Tag: caffeine research

New Study Reveals Shocking Findings on How Hot and Cold Coffee Affect the Body and Mind

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Dubai – Qahwa World

A groundbreaking study published in the British Journal of Nutrition has uncovered a surprising link between the temperature of beverages—particularly coffee—and human physical and mental health. The research suggests that the difference between a steaming cup of coffee and an iced drink goes far beyond taste, extending to real effects on mood, digestion, and sleep.

Conducted by researchers from San Diego State University, the University of California San Diego, and Wake Forest University under the direction of Professor Tianying Wu, the study involved more than 400 healthy adults of Asian and White backgrounds between the ages of 18 and 65. The goal was to determine how the temperature of foods and drinks affects emotional and physical well-being. Participants reported how often they consumed cold and hot drinks such as water, coffee, tea, milk, and juice, as well as hot and cold meals during summer and winter. They also recorded symptoms related to anxiety, depression, insomnia, and digestive issues such as gas and abdominal fullness.

The results were striking. Among Asian participants, frequent consumption of cold beverages and foods—especially during the summer—was associated with higher levels of anxiety, sleep disturbance, and digestive discomfort. Those who reported having cold hands, an indicator of poor blood circulation, experienced these negative effects more strongly. The findings suggest that cold consumption in warm months may intensify anxiety and insomnia, while no significant benefit was found from hot consumption within this group.

In contrast, White participants showed the opposite trend. Those who preferred hot drinks, particularly during winter, reported fewer symptoms of depression, insomnia, and gastrointestinal discomfort. Regular consumption of hot coffee or tea during colder months was linked to better mood, improved sleep, and reduced bloating or gas. Meanwhile, higher intake of cold drinks and foods corresponded with higher anxiety and poorer sleep, particularly among those with low body warmth or poor circulation.

The researchers note that these findings align with ancient perspectives in traditional Chinese and Ayurvedic medicine, which warn against consuming cold foods and beverages during winter and emphasize the health benefits of warmth. While Western medicine rarely considers temperature as a health factor, this study offers scientific evidence that thermal effects can influence human physiology.

According to the authors, cold drinks can lower core body temperature, slow gut activity, and disrupt the balance of gut microbiota, all of which may impair digestion and mood. Exposure to cold also constricts blood vessels and reduces oxygen flow to the brain, potentially heightening anxiety and disturbing neurotransmitter balance. Conversely, warm drinks stimulate blood circulation, support healthy digestion, and activate the parasympathetic nervous system—responsible for relaxation—thus improving mood stability and sleep quality.

While the study is observational and does not establish causation, the patterns are consistent enough to warrant attention. The researchers emphasize that individual factors—such as poor circulation or cold extremities—can make some people more vulnerable to the negative effects of cold consumption.

Interestingly, even within the Asian group, the differences were notable. Chinese participants, who reported the lowest intake of cold foods and beverages, also showed the fewest symptoms of anxiety, depression, and digestive issues. Indian participants, on the other hand, displayed stronger associations between cold consumption and adverse health outcomes. The study further observed that Asian immigrants who had lived longer in the United States were more likely to adopt Western dietary habits, including higher consumption of cold drinks.

The authors conclude that the temperature of what we eat and drink is not merely a matter of taste—it may influence our physical and mental balance more than we realize. The findings suggest that warm foods and beverages could promote mental and digestive well-being, particularly during colder months or among individuals sensitive to cold. As Professor Tianying Wu stated, “The temperature of what we consume may matter far more than we think—it can subtly influence our mood and health in unexpected ways.”

Global Study: Coffee Reduces Suicidal Thoughts While Energy Drinks Double the Risk

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Dubai, September 17, 2025 (Qahwa World) – Coffee has long been a global symbol of culture, community, and energy. But new scientific evidence now highlights a profound distinction between the world’s favorite caffeinated beverage and the rising wave of energy drinks. A comprehensive study published in the peer-reviewed journal Nutrients by researchers at the National University of Singapore reveals that coffee consumption may significantly reduce the risk of suicide attempts, while energy drink consumption—even in small quantities—appears to heighten it.

The First Global Meta-Analysis of Its Kind

The research team conducted the first systematic review and meta-analysis that examined the links between caffeine intake, suicide attempts, and suicidal ideation. Reviewing 17 studies across 11 countries, involving more than 1.57 million participants, the study provides one of the clearest pictures yet of how different caffeinated beverages can affect mental health.

The results are striking:

Energy drinks – Just one can per month was associated with a measurable increase in suicidal thoughts and behaviors. The risk escalated linearly with higher consumption, peaking among those consuming 21–30 cans per month, who were nearly three times more likely to attempt suicide compared to non-consumers.

Coffee – In contrast, drinking more than 60 cups per month correlated with a significant reduction in suicide risk. Those who consumed between 61–90 cups were 49% less likely to attempt suicide, while individuals drinking 91–120 cups monthly reduced their risk by 43%.

Why Energy Drinks Pose Unique Dangers

Researchers suggest that the harmful impact of energy drinks stems from more than just caffeine. These products typically combine caffeine with other stimulants and large amounts of sugar, creating a powerful cocktail that can overload the nervous system. The study notes that such a combination may trigger anxiety, emotional instability, and sleep disruption—all known risk factors for suicidal ideation.

Adolescents and young adults, who are among the largest consumers of energy drinks, appear especially vulnerable. Previous studies cited in the review have linked energy drink consumption with increased stress, poor academic performance, and risky behaviors. The findings raise urgent public health concerns as energy drinks continue to be aggressively marketed to younger demographics worldwide.

