Why You Should Improve Your Glucose Levels (Even If You Don’t Have Diabetes)

And often I hear doctors say, "If you don't have diabetes, you should not worry about your glucose levels." To me, it's like saying, "If you don't have cavities, you should not worry about brushing your teeth."

Hello angels, and welcome back to the Glucose Goddess Show. I'm Jessie Inchauspé, a French biochemist obsessed with helping you understand your health. And today we're going to talk about the most important thing that underpins all of my work on glucose essentially. And we're going to answer the question, how do we know that glucose levels matter if we don't have diabetes? This is a very important question. It's a question that I get a lot and it is so key to understand all of the evidence that we have today. So, this episode is going to be a big review of lots of amazing studies so that you have all the information to know that glucose levels matter even if you don't have diabetes.

First topic, your fasting glucose levels. This number should be measured by your doctor about once a year and it determines whether you are healthy or whether you have pre-diabetes or whether you have diabetes.

Now, why should you care about your fasting glucose levels if you don't yet have pre-diabetes or diabetes? The answer to this question is extremely obvious. It is so that you prevent getting pre-diabetes or diabetes. So, if you don't yet have these conditions, and I wish that you never have them, the importance of managing your fasting glucose levels is so that you never get them. So, we're talking about prevention here.

So today, if your fasting glucose number is healthy and is normal, that's fantastic. You want to keep it that way. You don't want to let it creep up until you get a pre-diabetes diagnosis.

And often I hear doctors say, "If you don't have diabetes, you should not worry about your glucose levels." To me, it's like saying, "If you don't have cavities, you should not worry about brushing your teeth." Only worry about brushing your teeth once you have cavities. Doesn't make any sense. Prevention is super, super important. If you are healthy, you want to stay healthy, then making sure your fasting glucose level never increases should be a number one priority. Especially because today in the world, over 1 billion people have either type two diabetes or pre-diabetes. This number is increasing every single year across the world. So, prevention should be a top priority.

Now, the American Diabetes Association and many other associations around the world say that you should make sure your fasting glucose levels stays below 100 milligrams per deciliter. If you get above 100 milligrams per deciliter, that's considered pre-diabetes. And then above 126, that's considered full-blown type 2 diabetes.

Now, there's some nuance to this. Even though the ADA says that anything under 100 is normal, this does not actually mean that being under 100 is optimal. I'm now going to show you a few studies that have proven that the ideal fasting glucose level if you want to thrive and avoid any kind of health conditions should probably be under 85 milligrams per deciliter. And by the way, if you are in a different unit, if you're on millimoles per liter, you can click the link in the description of this episode where I recapped all these blood tests, etc. in different units.

There are many studies linking higher fasting glucose levels even in the normal range and a higher risk for heart disease and heart problems. I'm going to cite two here, but there are many of them.

The first one is called fasting glucose level and the risk of incident atherosclerotic cardiovascular diseases. This study was done on one million Korean adults and they showed that the risk of heart disease, of cardiac problems, of stroke was actually lower when you are below 90 mg per deciliter. And any increase above 90 milligrams per deciliter increased the risk of a heart problem. So this study suggests that the goal should probably be to be under 90 milligrams per deciliter if you want to optimize your health and help your heart.

Another great study is called fasting blood glucose, an underestimated risk factor for cardiovascular death results from a 22-year follow-up of healthy non-diabetic men. So in this study the researchers looked at 2,000 people without diabetes. They followed them for over 20 years and they showed that men who were in the highest fasting glucose level range in the normal range, so above 85 milligrams per deciliter, had a significantly higher mortality rate from heart disease compared to those under 85 milligrams per deciliter. So, another large-scale piece of evidence that being below 85 is probably where you want to be.

Now another study that was not looking at just heart disease but looking at overall risk of death—so dying from whatever kind of cause. This study is called no evidence of an increased mortality risk associated with low levels of glycated hemoglobin in a non-diabetic UK population. So the study title says this because for a long time people believed that if you have really low fasting glucose level that could actually be worse for you. This has been disproven many times but that explains the title of the article, and in the paper they show on 17,000 people aged between 39 to 82 without diabetes and without heart disease who were followed for 11 years that the risk—listen to this—that the risk of death increased with average glucose levels even below the diabetic range. So again, it explains that even if your fasting glucose level is reported as normal by your doctor, by the standard guidelines, within that normal range, there is a variation. If you're below 85, your likelihood of heart disease and just dying of any cause is lower.

Now, another study I want to mention—and this goes back to answering the question of, oh, should you brush your teeth before you have cavities? Oh, should you worry about your glucose levels before you have diabetes? Of course, the resounding answer is yes. But because there are still some people who somehow don't get that prevention is important, I want to mention this study. This study is called fasting plasma glucose levels within the normal glycemic range in childhood as a predictor of pre-diabetes and type two diabetes in adulthood. Fascinating study.

