Category: News

Dubai, 22-07-2025 (QW):- For many, coffee is more than just a morning ritual—it’s a daily lifeline. But a new comprehensive study spanning 15 years and over 12,000 participants raises important questions about whether this beloved beverage is quietly altering our cardiovascular health, for better or worse.

Researchers from the Chengdu University of Traditional Chinese Medicine have published one of the most detailed investigations to date into the relationship between coffee consumption and serum lipid profiles, using data from the U.S. National Health and Nutrition Examination Survey (NHANES) from 2005 to 2020. The findings, published in Frontiers in Nutrition, reveal a nuanced, gender-sensitive, and dose-dependent picture of how coffee interacts with key markers of cardiovascular health.

A Double-Edged Sword in a Cup

At the heart of the study lies a central paradox: coffee appears to both harm and help aspects of our lipid profile—a key determinant of heart disease risk.

On one hand, increased coffee consumption was associated with elevated levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), both well-established contributors to atherosclerosis and cardiovascular disease. Specifically, each additional cup of coffee per day was linked to a 1.23 mg/dL increase in TC and a 1.22 mg/dL rise in LDL-C. Among heavy drinkers (≥3 cups/day), the effect was more pronounced—up to 8.45 mg/dL higher in TC and 7.86 mg/dL higher in LDL-C compared to non-drinkers.

On the other hand, the beverage seemed to benefit levels of high-density lipoprotein cholesterol (HDL-C)—commonly known as “good” cholesterol—and triglycerides (TG), but only under certain conditions and primarily in specific gender groups. In women, HDL-C rose with coffee intake up to 2.6 cups/day before declining—a phenomenon the authors describe as an “inverted U-shaped curve.” In men, a similar non-linear relationship was found with triglycerides, which peaked at 3 cups/day before trending downward.

A Gendered Effect: Why Men and Women Respond Differently

This study is particularly valuable for highlighting gender differences in how coffee consumption affects lipid profiles—an area often underrepresented in nutritional research.

In men, the relationship between coffee and both total cholesterol and LDL-C followed a nonlinear curve: lipid levels increased steadily up to a threshold (5.3 cups/day for TC, 6.4 cups/day for LDL-C), after which the trend plateaued. The authors suggest that testosterone’s anti-inflammatory properties may play a protective role, counteracting the cholesterol-raising effects of coffee compounds like cafestol and kahweol.

In contrast, women did not exhibit such plateauing trends. However, they showed clear sensitivity in HDL-C levels, which improved with modest consumption (peaking at 2.6 cups/day) but declined at higher intake levels.

The Mechanism Behind the Brew

So why does coffee have these effects?

The researchers point to diterpenes—compounds found in unfiltered coffee like cafestol and kahweol—as the likely culprits for increasing LDL-C and total cholesterol. These compounds are known to interfere with liver enzymes that regulate cholesterol metabolism and bile acid production. On the beneficial side, moderate coffee consumption may stimulate HDL-C production, though this effect appears to be offset at higher doses, possibly due to inflammation.

Indeed, the study discusses inflammation as a key mechanism. Elevated coffee consumption has been associated with increases in inflammatory markers like C-reactive protein and IL-6, which in turn can suppress HDL-C levels. This suggests that moderate intake may offer anti-inflammatory benefits, while overconsumption may reverse them.

Filtered vs. Unfiltered, Additives, and Caffeine: What’s Missing

While the study provides rich insights, it also acknowledges key limitations. It does not differentiate between brewing methods (filtered vs. unfiltered), which significantly affect diterpene content. Nor does it control for additives like sugar, milk, or cream—common accompaniments that could also influence lipid levels. Additionally, the role of caffeine versus decaf remains unclear due to a limited sample of decaffeinated coffee drinkers.

A Call for Balanced Consumption

The study concludes with a cautionary yet balanced message: while coffee may offer some cardiovascular benefits, especially in moderation, excessive consumption poses measurable risks, particularly in raising LDL-C and total cholesterol.

Clinicians, nutritionists, and public health policymakers should consider these nuanced findings when issuing dietary advice. Importantly, recommendations should account for individual cardiovascular risk profiles, gender differences, and consumption patterns.

