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1. Shard Calculation

Query:

Response:

Calculated Shard: 92 (from laksa146)

2. Crawled Status Check

Query:

curl -X POST \
  'http://laksa092.int.ahrefs:8124/' \
  -H 'Content-Type: text/plain' \
  -H 'X-ClickHouse-Database: crawler3' \
  -H 'Authorization: Basic YXBpOg==' \
  -d 'SELECT getAhrefsURLFromUnparsed(src_unparsed) AS found_url, ifNull(toUnixTimestamp(download_stamp), 0) AS crawl_time, ifNull(toUnixTimestamp(props_url_first_seen), 0) AS first_indexed_time, download_http_code AS http_code, src_unparsed AS src_unparsed, src_root_hash AS src_root_hash, history_drop_reason AS history_drop_reason, meta_title AS meta_title, meta_descriptions AS meta_descriptions, attrs_boilerpipe_text AS attrs_boilerpipe_text, attrs_markdown AS attrs_markdown, attrs_readable_markdown AS attrs_readable_markdown, meta_canonical AS meta_canonical FROM crawler3.page_info_local FINAL PREWHERE (src_root_hash, src_unparsed) IN ((getAhrefsRootHashFromUnparsed(getAhrefsUnparsedNoserviceFromURL(\'https://www.zmescience.com/medicine/how-much-coffee-07022013/\')), getAhrefsUnparsedNoserviceFromURL(\'https://www.zmescience.com/medicine/how-much-coffee-07022013/\'))) FORMAT JSONEachRow'

Response:

{"found_url":"https:\/\/www.zmescience.com\/medicine\/how-much-coffee-07022013\/","crawl_time":1776021359,"first_indexed_time":1507150761,"http_code":200,"src_unparsed":"com,zmescience!www,\/medicine\/how-much-coffee-07022013\/ s443","src_root_hash":"14543206048787838692","history_drop_reason":null,"meta_title":"How much coffee is too much? A new study shows 3 cups is maximum","meta_descriptions":["The apparently evergrowing consumption of coffee and caffeinated products continues to worry scientists, and until now, a maximum safety level had not"],"attrs_boilerpipe_text":"The apparently evergrowing consumption of coffee and caffeinated products continues to worry scientists, and until now, a maximum safety level had not been established.\nA common story\nWhen Matthew Penbross woke on a morning in August 2007, he wanted to be prepared. A natural desire, considering he was competing in the motocross races near Port Macquarie, Australia; to pump up and improve his reactions, he drank a few Red Bull’s, just as he usually did.\nAfter the first race however, he wasn’t feeling so well. He started feeling sharp chest pains, but despite these, he went on to actually win a race that day; 20 minutes after that, his heart stopped. He had no history of drug consumption or family history of heart disease – but he did drink a few energy drinks almost each day.\nThe number of stories like this has increased greatly in the past year – as have the sales, and the concern level, sometimes with coffee instead of the energy drink.\n“People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs. Caffeine is a stimulant and, when consumed at high enough levels, can have negative effects.\nHow much is too much\nIf you take the word of coffee and energy drink producers, their products are perfectly safe. Monster energy has always been a firm supporter of this idea:\n“Neither the science nor the facts support the allegations that have been made. Monster reiterates that its products are and have always been safe.”\nBut this is pretty much just not true.\n“People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs.\nCaffeine safety levels are quite hard to prove. Although scientists have established the toxic dose to be somewhere around 10 g, they say that the value can fluctuate depending on how a person processes the stimulant. Caffeine is filtered and eliminated through the body at different rates depending on each one’s metabolic system. Furthermore, physiological differences, as well as differences in the way people consume caffeine, have tied FDA in knots as it has debated how to regulate the substance.\nSmall, occasional quantities of coffee generally pose no threat for health and are actually benefic, but once this becomes a habit, and then, an addiction – this all starts to turn around.\n×\n“Whereas low-dose caffeine effects are wakefulness, a little bit of arousal, and slight euphoria,” Fredholm says, “high-dose effects are anxiety, irritation, and general mental discomfort—a completely different kettle of fish.”\nThose effects are extremely dangerous, especially considering how the mechanism is not exactly well understood.\n“High-dose caffeine effects are much more complex,” Fredholm explains. “It’s still unknown precisely what the primary mechanism of action is in the brain and elsewhere.”\nCoffee producers will argue that the toxic level of caffeine, 10 g, is roughly the equivalent of imbibing 75 cups of brewed coffee – way over what people drink. But the toxic dose is not what you want to look at here, because it’s not the toxicity of the coffee per se that you want to avoid. There is a high variability depending on sex, other drug usage and many other factors, but the previous belief was that levels up to 600 mg of pure caffeine (four to seven cups of coffee) each day should not pose any significant danger.\nA more accurate safety level\nA team at Health Canada, a government regulatory agency, reviewed more than 200 studies about caffeine’s effects on human health; this was the biggest study of the kind ever conducted. Their conclusions?