So, what happened here is that the scientists followed 2,000 children who were about 10 years old, and they had their glucose levels measured. Then, they were followed for 20 years until all of them were about 30 years old. Here's what the scientists found.

They found that the kids who at 10 years old had a fasting glucose level above 86 milligrams per deciliter—so, still normal, but in the sort of higher normal range—were three times more likely to get pre-diabetes as adults, and they were twice as likely to get diabetes as adults. Now, this sounds perfectly obvious. If you have a high fasting glucose level, even in the healthy range, that level might continue to increase. And once you get to 100, you have pre-diabetes. Once you get above 126, you have diabetes. If your fasting glucose level is higher, even within that normal range, it is more likely that you will then go into the unhealthy pre-diabetic or diabetic range. And this starts in childhood.

So a little story for me: before I worked on glucose levels and before I learned all of this, I was in my early 20s. My fasting glucose level was 96 milligrams per deciliter. So pretty high in the normal range. Of course, my doctors didn't say anything. And then I was able with my glucose hacks to get that down. I'm now at about 79. And my objective has been to stay below the 85 threshold because anything above 85 seems to cause potential problems later on—heart disease, general mortality, and of course likelihood of getting type 2 diabetes, which again we want to prevent at all costs.

So we have strong evidence that fasting glucose levels matter even if you don't have diabetes. It's not just a matter of staying under 100. Really you should try to stay under 85. We also understand the mechanism by which fasting glucose levels that are too high are going to cause problems. The mechanisms are oxidation, inflammation, insulin release, and glycation. We know that higher glucose levels in the blood are not good for you. They damage your cells. They damage your system.

And we also know something that is really getting a lot of attention today that I think we should talk about: if you have high fasting glucose levels in your 30s, you are then more likely to get Alzheimer's disease when you are older. The main study I want to mention is called Alzheimer's disease is type three diabetes: evidence reviewed. So again, this study showed us—and you can have a look at it, it's really fascinating—that high glucose levels, fasting glucose levels at midlife, lead to higher risk of Alzheimer's.

Managing your fasting glucose levels, even if you do not have diabetes, is 100% a good idea. Anybody who tells you otherwise just doesn't have access or doesn't have information from these recent studies. You should absolutely worry about your fasting glucose level—even if it's below 100—make sure it's in the lower, healthier part of the normal range and not at 99 or 96 like mine was. And if you do have diabetes or pre-diabetes, of course, your objective should be with your doctor to get that down so that you exit the pre-diabetes and the diabetes range altogether.

So to recap, stay under 85 if you can, not just 100. Oh, I have the translation here in the millimoles per liter if that's the units you're in. So 100 is 5.5 mmol/L and 85 is 4.7 mmol/L.

Something else you could measure is your fasting insulin levels because fasting insulin levels increase for years before fasting glucose levels increase and actually are a really good predictor—warning, warning—your fasting glucose level is going to increase. If you want a one pager of all these blood tests and the ranges, click in the description of this episode. There's a free PDF, my blood test guide, where you'll get all the information you need.

Now, let's look at glucose spikes. A very important topic as well. Here's the deal. Even if you don't have diabetes—so even if your fasting glucose level is normal, meaning under 100—it is very likely that you are still experiencing what's called glucose spikes after eating. Our glucose levels, so our blood sugar levels, spike after eating when we give our body too many carbs and sugars to eat in one sitting.

And so reducing your glucose spikes first and foremost—what does it teach us? It simply teaches us to eat less sugar or to help our body process sugar better when we do eat it. That is the core of all of my hacks. It's reducing sugar intake, for example, in the morning at breakfast, focusing on something savory. If you want to eat sugar, having it at the end of a meal instead of between meals to slow down the absorption of the sugar in your bloodstream. And focusing on reducing our glucose spikes and reducing our sugar intake is in line with some really big global guidelines from, for example, the World Health Organization that says in their guideline of sugar intakes for adults and children, they recommend to limit free sugars to less than 10% of daily total energy intake. And actually they recommend even getting to lower than 5% if you want to thrive and get additional health benefits. Another example, the UN Food and Agriculture Organization released a report called diet, nutrition and the prevention of chronic diseases, and they recommend again to limit sugar consumption to limit the onset of chronic diseases.

So globally we have a sugar problem. We're eating too much sugar and it's causing a lot of issues. So when we eat a lot of sugar, we experience a lot of glucose spikes. It is important to reduce our sugar intake, which also leads to smaller glucose spikes.

Here's an example of a glucose spike when you eat a slice of chocolate cake. As you can see, your glucose or blood sugar levels rise sharply and then they decrease. That is a glucose spike. The higher the spike, the worse it's going to be for your body. And studies show us that these spikes—the variability, the spikes and the dips, the variation—have a damaging consequence on our body. Even again, if you have normal fasting glucose levels.

