The Hidden Effects of Your Morning Brew: How Coffee and Tea Additives Can Disrupt Digestion and Sleep

Question: What common additions to coffee or tea might be unexpectedly impacting my digestion or sleep?

The Crema Conundrum and Digestive Ripples

While the beloved crema of an espresso might seem like mere aesthetic flair, its composition can offer clues into the beverage’s interaction with our bodies. Research suggests that lipids play a role in destabilizing the foam structure of espresso, particularly in pure Arabica varieties due to their higher lipid content compared to Robusta [1]. Although not a direct additive, understanding the intrinsic properties of coffee, like its lipid profile, sets the stage for how other components might be processed and absorbed. Furthermore, the often-overlooked coffee silverskin, a byproduct of coffee processing, contains compounds that undergo changes during in vitro gastrointestinal digestion, indicating that various coffee components are indeed subject to breakdown and transformation within our digestive systems [2]. This suggests that while coffee itself is digested, the impact of what we add to it is also a critical factor.

Sweeteners and Their Silent Impact

Many of us reach for sweeteners to balance the inherent bitterness of coffee or tea. However, the type and quantity of sweeteners can have unforeseen consequences. While not explicitly detailed in the provided snippets regarding coffee and tea additives, the broader scientific literature on dietary components, such as those discussed in the context of energy drinks, often highlights the significant impact of added sugars and artificial sweeteners on gut microbiota and metabolic processes [5]. These changes in gut bacteria can, in turn, influence nutrient absorption and even mood and sleep regulation. For instance, disruptions in the gut microbiome have been linked to altered neurotransmitter production, which plays a crucial role in managing sleep-wake cycles and can contribute to digestive discomfort [2, 5].

Milk, Dairy, and Their Derivatives

The choice of milk or milk alternatives can also subtly alter the digestive experience. Dairy milk contains lactose, which can be problematic for individuals with lactose intolerance, leading to bloating, gas, and abdominal discomfort. Even for those without overt intolerance, the fat and protein content of dairy can affect digestion speed and comfort. Non-dairy alternatives, such as oat, almond, or soy milk, introduce their own unique profiles of carbohydrates, fibers, and processing additives. Some of these, like certain thickeners or emulsifiers, can be poorly tolerated by sensitive individuals, potentially leading to digestive upset. The specific processing of these alternatives, including fermentation times or added ingredients, can further influence their impact [1, 2].

Caffeine’s Influence on Sleep Architecture

Beyond the additives, the very foundation of these beverages – caffeine – is well-known for its stimulant properties. Excessive caffeine intake, regardless of what it’s mixed with, is consistently linked to sleep disturbances [3, 4]. This is primarily due to caffeine’s ability to block adenosine receptors in the brain, which are crucial for signaling sleepiness. While individual tolerance varies significantly, consuming caffeinated beverages too close to bedtime can lead to difficulty falling asleep, reduced sleep quality, and more fragmented sleep patterns [4]. Studies have even noted the wide variation in caffeine content within the same coffee beverage from the same outlet on different days, emphasizing the challenge of precise consumption control [5].

Beyond the Brew: A Holistic View

It’s clear that the journey from bean or leaf to your cup involves more than just hot water. The intrinsic properties of coffee and tea, combined with the myriad of common additions like sweeteners and dairy or non-dairy milks, can all play a role in how your body responds. While caffeine’s impact on sleep is widely acknowledged, the subtle effects of these other components on your digestive system and overall well-being are often underestimated. By paying closer attention to what you add to your daily brew, you can better navigate potential digestive discomfort and optimize your sleep, ensuring your beloved beverage contributes positively to your health.

References

[1] — Ernesto Illy, Luciano Navarini — Neglected Food Bubbles: The Espresso Coffee Foam. — 2011-Sep — https://pubmed.ncbi.nlm.nih.gov/21892345/ [2] — Marlene Machado, Iva Fernandes, Ana Fernandes, Liliana Espírito Santo, Cláudia Passos, Aroa Santamarina, Alejandra Cardelle-Cobas, Manuel A Coimbra, Maria B P P Oliveira, Helena Ferreira, Rita C Alves — Impact of In vitro Gastrointestinal Digestion on the Chemical Composition and Prebiotic Potential of Coffee Silverskin. — 2025-Sep-05 — https://pubmed.ncbi.nlm.nih.gov/40911156/ [3] — Ryan C Emadi, Farin Kamangar — Coffee’s Impact on Health and Well-Being. — 2025-Aug-05 — https://pubmed.ncbi.nlm.nih.gov/40806142/ [4] — Tatiana Palotta Minari, José Fernando Vilela-Martin, Juan Carlos Yugar-Toledo, Luciana Pellegrini Pisani — Correlations Between Coffee Intake, Glycemic Control, Cardiovascular Risk, and Sleep in Type 2 Diabetes and Hypertension: A 12-Month Observational Study. — 2025-Aug-01 — https://pubmed.ncbi.nlm.nih.gov/40868130/ [5] — Jose Antonio, Brandi Antonio, Shawn M Arent, Darren G Candow, Guillermo Escalante, Cassandra Evans, Scott Forbes, David Fukuda, Maureen Gibbons, Patrick Harty, Andrew R Jagim, Douglas S Kalman, Chad M Kerksick, Jennifer A Kurtz, Joseph Lillis, Lonnie Lowery, Gianna F Mastrofini, Scotty Mills, Michael Nelson, Flavia Pereira, Justin Roberts, Michael Sagner, Jeffrey Stout, Jaime Tartar, Adam Wells — Common Questions and Misconceptions About Energy Drinks: What Does the Scientific Evidence Really Show? — 2024-Dec-27 — https://pubmed.ncbi.nlm.nih.gov/39796501/