Let’s talk about carbs, glycemic index and finally understand health implications of sugar levels
When being sweet is not a good thing: understand health implications of sugar levels in our body
It’s no secret: we live in a carbohydrate heavy society. Since a young age, we learn that carbs are our friends and healthy. In 1977, the US senate select committee updated its dietary goals for the United States. They stated we should increase our carbohydrate consumption to make up 55% to 60% of our daily energy intake and reduce overall fat consumption from 40% to 30%. Fat became the villain and carbs the hero. What happened over the following 40 years since then, has changed our country forever. Fiber depleted, processed carbohydrate consumption increased. We became fatter, to the point of morbid obesity. Diabetes became rampant, heart disease increased and the previously unknown metabolic syndrome became a common condition. Now, it is up to us to understand health implications of sugar levels.
As time went by, research started looking at the effects of carbohydrates on our bodies. The effects of glycemic loads and glycemic indexes were studied. We slowly learn that carbs aren’t the panacea we thought, as evidenced by the flurry of low carb diets that developed in the last 15 years or so.
The reason this happened is multi-factorial. For today though, let’s start by talking about blood glucose (blood sugar). We will also discuss everything we should know about the effects of carbs in our bodies.
What is normal blood sugar?
To understand the health implications of sugar levels in our blood, let’s start by defining what is normal. In healthy people, during a period of 24 hours, blood glucose fluctuates between 70-140 mg/dL. However, it is interesting to note that a study by Ferrannini showed that already at the upper end of the normal (120–140 ng/mL or 6.6–7.6 mmol/L) beta-cell function drops significantly by 60% and this seems to occur equally in lean as well as in obese individuals.
What are beta cells, you may ask? Beta cells are the cells in our pancreas that are responsible for insulin secretion. Insulin resistance, which is what happens in type 2 diabetes, starts with impaired secretion of insulin. So, you can see how this 60% function drop could be a big problem.
Remember, insulin is vital for the regulation of our blood sugar. It is essentially the key that opens the door in our cells, so that they can take sugar from our blood and use it for fuel.
Another interesting fact is that larger blood glucose spikes have been linked with higher oxidative stress, more so than constant high blood sugar (learn more about oxidative stress here). Higher oxidative stress means greater free radical formation. This leads to cell damage and likely higher propensity to heart disease and diabetes.
So, what the heck is a glycemic index and why should I care?
The glycemic index (GI) is a number that tells you information about the quality of the carbohydrate you are ingesting. It is important if we want to understand health implications of sugar levels. Clearly, not all carbs are created equal. The higher the GI of a particular food, the faster that carbohydrate absorption. This means the faster our blood sugar spikes and the harder our pancreas has to work by producing insulin.
How do you get that number that makes a GI?
Ok, so here we get a bit science-y, but bare with me. They give either 50 grams (or 25 grams) of white bread or a glucose (sugar) water solution and look at the change that it causes in our blood glucose (or if you want to get fancy, the glycemic response). This becomes the reference number against which we will compare all other foods. Then, you give either 25 or 50 grams of a particular carb. Again, you observe the glycemic response to that carb. This number you compare to the reference number, or standard, that you got from receiving that large amount of glucose (from white bread or glucose water).
Foods that contain quickly-digested, absorbed and metabolized carbohydrates have a GI equal to or greater than 70. Those with the opposite absorption and metabolism (that is, slow) have a GI less than or equal to 55.
In 2013, a group of experts from many prestigious universities worldwide organized a meeting in Stresa (Italy) titled “Glycemic Index (GI), Glycemic Load (GL) and Glycemic Response (GR): an International Scientific Consensus Summit.” They discussed all the health implications of GI, among other things, and concluded:
Large epidemiological investigations show that the combination of low GL and high cereal fiber intake reduced type 2 diabetes risk by two-fold in men and women. More recently, these trends have been confirmed in both men and women, with greater risk reduction in women. Heart disease (CHD) risk was also reduced with low GL and with low GI diets, again shown clearly in women, as well as risk of certain cancers, mainly breast and colorectal, although not all studies have demonstrated these benefits.
