Few beverages are as quintessentially American as coffee, though its roots stretch far beyond our morning mugs. It’s a daily ritual for many, but the interplay between coffee and health is as complex as the beverage itself—offering a mix of benefits and risks that hinge on consumption, preparation, and personal health goals.

shallow focus photography of coffee late in mug on table flat lay photography of coffee latte, ground coffee, and coffee beans person holding white ceramic cup with hot coffee

Coffee’s “Big Shots”

Coffee is more than just a delicious morning beverage; its caffeine and antioxidant content give it some big health benefits that make it a no-brainer for Boulder’s biohacking health-centric community. Antioxidants are like the superheroes of your body.  They’re tiny molecules that protect your cells from harm caused by toxins and stress and can also help repair cell damage.

The “big shots” that give coffee its superpower perks are:

Caffeine: Fast-Acting & Long-Lasting

Caffeine is best known for its stimulating effects on the central nervous system. A 12 oz cup of coffee contains between 96 – 260 mg of caffeine, depending on your source. A single espresso shot has 63 mg of caffeine and a cup of decaf coffee has 3 mg.  According to the FDA, up to 400 mg of caffeine a day (1–4 cups of brewed coffee) appears to be safe for most healthy adults, with 200 mg recommended as the maximum dose for pregnant women (1).

black coffee beans and gray mocha pot woman holding clear footed mug about to drink a coffee coffee bean lot

The caffeine in coffee acts rapidly (20% is absorbed in the stomach within 50 minutes) and can be long-lasting (2). Depending on individual diet (e.g., fiber content), metabolism, and genetics, it can take between 2 to 12 hours for half of the caffeine in a cup of coffee to be removed from the body (3). So if you want to improve your sleep, aim to have your last cup of coffee in the morning hours, ideally 12 hours before bedtime.

Other Components of Coffee: Antioxidants, Amino Acids, and …Ash??

CGA and caffeic acid are two of the more potent antioxidants found in coffee. Other beneficial components of coffee include tannins, lignin, amino acids, minerals (e.g., calcium, potassium, sodium, iron, and magnesium), diterpenes (e.g., cafestol and kahweol), prebiotics (including oligosaccharides and melanoidin antioxidants), and fatty elements (e.g., triacylglycerols, and fatty acids)(2). Notably, these components are thought to make up ~4% of coffee’s composition, with the remaining 96% consisting of water, protein, fiber, and ash (2). Ash, you say? You read that right – the roasting process that enhances coffee’s aroma, taste, and antioxidant capacity leaves an ash residue that accounts for ~8% of coffee’s composition (2)!

coffee beans on table coffee, drink, hot

Buzzing with Benefits

A variety of research shows numerous benefits associated with coffee consumption, including (1):

  • Anti-Inflammatory Aces: Coffee’s antioxidant properties make it a potent anti-inflammatory agent that works through the same mechanisms as NSAIDs and Aspirin (e.g., COX inhibition).
  • Weight Loss & Obesity: Coffee can help with weight loss and obesity prevention by reducing adipogenesis and lipid metabolism.
  • Blood Sugar & Diabetes: Coffee can improve glucose tolerance and insulin sensitivity and lower the risk of type 2 diabetes.
  • Anti-Aging: Coffee can have protective effects in the brain and lower the risk of:
    • Parkinson Disease.
    • Cognitive impairment.
    • Dementia.
    • Alzheimer’s Disease.

coffee filled white ceramic mug beside brown coffee beans on beige wooden surface brown pine cone on persons hand

  • Brain Boosting: Coffee can enhance alertness, cognitive performance, and memory.
  • Performance Enhancing: Coffee can have ergogenic effects on muscle endurance, strength, anaerobic power, and aerobic endurance by activating the sympathetic nervous system and increasing the availability of free fatty acids.
  • Heart Health: Coffee may protect against cardiovascular diseases and reduce mortality from heart attack, stroke, high blood pressure, and clogged arteries.
  • Anti-Cancer: Coffee consumption has benefits in the context of breast, colorectal, endometrial, liver, lung, lymphoma, melanoma, pancreatic, and prostate cancers.
  • Immune-Boosting: Coffee’s antioxidant and anti-inflammatory properties provide a natural boost to the immune system.
  • Blood Health: Coffee can improve lipid profile and lower the risk of dyslipidemia.
  • Gut Health: Coffee can modulate the microbes in your gut and have prebiotic effects by stimulating the growth of beneficial microorganisms.
  • Digestion: Some of the acids in coffee can increase the production of stomach acid and digestive hormones, which can speed up the movement of food through the gut. This can help explain the tradition of digestif coffee and after-dinner coffee held in many cultures.

coffee, cup, macbook black coffee beans on brown wooden table

  • Bowel Function: The caffeine content in coffee can stimulate the colon and intestinal muscles, producing the morning  “coffee poop” that many brew junkies relish.