Why This Study Matters

This research is among the most comprehensive of its kind, using nationally representative U.S. data over 15 years and robust statistical methods including restricted cubic spline regression and sensitivity analyses. With cardiovascular disease still a leading cause of death globally, understanding the subtle ways in which dietary habits like coffee consumption shape our health is crucial.

For coffee lovers, the takeaway is not to quit the habit—but to drink wisely. For healthcare professionals, it offers fresh insights into how one of the world’s most consumed beverages could be a tool—or a trap—depending on how it’s used.

Summary: Coffee consumption influences blood lipid levels in complex, gender-specific ways. While moderate intake may boost “good” cholesterol and offer some protection, heavy consumption appears to raise “bad” cholesterol and total cholesterol. The balance of benefit versus risk may depend on how much—and how—you drink.

Explore the full study here.

We’re thrilled to continue our “Barista Terminology” series on QahwaWorld.com—your go-to resource for mastering the craft of coffee. In Episode 9, we delve into the art of Sensory Evaluation, the professional practice of tasting coffee with intention and precision. From aroma and acidity to mouthfeel and aftertaste, this episode introduces the essential language baristas use to evaluate quality and uncover the unique character of every cup. Whether you’re developing your palate or deepening your sensory skills, these terms are key to truly understanding coffee.

Tasting coffee is more than just a sip — it’s a professional process of assessing aroma, flavor, texture, and aftertaste. Sensory evaluation allows baristas to identify quality, detect defects, and appreciate the depth of a coffee’s profile. In this episode, we explore the essential sensory terms used to describe and evaluate coffee in the most refined way.

1. Aroma

The smell of brewed coffee. It includes notes like floral, fruity, nutty, spicy, caramel, and chocolate. Aroma gives the first impression of a coffee’s character.

2. Flavor

The overall combination of taste and aroma. A complete flavor profile considers acidity, sweetness, bitterness, and balance.

3. Acidity

Often misunderstood — acidity is a positive trait when it brings brightness and vibrancy to the cup. It can be described as crisp, lively, or juicy.

4. Sweetness

A natural taste that softens acidity and bitterness. Sweetness suggests proper ripening and careful processing.

5. Bitterness

A basic taste that can add depth when balanced but becomes unpleasant if overpowering. Often linked to dark roasts or over-extraction.

6. Balance

The harmony between acidity, sweetness, and bitterness. A balanced cup has no single dominant trait.

7. Complexity

Describes a coffee with multiple, distinct flavors that unfold over time — for example, a mix of berries, spices, and floral notes.

8. Body

The physical weight or texture of coffee in the mouth. It can be light, medium, or full-bodied.

9. Mouthfeel

The tactile experience of coffee on the palate — creamy, smooth, gritty, or watery.

10. Aftertaste

The flavor that remains after swallowing. Can be pleasant (sweet, clean) or undesirable (bitter, ashy).

11. Clarity

How distinctly the coffee’s flavors are perceived. High clarity reveals the true nature of the bean and origin.

12. Clean Aftertaste

A lingering finish that leaves no off-flavors. Indicates proper processing and brewing.

13. Intensity

Refers to the strength or vividness of the flavor. A high-intensity coffee is bold and expressive; low intensity may feel flat or muted.

14. Uniformity

Consistency across multiple cups or sips of the same brew. Important in cupping and quality control.

15. Defects

Unpleasant flavors like moldy, fermented, or rubbery notes. Usually caused by poor processing, storage, or roasting.

 

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A new scientific breakthrough has uncovered a novel use for one of coffee’s most overlooked by-products. Researchers from Chiang Mai University have demonstrated that coffee parchment, the papery husk surrounding coffee beans, can serve as a functional feed additive in aquaculture — with significant benefits for Nile tilapia.

Published in the peer-reviewed journal Scientific Reports, the study shows that incorporating modest amounts of coffee parchment into fish feed not only improves growth and feed efficiency but also strengthens the immune system and enhances gut microbiota. The findings align with broader sustainability goals by transforming coffee waste into a valuable asset for the aquaculture sector.

Turning Coffee Waste into Aquafeed

Coffee parchment, a fibrous layer removed during the post-harvest process, makes up around 12% of the coffee cherry’s weight and is typically discarded. Despite its rich content of fiber and bioactive compounds such as polyphenols, caffeine, and flavonoids, its potential applications have remained largely untapped — until now.

