Should We Monitor Blood Glucose?
Article by Bryony Scutt
Unless yourself, a close friend, or family member experiences conditions such as diabetes, blood sugar levels are unlikely to be on your radar.
However, the prevalence of diabetes is continually rising, and this is a significant challenge to global health and well-being. In 2021, 537 million adults were reported to have diabetes, and this is predicted to rise to 643 million by 2030. This suggests poor glucose regulation and the risk of diabetes is increasing in the population. Two key things to keep in mind is that (one) we all have great variability in our blood glucose response to meals and (two) this changes throughout our life course (7,9).
What is blood sugar?
Blood sugar levels refer to how much glucose is in the blood, following the body breaking down carbohydrates found in food and drink. Naturally these glucose levels fluctuate throughout the day, however, for someone living with diabetes these changes are more dramatic and occur more frequently (1). It is important to note that glucose is not the enemy here, it is the essential fuel for your brain, tissues, and muscles (12).
High and low blood sugar
Low blood sugar, which is also called hypoglycaemia or often referred to as a “hypo”, is when blood sugar level drops too low, usually below 4mmol/litre. Levels as low as this are uncommon in people who do not have diabetes (1,2). Possible causes include not eating enough (fasting or insufficient nutrition), pregnancy complications, and releasing too much insulin following a meal (2). High blood sugar can also occur (hyperglycaemia), and this occurs when blood sugar levels are above 7 mmol/litre, which also mainly affects people with diabetes (1,4).
Why maintaining blood sugar is important
Checking blood sugars is a vital part of a diabetic person’s everyday routine, to help work out when to take medication, manage with food or for advice about activity (1). A low blood sugar level can be dangerous if not treated quickly and so if you ever need to treat someone who’s unconscious or very drowsy due to a hypo, follow the NHS advice (2). This includes placing them in the recovery position and calling for an ambulance if a glucagon injection isn’t available/ you are unsure how to use it. High blood sugar can also cause serious problems if it is at a very high level/ stays high for a long period of time, please also refer to the NHS advice for this. Call 111 if there are signs someone is seriously unwell, such as feeling or being sick due to high blood sugar (4).
For those without type 2 diabetes, learning about your glucose levels and how to reduce glucose spikes can help avoid developing insulin resistance, prediabetes, and type 2 diabetes. The science also shows that balancing glucose levels can help with cravings, constant hunger, fatigue, brain fog, hormonal and fertility issues, skin conditions, wrinkles, poor sleep, menopause symptoms, mental health symptoms and the immune system (10).
The blood sugar rollercoaster
The exaggerated peaks and troughs in blood glucose levels one can experience throughout the day, may be described as a rollercoaster. These can be extremely frustrating, affect mood and lead to poor health and chronic disease risk, particularly when these are severe and inappropriately managed (10,11). This rollercoaster response of glucose matters – research shows that oscillating glucose levels can have more profound negative effects on the body than a constant high glucose level, including implications on endothelial cell function and oxidative stress. Downstream effects later in life include diabetes complications and the future likelihood of diabetes (6).
Blood glucose monitors
For those with diabetes, daily blood sugar level checking is done either by a finger prick test or using an electronic blood sugar monitor called a continuous/ flash glucose monitor (CGM/FGM). This works by wearing a sensor on your skin, without the need for finger pricking (1). These can also be paired with an insulin pump, to control the delivery of insulin. There is also HbA1c which measures average blood sugar level over the last three months (1). Eligibility criteria for various monitors and insulin pumps can be found through the NHS/ Diabetes UK websites (1,2).
There is also an increase in applications of CGM devices within the general population, to monitor glucose levels and offer personalised nutrition (11). It is important to note however that the aim isn’t to completely flatten our glucose curve (due to the importance of glucose as fuel), but that there can be benefits from slightly reducing the intensity of peaks and troughs. We should strive for informed food choices and try not to become obsessive with monitoring. Unlike someone living with diabetes, this is also just for a temporary insight into blood sugar levels and not something that needs to be monitored for the rest of one's life.
Glycaemic index of foods
This is an index which ranks carbohydrates from 0 to 100 based on how quickly and significantly they raise blood sugar levels after a meal. Those at the high end of the index are rapidly digested and cause substantial fluctuations in blood sugar whereas those with a low glycaemic index are digested more slowly so the rise in blood sugar is more gradual (5).
Things that affect glycaemic index:
Processing and physical form
Fibre content
Ripeness
Fat and acid content (5)
Food examples
Those with a high glycaemic index:
White bread
Baked potato
Sugar-sweetened drinks
White basmati rice
White flour pasta
Low glycaemic index:
Whole oats
Bran cereals
Lentils
Kidney beans
Black beans (5)
Improving blood sugar control
If improving blood sugar response is a goal, there are lifestyle and diet changes that have been proven to be beneficial. These include:
Small bouts of post-meal light walking have been proven to improve glycaemic control, particularly in older people at risk of poor glucose tolerance (8).