\nThey concluded that 400 mg of caffeine per day (or about three 8-oz cups of brewed coffee) is a safe dose for healthy adults to consume, and below this level, the average user should not experience any health problem, and only vague psychological effects.\nThe team also set a limit of 2.5 mg per kg body weight per day for children. For an average 10-year-old in the U.S., that’s about 75 mg of caffeine, or two 12-oz cans of Coca-Cola.\nSource","attrs_markdown":"[![ZME Science](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2022\/12\/zme-logo-small-1.webp)](https:\/\/www.zmescience.com\/)\n\nNo Result\n\nView All Result\n\n[![ZME Science](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2022\/12\/zme-logo-small-1.webp)](https:\/\/www.zmescience.com\/)\n\nHow much coffee is too much? A new study shows 3 cups is maximum\n\n[Share](https:\/\/www.zmescience.com\/medicine\/how-much-coffee-07022013\/ \"Share this article\")\n\nShare this article\n\n[Facebook](https:\/\/www.facebook.com\/sharer\/sharer.php?u=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[X](https:\/\/twitter.com\/intent\/tweet?text=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum&url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[LinkedIn](https:\/\/www.linkedin.com\/sharing\/share-offsite\/?url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[Reddit](https:\/\/reddit.com\/submit?url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F&title=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum)\n\n[WhatsApp](https:\/\/api.whatsapp.com\/send?text=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum%20https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[Flipboard](https:\/\/share.flipboard.com\/bookmarklet\/popout?v=2&title=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum&url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[Bluesky](https:\/\/bsky.app\/intent\/compose?text=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum%20https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[Email](mailto:?subject=Check%20out%3A%20How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum&body=How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum%0A%0Ahttps%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[Copy Link](https:\/\/www.zmescience.com\/medicine\/how-much-coffee-07022013\/)\n\n[Comments](https:\/\/www.zmescience.com\/medicine\/how-much-coffee-07022013\/#comments-anchor)\n\n[![](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2022\/12\/zme-logo-small-1.webp)![ZME Science](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2022\/12\/zme-logo-small-1.webp)](https:\/\/www.zmescience.com\/)\n\n[Home](https:\/\/www.zmescience.com\/) → [Health](https:\/\/www.zmescience.com\/medicine\/) → [Diseases](https:\/\/www.zmescience.com\/medicine\/diseases-medicine\/)\n\n# How much coffee is too much? A new study shows 3 cups is maximum\n![Mihai Andrei](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2023\/02\/Andrei-Mihai-1024x1024-1-150x150.png)\n\n![Mihai Andrei](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2023\/02\/Andrei-Mihai-1024x1024-1-150x150.png)\n\nby[Mihai Andrei](https:\/\/www.zmescience.com\/author\/osamik\/)\n\n[February 7, 2013](https:\/\/www.zmescience.com\/medicine\/how-much-coffee-07022013\/)\n\nin [Diseases](https:\/\/www.zmescience.com\/medicine\/diseases-medicine\/), [Health](https:\/\/www.zmescience.com\/medicine\/)\n\nA A\n\nA\n\nA\n\nReset\n\nThe apparently evergrowing consumption of coffee and caffeinated products continues to worry scientists, and until now, a maximum safety level had not been established.\n\n### A common story\n[![coffee](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2013\/02\/coffee.jpg)](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2013\/02\/coffee.jpg)When Matthew Penbross woke on a morning in August 2007, he wanted to be prepared. A natural desire, considering he was competing in the motocross races near Port Macquarie, Australia; to pump up and improve his reactions, he drank a few Red Bull’s, just as he usually did.\n\nAfter the first race however, he wasn’t feeling so well. He started feeling sharp chest pains, but despite these, he went on to actually win a race that day; 20 minutes after that, his heart stopped. He had no history of drug consumption or family history of heart disease – but he did drink a few energy drinks almost each day.\n\nThe number of stories like this has increased greatly in the past year – as have the sales, and the concern level, sometimes with coffee instead of the energy drink.\n\n> “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs. Caffeine is a stimulant and, when consumed at high enough levels, can have negative effects.\n### How much is too much\nIf you take the word of coffee and energy drink producers, their products are perfectly safe. Monster energy has always been a firm supporter of this idea:\n\n> “Neither the science nor the facts support the allegations that have been made. Monster reiterates that its products are and have always been safe.”\n\nBut this is pretty much just not true.\n\n> “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs.\n\nCaffeine safety levels are quite hard to prove. Although scientists have established the toxic dose to be somewhere around 10 g, they say that the value can fluctuate depending on how a person processes the stimulant. Caffeine is filtered and eliminated through the body at different rates depending on each one’s metabolic system. Furthermore, physiological differences, as well as differences in the way people consume caffeine, have tied FDA in knots as it has debated how to regulate the substance.