At NutriChem, we don’t chase influencer headlines, we look at the science.
Lately, coffee has become a trendy health & wellness “boogeyman”: it raises cortisol, disrupts circadian rhythms, and supposedly derails your health. But does scientific evidence actually support this? Let’s unpack the nuance, starting with some basics about cortisol.
Coffee and Cortisol: The Real Story
Cortisol naturally peaks in the morning, helping us feel alert and ready to take on the day. Some studies show that caffeine can raise cortisol, particularly in people who don’t consume it regularly. But in habitual coffee drinkers, this effect is far less pronounced and usually remains within normal physiological ranges. In some cases, caffeine may even support the healthy morning cortisol rise that aligns with circadian rhythm.
What does this mean? For most people, one morning cup of coffee is simply not “burning out” their adrenals as so many internet personalities would have you believe. It’s often actually giving you a boost that your body is primed for in the morning anyway.
How Caffeine Works
Caffeine, most commonly found in coffee and teas, is the world’s most consumed psychoactive compound. Studies have shown that 60%-70% of Canadians and Americans consume coffee daily. Since its introduction to Europe in the 1700s, coffee has played a major role in the shaping of the Western World, allowing for shift work through the night, and keeping office workers focused and on task. The “coffee break” concept was not introduced in workplaces to truly give workers an unproductive “break” in their work; managers knew that consuming moderate quantities of caffeine significantly increased productivity.
Pharmacologically, caffeine exerts its effects by blocking adenosine receptors in the brain and nervous system. Normally, adenosine builds up in our bloodstream throughout the day as we exert ourselves, making us feel sleepy. By blocking these receptors, caffeine promotes wakefulness, attention, and improved reaction time.
Individual response depends on genetics; variations in the ADORA2A gene mean some people are more sensitive to caffeine’s stimulating effects. That explains why your friend can drink an espresso after dinner and sleep fine, while you’re still staring at the ceiling at midnight.
Benefits of Coffee (When Used Wisely)
- Cognitive performance: Low-to-moderate doses (50–200 mg caffeine) improve alertness, vigilance, and reaction time.
- Physical performance: Doses above ~200 mg enhance endurance, strength, and time-to-exhaustion, making caffeine a staple for athletes.
- Antioxidant powerhouse: Coffee is a major source of dietary antioxidants, which help combat oxidative stress and support metabolic and cardiovascular health.
- Metabolic effects: Caffeine increases fat metabolism by raising blood glycerol and free fatty acid levels, thanks to metabolites like paraxanthine.
When Coffee Can Backfire
- High doses: Beyond ~300–400 mg per day (3–4 cups), caffeine is more likely to cause anxiety, palpitations, appetite suppression, and energy crashes.
- Late consumption: Coffee after 2 p.m. can delay melatonin release by up to 40 minutes, making it harder to fall asleep.
- Individual tolerance: If coffee triggers jitters, chest tightness, or worsens anxiety, your body may not metabolize caffeine efficiently.
- Medication interactions: Caffeine can interfere with antibiotics, thyroid medication, and blood pressure drugs, among others. If you drink your coffee with dairy in it, be sure to space it out from your iron supplements by a few hours, otherwise the dairy could impair the absorption of iron.
Questions to Ask Yourself
- How much are you drinking? One morning cup may help; four throughout the day may harm.
- When are you drinking it? Earlier (i.e. before 12pm noon) is better for sleep quality.
- How do you feel afterward? Calm focus = good sign; racing heart/anxiety = time to reassess.
Bottom Line
Coffee is not inherently “good” or “bad.” Like any drug, it depends how humans use it. For many, that morning ritual supports energy, focus, and even long-term health. For others, especially those sensitive to stimulants or struggling with sleep and anxiety, it may be worth adjusting timing, dose, or switching to decaf. Overall though, the scientific consensus in large-scale meta-analyses and systematic reviews “is that moderate coffee intake is more beneficial than harmful across a wide range of health outcomes” (Emadi and Kamangar 2025).
At NutriChem, we strip away the guilt and simplify the science: your morning cup can be part of a healthy lifestyle if it works for your body. Before you ditch your ritual, ask: is coffee really the culprit, or is the problem how I use it?
