Photo Credit: Getty Images
By Abigail Hartle, OD
Sept. 14, 2026
Quick summary:
- Discussing blood sugar with patients can strengthen the doctor-patient relationship, support overall and ocular health and encourage more regular visits and referrals.
- Understanding the basics of glucose, insulin, insulin resistance, and the effects of glucose spikes helps clinicians educate patients more effectively, especially those with diabetes, prediabetes or related health concerns.
- Small, practical habits are worth mentioning to patients, addressing how they can help reduce blood sugar spikes and improve long-term health.
Discussing blood sugar is extremely beneficial for developing the patient-doctor relationship. It creates a sense that their doctor really cares about their systemic health, not just their eyes. I find that patients really appreciate the discussion, particularly the aging demographic. I think that attention to the details can encourage them to come back to see you in the future.
One reward of these efforts can be seen through an increase in referrals to the practice from friends, family and the patient’s primary care doctor. These conversations can also reinforce the need for an annual exam, ensuring the patient returns to your office annually instead of every few years.
KNOW THE BASICS
For both its impact on patient care and the opportunity for the business, it’s important to know the basics about blood sugar to properly educate patients.
We regularly encounter diabetic patients where we discuss the relationship between diabetes and the eye, discussing whether or not they have diabetic retinopathy or need further care. But how often do you take the time to discuss the role of blood sugar with these patients?
It is easy to skip that talking point or simply say, “keep controlling the blood sugar as best you can.” The reality is many people struggle with blood sugar management or don’t even understand how it works. Closing the knowledge gap can have a big impact on patients’ overall systemic and ocular health.
The discussion around nutrition and blood sugar can be a sensitive topic as many people can feel under scrutiny around the way they eat. An aging population may be set in a routine and long-time habits. Broach the subject with every diabetic patient but save the in-depth conversation for those who are receptive to the topic. Many diabetic, prediabetic and patients who express dissatisfaction with their weight or health are prime candidates for further discussion.
THE IMPACT OF GLUCOSE
Glucose is our body’s main energy source and the most basic building block to so many foods that we eat. Any starch, grain, vegetable or fruit are all built from long chains of glucose. Insulin is a hormone that is released into the blood stream in response to glucose.
The job of insulin is to move the glucose from the blood into one of three places in the body: muscles, the liver or fat. Muscles and the liver are ‘safe’ places to store glucose. Muscles keep a small supply of glucose that is necessary for contraction. In the liver, glucose is turned into glucagon, which is a helpful short-term storage solution.
When there is an immediate need of glucose, glucagon can be broken down via gluconeogenesis for quick energy stores. But we tend to eat more glucose that can be sufficiently stored in those areas and thus excess glucose gets stored in fat.
The release of insulin is a natural mechanism but long term, chronically elevated insulin will deplete reserves and decrease effectiveness. This is the root cause of insulin resistance and type 2 diabetes as more glucose stays in the blood because the uptake is not as efficient. These free glucose molecules can lead to the production of free radicals which ultimately cause inflammation, oxidative stress and aging.
GLUCOSE BY THE NUMBERS
Fasting glucose in a healthy person ranges from 60-100mg/dL. People with pre-diabetes have a fasting glucose level of 100-126mg/dL and diabetic fasting glucose level is 126+mg/dL. The American Diabetic Association recommends glucose levels should not rise above 140mg/dL after eating a meal and the spike of the meal should not be greater than 30mg/dL.
When glucose is measured via lab work or with a continuous glucose monitor (CGM), it can paint an interesting picture for patients on where they stand on a daily basis with their blood sugar. Many diabetics have CGMs. If nondiabetic patients are very interested in pursuing their levels, CGMs can be found online and are relatively inexpensive.
GLUCOSE IN THE REAL WORLD
The glucose response is affected by a lot more than just food and levels are very individualized. Poor quality sleep trends toward insulin resistance whereas restful, good quality sleep will support a healthy insulin response. Stress levels will impact glucose as well with increased stress leading to higher glucose spikes. The amount of lean muscle mass will significantly impact glucose levels with more lean muscle supporting uptake of glucose into the muscle cells thus creating less of a spike. Other factors affecting glucose are genetics and the gut microbiome.
EFFECTS OF GLUCOSE SPIKES
Any spike has the ability to have short-term and long-term consequences.
Short-term spikes can cause mood swings, fatigue, poor sleep quality, cravings, constant hunger, memory issues and can even incite headaches or migraines.
Long-term effects of glucose spikes are more broad and can be the underlying issue to many chronic diseases. It can impact aging, arthritis, Alzheimer’s/dementia (sometimes called type 3 diabetes), cancer, cataract development, gut issues, metabolic syndrome and type 2 diabetes, nonalcoholic fatty liver disease, skin issues (such as acne, eczema, or psoriasis) and hormone disruptions. In menopause, hormones and larger blood sugar spikes can lead to more severe symptoms such as hot flashes and weight gain.
