It’s trendy to be concerned about blood sugar spikes, but these can be a normal response to eating. Here’s when you don’t need to worry.
Over the last few years, two surprising things have started happening.
Normal, otherwise healthy people have started wearing devices that allow them to check their blood sugar levels throughout the day. Others have been cutting out refined carbohydrates such as white bread and pasta entirely.
In fact, authors, podcasters and wellness influencers have been selling the idea that we all need to check for blood sugar spikes and avoid them. According to this extreme view, we allow significant amounts of glucose in the bloodstream at our peril. Even in healthy people with no metabolic diseases, to risk a blood sugar spike is, they say, to welcome hormonal imbalances, acne, mood swings, and worse.
But now experts are pushing back. Here’s when to worry, and when that carbohydrate-heavy meal is unlikely to do any lasting damage.
Why does our blood sugar spike?
When we eat and digest sugary foods, such as refined sugar, fruit and carbohydrate-rich food, our blood sugar naturally inclines.
That’s because as we digest carbohydrates and sugars, they are broken down into glucose, which is then absorbed into the bloodstream, temporarily leading our blood sugar levels to rise. As it does so, the pancreas responds by secreting the hormone insulin, which helps move the glucose out of our bloodstream and into the body’s cells to provide energy.
It’s not only food that can raise our blood glucose levels. During high-intensity exercise, hormones such as adrenaline signal the liver to release more glucose into the bloodstream, providing extra fuel for working muscles. As a result, blood glucose can temporarily rise, says Jennifer Sherr, a paediatric endocrinologist from Yale School of Medicine, Connecticut in the US.
In people with diabetes the body does not produce enough insulin, or it no longer works as it should (insulin resistance). This means that after eating, their blood sugar can become dangerously high. In this case, it’s essential that people carefully manage their diet, exercise, and monitor their blood sugar levels to avoid spikes. Some people also need to take medications such as insulin or metformin.
Glucose spikes are normal
Among healthy individuals, a rise in blood glucose after eating is a normal physiological response. “The biggest misconception is that every glucose spike is harmful,” says Adrian Brown, associate professor in nutrition and dietetics from University College London in the UK.
Recently I experimented with giving up added sugar for six weeks. Since then, I’ve been especially attuned to the fact that when I eat sugary foods, my blood sugar is bound to rise.
Our blood sugar level typically peaks around one hour after eating and tends to return to baseline within the next two hours. If a spike is brief and occurs in someone with a normal metabolism, we should not be concerned, says Brown.
It’s when blood glucose remains elevated for longer than expected that it could indicate that the body is not regulating glucose normally, says Sherr. This could be a sign of insulin resistance, where the body doesn’t respond to glucose normally. Insulin resistance can happen if the body is exposed to high blood sugar levels over a long period of time. Eventually it can lead to prediabetes and type 2 diabetes. The persistently high blood glucose experienced by some diabetics can then lead to complications including nerve and eye damage, heart disease and stroke.
However some experts argue that there is not enough evidence to say that excessive blood glucose leads to insulin resistance directly. Instead, the explanation could be that when we eat more than our body needs these excess calories tend to be converted to fat, says Nicola Guess, a dietician and senior research fellow at the University of Oxford in the UK. The resulting weight gain is a risk factor for type 2 diabetes, she adds.
The rise of continuous glucose monitors
People with diabetes already monitor their blood sugar regularly. One way they do this is with continuous blood sugar monitors (CGMs), which measure blood sugar levels throughout the day.
There’s now a growing commercial market for these devices in otherwise healthy people. However, some experts warn that they are unnecessary for those without diabetes. One study of non-diabetic participants found that their blood sugar levels were in the healthy range 96% of the time, for instance.
Others urge caution that they can “prompt harmful dietary changes and distort perception of health”, especially as they can overestimate blood sugar levels. In a recent review, Brown and colleagues found “a lack of consistent, high-quality evidence showing that CGMs improve health outcomes in people who do not have diabetes.
Credit: bbc.com