Helpful Resources
Caffeine Content Table
| Coffee Type | Serving Size | Caffeine (approx) |
|---|---|---|
| Drip Coffee (home) | 8 oz (240 mL) | 80 - 120 mg |
| Starbucks - Tall | 12 oz (355 mL) | ~235 mg |
| Starbucks - Grande | 16 oz (473 mL) | ~310 mg |
| Starbucks - Venti | 20 oz (591 mL) | ~415 mg |
| Nespresso - Espresso | 40 mL (shot) | 55 - 65 mg |
| Nespresso - Lungo | 110 mL | 77 - 85 mg |
| Nespresso - Vertuo Mug | 230 mL | 170 - 200 mg |
Coffee Pairing Options for Targeted Benefits:
| Goal | Pairing | Why It Works |
|---|---|---|
| Reduce Jitters | 1 capsule Phosphogabamine (L-theanine + phosphatidylserine) | L-theanine balances caffeine’s stimulating effect, reducing anxiety and jitters. Phosphatidylserine may support focus and cognitive performance. |
| Curb Appetite Loss | Collagen peptides | Adds easily digestible protein, helping stabilize blood sugar and maintain satiety without feeling too “wired.” |
| Boost Antioxidants | Mushroom & antioxidant blend - Focus Fuel Coffee | Adaptogenic mushrooms can enhance antioxidant capacity and support resilience against stress. |
| Promote Bowel Movements | GI Rescue | Supports digestion and motility, helping coffee’s natural pro-motility effect work more effectively. |
References
Barbagallo, Massimo, et al. “Coffee Consumption Correlates with Better Cognitive Performance in Patients with a High Incidence for Stroke.” Journal of the American Heart Association, vol. 14, no. 1, 2024, Article e034365, https://doi.org/10.1161/JAHA.124.034365.
Dodd FL, Kennedy DO, Riby LM, Haskell-Ramsay CF. A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology (Berl). 2015 Jul;232(14):2563-76. doi: 10.1007/s00213-015-3895-0. Epub 2015 Mar 13. PMID: 25761837; PMCID: PMC4480845.
Emadi RC, Kamangar F. Coffee’s Impact on Health and Well-Being. Nutrients. 2025 Aug 5;17(15):2558. doi: 10.3390/nu17152558. PMID: 40806142; PMCID: PMC12348139.
Haskell CF, Kennedy DO, Milne AL, Wesnes KA, Scholey AB. The effects of L-theanine, caffeine and their combination on cognition and mood. Biol Psychol. 2008 Feb;77(2):113-22. doi: 10.1016/j.biopsycho.2007.09.008. Epub 2007 Sep 26. PMID: 18006208.
Kobylińska Z, Biesiadecki M, Kuna E, Galiniak S, Mołoń M. Coffee as a Source of Antioxidants and an Elixir of Youth. Antioxidants (Basel). 2025 Feb 27;14(3):285. doi: 10.3390/antiox14030285. PMID: 40227264; PMCID: PMC11939571.
National Coffee Data Trends Report 2025. More Americans Drink Coffee Each Day than Any Other Beverage, Bottled Water Back in Second Place. [(accessed on 1 August 2025)]. Available online:
https://www.ncausa.org/Newsroom/More-Americans-Drink-Coffee-Each-Day-Tha….
Planning Committee for a Workshop on Potential Health Hazards Associated with Consumption of Caffeine in Food and Dietary Supplements; Food and Nutrition Board; Board on Health Sciences Policy; Institute of Medicine. Caffeine in Food and Dietary Supplements: Examining Safety: Workshop Summary. Washington (DC): National Academies Press (US); 2014 Apr 23. 5, Caffeine Effects on the Cardiovascular System. Available from: https://www.ncbi.nlm.nih.gov/books/NBK202224/
Reichert CF, Deboer T, Landolt HP. Adenosine, caffeine, and sleep-wake regulation: state of the science and perspectives. J Sleep Res. 2022 Aug;31(4):e13597. doi: 10.1111/jsr.13597. Epub 2022 May 16. PMID: 35575450; PMCID: PMC9541543.
Statistics Canada Review Article 2023: Stats for the Bean Counters [accessed August 25th, 2025]. Available Online: https://www.statcan.gc.ca/o1/en/plus/4627-stats-coffee-bean-counters
Tom M. McLellan, John A. Caldwell, Harris R. Lieberman, A review of caffeine’s effects on cognitive, physical and occupational performance, Neuroscience & Biobehavioral Reviews,
Volume 71, 2016, Pages 294-312, ISSN 0149-7634, https://doi.org/10.1016/j.neubiorev.2016.09.001.
Vundrala Sumedha Reddy, S. Shiva, Srinidhi Manikantan, Seeram Ramakrishna,
Pharmacology of caffeine and its effects on the human body, European Journal of Medicinal Chemistry Reports, Volume 10, 2024, 100138,ISSN 2772-4174, https://doi.org/10.1016/j.ejmcr.2024.100138.
National Coffee Data Trends Report 2025. More Americans Drink Coffee Each Day than Any Other Beverage, Bottled Water Back in Second Place. [(accessed on 1 August 2025)]. Available online:
https://www.ncausa.org/Newsroom/More-Americans-Drink-Coffee-Each-Day-Tha….
