Should you be worried about high blood sugar levels even if you’re not diabetic?

Go on Instagram, TikTok, YouTube or X, and you’ll come across accounts dedicated to preventing blood sugar or glucose spikes, and curbing sugar cravings. Wellness influencers who claim breakfast oats as beneficial for blood sugar levels are as plenty as those who vilify oat milk in your morning coffee.

And we haven’t even included posts that celebrate lemon juice or apple cider vinegar as panacea for levelling out glucose spikes. What about those claims that eating your meal in a certain sequence (vegetables and meat first) can help tamper the rapid increase in blood sugar? 

It’s enough to confuse and make you wonder: Do you have to watch your glucose levels even if you’re not diabetic?

IS GLUCOSE THE NEW ENEMY?

It is helpful to understand the role and function of glucose – and how it is created and metabolised by your body. The food that you eat gets digested into nutritional components such as sugar (glucose), amino acids and fatty acids, explained Dr Andre Tan, a consultant with Alexandra Hospital’s Department of Medicine, Division of Endocrinology.

In the case of sugar or glucose, it either gets utilised to generate energy for the body or stored for future use. “Insulin is the hormone that helps to shift glucose into the cells of the body for utilisation,” said Dr Tan. “In healthy individuals, there will be an increase in blood glucose levels after a meal but this will be dealt with by the corresponding release of insulin.”

So, does that mean blood sugar or glucose increases after eating are normal and to be expected even? It depends on how high the levels are.

For non-diabetic individuals, that means no higher than 7.8mmol/L (140mg/dL) 90 minutes after eating, said Wong Hui Mei, Gleneagles Hospital’s principal dietitian, citing the International Diabetes Federation. “While occasional glucose spikes after consuming sugary meals, snacks or drinks are common, it is unlikely for a healthy, non-diabetic person to experience excessive spikes following a typical, balanced meal,” she said.

Glucose spikes can also follow after taking certain medications or during severe illness or infection in people who are healthy, said Dr Chan Soo Ling, a consultant with Ng Teng Fong General Hospital’s Department of Medicine, Division of Endocrinology.

SHOULD WE WORRY ABOUT HIGH GLUCOSE LEVELS IF WE DON’T HAVE DIABETES?

The short answer is “yes”, especially if the spikes are frequent, said Jaclyn Reutens, a clinical and sports dietitian at Aptima Nutrition and Sports Consultants, as they “might indicate a risk for pre-diabetes or diabetes”.

It begins in your pancreas, the organ responsible for secreting insulin. “Your pancreas will have to work extra hard to release insulin to bring the sugar level down to the desired normal range,” said Dr Chan. This is done by signalling the liver, muscles and fat cells to store the excess glucose to bring down the glucose level circulating in the blood, she explained.

However, “in the long run, the production of insulin is affected as the pancreas ‘tires out’ from overworking for years to produce more insulin,” said Dr Tan. “Because of this, glucose cannot properly move into the cells to generate energy or be stored for future use, and rises to a greater extent after meals.”

Added Dr Chan, "with prolonged and repeated sugar spikes, this will lead to the accumulation of excess glucose in the liver and fat cells, especially those around the visceral organs". "This will then result in insulin resistance”, which is when “the action of insulin is impaired and is not able to maintain the blood sugar level within the desired normal range”.

It’s not only prediabetes and Type 2 diabetes that you have to worry about. “Regular glucose spikes are usually followed by sugar crashes that can cause sudden hunger pangs, cravings, poor sleep, poor concentration and tiredness,” said Reutens. “Over time, these symptoms result in poor food choices that can lead to an increased risk of some cancers, PCOS and infertility, and liver problems.”

Wong cautioned that “long-term blood glucose spikes can cause blood vessels to harden and narrow, which can lead to a heart attack or stroke”.

SHOULD WE BE MONITORING OUR GLUCOSE LEVELS IF WE’RE NOT DIABETIC?

No one looks forward to the low energy level, irritability, maybe even a headache or dizziness that accompany a post-meal sugar crash. And you could be wondering: Should I monitor my blood sugar levels, especially when there's a family history of diabetes?

“Closely monitoring one’s own blood glucose levels after a meal is a double-edged sword,” said Dr Tan. The upside is, you may start to seek out the right advice to choose healthier foods or reinforce your resolve to keep to an already-healthy diet. “Additionally, in people with undiagnosed prediabetes or diabetes, it could lead to earlier diagnosis,” he said.

However, the downside could be a false sense of complacency, said Dr Tan. If you don’t have diabetes and don’t see a big jump in your blood sugar levels, you may think it is okay to continue eating the way you do. “Another downside could be increased anxiety or an unhealthy obsession with repeatedly checking blood sugar levels when the person is otherwise healthy,” he said.

If you have questions about your blood sugar levels, see your doctor for advice and further action.

WHICH IS FACT? WHICH IS SOCIAL MEDIA LORE?

You would already have read elsewhere that food containing highly processed carbohydrates (such as bubble tea and pork floss bun) break down into simple sugars – and are the culprits for raising blood sugar levels.

Conversely, “complex carbohydrates will take longer to be digested and absorbed, so that affects the timing of the rise in glucose levels”, said Dr Tan. Meals that are high in fat and fibre will also “stay in the stomach longer and be digested more slowly, and hence, the rise in blood glucose may be delayed”.

But what about the other food or drinks you’ve read about in social media posts? Should you take them with a pinch of salt, or is there a degree of truth worth looking into? We put them to the experts to find out what effect they have on your glucose levels.