Furthermore, low GI diets have been shown in clinical studies to improve glycemic (blood sugar) control in people with diabetes, improve serum lipids (aka cholesterol) and other cardiovascular risk factors and possibly to promote weight loss. In large epidemiological studies, again consumption of low GI diets has been associated with decreased risk of diabetes, CHD and certain cancers.
What about Glycemic Load?
Another measure we use to understand the health implications of sugar levels in our body is the GL. The GL tells you how high your blood sugar could go when you actually eat the food. It takes into account the amount of the food you eat and its carbohydrate content. We use the following equation (in case you are curious!):
Glycemic Load = GI x Carbohydrate (g) content per portion ÷ 100
Although there is debate, many experts believe the GL gives you a more accurate picture of a food’s real-life impact on your blood sugar. A low GL= 10 or less. Cantaloupe, for example, has a high glycemic index (70). But a serving of cantaloupe has so little carbohydrate that its glycemic load is only 4.
You can get a full list containing the GI and the GL of over 1000 food items through the American Diabetes Association. You will get a listing like the table below. To keep it simple, just look at the first column, which has a GI listed and the last column, which has the GL.
I know, this is so much information 😱. Also, who has time to be looking up GI and GL for all these foods? Well, most studies for diabetics tend to concentrate more in the glycemic index than the load. If you chose foods with low glycemic indexes, you will also choose the foods with the lowest glycemic load. So, I think it easier to concentrate on the GI.
How can I reduce my risk of diabetes?
Plant based diets 🌱 reduce the risk of type 2 diabetes and heart disease, according to epidemiological studies. According to the “fiber hypothesis”, this may be due to a direct effect of the fiber. The idea of glycemic index goes together with the fiber hypothesis, as fiber slows the rate of nutrient absorption from the gut.
Legumes and nuts are both low GI and full of fiber. In fact, recent clinical studies suggest that diets containing legumes and other low GI carbohydrates, as well as nuts, experience better glycemic control in type 2 diabetes.
Additionally, a diet characterized by a slightly lower GI and a moderately higher protein content was more efficient in counteracting weight gain after a period of caloric restriction and weight loss. Also, high protein diets consumed liberally improved metabolic risk markers in children of overweight parents.
Furthermore, a low GL combined with a traditional Mediterranean diet resulted in 18% protection against the occurrence of type 2 diabetes (when compared with just a regular Mediterranean diet) suggesting that even within an overall healthy diet there may be benefits of lowering the dietary GL.
What about low GI and heart health?
This is another aspect we need to know so that we can understand health implications of sugar levels. In general, most studies show a beneficial effect of low GI/GL diets on blood glucose values (particularly during the after eating, or post-prandial, period) and on blood (bad/LDL) cholesterol levels; for both people with diabetes and without. The favorable impact on blood total and LDL cholesterol seems to be much more relevant when the low GI/GL diet is also fiber rich.
What else does the research show about GI/GL and health?
Let me finalize with a few more highlights:
- Increased dietary GL and carbohydrate intake were associated with a poor short-term functional outcome after an acute ischemic stroke (brain infarct).
- High GI and GL are associated with a higher risk of osteoporosis-related fractures in an elderly Mediterranean population at high risk for cardiovascular disease.
- Another study showed that the intake of foods with higher GI is associated with depression risk.
There you have it, everything you ever wanted to know about the GI/GL and more! I hope you can see the impact this has on our body and why we need to understand health implications of sugar levels. By choosing low GI foods we can make it easier to maintain a healthy weight. We also avoid or better control diabetes and improve our risk profile for heart disease. Hope you are now ready to apply this to your everyday food choices! As always, reach out if you have any questions. Don’t forget to subscribe!!
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Have a healthy and sweet (but low GI 😆) week,
PS- Looking for ways to spice up your plant based diet year round? Check out these 👇🏼 cool suggestions by zero cater! Oranges 🍊 are low GI and only have a GL of 3-4, so they are certainly a worthy addition to your diet!