GLUCOSE GOALS
We want to encourage diets that stabilize blood sugars, keeping within the optimal range of 70-120mg/dL as much as possible. The second goal is to flatten the glucose curve and avoid glucose variability as this causes problems in the long run. Good control of blood sugar will ultimately benefit our patients’ systemic health and indirectly their eye health as well.
GLUCOSE TIPS TO SHARE WITH PATIENTS
I pass these tips along to patients when we have an in depth nutrition and blood sugar discussion. What I love is that these suggestions don’t necessarily involve eliminating food from the patient’s diet but by making small tweaks to their eating habits they can work to lower blood sugar.
Please remember that these tips are not absolute and may not work for every moment or meal of the day. I remind patients that incorporating them when possible can add up to make big changes.
1. Eat food in the right order: Vegetables first, protein second and carbs last.
When carbs are eaten first, the starch is broken down into glucose quickly and immediately absorbed into the blood stream, spiking blood sugar. Ultimately, the hormone ghrelin which will stimulate hunger onset more quickly as well. On the other hand, when vegetables and protein are eaten first, the fiber and fat delay gastric emptying. This allows the fiber to coat the intestines to slow the absorption of glucose. Eating foods in the right order suppress ghrelin, meaning we feel fuller longer.
2. Start a meal with a vegetable starter or a salad.
This is largely based off of #1, highlighting the importance of a vegetable starter over a carbohydrate-rich starter like bread.
3. Start the day right: breakfast matters!
A sugary or carbohydrate-rich breakfast will lead to a big spike followed by a crash of blood sugar (also called reactive hypoglycemia). This response will start a rollercoaster of spikes and crashes throughout the rest of the day. First thing in the morning, our bodies have been fasting and are in a very sensitive state so we want to start with a glucose stabilizing meal. Ideally, starting with high levels of protein first thing will aid in hunger control.
4. Aim for larger, fuller meals instead of multiple small meals or snacks throughout the day.
When we forgo snacks, we allow blood sugar levels to stabilize to a set point. This allows the body to rest from digestion. Conversely, multiple snacks throughout the day, especially if they are not stabilizing snacks, can lead to constant ups and downs in sugar levels that lead to constant hunger.
5. Save sweets for dessert instead of a snack.
Cake and cookies can still be enjoyed! By simply eating something sweet after a meal, the corresponding spike is reduced since the body has fiber and fat to slow digestion. When eaten alone, a sugar based sweet will lead to a dramatic spike. This one is similar to the first tip but specific to dessert.
6. Share the power of vinegar.
This tip can be done with any type of vinegar, even lemon juice although it is not as efficient as vinegar. Apple cider vinegar is the most common and typically balsamic vinegar is avoided due to its sugar content. Mix 1 tablespoon of vinegar in a tall glass of water, it will help to lessen the spike. The acetic acid in vinegar will temporarily inactivate the alpha amylase enzyme in our saliva needed to break down starch and sugar. As a result, glucose is broken down more slowly which lessens the glucose spike by 8-30%. Acetic acid also helps muscles take up glucose more efficiently. Note: Drink with a straw to protect teeth enamel. If drinking vinegar is not appealing, the same effect can be achieved by adding a vinaigrette to a salad at the start of a meal as well.
7. Make time for movement after eating.
By contracting our muscles, glucose in the bloodstream moves directly into the muscles. The muscles are burning glucose to begin with by moving and therefore they need the extra glucose immediately to fuel the mitochondria. The time window to move for an effective decrease in the glucose spike is 0-70 min after you finish eating and all you need is a minimum of 10 minutes. The beauty is any activity will do: walking, weight lifting, resistance training, vacuuming, dancing, etc.
8. Combine plain carbohydrates with fat, fiber or protein.
Any favorite food, if it is a high carbohydrate food, can still be consumed with a reduced spike by adding fat, fiber, or protein. When eating a banana, add nut butter. Combine chips or crackers with hummus or cheese.
9. Don’t forget the secret ingredient: cinnamon!
A chemical in cinnamon mimics insulin meaning more glucose will be absorbed for less insulin. By adding cinnamon to food or supplementing with it, it can help to decrease the spike. 1-6g of cinnamon is all that is needed!
10. Tap into the benefits of leftovers: eat resistant starches.
Resistant starch is found in foods with fibers that are resistant to digestion, meaning it cannot physically be broken down by our bodies into sugars so less glucose is released and less insulin is needed. Some natural foods have chemical structures that are tightly bound and can’t be broken down. These include as plantains, legumes, seeds, whole grains and artichokes. Another surprising source of resistant starch are carbs that have been cooked then cooled or slightly undercooked (such as al dente pasta). They will undergo a change in structure to make it slightly more difficult to digest and even reheating of food does not lessen the amount of resistant starch.
References
Inchauspé J. Glucose Revolution: The Life-Changing Power of Balancing Your Blood Sugar. 1st ed. Simon Element; 2022.
Read more from Dr. Hartle here.
Read more on nutrition and aging here.
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Abigail Hartle, OD, ABO, is a speaker and medical optometrist at an ophthalmology group in mid-Michigan called Specialty Eye Institute. To contact her: ahartle@midwestvision.com. |