1. Drinking lemon juice in water first thing in the morning

“The notion about drinking water with lemon juice first thing in the morning to help control sugar level is not scientifically proven,” said Dr Chan. Moreover, drinking such an acidic drink can upset the stomach in some people with sensitive stomachs and aggravate existing acid reflux issues. The highly corrosive drink can also cause possible tooth enamel erosion, she added.

But if you don’t have those issues and the lemony flavour stimulates your appetite for breakfast (which you shouldn’t be skipping), said Reutens, there is little harm drinking it.

2. Having oats for breakfast

“Oats are low on the glycaemic index (GI) because of their beta-glucan and a warm bowl of oats can certainly start your day off right,” said Reutens. “Just be mindful of the honey, fruits or maple syrup that you add as they will increase your glucose response.”

Dr Chan also highlighted that not all oats are the same. “The more processed the oats, the less beneficial fibre they contain. Instant oat has a higher GI than rolled oat and steel-cut oat.”

And don’t limit your breakfast options to oats either. “No single food can provide all the nutrients and health benefits required by our bodies,” said Wong. “Managing a healthy and balanced diet with proteins, fats, minimally processed wholegrains and fibre-rich foods, while limiting sugar and refined carbohydrates, can help achieve optimal blood glucose levels.”

3. Eating a savoury breakfast instead of a sweet one

While a savoury breakfast can mitigate glucose spikes better than a sweet one, a savoury brekkie can be “high in saturated fat, which can exacerbate insulin resistance”, said Reutens. “Therefore, a savoury breakfast is not superior to a sweet breakfast. Both types of breakfast have their healthier and not-so-healthy choices.”

If you’re keen on a savoury start to your day, aim for adequate protein to help promote longer satiety, said Dr Chan. “Eating carbohydrates with protein-rich food tends to help stabilise blood sugars by blunting the absorption of carbohydrates or sugars,” she said. “That being said, your blood sugar levels will still spike if you have a very high-carb diet with protein. It may not spike immediately post-meal (within two hours) but may occur several hours later.”

To start you off, opt for low-sugar, high-fibre cereals with milk, omelette with wholemeal toast, thosai with daal or chicken porridge, suggested Reutens. You may want to stay away from curry puff, hotdog bun, char siew pau, nasi lemak, roti prata and fried bee hoon with luncheon meat, she said.

4. Mixing apple cider vinegar in water and drinking it a few minutes before a meal

“Studies of apple cider vinegar’s impact on blood sugar levels tend to be small and have mixed results,” said Dr Chan. “There is little scientific evidence to support its benefits. Human studies supporting the daily use of apple cider vinegar are lacking. The efficacy and safety in long term use is also unknown.”

Reutens also noted that “no good research” suggests that apple cider vinegar helps to lower blood glucose levels. “The amount of carbohydrates and macronutrients such as protein, fat and fibre have a bigger impact on glucose control.”

But if you’re keen to continue with diluted apple cider vinegar because the drink encourages you to eat a more balanced meal, “there is no harm in doing so”, said Reutens. One to two tablespoons in water “is probably safe” but like lemon water, the acidity may lead to stomach irritation or indigestion, nausea and tooth enamel erosion, cautioned Dr Chan.

“To minimise the risk of tooth enamel erosion, sip diluted apple vinegar cider through a straw and rinse your mouth with water afterwards,” she advised.

5. Using oat milk for your coffee

Here’s where it gets confusing. While oats for breakfast can be beneficial, the same can’t be said of oat milk. Why is that?

To make oat milk, enzymes are added to oats to break down the starch into a simple sugar called maltose. Maltose has a GI of about 105, which is even higher than pure glucose. This is why even without the addition of sugar, unsweetened oat milk may not be suitable for those looking to prevent blood sugar spikes. And that’s not taking into account the sugar added to make such plant-based milks more palatable, said Dr Chan.

When in doubt, check the ingredient list and nutrition panel on the packaging, advised Reutens.

6. Eating carbohydrates last

Doesn’t everything get digested into a mush in the stomach? There may be merit eating your rice or noodles last, said Dr Chan. “Protein, fat and fibre can slow gastric emptying rate. If your stomach retains and processes its contents longer before they enter the intestine for the nutrients to be absorbed, it will help reduce spikes in blood sugar after a meal,” she said.

Dr Chan cited a study that found eating vegetables or protein before carbohydrates as opposed to the other way around created a glucose level that was consistently lower by about 17 per cent to 30 per cent for up to 120 minutes.

This means eating your vegetables, then your chicken or fish, followed by your rice or noodles, said Reutens. And “you should eat dessert straight after a meal, so that the main meal can mitigate the impact of the blood glucose spikes caused by your dessert”.

7. Choosing "less" bad alcoholic drinks

It may have ginseng or kombucha but unfortunately, alcoholic drinks such as cocktails “have little or no nutritional value and often contain a lot of added sugar”, said Wong. “Added sugar is empty in calories and may increase the risk of blood glucose spikes.”

If you must imbibe, Wong has two key principles to follow: First, choose an alcohol that is free or low in carbohydrates and sugar. This could be any distilled spirit such as rum, vodka, gin, tequila, whiskey or brandy. Then, opt for healthier mixers such as diet soda, seltzer water and diet tonic water instead of high-sugar juice, syrup and regular soda.

Second, drink in moderation and avoid drinking regularly. “The recommendation is one drink or one unit per day for women, and two drinks or two units per day for men,” said Wong. One unit of alcohol is defined as 100ml of wine, 30ml of spirits (about 1 shot glass) or 330ml of beer.