In this eight-week feeding trial, scientists evaluated the effects of varying levels of parchment (0, 5, 10, 20, and 40 grams per kilogram of feed) on 300 Nile tilapia fingerlings reared in a biofloc system, an environmentally friendly aquaculture method that recycles organic matter through microbial activity.

Growth and Immunity Enhanced at Optimal Doses

The results were striking. Fish that received 5 g/kg of coffee parchment (CP5 group) exhibited:

• Significant increases in weight gain and feed conversion efficiency

• Higher survival rates

• Upregulation of genes linked to growth, such as ghrelin and galanin

Importantly, the CP5 group also showed marked improvement in immune responses:

• Elevated lysozyme and peroxidase activity in both skin mucus and blood serum

• Enhanced expression of immune-related genes including IL-1β, TNF-α, NFkB, and MHC II-α

Regression analysis identified an optimal dosage range of 15.06–19.86 g/kg, beyond which the benefits declined, likely due to the high fiber content limiting nutrient absorption.

A Healthier Gut Microbiome

The study also revealed profound effects on the fish gut microbiome. Notably:

• The CP10 group displayed the highest microbial diversity

• A significant reduction in Proteobacteria, a phylum associated with inflammation

• An increase in Cetobacterium, a beneficial genus linked to vitamin B12 production and improved digestion

These changes suggest that coffee parchment may act as a prebiotic, supporting a healthier intestinal environment — a key determinant of fish health and performance.

Environmental and Economic Implications

With global coffee production expected to exceed 172 million 60-kg bags in 2024–25, the industry generates an estimated 6 million tons of organic waste each year. The majority of this by-product ends up in landfills or is incinerated.

By repurposing parchment for aquaculture feed, this research offers a scalable solution that:

• Reduces environmental waste

• Cuts feed costs in fish farming

• Supports a circular economy by reintegrating agro-industrial by-products

The Role of Biofloc Systems

The integration of coffee parchment was especially effective in the biofloc system, which is gaining popularity for its ability to minimize environmental impact while improving nutrient cycling.

In this study, coffee parchment not only served as a feed additive but also contributed carbon to the floc environment, stimulating microbial activity and reducing nitrogen waste — reinforcing its role as a dual-function input.

Next Steps for Validation

While the results are promising, the authors note that further studies are needed:

• In commercial aquaculture settings

• Over longer production cycles

• Including pathogen challenge tests to confirm disease resistance benefits

They also recommend exploring higher dosage thresholds and metabolomic analyses to better understand how coffee parchment modulates fish physiology.

Conclusion

This pioneering research opens the door to a sustainable, science-backed application of coffee waste — one that benefits aquaculture, reduces environmental burden, and adds value to the global coffee supply chain. Coffee parchment, once a discarded husk, may soon find itself at the center of a greener, more efficient food system.

Study Reference:
Hien Van Doan et al., “Impacts of coffee parchment on growth, immunity, and gut microbiota of Nile tilapia in biofloc system,” Scientific Reports (2025) 15:25057. https://doi.org/10.1038/s41598-025-03109-1

A groundbreaking study reveals how just two afternoon cups of coffee can disrupt deep sleep and reshape brain activity — especially in young adults.

If you’re in the habit of enjoying coffee in the afternoon, you might want to reconsider. A recent study conducted by researchers at the University of Montréal and published in Communications Biology found that even moderate doses of caffeine after midday can significantly alter how the brain functions during sleep — particularly in the crucial non-REM stages, which are responsible for the body’s restoration.

The study goes far beyond typical sleep hygiene advice. It details, with scientific precision, how caffeine affects the structure of brain activity and highlights age-related differences in how this stimulant disrupts our sleep cycles.

Inside the Study: How It Was Conducted

The research team recruited 40 healthy adults aged between 20 and 58, all with moderate caffeine habits. Each participant spent two nights at a sleep lab under carefully controlled conditions:

• On one night, participants consumed 200 mg of caffeine — the equivalent of about two cups of coffee.

• On the other, they were given a placebo.

• Neither the participants nor the researchers knew which treatment was administered on which night (a double-blind study).

During both nights, the team monitored each subject’s brain activity using electroencephalography (EEG) — a tool that captures electrical signals in the brain while sleeping.

