I’ll never forget the alarming incident that Samantha and I experienced a few years ago following a high sugar intake. Surely a health-conscious guy like me doesn’t go near sugar? Generally, no, but there is one occasion where it is not just ok, but encouraged. Immediately post-workout it is common practice to down a whey protein shake with a large dose of fast acting carbohydrate, i.e., sugar.
On this occasion we had had a big workout, chugged the aforementioned shake and then walked the two miles home. Towards the end of our walk we both experienced a blood sugar low to remember. Cold sweat, weakness, disorientation and difficulty stringing a sentence together, followed by a forced sit down on a wall. Samantha experienced a marked change in her personality and mood. She was suddenly suspicious and fearful of me, started pushing me away, accusing me of trying to poison her. Through the fog of disorientation, we had a difficult conversation but eventually managed to stagger home to get something to eat, which quickly improved our symptoms.
This is just one dramatic example of the health risks of sugar, but there are many more. I’m sure everyone has seen news or documentaries, or read about the health risks. But do you know what it means to have too much sugar, do you know how to look out for it and do you understand the health risks of sugar?
Read on to find out – you might be surprised by what you didn’t know!
What is sugar?
That’s a good question, and one that can be answered in a number of ways, but let’s start with a purely factual, scientific definition.
The basic unit of carbohydrates is a saccharide and, in general, sugars are considered to be monosaccharides or disaccharides. Any carbohydrate with more than one or two saccharide units is either an oligosaccharide or a polysaccharide.
Examples of monosaccharides are glucose, galactose and fructose. Examples of disaccharides are:
- Sucrose – 1 glucose, 1 fructose – standard table sugar is sucrose in crystalline form
- Lactose – 1 glucose, 1 galactose
- Maltose – 2 glucose
When you see added sugar on a food label, it’s generally sucrose – if you’ve ever made cakes, biscuits and puddings, you’ll have spooned in standard table sugar.
So that’s the literal scientific definition of a sugar – not that useful. In order to understand why too much sugar is bad for you, it may be more useful to think of sugar in the way it affects our bodies.
I like to think of the health risks of sugar in three ways
- The way in which it raises blood sugar
- For the sweetness it provides
- As a food additive
I know, they all sound quite innocuous, but read on to understand more. Let’s look at each of these in turn.
Health Risks of Sugar: The Effect of Food on Blood Sugar
The effect of a food on blood sugar is an important consideration when designing your meals. As a general rule of thumb, foods that raise blood sugar quickly are less healthy than foods that raise blood sugar slowly. The effect on blood sugar is measured using a scale called the Glycemic Index (GI). The scale goes from 0 to 100, with foods at the high end being associated with a rapid rise in blood sugar. A food is considered high GI if it has a GI of 70 or more.
Why is a rapid rise in blood sugar a bad thing? Here’s why…
When blood sugar (blood glucose) rises, the body releases the hormone insulin. Insulin tells the cells around the body to get ready to absorb nutrients, including glucose. We say that the cells are sensitive to insulin, they are receptive to its effects and so allow the passage of nutrients into the cells. As glucose is shuttled into cells and energy stores, so it is taken out of the blood, enabling blood sugar to be controlled within a defined healthy range.
When blood sugar rises quickly, as it may do in response to a high GI food, the body releases insulin rapidly in an attempt to stabilise blood sugar levels. High insulin levels lead to a rapid uptake of glucose into cells and a consequent rapid reduction in blood sugar. Insulin is not cleared instantly and it continues to drive blood sugar down whilst it is circulating. This can lead to blood sugar becoming too low. Low blood sugar can give rise to all sorts of ill effects, one of which is ravenous hunger. Of course, ravenous hunger is more than likely going to encourage another high GI feed, another rapid blood sugar rise and another insulin spike. And so the cycle continues.
Back to the story that started this article. What had happened is that Samantha and I had
- Had a fast-acting high GI carbohydrate which had spiked our insulin, driving blood sugar down
- Exacerbated the blood sugar low by walking home, taking more carbohydrate from the bloodstream whilst insulin was still driving it down, leading to a more dramatic blood sugar low
- Compromised the ability of our livers to deliver sufficient carbohydrate into the bloodstream by depleting its carbohydrate stores during the earlier workout. This function of the liver is anyway inhibited in the presence of insulin.