\n\nSmall, occasional quantities of coffee generally pose no threat for health and are actually benefic, but once this becomes a habit, and then, an addiction – this all starts to turn around.\n\n×\n\n## Get smarter every day...\nStay ahead with ZME Science and subscribe.\n\n## Thank you! One more thing...\nPlease check your inbox and confirm your subscription.\n\n> “Whereas low-dose caffeine effects are wakefulness, a little bit of arousal, and slight euphoria,” Fredholm says, “high-dose effects are anxiety, irritation, and general mental discomfort—a completely different kettle of fish.”\n\nThose effects are extremely dangerous, especially considering how the mechanism is not exactly well understood.\n\n[![coffee2](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2013\/02\/coffee2.jpeg) ![coffee2](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2013\/02\/coffee2.jpeg)](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2013\/02\/coffee2.jpeg)\n\n> “High-dose caffeine effects are much more complex,” Fredholm explains. “It’s still unknown precisely what the primary mechanism of action is in the brain and elsewhere.”\n\nCoffee producers will argue that the toxic level of caffeine, 10 g, is roughly the equivalent of imbibing 75 cups of brewed coffee – way over what people drink. But the toxic dose is not what you want to look at here, because it’s not the toxicity of the coffee per se that you want to avoid. There is a high variability depending on sex, other drug usage and many other factors, but the previous belief was that levels up to 600 mg of pure caffeine (four to seven cups of coffee) each day should not pose any significant danger.\n\n### Related**Posts**\n[When organ donation meets religion](https:\/\/www.zmescience.com\/medicine\/when-organ-donation-meets-religion\/)\n\n[Trump is ordering a sweeping censorship of science, starting with climate and health](https:\/\/www.zmescience.com\/science\/trump-is-ordering-a-sweeping-censorship-of-science-starting-with-climate-and-health\/)\n\n[Cash 4 Weight Loss programme shown to work and make people excited about exercise](https:\/\/www.zmescience.com\/medicine\/rewards-for-exercise-works\/)\n\n[Tips for Staying Healthy as You Age](https:\/\/www.zmescience.com\/medicine\/tips-staying-healthy-age\/)\n### A more accurate safety level\nA team at Health Canada, a government regulatory agency, reviewed more than 200 studies about caffeine’s effects on human health; this was the biggest study of the kind ever conducted. Their conclusions?\n\nThey concluded that 400 mg of caffeine per day (or about three 8-oz cups of brewed coffee) is a safe dose for healthy adults to consume, and below this level, the average user should not experience any health problem, and only vague psychological effects.\n\nThe team also set a limit of 2.5 mg per kg body weight per day for children. For an average 10-year-old in the U.S., that’s about 75 mg of caffeine, or two 12-oz cans of Coca-Cola.\n\n[Source](http:\/\/cen.acs.org\/articles\/91\/i5\/Caffeine-Jitters.html)\n\n[![Add ZME Science as a preferred source on Google Search](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2025\/12\/Preferred_source_publisher_butto.width-1000.format-webp.webp) ![Add ZME Science as a preferred source on Google Search](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2025\/12\/Preferred_source_publisher_butto.width-1000.format-webp.webp)](https:\/\/www.google.com\/preferences\/source?q=https:\/\/www.zmescience.com)\n\n[![Follow ZME Science on Google News](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2025\/12\/3128386d62367110cebacf04b3d00b3e1738087212514.png)![Follow ZME Science on Google News](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2025\/12\/3128386d62367110cebacf04b3d00b3e1738087212514.png)](https:\/\/news.google.com\/publications\/CAAqKQgKIiNDQklTRkFnTWFoQUtEbnB0WlhOamFXVnVZMlV1WTI5dEtBQVAB?hl=en-US&gl=US&ceid=US%3Aen)\n\nTags: [coffee](https:\/\/www.zmescience.com\/tag\/coffee\/)[health](https:\/\/www.zmescience.com\/tag\/health\/)\n\n![Mihai Andrei](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2023\/02\/Andrei-Mihai-1024x1024-1-150x150.png)\n\n![Mihai Andrei](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2023\/02\/Andrei-Mihai-1024x1024-1-150x150.png)\n\n### [Mihai Andrei](https:\/\/www.zmescience.com\/author\/osamik\/)\nDr. Andrei Mihai is a geophysicist and founder of ZME Science. He has a Ph.D. in geophysics and archaeology and has completed courses from prestigious universities (with programs ranging from climate and astronomy to chemistry and geology). He is passionate about making research more accessible to everyone and communicating news and features to a broad audience.