Is drinking coffee/caffeine bad for your kidneys?

This is a question that often comes up when I see patients in my office for treatment of chronic kidney disease (CKD). As always, I tend to emphasize the huge role that diet plays in the management of CKD. I noticed that my recent posts might be becoming too wordy, so I am going to keep myself very brief today!


Ever since coffee was discovered over a millennium ago in Ethiopia, pages upon pages have been written about the myriad health effects of caffeine. Being a psychoactive substance, caffeine has been regulated and even banned for multiple reasons ranging from the religious, to its effect on "overstimulating the senses". Books have been written about even the "sexual hysteria" it could cause! 


But lets talk about it from an objective, health perspective. I am going to restrict myself to the cardiovascular and renal effects of coffee (the effects of coffee are dose dependent; please note that a single, 8 oz cup of coffee has about 100-200 mg of caffeine). 


Image courtesy of amenic181/ FreeDigitalPhotos.net



CARDIOVASCULAR EFFECTS, BLOOD PRESSURE, AND KIDNEY DISEASE

There is some evidence that caffeine can cause momentary increases in the blood pressure (up to 10 mm Hg), especially in people who are not habitual coffee drinkers. However, this effect is enhanced in the elderly, and people who have underlying hypertension. Beyond this short lived spike in blood pressure, there is some data that caffeine could have a long term chronic effect on raising the blood pressure as well.

Given hypertension's deleterious effects on the kidneys', it would seem plausible that moderating caffeine intake could indirectly have a beneficial effect on the kidneys. However, despite the possibility of these kidney damaging effects of caffeine that would "make sense", the evidence has not quite panned out that way. And so, if we look at the aggregate data available at this time, it would appear that consuming the equivalent of 3-4 cups of coffee daily does not increase the risk of kidney disease. This applies to the average person. There still are special situations like kids and the elderly where caution needs to be taken given the other cardiovascular and diuretic effects. A similar rider might also apply to people who are at risk of forming kidney stones. 


My take home message: if you don't fit any of the special categories mentioned above, it is probably safe to consume moderate amounts of coffee from a kidney standpoint! 


Nephrology
Bradenton / Sarasota, FL

Comments

  1. I have stage 3 CKD/Failure-- I'm not sure, based on what you wrote here, whether drinking moderate amounts of coffee is safe for me, or would be detrimental to my kidneys... could you please elaborate and address those with CKD?? Thanks!

    ReplyDelete
    Replies
    1. Regular coffee, under 4 cups per day does not have a direct deleterious effect on the kidneys. However, if you suffer from high blood pressure, caffeine intake does worsen blood pressure control, so you might need to watch that.
      Thanks!

      Delete
  2. I have ckd stage 3, and due to my hypertension, I decided not to take coffee or tea anymore since it raises my blood pressure, but Dr. Chauhan, what about decaffeinated coffee or tea (not dark)?

    ReplyDelete
  3. only 1 kidney left, is coffee bad for me sir/doc?

    ReplyDelete
    Replies
    1. The questions that need to be first answered is whether you have any residual renal dysfunction in the solitary kidney, and do you have high blood pressure. If not, moderate consumption should not be a problem.

      Delete
  4. i ingest around 800mg of caffeine a day, I have been battling Angioedema lately, can that be linked to kidney damage from too much caffeine. I have been supplementing with ginger root and that seems to keep the angioedema and hives at bay... what are your thoughts on this?

    ReplyDelete
    Replies
    1. Has your kidney function been objectively assessed? What is your GFR? Regardless of the cause, kidney damage will worsen edema in general.
      Angioedema however can also be from an allergic response, independent of kidney disease

      Delete
  5. I have CKD Stage 3B and high BP which is controlled somewhat by meds. Will 3 to 4 cups of Joe a day do more damage to my kidneys?

    ReplyDelete
    Replies
    1. We do not have good evidence that is does. As long as BP is well controlled

      Delete

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