“Putting clothing on your carbs” - adding fats, proteins and/or fibre. This works by slowing the absorption of sugar from food.
Other ‘hacks’ include changing the order you consume foods by eating carbohydrates towards the end of your meal, so that they aren't hitting your stomach when it is empty.
Summary
Blood sugar balance and its careful management is extremely important for those living with diabetes, but some consideration as to how it affects those with normal glucose control is also owed. Blood sugar levels fluctuate throughout the day in response to meals, show individual variability and can change throughout our lifetimes. Considering different foods and their associated glycaemic index can be helpful for reducing such dramatic rollercoaster responses to mealtimes. Light exercise such as walking and small diet changes can also be beneficial for long term glycaemic control.
Take home messages
Make sure to follow the NHS guidance for what to do when someone is experience a hypo
Understand that blood sugar levels rise and fall throughout the day, and this is important for our bodies’ daily functions
Reducing the rollercoaster rise and falls can be protective for long-term health and have many benefits
The glycaemic index can help guide our food choices
This blog post was written by Bryony Scutt, a Clinical Nutrition and Public Health master’s student at University College London. Bryony also has a bachelor’s degree in chemistry from The University of Birmingham and has really enjoyed moving towards the nutrition field and looks forward to a future career helping people to improve their relationship with food. Bryony also enjoys experimenting with new recipes, getting outside in nature, and trying out new sports. You can find Bryony on LinkedIn here.
References:
(1) Diabetes UK. Checking Your Blood Sugar Levels. Available at: https://www.diabetes.org.uk/guide-to-diabetes/managing-your-diabetes/testing Accessed 14/06/23
(2) NHS UK. Low Blood Sugar (hypoglycaemia). Available at: https://www.nhs.uk/conditions/low-blood-sugar-hypoglycaemia/ Accessed 14/06/23
(3) Diabetes UK. David Flash Campaign Story. Available at: https://www.diabetes.org.uk/your-stories/david-flash-campaign-story Accessed 14/06/23
(4) NHS UK. High Blood Sugar (hyperglycaemia). Available at: https://www.nhs.uk/conditions/high-blood-sugar-hyperglycaemia/ Accessed 14/06/23
(5) Harvard T.H. CHAN. The Nutrition Source. Carbohydrates and Blood Sugar. Available at: https://www.hsph.harvard.edu/nutritionsource/carbohydrates/carbohydrates-and-blood-sugar/ Accessed 16/06/23
(6) Ceriello, A., Esposito, K., Piconi, L., Ihnat, M. A., Thorpe, J. E., Testa, R., Boemi, M., Giugliano, D., 2008, Oscillating Glucose Is More Deleterious to Endothelial Function and Oxidative Stress Than Mean Glucose in Normal and Type 2 Diabetic Patients. Diabetes, 57 (5); 1349-1354 https://doi.org/10.2337/db08-0063
(7) Hall, H., Perelman, D., Breschi, A., Limcaoco, P., Kellogg, R., McLaughlin, T., Snyder, M., 2018, Glucotypes reveal new patterns of glucose dysregulation. PLoS Biol. 16(7); https://pubmed.ncbi.nlm.nih.gov/30040822/
(8) DiPietro, L., Gribok, A., Stevens, M. S., Hamm, L. F., Rumpler, W., 2013 Three 15-min Bouts of Moderate Postmeal Walking Significantly Improves 24-h Glycemic Control in Older People at Risk for Impaired Glucose Tolerance. Diabetes Care, 36 (10); 3262-3268 https://diabetesjournals.org/care/article/36/10/3262/30770/Three-15-min-Bouts-of-Moderate-Postmeal-Walking
(9) International Diabetes Federation. IDF Diabetes Atlas. Available at: https://diabetesatlas.org/ Accessed 16/06/23
(10) Breymeyer, K. L., Lampe, J. W., McGregor, B. A., and Neuhouser, M. L., 2016, Subjective mood and energy levels of healthy weight and overweight/ obese healthy adults on high- and low- glycemic load experimental diets, Appetite. 1 (107); 253-259; https://pubmed.ncbi.nlm.nih.gov/27507131/
(11) Christina Vetter, 2002. Zoe. What is a continuous glucose monitor and how can it help you?. Available at: https://joinzoe.com/continuous-glucose-monitor Accessed 16/06/23
(12) EUFIC, 2013. Glucose and The Brain: Improving Mental Performance. Available at: https://www.eufic.org/en/whats-in-food/article/glucose-and-mental-performance Accessed 16/06/23