Doppio Drawbacks

Coffee is not without its drawbacks, especially if you drink too much or have certain health conditions. Some of the potential risks of coffee are:

  • Compromised Sleep & Insomnia.
    • Coffee can interfere with sleep quality and quantity, especially if consumed late in the day or close to bedtime. Compromised sleep can affect mood, immunity, metabolism, and overall health.
    • The Mayo Clinic recommends avoiding caffeine for at least six hours before you go to bed. However, a 2023 analysis of all coffee-sleep studies found that drinking coffee – at any time during the day – reduced sleep quality by 7% and reduced sleep time by 45 min on average (range: 24 – 114 min, depending on dose consumed; 400 mg resulting in 1.2h sleep deficit)(4). Drinking later or greater doses of coffee resulted in greater sleep deficits (4).
  • Anxiety.
    • Coffee can cause or worsen anxiety, nervousness, jitteriness, and panic attacks in some people, especially those who are sensitive to caffeine or have anxiety disorders.
    • A recent study found that in healthy individuals, coffee significantly increased the risk of anxiety (5). Consuming low doses of caffeine (.g., <400 mg, ~1 – 4 cups of coffee) moderately increased risk for anxiety and consuming > 400 mg of caffeine strongly increased in risk for anxiety (5).
    • The Mayo Clinic suggests limiting caffeine intake to 100 mg a day (~one 8-oz cup of brewed coffee) if you have anxiety or panic issues.

person pouring coffee into glass  person standing on white line with cup on ground person pouring liquid on drinking glass

  • Gastrointestinal problems.
    • Although coffee can benefit the gut microbiome, its acidity and ash content can irritate the stomach and esophagus, causing heartburn, acid reflux, indigestion, and ulcers.
    • Coffee can also affect your bowel movements, causing diarrhea (through gut stimulation) or constipation (through dehydration).
    • The Mayo Clinic advises drinking less coffee or switching to decaf if you have gastrointestinal issues.
  • Drug interactions.
    • Coffee can interact with some medications and supplements, altering their effectiveness or causing side effects (1). For example, coffee can:
    • Reduce the absorption of iron, calcium, and some antibiotics. Women who are at risk for low iron or osteopenia (e.g., female athletes and elder women) may want to discuss this risk with a clinician or health coach.
    • Increase the effects of some painkillers, antidepressants, and stimulants. Barrea et al., 2023 provide a nice table of coffee-drug interactions (Table 3)(1).
    • The Mayo Clinic recommends checking with your doctor or pharmacist before drinking coffee if you are taking any medications or supplements.

person holding white ZOE brand paper cup Woman Wearing Black Top Holding White Cup Glass cup with splash of coffee in air

  • Potential Toxin Exposure
    • There are three main sources of coffee contamination with possible toxins: roasting, which produces ash and other toxins, soil, water, and air pollution, which are absorbed by coffee plants during growth, and drinking water contamination (1)(6).
    • Two common toxic contaminants found in coffee are Polyaromatic Hydrocarbons (PAHs)and Acrylamide. These toxins can increase risk for:
      • Genetic damage.
      • Cancer (e.g., breast, lung, and colon cancer).
      • Diabetes, cardiovascular disease, autoimmune disorders, and inflammatory processes (all the things the antioxidants in coffee can help reduce).
    •  Other toxins like heavy metals (e.g., lead and cadmium) are thought to exist in coffee in very small doses but can accumulate in the body over time, especially with high consumption. There are currently no regulations about the amount of PAH, Acrylamide, or other toxins that can be included in coffee.

coffee, espresso, latte white muffin tray on top of white ceramic mug white ceramic mug with black liquid

  • High Blood Pressure, Heart Palpitations, & Cardiac Arrythmias
    • Coffee can cause a short but dramatic increase in blood pressure that can be harmful for those who already have hypertension, are prone to cardiovascular problems, or consume coffee after engaging in sustained cardiovascular exercise (when the heart requires rest). The caffeine content in coffee can cause heart palpitations or cardiac arrhythmias. Those with heart issues should discuss this with a doctor.
    • The Mayo Clinic advises limiting caffeine intake to 200 mg per day (about 16 ounces of brewed coffee) for those with high blood pressure or heart disease.
  • Compromised Performance and Recovery
    • The elevation in blood pressure and heart rate that caffeine induces can compromise recovery if coffee is consumed after a large exertion (in which the heart needs to slow down to recover).
    • The caffeine in coffee can also induce vasoconstriction – which can be helpful at low doses but can limit blood oxygen supply if it occurs in excess.
    • Caffeine can also stimulate the adrenal glands to produce and secrete stress hormones like cortisol. This can be good in contexts of cognitive or physical performance, but can also lead to adrenal burnout and fatigue if it impedes adequate recovery time.

man standing near gray tumberls  White Ceramic Mug on Black and Silver Coffee Maker  White Ceramic Mug With Coffee Beans

