.” With the FDA’s blessing, the state of California ended up overturning the ruling to the delight of the National Coffee Association, as well as Cleveland Clinic— a leading cancer research institute.3,4

However, the IARC did note that there may be increased esophageal cancer risk from drinking very hot coffee, as shown in studies of South American mate and tea consumption in Asia. The carcinogenic effect probably happens from beverages heated to 150 degrees Fahrenheit and above. 2

Nutrition Facts

What, exactly, is in a cup of coffee?

An eight-ounce cup of brewed coffee has about 95 mg of caffeine. It also contains over a thousand other compounds being studied by food scientists for their potential anti-inflammatory, antioxidant, and anti-cancer properties. For example, coffee has healthful polyphenol antioxidants, like chlorogenic acid (CGA), and natural oils called diterpenes (cafestol and kahweol), that have shown mixed results in research.6

Evidence In Favor Of Coffee

A meta-analysis examines multiple studies on a topic to determine an overall effect. A 2017 umbrella review of over 200 such meta-analyses in the British Medical Journal (BMJ), was conducted by UK investigators to evaluate evidence linking coffee to human health. The researchers found that coffee was linked to more health benefits than harm.

It was found across intakes: high versus low consumption, any versus no coffee, and an extra cup per day.7

Specifically, the UK investigators found that three to four daily cups of coffee versus no coffee had the greatest health impact, including fewer deaths from all causes, lower heartrelated deaths, and decreased cardiovascular disease. High versus low coffee consumption was also linked to an 18 percent lower risk of neurological, liver, and metabolic disorders and cancer (prostate, endometrial, oral, skin, leukemia, liver, and non-melanoma skin cancer).7

Another meta-analysis was published in 2012 on the association between coffee consumption and heart failure. Five extensive studies were examined, consisting of more than 140,000 participants and 6,500 heart failure events. The researchers observed a “J-shaped” relationship between coffee intake and heart disease incidence. Compared to no coffee consumption, which showed a slightly elevated heart disease risk, four cups/ servings per day showed the strongest risk reduction (i.e., the base of the “J” on a graph), with risk again increasing as coffee consumption rose beyond four cups. This association was unaffected by sex and baseline heart attack or diabetes history. 8

In 2013, a large study of nearly 75,000 female nurses and over 39,000 male health professionals examined the association between caffeinated and caffeine-free beverages, including coffee, on type 2 diabetes risk. Study participants had no diabetes, cardiovascular diseases, or cancer at baseline. After controlling for lifestyle factors, caffeinated and decaffeinated sugar-sweetened beverages were strongly linked to higher diabetes risk. In comparison, caffeine-free artificially sweetened beverages were linked to higher diabetes risk in women. On the other hand, both caffeinated and decaf coffee was linked to lower diabetes risk in women and men (four to eight percent for every added cup), as was caffeinated tea in women. The authors concluded that regardless of caffeine, sugary drinks were associated with higher diabetes risk and coffee with lower risk.9

Regarding liver disease, early research has shown that caffeinated coffee can protect the liver from cirrhosis, with four or more daily cups conferring added protection. Research from 2021, however, suggests that even decaf coffee can help prevent chronic liver disease leading to cirrhosis. In this study from the UK, medical records of nearly a halfmillion participants showed that all types of coffee (instant, ground, and decaf) protected against chronic liver disease onset and progression.10

Research also shows that coffee promotes weight loss via caffeine. That said, a recent meta-analysis from Spain showed that over 200 mg of caffeine, or more than two cups of coffee, was needed before submaximal-intensity aerobic exercise for increased fat loss in a 150-lb person (i.e., at least 3 mg of caffeine per kilogram of body weight). Further, the effect was also only significant in people with no exercise history, occurred after about a five hour fasting period before exercise, and may wear off over time.11

Potential Adverse Effects

There are also potential downsides to coffee that should be considered.

