Coffee is one of the most popular beverages in the world, loved for its taste, energy-supporting qualities and ability to be tailored to personal preferences—whether you prefer cold brew or a creamy Lavender Latte. Interestingly, coffee doesn’t just provide a morning pick-me-up! Studies suggest it may also benefit our health in various ways. For instance, research has shown that drinking more coffee is linked to a reduced risk of developing type 2 diabetes, regardless of whether it’s caffeinated or decaffeinated.

Coffee is rich in compounds like caffeine and polyphenols that may support better insulin function and fight inflammation. But not all coffee is created equal. Flavored drinks, coffeehouse treats and instant coffee mixes often include added sugar and saturated fat, which might negate some of those health benefits. That’s why we must take the type of coffee and its preparation under consideration.

To better understand how drinking coffee might be connected to blood sugar levels and other related health markers in Korean adults, researchers looked at factors like fasting glucose, insulin levels, long-term blood sugar (HbA1c) and measures of insulin resistance and insulin production among those who drank different coffee drinks, and the results were published in Nutrients.

How Was The Study Conducted?

Researchers conducted this study using data collected from the Korea National Health and Nutrition Examination Survey (KNHANES) between 2019 and 2021. Out of 22,559 people surveyed during this period, the researchers included 7,453 participants for their main analysis. For a specific analysis comparing coffee types, they excluded additional participants who consumed coffee in ways they could not analyze accurately, leaving them with 6,613 participants. 

The researchers looked at coffee consumption by asking people what they ate and drank over a 24-hour period. They then categorized coffee into two types: black coffee versus coffee with sugar and/or cream. The researchers then grouped participants by how much coffee they drank into non-drinkers, up to 1 cup/day, 2 cups/day and 3 or more cups/day. 

General characteristics of the participants, such as their lifestyle habits and demographics, were assessed, and they compared different characteristics across coffee drinking habits using appropriate statistical tests.

To study how coffee affects markers linked to blood sugar control, the researchers used a statistical model that adjusts for several factors like age, gender, diet quality, physical activity and income. These adjustments help ensure the results are not skewed by other variables. Additionally, they examined if factors like sex or age influenced coffee’s effects and conducted separate analyses where necessary. 

What Did The Study Find?

After conducting analyses, the researchers found that drinking 2 cups of coffee each day appeared to be linked with slightly better glucose metabolism compared to no coffee at all. Specifically, this was seen in lower levels of markers like HOMA-IR (insulin resistance) and fasting insulin, which are related to insulin resistance. 

When breaking it down further, drinking up to 1 cup of black coffee daily was significantly associated with better glucose metabolism. However, coffee with sugar or cream didn’t show any clear benefits for these markers. This suggests that plain black coffee might have some positive effects on how the body processes sugar.

The analysis showed differences between men and women. For women, drinking two or more cups of coffee daily, especially black coffee, was associated with healthier levels of health markers related to blood sugar regulation, meaning their blood sugar and insulin levels seemed better controlled. 

For instance, women who drank two or more cups of coffee had lower odds of issues with insulin resistance and elevated fasting insulin compared to those who didn’t drink coffee at all. The associations were stronger with black coffee, suggesting it might have unique health benefits. However, in men or individuals who added sugar or cream to their coffee, these benefits were not observed. This indicates that the way coffee is consumed and individual differences, like sex, may play an important role in its potential effects on health.

The study also observed a noticeable pattern where higher coffee intake seemed linked to better glucose metabolism in older adults. However, these results should be interpreted carefully, especially given the unique health factors that often apply to older populations.

This study comes with some limitations. Because it was cross-sectional, we cannot determine cause and effect. However, removing participants who had diseases or were on special diets for health conditions helps reduce the chance of reverse causation. 

But it is important to note that there were trends when assessing the qualities of certain groups of participants. For example, heavy coffee drinkers tended to have a higher BMI, more education, eat more calories daily, exercise less and sleep fewer hours. Many of them were also current smokers. These factors may impact overall health, including blood glucose control. 

The study also couldn’t account for different types of coffee, like decaf, or other caffeine sources such as tea or energy drinks, which may impact the results. Finally, coffee habits were measured only once, not allowing for changes in habits that may impact outcomes. 

How Does This Apply to Real Life?

Based on this study, if you are a coffee lover, considering how you take it might make a difference. Love a good caramel latte or extra-sweet frappuccino? Well, here’s some food (or should we say, drink) for thought. Opting for black coffee or dialing back on the sugar and cream might not just save you a few calories; it could actually help regulate your blood sugar levels, particularly for women and older adults. 

Simple adjustments like reducing sweeteners or creamers in your cup might not only enhance the health benefits highlighted by the study but also align with broader dietary goals such as maintaining a balanced blood sugar level.

Additionally, these findings remind us of the importance of personalized health choices. Coffee consumption isn’t a one-size-fits-all matter—it may have varying effects based on factors like age, gender and individual health profiles. Reflecting on how these variables apply to your own habits could help you make informed decisions about your daily coffee intake. 

By staying mindful of preparation methods and moderating consumption where necessary, coffee can remain an enjoyable part of your routine while potentially contributing to improved metabolic wellness. Unfortunately, this study did not address whether using sugar substitutes impacts the evaluated outcomes. 

The Bottom Line

Coffee remains a beloved beverage enjoyed by millions worldwide, but as this new study published in Nutrients highlights, the way we choose to consume it may impact its health benefits. If you are focused on supporting better glucose metabolism, opting for plain black coffee may be your best bet. Women and older adults in particular may find greater benefits, as suggested by the study, though individual health considerations should always guide dietary decisions. Moderation and mindful consumption are key takeaways, especially when it comes to avoiding additives like sugar and cream that may diminish coffee’s positive effects.

Ultimately, this research underscores the importance of tailoring coffee habits to align with personal health goals. While the study provides compelling evidence of potential links between coffee and improved sugar metabolism, it also reminds us that there is no universal solution. Factors such as lifestyle, individual metabolic needs and even cultural habits play a significant role in determining the overall impact of coffee on health.