This is the fourth in a four-part series of how what we drink affects bladder health including urinary incontinence and OAB
Over the last few days, we have covered the possible impact of alcohol, caffeine, citric acid and sodas on bladder symptoms. Today, I want to discuss how the total volume of fluid we take in can impact bladder symptoms and cover more about what really is a healthy amount of water to drink.
It is difficult to discuss recommended daily fluid consumption without pointing out that most of the advice and recommendations that we are exposed to is more marketing than science (for example, “8 – 8oz glasses of water per day”). In fact, it is not possible to make a general recommendation on fluid intake because so many factors affect our need for water including age, gender, diet, body mass, activity level and environment. And some of these factors are forever changing. Would you really expect to require the same amount of water if you were living in Minneapolis in January versus New Orleans in July (or almost any other month)? Water is essential for life so hydration is important for us to function normally. Consequently, we have very sensitive mechanisms for controlling our water balance. Total body water can be maintained at a normal level across a range of activities and environments. Internal signals including thirst drive us to maintain normal hydration.
Often cited as a reason for extra water intake is the need to “detoxify” the body. Search for “detox water” and you will find numerous recipes promoted to cleanse the body of toxins. In reality, we have very robust mechanisms in the kidneys, liver and intestines for excreting toxins that normally form in the body and need to be eliminated. There is simply no scientific evidence that increasing water intake above normal hydration levels allows any more effective or efficient removal of these toxins. Excessive water intake is not “detoxifying”.
With that out of the way, can reduction of fluid intake have an effect on overactive bladder (OAB) symptoms including urinary frequency, urgency or incontinence? Over years of reviewing thousands of volume-based voiding diaries, I have noticed that most patients with OAB do not take in excessive fluids. In fact, many patients have reduced fluid intake to quite extreme levels to reduce the frequency of trips to the bathroom. Yet there are several studies that suggest that decreasing fluid intake can have substantial impacts on the number of voids and incontinence episodes.
I am always cautious in how I counsel my OAB patients regarding fluid intake. We always base our discussions on a volume-based 3-day diary so that we can evaluate their true urine output, not just how much water they are drinking. After all, it’s the amount of urine produced that matters to bladder symptoms.
If total urine output is already low, I don’t recommend further restriction. Consuming extra fluid beyond thirst may provide no benefits but restricting water when you are thirsty can be dangerous. In addition, many of the medications that we use to treat OAB can be constipating and further promotion of constipation with excessive fluid restriction can be problematic. Patients with a history of kidney stones may also need to avoid fluid restriction as most guidelines suggest that they should drink enough fluid to produce 2-3 liters of urine per day.
However, those patients who are not at particular risk from dehydration and have not already restricted fluid intake may see benefits from reducing fluid intake moderately. However, I do recommend continuing to drink when they are thirsty (remember those sensitive mechanisms for maintaining normal body water). And I have them maintain a diary of urine output periodically to check their urine output (rather than just focusing on fluid intake).
Hopefully, over the past few posts, I have provided some insight as to the wide range of impacts that what we drink can have on bladder symptoms, particularly for those who suffer from overactive bladder (OAB). I hope that the theme of moderation has been clear throughout. It is often easier to maintain changes in what we eat and drink when they are reductions, rather than eliminations.