Blood sugar isn't a topic that gets much discussion gut-health space, but it plays a really important role!
In this post, we're going to dive into how blood sugar levels can impact digestion, and likewise how poor gut health can impact blood sugar levels. You'll also learn some simple ways that you can keep your blood sugar levels balanced, without giving up carbs.
First, Carbohydrate 101...
Carbohydrates include sugar, starch, and fibre.
Sugars include maple syrup, dates, cane sugar, honey, and the sugar occurring naturally in foods like fruit and dairy products. Isolated sugar is a simple carbohydrate, meaning it is easily broken down into glucose and taken into the bloodstream for energy. Naturally occurring sugar in fruits is a complex carbohydrate as the fibre and nutrients slow the absorption of the glucose.
Starches include whole grains (like brown rice, quinoa, and oats), grain products (like flours, breads, pastas, and bakes goods), legumes (lentils, beans, chickpeas), and starchy veggies (potatoes, squash, beets, etc.). Starches are complex carbohydrates, because they require the body to break them down into sugars. All starches eventually become glucose in the bloodstream, this can happen quickly or slowly depending on how much fibre and protein are present.
Fibres are carbohydrates not fully broken down by digestion. They do not become glucose in the bloodstream, staying in the GI tract instead to feed gut bacteria and contribute to awesome poops. Fibre is a complex carbohydrate and is the most important type of carb for gut health.
When we ingest carbohydrates, digestion starts working to break them down into glucose and send the glucose into the bloodstream. The speed at which this happens determines the glycemic index of the food. For example, maple syrup quickly enters the bloodstream as glucose (high glycemic) while chickpeas take time because the carbohydrates must be separated from fibre and protein and then broken down into glucose (low glycemic).
Ideally, you want to consume mostly low glycemic, complex carbohydrates.
How Blood Sugar Impacts Gut Health
Blood sugar is really a Goldilocks situation. Not too high, not too low... you want to keep it just right!
When blood sugar drops too low, your body initiates a stress response. Cortisol, your stress hormone, is release because it is able to pull glucose from protein stores, and tell the liver to make glucose via gluconeogenesis. Cortisol is also the hormone that wakes you up. If you have ever woken up at 2-3 AM, it could be because your blood sugar dropped 6-7 hours after your last meal and your cortisol increased to compensate.
Cortisol can also increase anxiety levels. If you regularly experience anxiety, it could be because your blood sugar is often dropping too low and you're initiating this physical stress response, which turns into a mental one.
As you may or may not know, this stress response shuts down digestion.
If the body goes through blood sugar spikes and crashes throughout the day, the stress response is activated, which over-time can begin to impact digestive processes.
Over time, dramatic spikes in blood sugar levels can lead to something called diabetic gastroparesis.. When this occurs, slowed gastric emptying, it can impact the vagus nerve, thus impacting motility. This can lead to a cascade of digestive issues, like constipation and dysbiosis (imbalanced gut bacteria).
Another way in which unstable blood sugar can impact gut health is that it can greatly influence food choices. As we know - the food choices we make directly impact our gut health.
When blood sugar is low, you are hardwired to crave high glycemic foods because your body is saying "I need glucose, stat!" This makes you more likely to reach for a processed, sugar-laden snack, versus a more nutritious alternative that would take more time and energy to digest. It's not a lack of willpower, it's a biological drive for survival.
How Gut Health Impacts Blood Sugar
Science is showing that our microbiome may play a major role in glucose regulation and insulin resistance. Studies show that different people see different effects on their blood sugar levels when eating the same foods.
Why would a food raise blood sugar faster in one person compared to another? This is due to variations in microbiome composition.
Imbalances in the microbiome can contribute to inflammation in the body, which can contribute to insulin resistance and diabetes. This is especially true when there is an overgrowth of gram-negative bacteria that can increase endotoxin levels and leaky gut
When there is dysbiosis in the gut, either too little beneficial bacteria or too many pathogenic or opportunistic organisms, the gut lining can become inflamed and "leaky". If the gut becomes leaky it allows undesirable substances, like those endotoxins associated with overgrowth of bad bacteria, into the bloodstream. This gut inflammation will also drive up cortisol.
This can lead to systemic low-grade inflammation, which has been shown to contribute to insulin resistance which is when the cells become less sensitive to the effects of insulin. When the cells are less insulin sensitive, glucose stays in the blood stream longer while more insulin is released. This means higher blood sugar levels, even when eating lower glycemic foods.