\n\n### Related **Posts**\n[![A woman holding a smiling baby close to her face, both enjoying a tender moment.](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2026\/03\/jonathan-borba-RWgE9_lKj_Y-unsplash-350x250.jpg) ![A woman holding a smiling baby close to her face, both enjoying a tender moment.](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2026\/03\/jonathan-borba-RWgE9_lKj_Y-unsplash-350x250.jpg)](https:\/\/www.zmescience.com\/other\/economics\/american-maternal-health-is-in-a-state-of-emergency-a-higher-minimum-wage-could-save-the-lives\/)\n\n[Economics](https:\/\/www.zmescience.com\/other\/economics\/)\n\n### [American Maternal Health Is in a State of Emergency. A Higher Minimum Wage Could Save Lives](https:\/\/www.zmescience.com\/other\/economics\/american-maternal-health-is-in-a-state-of-emergency-a-higher-minimum-wage-could-save-the-lives\/)\nby[Mihai Andrei](https:\/\/www.zmescience.com\/author\/osamik\/)\n\n[1 month ago](https:\/\/www.zmescience.com\/other\/economics\/american-maternal-health-is-in-a-state-of-emergency-a-higher-minimum-wage-could-save-the-lives\/)\n\n[![1\\. Elephant bathing in river amidst rocks and greenery.](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2026\/01\/Sitting_Asian_elephant_Elephas_maximus_bathing_in_Tad_Lo_river_Laos-350x250.jpg) ![1\\. 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All Rights Reserved.\n\nShare\n\nSHARE THIS ARTICLE\n\n×\n\n[Facebook](https:\/\/www.facebook.com\/sharer\/sharer.php?u=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[X (Twitter)](https:\/\/twitter.com\/intent\/tweet?url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F&text=How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum)\n\n[LinkedIn](https:\/\/www.linkedin.com\/sharing\/share-offsite\/?url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[Reddit](https:\/\/reddit.com\/submit?url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F&title=How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum)\n\n[WhatsApp](https:\/\/api.whatsapp.com\/send?text=How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum%20https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[Flipboard](https:\/\/share.flipboard.com\/bookmarklet\/popout?v=2&url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F&title=How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum)\n\n[Bluesky](https:\/\/bsky.app\/intent\/compose?text=How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum%20https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[Email](mailto:?subject=How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum&body=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F)\n\n[Copy Link](https:\/\/www.zmescience.com\/medicine\/how-much-coffee-07022013\/)\n\n[Comments](https:\/\/www.zmescience.com\/medicine\/how-much-coffee-07022013\/#comments-anchor)","attrs_readable_markdown":"The apparently evergrowing consumption of coffee and caffeinated products continues to worry scientists, and until now, a maximum safety level had not been established.\n\n### A common story\n[![coffee](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2013\/02\/coffee.jpg)](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2013\/02\/coffee.jpg)When Matthew Penbross woke on a morning in August 2007, he wanted to be prepared. A natural desire, considering he was competing in the motocross races near Port Macquarie, Australia; to pump up and improve his reactions, he drank a few Red Bull’s, just as he usually did.\n\nAfter the first race however, he wasn’t feeling so well. He started feeling sharp chest pains, but despite these, he went on to actually win a race that day; 20 minutes after that, his heart stopped. He had no history of drug consumption or family history of heart disease – but he did drink a few energy drinks almost each day.\n\nThe number of stories like this has increased greatly in the past year – as have the sales, and the concern level, sometimes with coffee instead of the energy drink.\n\n> “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs. Caffeine is a stimulant and, when consumed at high enough levels, can have negative effects.\n### How much is too much\nIf you take the word of coffee and energy drink producers, their products are perfectly safe. Monster energy has always been a firm supporter of this idea:\n\n> “Neither the science nor the facts support the allegations that have been made. Monster reiterates that its products are and have always been safe.”\n\nBut this is pretty much just not true.\n\n> “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs.\n\nCaffeine safety levels are quite hard to prove. Although scientists have established the toxic dose to be somewhere around 10 g, they say that the value can fluctuate depending on how a person processes the stimulant. Caffeine is filtered and eliminated through the body at different rates depending on each one’s metabolic system. Furthermore, physiological differences, as well as differences in the way people consume caffeine, have tied FDA in knots as it has debated how to regulate the substance.\n\nSmall, occasional quantities of coffee generally pose no threat for health and are actually benefic, but once this becomes a habit, and then, an addiction – this all starts to turn around.\n\n×\n\n> “Whereas low-dose caffeine effects are wakefulness, a little bit of arousal, and slight euphoria,” Fredholm says, “high-dose effects are anxiety, irritation, and general mental discomfort—a completely different kettle of fish.”\n\nThose effects are extremely dangerous, especially considering how the mechanism is not exactly well understood.