Drinking Water to Lower Blood Sugar: Does it Work? How Much?

Carbohydrates are not your enemy. Low- and medium-glycemic carbs from vegetables, fruits, and fiber-filled whole grains, beans, and legumes provide vital nutrients that should be part of a balanced diet. 

However, consuming an excessive amount of carb-heavy foods and drinks can increase blood sugar levels, and chronically elevated glucose over time may lead to metabolic syndrome, insulin resistance and potentially type 2 diabetes.

There are plenty of ways to prevent this from happening, from switching to a low-glycemic diet to exercising regularly. One simple thing everyone at any age can do that may lower blood sugar: Drink more water. 

But, does drinking water really help lower blood sugar? Let’s dive deeper to find out.

Does Drinking Water Lower Blood Sugar?

The quick answer is yes, drinking water may help lower blood sugar. 

Water not only prevents dehydration, but also helps flush out excess sugar through your urine. 

One analysis of data from 3,961 adults who participated in the National Health and Nutrition Examination Survey had their urine analyzed for any potential cross-sectional association between hydration and metabolic dysfunction. The participants with urine specific gravity (a test that shows the concentration of all chemical particles in urine) greater than 1.013 had less favorable metabolic markers. Data analysis also showed that increasing quartiles of urine specific gravity was associated with higher fasting glucose, glycated hemoglobin, and elevated insulin¹.

Another observational study showed that water intake was inversely and independently associated with high blood sugar levels². 

A study conducted on healthy Japanese men and women showed increased health benefits, such as protecting kidney function, diluting blood waste materials, and lowering blood pressure; however, drinking an additional 37 ounces (1100 mL) of water a day did not prove effective in lowering slightly elevated fasting blood glucose levels³. 

Still, drinking water prevents dehydration and promotes healthy metabolism in non-diabetics. 

Dehydration can elevate blood sugar levels due to a higher concentration of glucose in the bloodstream. When you’re dehydrated, your body releases a hormone called vasopressin, which tells your kidneys to retain water instead of flushing out excess glucose in urine. 

One long-term study on more than 4,000 Swedish people showed that an increase in vasopressin in the blood was linked to an increase in insulin resistance⁴ and increased odds in developing type 2 diabetes. 

How Much Water Do You Need Every Day?

Before chugging all of the water, learn how much water you might need to drink each day.

The Institute of Medicine of the National Academies⁵ (from their 2005 report) recommends the following daily average intake of water:

• 2.7 liters (91 ounces) a day of total water for women ages 19-70+
• 3.0 liters (101 ounces) a day of total water for pregnant women ages 14-50
• 3.8 liters (128 ounces) a day of total water for lactating women ages 14-50
• 3.7 liters (125 ounces) a day of total water for men ages 19-70+
  

Active people will likely require additional water or fluids to meet their training needs. The recommendations above include average daily amounts of total liquid intake (from all beverages, water, and water-containing foods) under normal conditions that don’t account for extreme heat and humidity so you may need to make adjustments based on the conditions that day.

While it’s important to drink enough water, it’s possible to drink too much water in a day. Excessive water consumption could cause water intoxication, a rare condition that can occur when the amount of water intake exceeds excretion in the kidney. This could lead to a more serious condition called hyponatremia, which happens when the level of sodium in the blood is too low and the body holds onto too much water. Hyponatremia needs to be treated by a doctor. 

Use the guidelines above to estimate the amount of water you drink each day, adjusting for your activity level and the conditions. 

How Does Drinking Water Lower Blood Sugar?

Drinking water may counter high blood glucose levels by:

• Helping the kidneys flush out extra glucose through urine
• Reducing the risk of overeating 
  

Water can act as a temporary natural appetite suppressant, and may be used as a tool to thwart overeating. The average stomach volume is 2.5 ounces, but it can expand to about 33 ounces in the average adult. Drinking water fills some of that volume, leaving less space for food. 

