Diabetes is a worldwide epidemic that is rising at a terrifying rate. The number of adults living with diabetes globally was estimated at 422 million in 2014, compared to 108 million in 1980 - an increase of almost 400%.
Even with adjustments for our ageing population, the global prevalence of diabetes has nearly doubled. If that isn’t daunting enough, the number of adults living with diabetes is projected to reach an unimaginable 592 million in 2035. In Australia alone, 5 in every 100 people have a known diagnosis of diabetes. That’s 1 in every 20 families, and this doesn’t include unknown diagnoses.
With these scary statistics in mind, I think it’s about time we spoke about the considerations to be made for preventing or managing type 2 diabetes.
What is Diabetes?
There are many different types of diabetes, including type 1, type 2, and gestational diabetes. Though the cause and contributors of these forms of the disease vary greatly, the dietary factors that impact diabetes management (both positively and negatively) are largely the same. For the purpose of clarity, today we are going to focus on type 2 diabetes and insulin resistance.
Type 2 diabetes is a chronic condition characterised by insulin resistance and high levels of glucose (hyperglycemia). This leads to multiple metabolic challenges for affected individuals including:
(a) too much sugar in the blood (which damages healthy tissues)
(b) too much energy being stored (which leads to fatty liver and/or overweight and obesity)
(c) inadequate available energy to burn (which leads to a tired, hungry, and frustrated individual!)
Now, type 2 diabetes is a progressive condition meaning you won’t wake up one day and suddenly have it. Something called insulin resistance develops in the background for many years before a diagnosis of type 2 diabetes.
Insulin resistance is when the body becomes resistant to the signal of insulin, which is the hormone ultimately responsible for lowering blood glucose levels after they have risen. But insulin resistance isn’t inevitable, we have a chance to slow the development of this condition right down, or even reverse it!
To help you do that, let’s break things down a little.
The Effect of Carbohydrates on Blood Glucose Levels
Diabetes can be considered a form of “carbohydrate intolerance”. That’s because dietary carbohydrates have the greatest impact on blood glucose levels.
When any one of us consumes a meal containing carbohydrates, our body’s digestive processes break the carbohydrates down into molecules of glucose which end up in the bloodstream (aka ‘blood sugar’). Glucose can provide your billions of cells with energy.
However, glucose is not able to freely cross cell membranes willy nilly, and requires the help of insulin to do so. The pancreas has the job of producing insulin in response to elevated blood glucose levels. Insulin is like the key that unlocks the cell doors and allows glucose to move inside to be used for energy or stored for a rainy day (as glycogen or fat).
While glucose is a great source of energy, it is extremely damaging if it is left to roam around in the blood for too long (hyperglycaemia). Glucose is sticky, like glue, so if it is unable to move into the cells swifty, glucose will literally start sticking to things and cause damage! If we are insulin resistant or have type 2 diabetes, this is exactly what happens.
Insulin Resistance
In the early stages of insulin resistance the body compensates by producing more insulin to keep blood glucose levels within the normal range by simply making more keys to unlock the locks on the cell doors - glucose gets squashed into the tissues to prevent it from building up in the blood.
However, if nothing is done to address the insulin resistance and/or minimise the glucose demand, the pancreas will eventually “burn out” and won’t be able to keep up - it can’t make an unlimited number of keys to open your cell doors.
This is called relative insulin deficiency and is essentially when insulin production is “maxed out”. This is a metabolic disaster and invariably leads to blood glucose levels that stay too high for too long after meals. The body is no longer any good at moving glucose into the cells to be used for energy.
The worst part is though (yes - it gets worse) someone with insulin resistance isn’t any good at using fats for energy either. That’s because high levels of insulin “turn on” fat storage and “turn off” fat burning.
As you can imagine - this is a real energy crisis where affected individuals are left without any good sources of energy to use. They often feel tired, hungry, irritable, frustrated and unwell. Eventually this individual will be diagnosed with type 2 diabetes.
What Causes Insulin Resistance?