The result: a horrendous blood sugar low.
So, what are the other problems with this insulin response to high GI foods?
First, it can encourage poor eating behaviours and lead to overeating. You’re far more likely to eat too much, too quickly when you have low blood sugar.
Second, this kind of eating behaviour can lead to constantly high circulating insulin levels. Insulin soars following a high GI meal and does not clear before the next high GI meal comes along. The next high GI meal just tops it up. This is a problem for lots of reasons. Here are two of them
- Insulin switches off lipolysis, or fat breakdown. Insulin is a storage hormone so whilst it’s circulating, you’re going to be storing carbohydrate and fat, not breaking them down. If insulin is permanently high then you’re going to struggle to reduce unwanted fat stores, you’re far more likely to accumulate fat.
- The body’s cells can become insensitive to insulin, they become resistant. The body releases more and more insulin in an attempt to stabilise blood sugar, exacerbating the issue. This insulin resistance can cause all sorts of health problems. For example, insulin also promotes the uptake of fat into fat cells. When fat cells become insulin resistant the fat ends up in other organs such as the liver and can cause fatty liver disease. If insulin resistance continues and worsens, it can lead to type 2 diabetes.
So, how do you avoid these problems? The answer is to eat foods that are slower to digest. In general, this means choosing foods that are unprocessed and contain fibre and low GI carbohydrate. Combining foods into meals will help lower the overall GI of the meal, so including protein, soluble fibre, liquid and some fat will all help to slow the impact on blood sugar. When you do this, the insulin response will be much more moderate, hunger will be kept at bay for longer, insulin levels will be kept in check and the body will have a healthier response to your eating behaviours. On top of that, unprocessed foods tend to be higher in vitamins, minerals and other beneficial nutrients, so they are a healthier choice anyway.
What sort of foods have a high GI? Generally, highly processed foods such as breakfast cereals, cakes, breads, crackers, pastries, rice cakes, sugary drinks, sweets and so on. These are foods that either are made from sugar or have been milled, stripped of their fibre and packaged into a food that provides instant gratification. Often, they will have had a lot of sugar added.
But, here’s a really important point.
A food does not need to contain any added sugar for it to be high GI. Take Weetabix, for example. If you look at the food label for Weetabix it says, per 100g, 69g carbohydrate of which only 4.4g is sugar. That looks ok, not much sugar there. But look up the glycemic index of Weetabix, as in this article here, and you’ll see Weetabix, with a GI of 75, is a high GI food. That means it’s going to raise your blood sugar quickly. As far as the body is concerned, Weetabix looks like sugar.
Why does it look like sugar? Because, even though not a lot of sugar has been added, the product is processed, quickly and easily broken down and assimilated into the bloodstream. It might as well be sugar. Here’s an interesting report on Weetabix which talks about the claim made that Weetabix provides slow release energy. It does, but only when consumed with milk. That’s a good example of how you can lower the GI of a food by combining it with lower GI foods. Nevertheless, Weetabix is high GI food. Have it with milk by all means, but there are better choices, like oats, for slow release energy.
So, with that discussion in mind, here’s my first altered definition of sugar: any food that has a glycemic index greater than 70.
Don’t rely on the ‘of which sugar’ numbers on the food label, look up the glycemic index instead. In general, try to minimise foods with a GI greater than 70. I say ‘in general’ because there are exceptions. For example, watermelon has a GI of 72. It’s great healthy fodder. But the difference is that it also has very little sugar in it, so it has a low glycemic load. It’s really the processed refined grains and sugary drinks and snacks that are to be particularly avoided. If you must have them, have them in moderation and infrequently. Combine them with lower GI foods to keep the meal GI low.
As a closing remark to this section, you might find it interesting that table sugar – sucrose – has a GI of around 63. In other words, it doesn’t fit in with the above definition of sugar! Before you decide to shovel in spoonfuls of sugar in an attempt to lower the GI of your breakfast cereal, just be aware that there are lots of other good reasons, outlined below, why this would not be a good idea.
