What is a Normal Value for Blood Glucose in Healthy Humans?
Jul 25, 2023In this post, we are going to explore the question: what is a normal value for blood glucose in healthy humans?
For us, as families living with Type 1 diabetes, it is important to know what a normal, non-diabetic blood glucose level is.
When we were at our children’s hospital when our son was first diagnosed with Type 1 diabetes, and the diabetes educator was explaining T1D blood sugar targets, my husband asked: “Wait, what is the blood glucose of someone who doesn’t have diabetes?”.
I still vividly remember him asking that…
‘what a simple yet vital thing for us to know!’. How can we help our son maintain health if we don’t know the steady-state level of blood glucose that a healthy human body naturally maintains?
What Are Normal Blood Glucose Levels in Healthy Humans
Let’s take a look at normal blood glucose levels in healthy humans.
I’m curious: were you told by your diabetes care provider what normal human blood glucose levels are?
When we discuss “normal blood glucose levels”, we tend to talk about it in the fasted state- during the times when we are not eating.
“The human body attempts to maintain homeostasis in blood glucose levels (4 to 6 mmol/l or about 72 to 108 mg/dl).”
In a non-diabetic person, the body will naturally maintain blood glucose levels in this tight and narrow range in order to maintain health. The body must maintain the stability of its internal environment to survive and function properly, and this includes regulation of blood glucose.
As blood is being delivered round the body at all times, from the top of your head to the tip of your toes, it is vital for that blood to be healthy and not contain excess amounts of glucose.
The Importance of Knowing Normal Blood Glucose Levels
Healthy blood is essential for cells and organs to work properly, and chronically high glucose levels lead to diabetic complications. A healthy body knows this, so it regulates glucose constantly through each minute of the day.
How Much Glucose is Actually in Human Blood?
The highest concentration of glucose located in our body is found in the blood stream, yet interestingly, there is estimated to be only 4 grams of glucose or 1 tsp in the blood stream of an adult male weighing 155 lb. There is not a lot of glucose in the blood stream any one point in time in a healthy human!
Varying Definitions of Normal Fasting Glucose
Now you might think it would be fairly easy to know the value of normal blood glucose, but medical leaders, organizations, and researchers give slightly different numbers for normal fasting glucose in healthy humans.
Some organizations provide us with the highest possible number for fasting glucose to be considered normal. You can see in this chart that organizations such as the Centers for Disease Control and Prevention (CDC) in the US, the National Institute for Health and Care Excellence in the United Kingdom, and the Mayo Clinic tell us that all fasting blood glucose values below 100 mg/dl or 5.5 or 5.6 mmol/L are normal.
Other organizations provide a range of values for normal fasting blood glucose.
The World Health Organization declares that “The expected values for normal fasting blood glucose concentration are between 70 mg/dL (3.9 mmol/L) and 100 mg/dL (5.6 mmol/L).”,
While Diabetes UK and Diabetes Singapore share that healthy individuals have normal blood sugar levels between 4.0 to 5.4 mmol/L (72 to 99 mg/dL) when fasting.
Endocrinology researchers and physicians from the UCL Institute of Child Health in the United Kingdom indicate normal fasting blood glucose values for infants, children and adults are between 3.5–5.5ā€…mmol/L, which is equivalent to 63-99 mg/dl.
And Dr. Richard Bernstein tells his patients that a normal blood sugar to shoot for is 83 mg/dl, which is 4.6 mmol/L, and that normal blood sugars in non-diabetic children may be lower.
These reported blood glucose values give us a good idea of where the body likes to be in a balanced, fasted state.
Hemoglobin A1C as a Guide
We can also use results from Hemoglobin A1C tests as a guide for normal blood sugars. These tests measure average blood glucose over a 2–3 month period.
In a study published in 2002 in the Diabetes Care journal, an analysis of almost 8,000 American young people aged 5-24 years, who had not been treated for diabetes, found that the mean A1C of these children and adolescents was 4.99%.
The A1C RANGE among this group of young people was between 4.47% & 5.52%.
Conclusion
As parents of children living with Type 1 diabetes, when we know the normal value of blood glucose in healthy humans, we can set a target for our child’s blood glucose that aims to give us peace of mind for their future.
And yet we are faced with the challenge of managing diabetes while trying to “stay between the lines”, avoiding the potential for a medical emergency from low blood sugars - on one end of the spectrum - and avoiding the awful possibility of diabetic complications from high blood sugars - on the other end.
It can feel like walking a tight rope!
We can’t just decide to aim for normal blood sugars in Type 1 diabetes. We first need to understand how to safely achieve that.
The way to safely strive for normal blood glucose is to ensure your child’s treatment plan has been designed for safety, so you can keep blood glucose as normal as possible without serious high or low blood sugars and more closely align with where the body naturally wants blood glucose to be for optimal health.
And back to my earlier question that I’m curious about: were you told by your diabetes care provider what normal blood glucose levels are?
And what blood glucose targets WERE you given – drop your answers in the comments below.
For more information, visit: https://www.t1dnutrition.com/
For more information about The Nutrition Effect program: https://www.t1dnutrition.com/programs
Get the latest information about Type 1 diabetes by following T1D Nutrition on Facebook: https://www.facebook.com/t1dnutrition/
Check out the T1D Nutrition YouTube Channel: https://www.youtube.com/@t1dnutrition
REFERENCES
Bernstein, R.K. (2011). Dr. Bernstein’s Diabetes Solution: The Complete Guide to Achieving Normal Blood Sugars. New York: Little, Brown and Company.
Güemes, M., Rahman, S.A., & Hussain, K. (2016). What is a normal blood glucose? Archives of Disease in Childhood; 101: 569-574. http://dx.doi.org/10.1136/archdischild-2015-308336
Röder, P. V., Wu, B., Liu, Y., & Han, W. (2016). Pancreatic regulation of glucose homeostasis. Experimental & molecular medicine, 48(3), e219. https://doi.org/10.1038/emm.2016.6
Saddine, J., Fagot-Campagna, A., Rolka, D., Narayan, K.M.V., Geiss, L., Eberhardt, M. & Flegal, K. (2002). Distribution of HbA1c Levels For Children and Young Adults in the U.S. Third National Health and Nutrition Examination Survey. Diabetes Care, 25, 1326-30. 10.2337/diacare.25.8.1326.
Wasserman, D.H. (2009). Four grams of glucose. American Journal of Physiology, Endocrinology and Metabolism, 296(1): E11–E21. doi: 10.1152/ajpendo.90563.2008
CDC: https://www.cdc.gov/diabetes/basics/getting-tested.html
Mayo Clinic: https://www.mayoclinic.org/diseases-conditions/prediabetes/diagnosis-treatment/drc-20355284
WHO: World Health Organization (2023). Mean fasting blood glucose. In The Global Health Observatory. https://www.who.int/data/gho/indicator-metadata-registry/imr-details/2380
Diabetes UK: https://www.diabetes.co.uk/diabetes_care/blood-sugar-level-ranges.html
Diabetes Singapore: https://www.diabetes.org.sg/resource/managing-diabetes/