A Hyperactive Brain During Sleep

The EEG readings revealed remarkable changes when participants consumed caffeine:

• Brain signals were more random and complex, especially during non-REM sleep, which is the stage where deep rest and body repair typically occur.

• Brain activity appeared to resemble a “critical state,” a condition of heightened responsiveness often seen during wakefulness.

• Non-REM sleep became shallower, reducing the depth and effectiveness of recovery.

“Caffeine delays but does not prevent sleep,” said lead researcher Prof. Philipp Thölke. “Even though we can sleep under the influence of caffeine, the brain — and therefore also sleep — is impacted. It leads to shallower sleep with increased information processing during the sleep stages where the brain normally enters deep restorative rest.”

Younger Adults Are More Vulnerable

Interestingly, the study found that age plays a major role in how caffeine impacts sleep. Among participants:

• Younger adults (ages 20–27) were more strongly affected during REM sleep, the stage associated with dreaming and emotional processing.

• Older participants (ages 41–58) showed less disruption during REM, which researchers believe may be due to age-related changes in adenosine receptors — brain structures that regulate sleep pressure.

Caffeine blocks adenosine receptors, which is how it keeps us alert. Since older adults have fewer of these receptors, caffeine’s effects are somewhat blunted in this group — at least during REM sleep. However, the disruption of non-REM sleep was observed across all age groups.

Why This Matters

While caffeine is consumed daily by billions, this study highlights that even a modest amount taken after noon can significantly alter the structure and quality of sleep. Over time, this can contribute to:

• Chronic fatigue

• Weakened immune function

• Impaired memory and cognitive performance

• Increased risk of heart disease, diabetes, and mood disorders

Sleep experts have long warned that sleep is not just about duration — depth and brain rhythm are equally important, and caffeine interferes with both.

Important Caveats

• The study was conducted exclusively on healthy adults with no diagnosed sleep disorders.

• It may not apply to people with neurological or psychiatric conditions like Parkinson’s disease, insomnia, or anxiety.

• Individual sensitivity to caffeine varies and may be influenced by genetics and long-term habits.

Final Takeaway: Rethinking Your Coffee Cutoff Time

So when should you stop drinking coffee? While there’s no universal answer, this study reinforces a common rule of thumb: avoid caffeine after noon if you want to ensure deeper, more restorative sleep.

You don’t need to give up coffee — but you should be mindful of when you consume it.

Sources

• Original Study – Communications Biology (Nature)

• University of Montréal Press Release

• PsyPost: Study Summary

We’re excited to continue our “Barista Terminology” series on QahwaWorld.com—your guide to mastering essential coffee concepts and café communication. In Episode 8, we shift our focus from brewing tools to human connection, exploring the key customer service terms that shape the hospitality experience in cafés. From “dine-in” to “guest experience,” this episode breaks down the language baristas use to ensure service is smooth, professional, and warmly memorable. Whether you’re new behind the bar or refining your service style, these terms are the foundation of great customer interaction.

Great coffee is only part of the café experience. How a barista communicates with guests — from the moment they enter to the moment they leave — defines hospitality. In this episode, we explore key customer service terms and phrases used in café environments to ensure efficiency, clarity, and warmth in daily interactions.

1. Dine-In

A customer who will enjoy their coffee at the café. Orders are typically served in ceramic cups.

2. Takeaway

A customer who wants their order to-go. Drinks are usually served in disposable cups.

3. Order Queue

The list or sequence of pending orders. Helps baristas organize workflow and prioritize drinks.

4. Call Out

Announcing a customer’s name or order when it’s ready. Often used in busy cafés to avoid confusion.

5. Modifiers

Customizations or changes a customer requests, such as extra milk, decaf, no sugar, or plant-based alternatives.

6. Double

A request for a double shot of espresso instead of a single — common in milk-based drinks like lattes.

7. Upselling

A polite suggestion to enhance the customer’s order, such as adding a pastry, using premium beans, or upgrading to a larger size.

8. Regulars

Customers who visit frequently and are familiar with the menu and staff. Building rapport with them improves loyalty and atmosphere.

9. Allergen Alert

Flagging ingredients like nuts, soy, or dairy that may cause allergic reactions. Essential for customer safety.

10. Wait Time

Estimated time a customer will wait for their order. Good communication reduces frustration and manages expectations.

11. Customer Flow

Refers to the pattern of how customers move through the café — from entrance, to order point, to pickup or seating. Important for layout and efficiency.