Coffee’s Protective Role and Neurological Pathways

On the other hand, coffee demonstrated a consistent association with lower suicide risk—but only at higher levels of consumption. Scientists point to coffee’s neurochemical effects: caffeine antagonizes adenosine receptors in the brain, boosting the release of neurotransmitters such as dopamine and glutamate. These compounds are closely tied to improved mood, reduced fatigue, and heightened alertness.

The study also connects these findings with earlier research showing that coffee consumption reduces the risk of depression. A 2016 meta-analysis found that every additional daily cup of coffee was linked to an 8% decrease in depression risk, reinforcing coffee’s potential role as a mood stabilizer.

Gender and Lifestyle Factors

The Singaporean researchers also explored other variables. Men were found to consume significantly more energy drinks than women, and this gender gap correlated with higher rates of suicidality among male participants. Societal pressures, risk-taking behaviors, and physiological differences may all contribute to this disparity.

In addition, the study observed that individuals consuming high levels of caffeinated beverages often reported concurrent use of alcohol, cigarettes, or other substances. This overlap suggests that caffeine intake may be part of broader lifestyle patterns, complicating the direct attribution of causality.

Implications for Public Health

While the study stops short of claiming a direct cause-and-effect relationship, its findings carry critical implications. With 700,000 people dying by suicide globally each year, and millions more struggling with suicidal thoughts, identifying modifiable lifestyle factors is an urgent priority.

The protective signal associated with coffee suggests that moderate to high consumption could play a role in supporting mental well-being, though more research is needed to establish thresholds and clarify mechanisms. Conversely, the risks tied to energy drinks highlight the need for public health campaigns, regulatory oversight, and targeted interventions—particularly in protecting adolescents from excessive consumption.

A Beverage Divide with Cultural Resonance

Coffee’s story is centuries old, rooted in Yemen’s Sufi traditions before spreading worldwide as a daily ritual of comfort and connection. Energy drinks, by contrast, are a modern creation of aggressive marketing, synthetic additives, and a promise of instant performance. This study places them on opposite sides of the public health debate: one linked with stability and resilience, the other with heightened risk and vulnerability.

Conclusion

The Singapore study underscores that not all caffeine is created equal. Coffee—consumed by billions daily—may serve as more than just a morning pick-me-up. At higher levels of intake, it appears to buffer against some of the darkest mental health outcomes. Energy drinks, however, show the opposite pattern, fueling concern among scientists, educators, and policymakers.

As the global coffee community celebrates the beverage’s cultural and economic significance, this research adds another layer to coffee’s enduring legacy: a potential ally in the fight for mental health.

German–UK Study Finds Morning Coffee Boosts Positive Mood and Relieves Withdrawal Symptoms

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Dubai – Qahwa World

A new scientific study published in Scientific Reports has revealed that the morning cup of coffee does more than increase alertness: it significantly enhances positive mood, making people feel happier and more enthusiastic in the early hours of the day.

Conducted by researchers from Bielefeld University in Germany and the University of Warwick in the United Kingdom, the study provides strong evidence that caffeine is closely linked to improved well-being, particularly in the morning.

The research tracked 236 adult participants across two separate studies.

  • The first study involved 115 participants over 14 days, resulting in 8,335 individual mood assessments.

  • The second study involved 121 participants over 28 days, generating nearly 19,960 assessments.

Using the Experience Sampling Method (ESM), participants were asked to record their mood seven times a day on their smartphones. They also noted whether they had consumed a caffeinated drink in the previous 90 minutes.

Key Findings

  • Caffeine consumption was strongly associated with higher positive mood (happiness, enthusiasm, and energy), especially during the first 2.5 hours after waking up.

  • The impact on negative mood (feelings such as sadness, anger, or irritation) was minimal and less consistent.

  • Results were consistent across different levels of caffeine intake and were not significantly affected by whether participants reported sleep disturbances, anxiety, or other psychological conditions.

  • Researchers suggested that the morning effect could partly be due to reversal of mild overnight caffeine withdrawal symptoms, as even moderate consumers may wake up experiencing them.

Scientific Explanation

Caffeine improves mood through two main mechanisms:

  1. Blocking adenosine receptors in the brain, reducing drowsiness and boosting alertness.

  2. Stimulating dopamine production, a neurotransmitter known as the “happiness hormone,” which is linked to motivation and reward.

Professor Anu Realo, a co-author of the study, explained:

“Even moderate caffeine consumers may experience mild withdrawal symptoms that disappear with the first cup of coffee in the morning.”

Lead researcher Jostin Hachenberger added that caffeine’s mood-enhancing effect was largely independent of social or psychological factors but could be influenced by physical conditions, such as fatigue.

Critical Notes

  • Since most participants were habitual caffeine consumers, the study could not determine how coffee might affect people who completely avoid caffeine.

  • The findings do not support the claim that caffeine worsens anxiety; rather, the researchers noted that those who are sensitive to caffeine’s negative effects usually self-select out by avoiding it.

Global Context

  • Approximately 80% of adults worldwide consume coffee or tea daily, highlighting the global significance of these findings.

  • Interestingly, caffeine’s appeal is not limited to humans: previous studies have shown that bees and wasps are attracted to nectar containing caffeine, underlining its powerful influence in nature.

Conclusion

The study concludes that the morning cup of coffee is more than just a daily ritual. It has a scientifically measurable impact on enhancing positive mood and boosting emotional well-being, particularly in the hours after waking. While it may not significantly reduce negative emotions such as sadness or anger, its role in fostering happiness, enthusiasm, and energy makes coffee one of the most influential beverages in modern life.