There are many causes and contributors of insulin resistance, with some of the main offenders being diet and genetics. You see, insulin resistance was an evolutionary advantage once upon a time. The ability to create more keys to unlock cell doors and move more glucose (energy) into cells for fat storage to use in times of food scarcity would have separated the strong from the weak - back in the day. However, in an environment where highly processed foods are everywhere, this does not pose as an advantage.
Thyroid health also plays an integral role in one’s susceptibility to developing insulin resistance. This is because the thyroid is a major regulator of carbohydrate metabolism and pancreatic function. For example, low thyroid function (hypothyroid) can slow the response of insulin to elevated blood sugar and thus, the rate of glucose uptake by cells. So, if you have hypothyroid, whether it be autoimmune or caused by nutritional deficiency, it’s well-worth seeing what you can do about improving your insulin sensitivity.
How Do I Know if I’m Insulin Resistant?
It is generally recognised that anyone with a fasting or random blood glucose level below 5.5 mmol/L is “healthy” and free from diabetes. However, blood glucose testing does not account for the extra insulin that may be circulating in one’s system in order to maintain that control. So, insulin resistance is commonly missed and it often goes undiagnosed until very late on in the piece. Some people don’t even find out they are insulin resistant until they find out they have type 2 diabetes - a tragic reality.
With that said, insulin testing, in combination with glucose testing, offers clinicians and patients a window for early detection of insulin resistance and prevention of type 2 diabetes. If your fasting insulin levels are high (>10), you might want to take some action to improve your insulin sensitivity, even if your blood glucose levels appear normal. Prevention is better than cure, right?
Let’s recap.
When a pen drops in a quiet room - you can hear it very well. However, when a pen drops in a noisy room, you won’t even notice it. When your insulin levels are low (quiet room), your body is a lot more sensitive to it. However, when insulin levels are high (noisy room), your body is more resistant.
A way to improve insulin sensitivity then, is to reduce the amount of insulin your body makes, so it can start to hear it better. If your body produces insulin in response to glucose elevating, then strategies to minimise blood glucose fluctuations should be beneficial in improving insulin sensitivity.
If we can help our body manage our blood glucose levels by minimising the glucose input, we can prevent the need for all that extra insulin!
Sounds reasonable, right?
The Management of Blood Glucose Levels
Blood glucose levels are affected by multiple factors including diet, illness, stress, and exercise. Though all factors must be taken into consideration, dietary carbohydrates undoubtedly have the greatest impact on blood glucose levels.
By simply reducing our intake of dietary carbohydrates, we can reduce the glucose load coming into our body, and ultimately, reduce our insulin requirements. In many people, this simple diet change may help to prevent the progression of insulin resistance and/or development of type 2 diabetes, and possibly even reverse it!
This does not mean that the one-single answer to achieving normal blood glucose levels and avoiding diabetes is to eliminate carbohydrates from your diet - it just means that reducing your carbohydrate load is a very useful strategy to implement as part of a healthy diet and lifestyle.
Carbohydrates include starches and sugars and are found across all major food groups, including most processed and packaged foods, breads, cereals, vegetables, legumes, fruit, dairy, nuts and seeds. A low-carbohydrate diet tends to reduce most processed and packaged foods, in addition to breads, cereals and legumes, but might still include non-starchy vegetables, low-sugar fruits, high-quality proteins, and healthy fats!
To Sum It Up...
Though type 2 diabetes is a serious and widely prevalent disease, it is also mostly preventable. And if you already have a diagnosis of type 2 diabetes, you can still improve your insulin sensitivity and achieve healthy, normal blood glucose levels again (possibly even without all the medications!). Out of all dietary approaches that are actively studied, low-carbohydrate diets are the most effective strategy for improving glycaemic control and cardiovascular risk factors in type 2 diabetes.
The earlier that insulin resistance or diabetes can be identified and treated, the better one’s health outcomes. It is possible for an individual with compromised carbohydrate tolerance to achieve normal blood glucose levels and live a long, happy, and healthy life.