So food choices can impact blood sugar as well as gut health. Imbalances in blood sugar can have negative effects on gut health and imbalances in gut health can have negative effects on blood sugar.
5 Ways to Keep Blood Sugar Stable
1. Create an Intentional Eating Schedule
Intuitive eating is a skill that takes time to develop. Hunger cues kick in as blood sugar drops and get more severe the lower blood sugar goes. If you wait until you're hangry to eat, you've already exposed your body to the effects of low blood sugar.
Try to eat within 1-2 hours of waking up, before drinking coffee, and have a breakfast that is made up of good quality proteins, some healthy fats, and whole-food carbohydrates. The best breakfasts for blood sugar are savoury, rather than sweet. Think an egg and veggie scramble with avocado toast. If you prefer a sweet breakfast, organic Greek yogurt (full-fat, only ingredients should be cream and bacteria) with berries and a sprinkle of pumpkin seeds is another great option.
Throughout the day, eating balanced meals roughly every 3-4 gives your body enough time to properly digest your meals, while also not being so long that your blood sugar levels will drop too low between meals. This is a better option than grabbing quick, imbalanced snacks every 1-2 hours.
2. Balance Starch/Sugar with Protein, Fibre, and Fat
Sugars and starches should always be paired with a protein, fibre and fat for steady glucose release. For packaged starchy foods like breads, pastas, and crackers, look for 1 gram of fibre for every 5 grams of total carbohydrates on the nutrition label. For example, a serving of crackers with 25 grams of carbs should have at least 5 grams of fibre. Then pair with some protein and fat.
The same goes for whole food sugars and starches like fruit, whole grains, potatoes, and other starchy veggies. Always pair them with a protein and a fat.
Proteins include foods like eggs, chicken, fish, meat, and tempeh.
Fats include foods like nuts/seeds, nut butter, cheese, avocado, olives, and butter/ghee/oil.
(Many whole foods contain a combination of fat/protein, so I have categorized these by which macronutrient they contain most of.)
For example, if you love having maple syrup in your coffee try to have your sweet coffee with or after your breakfast and ensure you have a breakfast full of protein and fat. This will keep blood sugar more stable than drinking the sweet coffee alone.
3. Line Your Gut with Fibre First
Balancing your meals is the first step, but there is even more you can do to slow down glucose from entering your blood stream during meals. The order you eat your food in can make a huge difference!
If you eat starches or sugars on an empty stomach, your blood sugar will increase faster than if you eat them after you have lined your intestines with some fibre. When you're eating, consume your veggies first, then have your protein, and finally your starches. It will take longer for that glucose to make its way into your bloodstream and be a more gradual release.
This is also a great strategy for when you want to eat foods that you know are going to be higher glycemic or have more starch or sugar than you usually eat. If you are going out to enjoy your favourite pasta dish, try ordering a small green salad with lemon and olive oil as a starter for better blood sugar, without giving up the pasta.
As far as dessert, after a meal the best time to eat sweets. Especially, if your meal was packed with fibre, protein, and fat.
4. Move Your Body
Lean muscle increase insulin sensitivity, so resistance training that builds muscle can help improve blood sugar levels, even if you do not change your diet. Strength training can include weight lifting, bodyweight exercises, or exercising with resistance tools like bands.
After meals, taking a quick walk can help the body make more efficient use of the glucose you consumed and keep it from hanging out in your bloodstream too long. Even a ten minute walk can significantly reduce post-meal glucose spikes.
Working out first thing in the morning can help balance your blood sugar levels all day long. When it comes to blood sugar, the first things you do in a day really set you up so starting the day with movement and a balanced breakfast have a huge impact.
5. Never Drink Alcohol on an Empty Stomach
While alcohol is never going to be beneficial for gut health, consuming it on an empty stomach is particularly stressful to the body. Having that glass of wine while you cook dinner can drop your blood sugar levels too low so it's better to wait until you have eaten at least a little bit.
Alcohol increases intestinal permeability ("Leaky Gut") so it's best to consume on occasion only and when you do, during or after a meal will slow the absorption. Over-consuming alcohol on a regular basis can have terrible effects on digestion, intestinal health, and increase risk of nutrient deficiencies.