How to Drink Coffee Wisely

The way you drink coffee can also affect its health impact. Here are some tips to make your coffee habit healthier:

  • Choose filtered coffee. Filtered coffee is brewed with a paper filter that removes some of the compounds that can raise your cholesterol levels and increase your risk of heart disease. Pour overs are great ways to ensure filter use. Unfiltered coffee, such as espresso, French press, or Turkish coffee, contains more of these compounds and should be consumed in moderation. The Mayo Clinic recommends drinking no more than three to four cups of unfiltered coffee a day. In addition to using paper filters, ensure you or your vendor use filtered water also.
  • Avoid added sugar and cream. Sugar and cream can add extra calories, fat, and sugar to your coffee, which can negate its health benefits and contribute to weight gain, diabetes, and other problems. The Mayo Clinic suggests drinking your coffee black or adding a small amount of sugar-free nut milk or a natural sweetener, such as stevia or honey.
  • Drink water. Coffee can dehydrate you, as caffeine is a diuretic that makes you urinate more. Dehydration can cause headaches, fatigue, dry skin, and kidney problems. The Mayo Clinic advises drinking plenty of water throughout the day to stay hydrated and balance your coffee intake.

clear glass coffee pitcher beside turntable White Ceramic Mug With Coffee woman holding cup while looking outside

The Bottom Line

Coffee can be a friend or a foe, depending on how you drink it. Coffee can have many health benefits, such as lowering the risk of some diseases and improving your mood and brain function. However, coffee can also have some health risks, such as raising your blood pressure, disrupting your sleep, and causing anxiety and stomach problems. The key is to drink coffee in moderation, choose filtered coffee, avoid added sugar and cream, and drink water.

Science Says Coffee Promotes Longer Healthy Life

But are the benefits worth the drawbacks and risks? A 2022 study compared the risks and benefits of coffee consumption across multiple scientific studies (Doepker et al., 2022). They found that even when varying the amount and frequency of coffee consumed, coffee consumption was consistently associated with reduced all-cause mortality, meaning that coffee drinkers had a lower chance of dying from any cause than people who did not drink coffee. They also found that drinking more coffee was better than drinking less, up to a point. They estimated that drinking one cup of coffee a day could help you avoid losing 3.35% of your healthy life and drinking three cups daily could help you avoid losing up to 6% of healthfully lived years.

By following these tips, you can enjoy your coffee without compromising your health. So Good Morning Boulder; let’s get our coffee brewing!



  1. Barrea, L., et al. (2023). “Coffee consumption, health benefits and side effects: a narrative review and update for dietitians and nutritionists.” Crit Rev Food Sci Nutr 63(9): 1238-1261. https://pubmed.ncbi.nlm.nih.gov/34455881/.
  2. Ribeiro, M., Alvarenga, L., Cardozo, L. F. M. F., Kemp, J. A., Lima, L.
    S., Almeida, J. S. d., Leal, V. d. O., Stenvinkel, P., Shiels, P. G. and Mafra, D. (2022) The magical smell and taste: Can coffee be good to patients with cardiometabolic disease? Critical Reviews in Food Science and Nutrition, (doi: 10.1080/10408398.2022.2106938).https://eprints.gla.ac.uk/276922/2/276922.pdf
  3. Reddy, Vundrala Sumedha, et al. “Pharmacology of caffeine and its effects on the human body.” European Journal of Medicinal Chemistry Reports (2024): 100138. https://www.sciencedirect.com/science/article/pii/S2772417424000104
  4. Gardiner C, Weakley J, Burke LM, Roach GD, Sargent C, Maniar N, Townshend A, Halson SL. The effect of caffeine on subsequent sleep: A systematic review and meta-analysis. Sleep Med Rev. 2023 Jun;69:101764. doi: 10.1016/j.smrv.2023.101764. Epub 2023 Feb 6. PMID: 36870101. https://pubmed.ncbi.nlm.nih.gov/36870101/.
  5. Liu C, Wang L, Zhang C, Hu Z, Tang J, Xue J, Lu W. Caffeine intake and anxiety: a meta-analysis. Front Psychol. 2024 Feb 1;15:1270246. doi: 10.3389/fpsyg.2024.1270246. PMID: 38362247; PMCID: PMC10867825. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10867825/pdf/fpsyg-15-1270246.pdf.
  6. Mollakhalili, N., et al. (2022). “Potentially toxic elements (PTEs) in coffee: a comprehensive review of toxicity, prevalence, and analytical techniques.” International Journal of Environmental Health Research 34: 1-18. https://www.researchgate.net.
  7. Mayo Clinic (n.d.). Coffee and health: What does the research say? Retrieved April 27, 2021 from: https://microsoftstart.msn.com/en-us/health/ask-professionals/in-expert-answers-on-coffee/in-coffee?questionid=ijgijat8&type=nutrition&source=bingmainline_nutritionqna


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