12. Smile in the Voice

A service expression meaning to speak warmly and helpfully, especially when customers cannot see your face (e.g., over the phone or behind a mask).

13. Bar Call

Communication between baristas (e.g., “Double cappuccino for here!”). Helps coordinate timing and clarity.

14. Last Call

A final notice before closing time, informing customers that the café will close soon and last orders should be placed.

15. Guest Experience

The overall impression a customer has from their visit — includes service, cleanliness, friendliness, and coffee quality.

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In the world of specialty coffee, few words are praised as often — and understood as little — as “balance.” Baristas champion it. Roasters chase it. Judges score it. But what does balance in coffee really mean?

To the untrained ear, balance may sound like neutrality, a lack of extremes. But to the sensory professional or curious enthusiast, balance is something much deeper — a dynamic harmony between opposing forces: sweet and bitter, acidic and smooth, sharp and mellow. It is not about muting flavors but orchestrating them.

From Biology to the Brew: Understanding Taste

Our experience of balance begins with biology. The human tongue detects four primary tastes: sweet, sour, salty, and bitter. Each is sensed more intensely in specific regions of the tongue — sweetness at the tip, bitterness at the back, and saltiness and sourness along the sides.

But coffee, like wine, is more than the sum of its taste parts. It is shaped by interactions — modulations — that change how we perceive those core flavors. Acidity can amplify sweetness, salt can mellow bitterness, and sugar can mask sharp sour notes. These taste interactions are where the magic of balance begins.

The Six Modulations: Crafting a Cohesive Cup

According to sensory research and practices endorsed by the Specialty Coffee Association, six primary taste interactions determine the flavor profile of a cup:

1. Acids + Sugars → Acidy
   A bright, juicy cup — like a lightly roasted Ethiopian — where acidity enhances fruity sweetness.

2. Salts + Sugars → Mellow
   Found in low-acid or Brazilian coffees, where natural salts soften sharpness and smooth out the flavor.

3. Sugars + Acids → Winey
   Prominent in fermented or honey-processed coffees. Sweetness softens acidity, evoking wine or dried fruit notes.

4. Sugars + Salts → Bland
   When sugar dominates too much, the cup feels flat and underwhelming. Complexity is lost.

5. Acids + Salts → Sharp
   A common issue in underdosed espresso or overly bright brews. Lacking sweetness, the acidity and saltiness clash.

6. Salts + Acids → Soury
   Overly mineral-heavy or dark roasted coffees may dampen acidity, leading to a dull finish.

These modulations aren’t just curiosities. They’re tools for roasters, baristas, and tasters who want to shape a balanced experience. And they underscore a critical truth: balance isn’t accidental — it’s engineered.

The Roaster’s Role: Designing for Balance

In the roastery, balance begins with green coffee selection. A washed Guatemalan coffee with bright acidity may be paired with a naturally processed Brazil for body and sweetness. Roast curves are carefully adjusted to retain or mute specific acids. Post-roast, blending becomes a strategic act of flavor engineering.

And yet, balance is not reserved for blends. A single-origin can be balanced too — if the inherent sugars, acids, and salts are in the right proportion, and the roast development nurtures their harmony.

Barista and Brewer: The Final Sculptor

Once roasted, brewing becomes the final step in modulating balance. Brew ratio, temperature, grind size, and water quality all influence how each taste emerges. Too coarse, and sweetness is lost. Too fine, and bitterness overwhelms. A well-calibrated pour-over reveals not only the origin but also the balance that was coaxed throughout the process.

Why Balance Matters

In coffee competitions, balance is often the deciding factor between a high-quality cup and a great one. It reflects a coffee’s completeness — a seamless transition from start to finish, with no single note dominating. A balanced cup feels structured, intentional, and elegant.

For everyday drinkers, balance matters because it makes coffee enjoyable. A well-balanced brew is more forgiving, more memorable, and more emotionally satisfying. It doesn’t fatigue the palate or require explanation. It simply feels “right.”

Final Brew Thought

As coffee drinkers, we’ve learned to praise complexity and intensity. But complexity without balance can feel chaotic. True balance is the mark of craftsmanship — from farm to roastery to cup.

In the words of seasoned cuppers, the best coffee doesn’t just taste good — it feels whole.