Ask LH: How Much Coffee Is Too Much?

Dear Lifehacker, I'd love a clear explanation of caffeine and how much is good/healthy/safe for a typical adult. I love coffee and tea but have moderated my intake for concern of its affect on my health. From davo10101


Dear davo10101,

Caffeine is indeed a stimulant, psychoactive drug (just like MDMA or methamphetamines) and like any other drug it has been proven to be highly addictive. As the saying goes, however, the dose makes the poison, so it is worthwhile to question just how much caffeine someone can consume in a day without experiencing adverse health effects.

Most health professionals recommend somewhere between 300mg and 400mg, depending on your body weight and personal tolerance to caffeine. So how many cups of coffee can you drink within this limit? ABC's Fact File on caffeine quotes the following average caffeine amounts for some of the most popular consumables containing the substance:

•Tea (black, green or white) — 30 to 100mg (depending on type and strength of brew) •Coffee (instant) 150ml cup — 60 to 100mg •Coffee (espresso) 150ml cup — 40 to 90mg (depending on the beans used and the strength of the brew) •Coffee (drip-percolated) 150ml cup — 100 to 150mg (depending on the beans used and the strength of the brew) •Coffee (decaffeinated) 150ml cup — 3mg •Cocoa and hot chocolate drink 150ml — 10 to 70mg (depending on type of chocolate used and the strength of the drink) •Chocolate bar - 30g — 20 to 60mg •Cola drink 375ml — 35mg •Energy drink — 80mg (on average but there are some with up to 300mg)

Indeed, some studies have suggested that caffeine is not necessarily bad for you in the right doses. Indeed it can have a number of beneficial effects as most coffee-drinkers would already know. One 1987 study tested the effect of a low dose of caffeine (in a range of 32, 64, 128 and 256 mg) on people's performance and mood and found that even the smallest dose, equating to less than the amount of caffeine in an average cup of coffee, improved both these factors. Even at the highest dose of 256mg, no adverse effects — such as anxiety or impaired physical functioning — were detected. From this study you could say that a few cups of coffee a day would be fine for your health — which is true, as long as you're not consuming caffeine on a regular basis. The matter of caffeine dependence and tolerance from extended consumption still has to be taken into account.

One study on caffeine dependence identified 16 people suffering from caffeine dependence out of a sample size of 99. However, their median daily caffeine intake sat around 357mg — well within the recommended 300 to 400mg dosage as listed above. In the second part of the study where they tested the subjects for caffeine withdrawal, eight of 11 showed functional impairment without their daily dose of caffeine. Studies have shown that as little as a single cup of coffee can be enough to get you dependent on coffee, with withdrawal symptoms like headaches, muscle pain and stiffness, lethargy, nausea, vomiting, depressed mood, and marked irritability a distinct possibility.

For more info, check out this video that gets into the nitty gritty of what caffeine is doing to your body. According to the video, caffeine doesn't become toxic unless you've had around 75 cups of coffee — but that doesn't mean that any more than three cups is highly recommended for daily consumption.

The verdict? A couple of cups of coffee a day won't kill you, but taking a break now and then will probably benefit your overall health. Try swapping coffee for tea on the weekends when mental alertness isn't as important, or check out a few of the ways you can keep yourself awake and aware without relying on caffeine.

Cheers, Lifehacker


Comments

    "and like any other drug it has been proven to be highly addictive."

    Sorry, come again? Drug =/= addictive...

    "•Tea (black, green or white) — 30 to 100mg (depending on type and strength of brew)"
    >> Try swapping coffee for tea on the weekends

    What?

      I feel like that's probably allowing for the strongest possible brew. By most estimates, tea generally has half to a third as much caffeine as coffee - though you could always go for a caffeine free blend of either.

    How many articles on "How much coffee is too much" are too much? Right now a good dozen really seemed like way too many. Didn't need a thirteenth.

    a while back my brother who gives blood regularly was not able to due to low iron levels, this was a surprise as he is very fit and maintains a healthy diet and lifestyle. In determining the cause of his low iron wasn't the quantity per se, but the timing of his caffeine in take. He was drinking coffee with most of his daily meals which had a compounding affect on his vitamin and iron absorption.

    This is pointed out in the Red Cross blood donation literature/leaflet on page 6;
    http://www.donateblood.com.au/files/pdfs/Why%20iron%20and%20haemoglobin%20are%20important%20June%202012.pdf
    Page 6;
    how can combinations of food improve iron absorption?
    The absorption of the non-haem iron in a meal can be improved by consuming with:
    – vitamin C (ascorbic acid) - found in oranges, berries, kiwi fruit, grapefruit, tomato, broccoli, and capsicum. Sources of vitamin C are often at their iron-richest when raw, lightly cooked or steamed.
    – organic acids - found in grapes, tomato, citrus fruits and pineapple
    – foods containing haem iron are there foods that reduce iron absorption?

    Substances which reduce iron absorption if consumed with or within an hour following a meal, include:
    – calcium found in dairy and soy products
    – polyphenols found in tea, coffee, cocoa and red wine (inhibit absorption of non-haem iron only)
    – oxalic acid found in spinach, rhubarb and sweet potato
    – phytates found in cereals and legumes

    Is spinach a good source of iron?
    Spinach is a source of non-haem iron which is not as easily absorbed as haem iron. It also contains oxalic acid which reduces iron absorption. It is therefore especially important to
    combine spinach with vitamin C-rich foods and haem sources of iron, and avoid consuming with other inhibitors such as milk or caffeine drinks.
    -----

    There are numerous sites that talk about the same thing;
    - http://allaboutvitaminc.com/vitamin-c-absorption-coffee/
    - http://www.fitday.com/fitness-articles/nutrition/vitamins-minerals/the-effect-of-caffeine-on-vitamin-absorption.html

    Over the long term it could have an affect on your performance if you don't have enough iron in your blood to move oxygen about, reducing your energy, as well as reducing calcium levels for your bones.

    So drink your coffee with morning and afternoon breaks and not with meals/supplements.

    When the world starts blurring around the edges, one cup more and you should be good.

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