\n\n[![coffee2](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2013\/02\/coffee2.jpeg)](https:\/\/cdn.zmescience.com\/wp-content\/uploads\/2013\/02\/coffee2.jpeg)\n\n> “High-dose caffeine effects are much more complex,” Fredholm explains. “It’s still unknown precisely what the primary mechanism of action is in the brain and elsewhere.”\n\nCoffee producers will argue that the toxic level of caffeine, 10 g, is roughly the equivalent of imbibing 75 cups of brewed coffee – way over what people drink. But the toxic dose is not what you want to look at here, because it’s not the toxicity of the coffee per se that you want to avoid. There is a high variability depending on sex, other drug usage and many other factors, but the previous belief was that levels up to 600 mg of pure caffeine (four to seven cups of coffee) each day should not pose any significant danger.\n\n### A more accurate safety level\nA team at Health Canada, a government regulatory agency, reviewed more than 200 studies about caffeine’s effects on human health; this was the biggest study of the kind ever conducted. Their conclusions?\n\nThey concluded that 400 mg of caffeine per day (or about three 8-oz cups of brewed coffee) is a safe dose for healthy adults to consume, and below this level, the average user should not experience any health problem, and only vague psychological effects.\n\nThe team also set a limit of 2.5 mg per kg body weight per day for children. For an average 10-year-old in the U.S., that’s about 75 mg of caffeine, or two 12-oz cans of Coca-Cola.\n\n[Source](http:\/\/cen.acs.org\/articles\/91\/i5\/Caffeine-Jitters.html)","meta_canonical":null}

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Meta Title	How much coffee is too much? A new study shows 3 cups is maximum
Meta Description	The apparently evergrowing consumption of coffee and caffeinated products continues to worry scientists, and until now, a maximum safety level had not
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Boilerpipe Text	The apparently evergrowing consumption of coffee and caffeinated products continues to worry scientists, and until now, a maximum safety level had not been established. A common story When Matthew Penbross woke on a morning in August 2007, he wanted to be prepared. A natural desire, considering he was competing in the motocross races near Port Macquarie, Australia; to pump up and improve his reactions, he drank a few Red Bull’s, just as he usually did. After the first race however, he wasn’t feeling so well. He started feeling sharp chest pains, but despite these, he went on to actually win a race that day; 20 minutes after that, his heart stopped. He had no history of drug consumption or family history of heart disease – but he did drink a few energy drinks almost each day. The number of stories like this has increased greatly in the past year – as have the sales, and the concern level, sometimes with coffee instead of the energy drink. “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs. Caffeine is a stimulant and, when consumed at high enough levels, can have negative effects. How much is too much If you take the word of coffee and energy drink producers, their products are perfectly safe. Monster energy has always been a firm supporter of this idea: “Neither the science nor the facts support the allegations that have been made. Monster reiterates that its products are and have always been safe.” But this is pretty much just not true. “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs. Caffeine safety levels are quite hard to prove. Although scientists have established the toxic dose to be somewhere around 10 g, they say that the value can fluctuate depending on how a person processes the stimulant. Caffeine is filtered and eliminated through the body at different rates depending on each one’s metabolic system. Furthermore, physiological differences, as well as differences in the way people consume caffeine, have tied FDA in knots as it has debated how to regulate the substance. Small, occasional quantities of coffee generally pose no threat for health and are actually benefic, but once this becomes a habit, and then, an addiction – this all starts to turn around. × “Whereas low-dose caffeine effects are wakefulness, a little bit of arousal, and slight euphoria,” Fredholm says, “high-dose effects are anxiety, irritation, and general mental discomfort—a completely different kettle of fish.” Those effects are extremely dangerous, especially considering how the mechanism is not exactly well understood. “High-dose caffeine effects are much more complex,” Fredholm explains. “It’s still unknown precisely what the primary mechanism of action is in the brain and elsewhere.” Coffee producers will argue that the toxic level of caffeine, 10 g, is roughly the equivalent of imbibing 75 cups of brewed coffee – way over what people drink. But the toxic dose is not what you want to look at here, because it’s not the toxicity of the coffee per se that you want to avoid. There is a high variability depending on sex, other drug usage and many other factors, but the previous belief was that levels up to 600 mg of pure caffeine (four to seven cups of coffee) each day should not pose any significant danger. A more accurate safety level A team at Health Canada, a government regulatory agency, reviewed more than 200 studies about caffeine’s effects on human health; this was the biggest study of the kind ever conducted. Their conclusions? They concluded that 400 mg of caffeine per day (or about three 8-oz cups of brewed coffee) is a safe dose for healthy adults to consume, and below this level, the average user should not experience any health problem, and only vague psychological effects. The team also set a limit of 2.5 mg per kg body weight per day for children. For an average 10-year-old in the U.S., that’s about 75 mg of caffeine, or two 12-oz cans of Coca-Cola. Source