The UK researchers in BMJ note that most harmful associations of coffee were canceled out when adjusting for smoking status—except in women at increased risk of bone fractures and pregnant women. Contradicting earlier scientific thought that coffee was good for osteoporosis, the researchers found that an older woman’s fracture risk increased significantly with each cup of coffee. In contrast, the reverse appears true in men.7 Research also shows that compared to pregnant women who don’t drink coffee, those who do are more likely to experience fetal harm or loss, premature birth, or low birth weight.12

Cholesterol is another concern. If one drinks unfiltered or French Press coffee, higher amounts of diterpenes will be consumed. These can raise blood fat levels of triglycerides, total cholesterol, and low-density lipoprotein (LDL) cholesterol, depending on caffeine sensitivity and the volume of coffee consumed. By comparison, espresso has about half the diterpenes of unfiltered coffee, while paper filters trap most diterpenes in filtered coffee.13

Recent research suggests that coffee may raise the risk of one type of arrhythmia or irregular heartbeat. In a small, randomized trial of 100 adults with real-time electrocardiography patch monitoring, coffee was shown to cause premature ventricular contractions (PVCs). PVCs were 54 percent more likely to happen on coffee-drinking days, with risk more than doubling after one or more cups. Meanwhile, atrial arrhythmias were unaffected, and supraventricular tachycardia incidence went down with coffee versus no coffee.14

Of course, too much caffeine is an issue for those sensitive to the drug. While the FDA considers four to five daily cups of coffee (400 mg of caffeine) safe, more than this can lead to adverse effects ranging from headaches and insomnia, to anxiety, jitters, and nausea. Further, drug interactions can also happen in people taking medications who drink caffeinated coffee.13

Gastroesophageal reflux disease (GERD), or acid reflux, is another common effect of too much coffee, leading to more serious conditions like esophagitis and even respiratory symptoms.

On Balance

Experts say the weight of evidence favoring coffee makes it a safe beverage choice for most people when consumed in moderation. As Gottlieb commented regarding the cancer warning label, they (FDA officials) didn’t want to “mislead consumers to believe that drinking coffee could be dangerous to their health when it actually could provide health benefits.” 3

Still, it’s prudent to be aware of other cautionary studies that may arise as more is learned about coffee. As researchers note, coffee’s acute everyday physiological effects are complex.

For coffee enthusiasts, moderate consumption is generally considered three to four cups daily. It’s advisable not to drink coffee (or tea) too hot, at or above 150 degrees Fahrenheit; it’s probably wise to stay with filtered or instant coffee to maintain healthy blood fats and be careful of too much sweetener (especially artificial). H

1. Loomis, D., Guyton, K.Z., Grosse, Y., et al. (2016, July). Carcinogenicity of drinking coffee, mate, and very hot beverages. The Lancet Oncology, 17(7), P877-78.

2. Aubrey, A. (2016, June 15). Java Lovers, Rejoice: Coffee Doesn’t Pose a Cancer Risk, WHO Panel Says [Radio broadcast]. NPR’s All Things Considered.

3. Ingber, S. (2018, August 30). Coffee Does Not Merit Cancer Warning Label Ordered in California, FDA Says. NPR.

4. Food and Drug Administration. (2018, August 29). Statement from FDA Commissioner Scott Gottlieb, M.D., on FDA’s support for exempting coffee from California’s cancer warning law [Press release].

5. Frey, M. (2021, August 19). “Coffee Nutrition Facts and Health Benefits.” Verywell Fit.

6. West, M. (2023, March 6). Coffee and cholesterol: Risks, benefits, and more. Medical News Today.

7. Poole, R., Kennedy, O.J., Roderick, P., et al. (2017). Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ, 359(j5204).

8. Mostofsky, E., Rice, M. S., Levitan, E. B., & Mittleman, M. A. (2012, July). Habitual Coffee Consumption and Risk of Heart Failure. Circulation: Heart Failure, 5(4), 401-405.

9. Bhupathiraju, S. N., Pan, A., Malik, V. S., et al. (2013, January). Caffeinated and caffeine-free beverages and risk of type 2 diabetes: The American Journal of Clinical Nutrition, 97(1), 155-166.

10. Kennedy, O. J., Fallowfield, J. A., Poole, R., et al. (2021, June 22). All coffee types decrease the risk of adverse clinical outcomes in chronic liver disease: a UK Biobank study. BMC Public Health, 21, 970.

11. Collado-Mateo, D., Lavin-Perez, A. M., MerellanoNavarro, E. & Del Coso, J. (2020, November 24). Effect of Acute Caffeine Intake on the Fat Oxidation Rate during Exercise: A Systematic Review and Meta-Analysis. Nutrients, 12(12), 3603.

12. James, J. E. (2021). Maternal caffeine consumption and pregnancy outcomes: a narrative review with implications for advice to mothers and mothers-tobe. BMJ Evidence-Based Medicine, 26, 114-115.

13. West, M. (2023, March 6). Coffee and cholesterol: Risks, benefits, and more. Medical News Today.

14. Phend, C. (2021, November 14). Coffee Causes This One Arrhythmia, Trial Shows. MedPage Today.