What Causes The Dawn Effect

Probably the most common question I get from people on my Facebook pages, blogs, and programs, is about high morning blood sugar levels.  They want to know why they wake up with a blood glucose level that was higher than when they went to bed.  This is a logical question, and stems from much frustration.  In fact, I completely understand the confusion. How is it possible to have higher blood sugars in the morning when you haven’t eaten anything all night?

The Dawn Phenomenon

“The dawn phenomenon, sometimes called the dawn effect, is an early-morning (usually between 2 a.m. and 8 a.m.) increase in blood sugar (glucose) which occurs to some extent in all humans, more relevant to people with diabetes.” – from Wikipedia, the free encyclopedia.

This rise in blood glucose during the early morning hours is called “the Dawn Phenomenon,” and many people with diabetes, pre-diabetes, or metabolic dysfunction will experience it.

When you wake up in the morning, the body needs to shift gears.  When you’re sleeping, your body is in rest and repair mode, called parasympathetic function.  When the sun comes up and you start your day, you shift into sympathetic function.  The body gives us a little burst of energy from various hormones, which raise blood sugar and activates our muscles, and senses.  Without this, most of us would be too weak and foggy-brained to get out of bed and get going.

People who don’t have diabetes are, of course, at an advantage, because as their blood glucose increases, so does insulin, and their livers are sensitive and responsive to that insulin. People with diabetes and blood sugar problems don’t properly respond to insulin, so their early morning blood glucose levels can rise dramatically.

What Causes the Dawn Effect?

If these early morning blood sugar spikes aren’t caused by food, what is the cause?

There are numerous sources in the body that stimulate the production of glucose.  The main producer and releaser of sugar into the bloodstream is the liver, through a process called gluconeogenesis (production of new sugar) and glycogenolysis (breakdown of stored sugar). The liver can produce a significant amount of glucose from the stored starch, protein, and fatty acids, and is the main culprits behind the dawn effect.

Somewhere between the hours of 4 AM and 10 AM, our bodies produce a slurry of hormones, including cortisol, glucagon, growth hormone and epinephrine. All of these hormones increase release of glucose from the liver.   It’s actually a wonderful adaptive feature of the human body.

Again, to people with diabetes, gluconeogenesis can seem like a personal affront, but our organs do this to make sure our blood glucose doesn’t dip too low at night or other times when we are unable to eat.  It also gives us that surge of fuel to get going in the morning.

Without the corresponding effects of insulin to suppress the breakdown and release of sugar from the liver, the blood glucose levels rise inappropriately.

Is the Dawn Phenomenon a Serious Problem?

It can be, depending on the individual. According to the American Diabetes Association, some people find that their blood glucose levels continue to rise until they eat something. For others, these levels will settle down on their own a few hours after waking, regardless of whether food is eaten or not.

Either way, that can be a long time for the body to experience elevated blood glucose levels. And, while some of my clients’ glucose increase is pretty mild, others are much more dramatic. When you add up the total number of hours spent each morning in an elevated range, this can have a major on your overall health.

Needless to say, I recommend that you do what you can to improve your insulin sensitivity to get the dawn phenomenon under control.

What Can You Do?

The first thing I tell all of my clients is to determine what is triggering the effect and come up with some possible solutions.

“The dawn phenomenon is not necessarily something that needs to be fixed. It’s important to keep in mind that even though your fasting glucose may be elevated, you may have lower or normal glucose values throughout the rest of the day. Additionally, it’s not uncommon for patients reversing their diabetes through nutritional ketosis to experience the dawn phenomenon and still see improvements in their HbA1c. Why? Because HbA1c is a measure of your blood glucose over the last 3 months. The average value matters more than any individual blood glucose value.” – Brent Creighton, PhD

For instance, some people may have high glucose levels in the morning simply because their medications (like insulin, sulfonylureas, and metformin) wore off during the night. If you are on any long-acting medication, talk to your doctor about changing your medicine, doses or times. Your doctor may recommend you take your metformin later in the evening, and this could keep a lid on your liver.

Keep in mind that some medicines can be too strong, and if your glucose dips too low during the night, you may experience a rebound high in the morning. This is called the Somogyi effect.

Some other things you can do to prevent the dawn effect are:

• Some people have had success eating a little bit of protein, such as some nuts or cheese at bedtime. Doing so may keep a low, steady level of glucose in the blood, helping to prevent early morning lows AND highs.
• Even though we typically don’t recommend snacking, a protein snack like nuts or cheese at bedtime may help keep blood glucose steady. The best thing to do would be to experiment and keep a journal of what works best for you.
• Eating some food with fat and protein within one hour of waking can stop the dawn effect.  Many people find that when they eat something, the changes in hormones from eating will stop this effect and level out their blood sugar.  One hard boiled egg or a protein smoothie may be enough to solve the problem.
• Adjusting your exercise schedule may help as well.  Instead of exercise first thing in the morning, which can raise blood sugar even more, it may be better to exercise in the afternoon or evening to avoid this hormone surge.
• Believe it or not, vinegar is a wonderful natural way of avoiding the dawn effect. You can take apple cider vinegar in either tablet or liquid form at night and in the morning upon waking. Though more research is needed, vinegar has been shown to reduce insulin resistance.
• Intermittent fasting has been shown to improve insulin sensitivity and reduce the dawn phenomenon.  I’ve seen the best success with a 24 hour intermittent fast done between lunch one day and the next, several days per week.  In you would rather do this daily, then you can use an eating window between 8:00 AM and 2:00 PM, and fast between 2:00 PM and 8:00 AM the next morning.

“The doctor of the future will give no medicine, but will involve the patient in the proper use of food, fresh air and exercise.” – Thomas Edison