Markdown	[![ZME Science](https://cdn.zmescience.com/wp-content/uploads/2022/12/zme-logo-small-1.webp)](https://www.zmescience.com/) No Result View All Result [![ZME Science](https://cdn.zmescience.com/wp-content/uploads/2022/12/zme-logo-small-1.webp)](https://www.zmescience.com/) How much coffee is too much? A new study shows 3 cups is maximum [Share](https://www.zmescience.com/medicine/how-much-coffee-07022013/ "Share this article") Share this article [Facebook](https://www.facebook.com/sharer/sharer.php?u=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F) [X](https://twitter.com/intent/tweet?text=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum&url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F) [LinkedIn](https://www.linkedin.com/sharing/share-offsite/?url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F) [Reddit](https://reddit.com/submit?url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F&title=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum) [WhatsApp](https://api.whatsapp.com/send?text=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum%20https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F) [Flipboard](https://share.flipboard.com/bookmarklet/popout?v=2&title=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum&url=https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F) [Bluesky](https://bsky.app/intent/compose?text=How+much+coffee+is+too+much%3F+A+new+study+shows+3+cups+is+maximum%20https%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F) [Email](mailto:?subject=Check%20out%3A%20How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum&body=How%20much%20coffee%20is%20too%20much%3F%20A%20new%20study%20shows%203%20cups%20is%20maximum%0A%0Ahttps%3A%2F%2Fwww.zmescience.com%2Fmedicine%2Fhow-much-coffee-07022013%2F) [Copy Link](https://www.zmescience.com/medicine/how-much-coffee-07022013/) [Comments](https://www.zmescience.com/medicine/how-much-coffee-07022013/#comments-anchor) [![](https://cdn.zmescience.com/wp-content/uploads/2022/12/zme-logo-small-1.webp)![ZME Science](https://cdn.zmescience.com/wp-content/uploads/2022/12/zme-logo-small-1.webp)](https://www.zmescience.com/) [Home](https://www.zmescience.com/) → [Health](https://www.zmescience.com/medicine/) → [Diseases](https://www.zmescience.com/medicine/diseases-medicine/) # How much coffee is too much? A new study shows 3 cups is maximum ![Mihai Andrei](https://cdn.zmescience.com/wp-content/uploads/2023/02/Andrei-Mihai-1024x1024-1-150x150.png) ![Mihai Andrei](https://cdn.zmescience.com/wp-content/uploads/2023/02/Andrei-Mihai-1024x1024-1-150x150.png) by[Mihai Andrei](https://www.zmescience.com/author/osamik/) [February 7, 2013](https://www.zmescience.com/medicine/how-much-coffee-07022013/) in [Diseases](https://www.zmescience.com/medicine/diseases-medicine/), [Health](https://www.zmescience.com/medicine/) A A A A Reset The apparently evergrowing consumption of coffee and caffeinated products continues to worry scientists, and until now, a maximum safety level had not been established. ### A common story [![coffee](https://cdn.zmescience.com/wp-content/uploads/2013/02/coffee.jpg)](https://cdn.zmescience.com/wp-content/uploads/2013/02/coffee.jpg)When Matthew Penbross woke on a morning in August 2007, he wanted to be prepared. A natural desire, considering he was competing in the motocross races near Port Macquarie, Australia; to pump up and improve his reactions, he drank a few Red Bull’s, just as he usually did. After the first race however, he wasn’t feeling so well. He started feeling sharp chest pains, but despite these, he went on to actually win a race that day; 20 minutes after that, his heart stopped. He had no history of drug consumption or family history of heart disease – but he did drink a few energy drinks almost each day. The number of stories like this has increased greatly in the past year – as have the sales, and the concern level, sometimes with coffee instead of the energy drink. > “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs. Caffeine is a stimulant and, when consumed at high enough levels, can have negative effects. ### How much is too much If you take the word of coffee and energy drink producers, their products are perfectly safe. Monster energy has always been a firm supporter of this idea: > “Neither the science nor the facts support the allegations that have been made. Monster reiterates that its products are and have always been safe.” But this is pretty much just not true. > “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs. Caffeine safety levels are quite hard to prove. Although scientists have established the toxic dose to be somewhere around 10 g, they say that the value can fluctuate depending on how a person processes the stimulant. Caffeine is filtered and eliminated through the body at different rates depending on each one’s metabolic system. Furthermore, physiological differences, as well as differences in the way people consume