Nutritional Pearls: Coffee Consumption and Health Risks

The Research

Recently, a team of European researchers analyzed data gathered for a UK Biobank study to assess any link between coffee consumption, the type of coffee consumed, and risk of death from heart disease.¹

The UK Biobank study is a long-term, large-scale study that recruited the participation of more than 500,000 men and women aged 40 and 69 years between 2006 and 2010. As with other prospective studies, the participants responded to demographic, medical history, lifestyle, and dietary questionnaires. Additionally, participants underwent a physical exam along with providing blood samples.

For their analysis, the authors chose to exclude those who reported having heart failure or having experienced a heart attack or stroke. They also excluded those who reported consuming more than 25 cups of coffee per day and those who left the dietary questions about coffee consumption blank. This left more than 460,000 participants, of whom 77.9% reported drinking coffee daily.

What's unusual about this study is that the dietary questionnaire asked participants to identify the kind of coffee they consumed most frequently: caffeinated vs decaffeinated, as well as ground, instant, or other. Oftentimes, studies involving coffee don't differentiate more between caffeinated vs decaffeinated.

How much coffee—whether caffeinated or decaffeinated—the participants consumed was grouped into 3 levels: none, light-to-moderate (one-half to 3 cups per day), and high (more than 3 cups per day).

In 2020, the authors compared the coffee consumption of those who passed away over the course of the study with those who did not. In addition, they compared those who experienced (and survived) a stroke or heart attack with those who did not have a stroke or heart attack.

The Results

Compared to those who did not drink coffee, those who kept their coffee intake at 3 cups per day or less were 12% less likely to die of any cause. Furthermore, those drinking more than 3 cups per day were no less—or more—likely to die than those who didn't drink coffee.

When it came to the possibility of dying of cardiovascular disease, the benefit of drinking a moderate amount of coffee every day was even greater—those coffee drinkers were 17% less likely to die of heart disease.

They were also 21% less likely to experience a stroke and just slightly (4%) less likely to have a heart attack.

Those who drank more than 3 cups of coffee per day, however, were 10% more likely to experience a heart attack.

About 100,000 of the participants in this study also underwent comprehensive imaging of their hearts as well as procedures to measure arterial stiffness, which is an indicator of arterial health (think "hardening of the arteries"). Those who drank moderate amounts of coffee had significantly decreased arterial stiffness and increased measures of cardiac health such as stroke volume and ventricular mass.

What about the coffee type? The Biobank participants overwhelmingly drank either ground or instant coffee, if they drank it at all. The authors noted that "we did not find statistically significant association between regular instant coffee consumption and health outcomes."¹  Decaffeinated ground coffee, on the other hand, conferred similar health benefits to caffeinated ground coffee, at least with respect to the overall risk of death from any cause.

There were some limitations of this study. First, the coffee consumption data was assessed by questionnaires, so there is likely recall bias that could potentially lead to inaccuracies. Additionally, as the authors note, this single snapshot of coffee consumption likely does not reflect the participants’ total lifetime consumption. Finally, while there were favorable effects observed regarding the dose–response relationship between the amount of regular coffee consumption and cardiac changes, the observed effect sizes in the study were small.

What’s the Take Home?

The take-home message here is that if you drink a moderate amount of coffee regularly, it's almost certainly good for your health and your heart. Instant coffee? Not so much, which is likely because it is far more processed than simply grinding the beans.

Reference:

1. Simon J, Fung K, Raisi-Estabragh Z, et al. Light to moderate coffee consumption is associated with lower risk of death: a UK Biobank study. Eur J Prev Cardiol. 2022;29(6):982-991. doi: 10.1093/eurjpc/zwac008.

Dr. Gourmet is the definitive health and nutrition web resource for both physicians and patients with evidence-based resources including special diets for coumadin users, patients with GERD/acid reflux, celiac disease, type 2 diabetes, low sodium diets (1500 mg/d), and lactose intolerance.

Timothy S. Harlan, MD, FACP, CCMS, is a practicing, board-certified Internist. He is currently an Associate Professor of Medicine at George Washington University and Director of the GW Culinary Medicine Program.

Health meets Food: the Culinary Medicine Curriculum, is an innovative program teaching medical students about diet and lifestyle that bridges the gap between the basic sciences, clinical medicine, the community, and culinary education. Medical students work side-by-side in the kitchen with culinary students to teach each other, and most importantly, teach the community and patients how to return to their kitchens and transform their health. 

He served as Associate Dean for Clinical Services at Tulane University School of Medicine and is the founder and Senior Advisor of the Goldring Center for Culinary Medicine, the first of its kind teaching kitchen operated by a medical school.

Dr Harlan attended medical school at Emory University School of Medicine in Atlanta, Georgia, and pursued his residency at Emory University School of Medicine Affiliated Hospitals in Atlanta, GA.