So, how often do people actually get glucose spikes if they have normal levels of fasting glucose? Well, one great study that started measuring this is called glucotypes that reveal new patterns of glucose dysregulation. And the researchers here showed something very simple. They showed that in most people without diabetes, eating something as simple as breakfast cereal can send your glucose levels so high—can make such a big glucose spike—that you end up spiking into a range that was previously thought to only be attainable by people with diabetes. So for a long time, we thought if you don't have diabetes, your spikes are going to be small. Your body is going to be able to manage them. Don't worry about it. This study and many subsequent ones showed us that that is not the case. Even if you don't have diabetes, you can get big damaging spikes that lead to oxidation, inflammation, that hurt the cells in your blood vessels, that create a lot of insulin release—which is really bad for chronic diseases, etc. So, if somebody tells you, "If you don't have diabetes, your glucose spikes are nothing to worry about," point them to this study that shows exactly the opposite.

Okay, now for a few studies that show specifically the link between glucose spikes and heart disease in people without diabetes.

The first one is called oscillating glucose is more deleterious to endothelial function and oxidative stress than mean glucose in normal and type two diabetic patients. This study showed us that in terms of impact on our heart health, on our cardiovascular health, the variations—the spiking—are damaging the cells in our blood vessels, which could increase our risk of having a heart problem.

Another one shows us that variability in our glucose levels is linked to higher risk of death even if we don't have diabetes. The study is called visit-to-visit glycemic variability and risks of cardiovascular events and all-cause mortality: the ALLHAT study. In this study scientists looked at 5,000 people without diabetes and they showed that people with higher variability between their glucose measurements were at a higher risk of death. Specifically the people in the highest quartile of glucose variability had a 2.67 times greater risk of dying of anything than people who were in the most stable quartile. Again, this was done in people without diabetes and people who had normal fasting glucose levels. So even if you have normal fasting glucose levels, the variability in your glucose levels that could be caused by glucose spikes will have an association with a higher risk of death.

And other than the cardiovascular risk and the all-cause death risk, which are quite intense, we also have great data showing us correlations between glucose spikes and many other conditions. Let me read a few here.

Hunger and cravings. The study is called postprandial glycemic dips predict appetite and energy intake in healthy individuals. This study shows that when you spike high during a meal and then you drop low, this will create more cravings and more hunger—again, in people without diabetes. So, if you want to simply feel better, have fewer cravings, and be less hungry all the time, managing glucose levels is key.

Another example, menopause symptoms. The study is called a high glycemic index and glycemic load diets as risk factors for insomnia: analysis from the Women's Health Initiative. This study shows an association between having a diet that creates lots of glucose spikes and more menopause symptoms. And we are now discovering in the research that menopause and diet are linked and potentially when you reduce your glucose spikes, you can also help reduce your menopause symptoms.

Another one, this one on the immune system. I find this fascinating. The study is called the effect of short-term hyperglycemia on the innate immune system. The study shows us that after a meal, when we have a high glucose level—so we have a glucose spike—it temporarily inactivates our immune system. And our immune system is so key, as you know, to protect us against viruses and colds, etc. So if our immune system is compromised we could be suffering consequences, and big glucose spikes after eating hurt our immune system. I mean, it's wild.

Okay, one last one. Mental health. The study is called high glycemic index diet as a risk factor for depression: analysis from the Women's Health Initiative—again showing that if you have lots of glucose spikes in your diet, if you have what's called a high glycemic index diet, you are more likely to have mental health disturbances.

If you want more studies, have a look on my website, glucosegoddess.com/science. I've linked over 300 scientific papers that are really interesting and show all of these links. So, if you want to deep dive into the topic, I'll put the link to my science page in the description of this episode.

So overall, this research shows us it is a good idea to make sure our fasting glucose level is in the lower range of the normal range and that yes, we should worry about it even if we are still healthy because if we are healthy and we want to stay healthy, it is important to monitor our fasting glucose level and make sure it stays in the optimal range. And if we want to improve our quality of life, reduce symptoms, reduce potential for long-term problems, we should also focus on reducing glucose spikes, aka the variability of our glucose levels day to day.

Now, importantly, there's a lot of evidence showing that high fasting glucose levels and high glucose spikes have an impact on us. We don't have evidence showing us that high fasting glucose levels are good for us or that we should increase the amount of glucose spikes in our day-to-day life to improve our health.

So, what do you do if you want to get started? I have 10 glucose hacks that underpin all of my work that are super easy. I have linked in the description of this episode a one-page PDF that you can download with these 10 glucose hacks in them. My hacks will help you reduce sugar intake, increase your veggie intake, increase movement with lots of fun, really easy techniques, and will help you feel the results immediately on your energy, your mood, your cravings, your brain fog.

In conclusion, learn about your glucose levels, care about your fasting glucose levels, care about your glucose spikes. It's a great decision and a great focus that you can put on your health. It's going to help you in so many different aspects. It's going to help you feel amazing, which is the goal, and it's going to help you understand how your food impacts your body and your health.

Thank you for watching everyone. I'll see you next time.