caffeine, have tied FDA in knots as it has debated how to regulate the substance. Small, occasional quantities of coffee generally pose no threat for health and are actually benefic, but once this becomes a habit, and then, an addiction – this all starts to turn around. × ## Get smarter every day... Stay ahead with ZME Science and subscribe. ## Thank you! One more thing... Please check your inbox and confirm your subscription. > “Whereas low-dose caffeine effects are wakefulness, a little bit of arousal, and slight euphoria,” Fredholm says, “high-dose effects are anxiety, irritation, and general mental discomfort—a completely different kettle of fish.” Those effects are extremely dangerous, especially considering how the mechanism is not exactly well understood. [![coffee2](https://cdn.zmescience.com/wp-content/uploads/2013/02/coffee2.jpeg) ![coffee2](https://cdn.zmescience.com/wp-content/uploads/2013/02/coffee2.jpeg)](https://cdn.zmescience.com/wp-content/uploads/2013/02/coffee2.jpeg) > “High-dose caffeine effects are much more complex,” Fredholm explains. “It’s still unknown precisely what the primary mechanism of action is in the brain and elsewhere.” Coffee producers will argue that the toxic level of caffeine, 10 g, is roughly the equivalent of imbibing 75 cups of brewed coffee – way over what people drink. But the toxic dose is not what you want to look at here, because it’s not the toxicity of the coffee per se that you want to avoid. There is a high variability depending on sex, other drug usage and many other factors, but the previous belief was that levels up to 600 mg of pure caffeine (four to seven cups of coffee) each day should not pose any significant danger. ### RelatedPosts [When organ donation meets religion](https://www.zmescience.com/medicine/when-organ-donation-meets-religion/) [Trump is ordering a sweeping censorship of science, starting with climate and health](https://www.zmescience.com/science/trump-is-ordering-a-sweeping-censorship-of-science-starting-with-climate-and-health/) [Cash 4 Weight Loss programme shown to work and make people excited about exercise](https://www.zmescience.com/medicine/rewards-for-exercise-works/) [Tips for Staying Healthy as You Age](https://www.zmescience.com/medicine/tips-staying-healthy-age/) ### A more accurate safety level A team at Health Canada, a government regulatory agency, reviewed more than 200 studies about caffeine’s effects on human health; this was the biggest study of the kind ever conducted. Their conclusions? They concluded that 400 mg of caffeine per day (or about three 8-oz cups of brewed coffee) is a safe dose for healthy adults to consume, and below this level, the average user should not experience any health problem, and only vague psychological effects. The team also set a limit of 2.5 mg per kg body weight per day for children. For an average 10-year-old in the U.S., that’s about 75 mg of caffeine, or two 12-oz cans of Coca-Cola. [Source](http://cen.acs.org/articles/91/i5/Caffeine-Jitters.html) [![Add ZME Science as a preferred source on Google Search](https://cdn.zmescience.com/wp-content/uploads/2025/12/Preferred_source_publisher_butto.width-1000.format-webp.webp) ![Add ZME Science as a preferred source on Google Search](https://cdn.zmescience.com/wp-content/uploads/2025/12/Preferred_source_publisher_butto.width-1000.format-webp.webp)](https://www.google.com/preferences/source?q=https://www.zmescience.com) [![Follow ZME Science on Google News](https://cdn.zmescience.com/wp-content/uploads/2025/12/3128386d62367110cebacf04b3d00b3e1738087212514.png)![Follow ZME Science on Google News](https://cdn.zmescience.com/wp-content/uploads/2025/12/3128386d62367110cebacf04b3d00b3e1738087212514.png)](https://news.google.com/publications/CAAqKQgKIiNDQklTRkFnTWFoQUtEbnB0WlhOamFXVnVZMlV1WTI5dEtBQVAB?hl=en-US&gl=US&ceid=US%3Aen) Tags: [coffee](https://www.zmescience.com/tag/coffee/)[health](https://www.zmescience.com/tag/health/) ![Mihai Andrei](https://cdn.zmescience.com/wp-content/uploads/2023/02/Andrei-Mihai-1024x1024-1-150x150.png) ![Mihai Andrei](https://cdn.zmescience.com/wp-content/uploads/2023/02/Andrei-Mihai-1024x1024-1-150x150.png) ### [Mihai Andrei](https://www.zmescience.com/author/osamik/) Dr. Andrei Mihai is a geophysicist and founder of ZME Science. He has a Ph.D. in geophysics and archaeology and has completed courses from prestigious universities (with programs ranging from climate and astronomy to chemistry and geology). He is passionate about making research more accessible to everyone and communicating news and features to a broad audience. ### Related Posts [![A woman holding a smiling baby close to her face, both enjoying a tender moment.](https://cdn.zmescience.com/wp-content/uploads/2026/03/jonathan-borba-RWgE9_lKj_Y-unsplash-350x250.jpg) ![A woman holding a smiling baby close to her face, both enjoying a tender moment.](https://cdn.zmescience.com/wp-content/uploads/2026/03/jonathan-borba-RWgE9_lKj_Y-unsplash-350x250.jpg)](https://www.zmescience.com/other/economics/american-maternal-health-is-in-a-state-of-emergency-a-higher-minimum-wage-could-save-the-lives/) [Economics](https://www.zmescience.com/other/economics/) ### [American Maternal Health Is in a State of Emergency. A Higher Minimum Wage Could Save Lives](https://www.zmescience.com/other/economics/american-maternal-health-is-in-a-state-of-emergency-a-higher-minimum-wage-could-save-the-lives/) by[Mihai