A study published in the Journal of Natural Science, Biology, and Medicine reported on what happened to a group of overweight women who drank large quantities of water for eight consecutive weeks. The results showed that drinking water contributed to a decrease in body weight and an increase in appetite suppression⁶. 

Be careful to watch what you eat though: If you drink enough water to suppress your appetite, but your meal consists of a tray of pastries, your blood sugar will spike regardless. 

Two of the symptoms of high blood sugar are increased thirst and dryness of the mouth. This is the body’s counteractive mechanism urging you to drink water so it can clear out excess glucose and recalibrate blood glucose concentrations. 

So, by increasing your water consumption, you’ll feel the need to urinate frequently. This can excrete excess sugars from your blood and bring down your glucose levels.

The Effect of Water Temperature

Does the temperature of the water you drink have an effect on the rate at which your blood sugar decreases? For example, does drinking hot water lower blood sugar faster than cold water? Research doesn’t provide any associations or links between water temperature and decreased blood sugar levels.

With regards to the water temperature, here are several points to consider:

1. Drinking water at the temperature you find most comfortable will encourage you to drink optimal quantities.
2. Water temperature may have an effect on cognitive function⁷ in mice models, with water consumed at 77ºF showing better results in mice than water ingested at 32ºF.

<p class="pro-tip"><strong>Learn about </strong> <a href="/blog/weather-affect-metabolic-health">how the temperature outdoors can affect your blood sugar</a>.</p>

What About Caffeinated Drinks?

Some studies suggest that caffeine impairs blood glucose management, although other research indicates that some caffeine is okay. 

In a study conducted on 10 healthy men, it was observed that caffeinated coffee raised blood sugar levels⁸ whether the test subjects ate a high or low glycemic index (GI) meal. However, when these same individuals drank decaffeinated coffee, blood sugar levels did not change as much.

The takeaway: Caffeine affects everyone differently. If you hope to lower your blood sugar levels, it may be a good idea to limit caffeine intake. 

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Beverages to Avoid

To keep glucose levels from spiking, try to drink water with and between meals. Avoid the following beverages:

• Sodas
• Fruit juices
• Energy and sports drinks
• Sweetened tea
• Drinks with high carb content and added sugars
  

If you’re looking for something other than water for an occasional change, try drinking unsweetened versions of these:

• Unsweetened herbal teas
• Vegetable juices
• Milk alternatives, such as oat milk
  

Tips for Drinking More Water

If you don’t like the taste of plain water, there are several easy hacks you can try to increase your fluid intake, such as: 

• Sip carbonated or sparkling water instead of plain. Many naturally flavored sparkling waters provide a bit of fruity flavor without added sugar or artificial sweeteners.
• Add sliced fruit, such as lemons, limes, cucumbers, or strawberries to your water.  
• When fresh mint is available, infuse water with the leaves and stems for a hint of mint refreshment.
• Cinnamon⁹ and powdered probiotics¹⁰ may also help with glucose regulation. Make a mug of herbal or black tea and drop in a cinnamon stick, or whisk in powdered probiotics into any tea or coffee drink. Read more about the benefits of cinnamon here.
• Tea and coffee count toward your total daily water intake. Just keep an eye on your caffeine intake, as some people can experience increased blood sugar from caffeine.
• Fruits and vegetables contain water as well, which also counts toward your total daily intake. Try low-glycemic produce such as celery, lettuce, cucumbers, watercress, zucchini, strawberries, tomatoes, bell peppers, cauliflower, and cabbage.
  

Try drinking more water before, during, and after meals, and adding in more water-packed fruits and veggies to your diet.

Regulating blood sugar can be done at home with a few tweaks to your daily habits.

It starts with adapting a mindset of healthy eating, drinking, and living. Cheers!

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• What Should Your Blood Sugar Be at Bedtime?
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• The Relationship Between Alcohol and Your Blood Sugar

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• Low Glycemic Diet & Tips for Managing Blood Sugar
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