Andrei](https://www.zmescience.com/author/osamik/) [1 month ago](https://www.zmescience.com/other/economics/american-maternal-health-is-in-a-state-of-emergency-a-higher-minimum-wage-could-save-the-lives/) [![1\. Elephant bathing in river amidst rocks and greenery.](https://cdn.zmescience.com/wp-content/uploads/2026/01/Sitting_Asian_elephant_Elephas_maximus_bathing_in_Tad_Lo_river_Laos-350x250.jpg) ![1\. Elephant bathing in river amidst rocks and greenery.](https://cdn.zmescience.com/wp-content/uploads/2026/01/Sitting_Asian_elephant_Elephas_maximus_bathing_in_Tad_Lo_river_Laos-350x250.jpg)](https://www.zmescience.com/ecology/animals-ecology/why-elephant-gut-bacteria-makes-coffee-smooth/) [Animals](https://www.zmescience.com/ecology/animals-ecology/) ### [Elephant “poop coffee” is a thing. 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Readable Markdown	The apparently evergrowing consumption of coffee and caffeinated products continues to worry scientists, and until now, a maximum safety level had not been established. ### A common story [![coffee](https://cdn.zmescience.com/wp-content/uploads/2013/02/coffee.jpg)](https://cdn.zmescience.com/wp-content/uploads/2013/02/coffee.jpg)When Matthew Penbross woke on a morning in August 2007, he wanted to be prepared. A natural desire, considering he was competing in the motocross races near Port Macquarie, Australia; to pump up and improve his reactions, he drank a few Red Bull’s, just as he usually did. After the first race however, he wasn’t feeling so well. He started feeling sharp chest pains, but despite these, he went on to actually win a race that day; 20 minutes after that, his heart stopped. He had no history of drug consumption or family history of heart disease – but he did drink a few energy drinks almost each day. The number of stories like this has increased greatly in the past year – as have the sales, and the concern level, sometimes with coffee instead of the energy drink. > “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs. Caffeine is a stimulant and, when consumed at high enough levels, can have negative effects. ### How much is too much If you take the word of coffee and energy drink producers, their products are perfectly safe. Monster energy has always been a firm supporter of this idea: > “Neither the science nor the facts support the allegations that have been made. Monster reiterates that its products are and have always been safe.” But this is pretty much just not true. > “People often don’t understand the potential risk of these beverages,” says Bruce A. Goldberger, director of forensic toxicology at the University of Florida’s pathology labs. Caffeine safety levels are quite hard to prove. Although scientists have established the toxic dose to be somewhere around 10 g, they say that the value can fluctuate depending on how a person processes the stimulant. Caffeine is filtered and eliminated through the body at different rates depending on each one’s metabolic system. Furthermore, physiological differences, as well as differences in the way people consume caffeine, have tied FDA in knots as it has debated how to regulate the substance. Small, occasional quantities of coffee generally pose no threat for health and are actually benefic, but once this becomes a habit, and then, an addiction – this all starts to turn around. × > “Whereas low-dose caffeine effects are wakefulness, a little bit of arousal, and slight euphoria,” Fredholm says, “high-dose effects are anxiety, irritation, and general mental discomfort—a completely different kettle of fish.” Those effects are extremely dangerous, especially considering how the mechanism is not exactly well understood. [![coffee2](https://cdn.zmescience.com/wp-content/uploads/2013/02/coffee2.jpeg)](https://cdn.zmescience.com/wp-content/uploads/2013/02/coffee2.jpeg) > “High-dose caffeine effects are much more complex,” Fredholm explains. “It’s still unknown precisely what the primary mechanism of action is in the brain and elsewhere.” Coffee producers will argue that the toxic level of caffeine, 10 g, is roughly the equivalent of imbibing 75 cups of brewed coffee – way over what people drink. But the toxic dose is not what you want to look at here, because it’s not the toxicity of the coffee per se that you want to avoid. There is a high variability depending on sex, other drug usage and many other factors, but the previous belief was that levels up to 600 mg of pure caffeine (four to seven cups of coffee) each day should not pose any significant danger. ### A more accurate safety level A team at Health Canada, a government regulatory agency, reviewed more than 200 studies about caffeine’s effects on human health; this was the biggest study of the kind ever conducted. Their conclusions? They concluded that 400 mg of caffeine per day (or about three 8-oz cups of brewed coffee) is a safe dose for healthy adults to consume, and below this level, the average user should not experience any health problem, and only vague psychological effects. The team also set a limit of 2.5 mg per kg body weight per day for children. For an average 10-year-old in the U.S., that’s about 75 mg of caffeine, or two 12-oz cans of Coca-Cola. [Source](http://cen.acs.org/articles/91/i5/Caffeine-Jitters.html)
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