Health Risks of Sugar: Sugar as a Sweetener
We have evolved to like sweet things. This was to our advantage when our genes were being shaped, because food was not as abundant and easily available as it is today. If you found something sweet, chances are it had a good deal of calories. Yay! Scoff the lot in case you don’t come across this opportunity again for a while. We’re programmed to keep eating the sweet thing once the sweet thing has been tasted. Sweet things are moreish.
Not only that, sweet things release serotonin in the brain and produce a pleasure or reward response. Having experienced this once, our brains want to experience it again. We seek out the sweet thing once more in an attempt to reproduce that pleasure response. Something less sweet just won’t hit the spot, you need that sweet thing! You become addicted to sweetness. You’ll have heard the phrase sugar addiction – well that’s what it is. It’s like an addition to anything else – cocaine, alcohol, caffeine, chocolate, nicotine. If you don’t get it, you start to get withdrawal symptoms and when you try to substitute it with something else, it doesn’t hit the mark.
That means sugar can affect your mood. It might raise your mood when you eat it, but away from your sugar feeds you’re likely to experience low mood. As you’ll have seen in our article about the links between diet and mental health, a diet high in sugar and high GI foods has been associated with an increased risk of mental health issues.
Also remember from the previous section, you’re also likely to experience low energy when your blood sugar hits that low point. So, as with any addiction, you’re going to experience low mood and low energy, accompanied by an insatiable urge to get your sugar fix.
So how do you avoid becoming addicted to sugar or get over a current addiction?
First of all, stop consuming the offending foods. You may have to go ‘cold turkey’ for a while, but your taste buds should adapt quite quickly. Our clients report anything up to a week to get over a particular favourite food. Typically, it’s chocolate. If it helps, find a substitute food that gives you some pleasure but doesn’t have the calorie count or addictive qualities.
To avoid a sugar addiction in the first place…. well, just don’t go there! If your taste buds are not constantly overstimulated with intense flavours then you will be able to derive the same pleasure response from healthy unrefined foods. You’ll enjoy the taste of vegetables and all sorts of healthy tucker! Being addicted to fruit and vegetables wouldn’t be a bad thing.
If you like sweet things but are calorie conscious then you can try calorie free sweeteners. They’ll give you the pleasure hit without the calories. But, be warned, you can become addicted to these sweeteners too. In fact, there is some evidence that they are worse because they do not provide calories. The body has a way to tally the sweet signals with the calorie input they provide and decide to stop feeding when sufficient calories have been consumed. With calorie free sweeteners you may not get that feedback and so continue to consume the sweetened food without ever feeling satisfied.
So, here’s my second altered definition of sugar: anything that has been added to food to sweeten it or, on its own, provides a sweet hit. This ingredient is likely to have addictive properties that make people want to overeat in a single sitting and keep them coming back for more.
Health Risks of Sugar: Sugar as a Food Additive
This last section also talks about sugar as a food additive, but this time focuses on other features. There are three main areas of concern
- Calorie content. It’s easy to dissolve a lot of sugar into food and drinks without increasing the volume of that product. So, you can cram a lot of calories into a small space. Sugary drinks are an example. They are no more filling, in terms of the volume they occupy in your stomach, than water. Yet they can be loaded with sugar. Calorie dense foods such as sweets, cakes and biscuits can be loaded with sugar and deliver a large calorie hit without filling you up.
- Nutrient content. Well, there aren’t any nutrients! We’re talking vitamins, minerals and phytonutrients here. White table sugar is devoid of any health benefits. It delivers nothing in return for the cost of being processed by the body. So, net, it is a consumer of precious health-giving nutrients. When you eat, it is an opportunity to give your body some goodness, to nourish it with health providing nutrients. If you eat foods that have nothing to give in terms of health, then you will ultimately deplete your body of precious nutrients.
- Tooth decay. Bacteria in your mouth will feed on simple sugars and produce decay-causing acid to be produced in your mouth. A high sugar intake has been associated with tooth decay. If you eat sugary or high GI carbs, your mouth will be awash with simple sugars. That’s perfect fodder for bacteria that live in your mouth and great if you want to encourage tooth decay.
So that brings me on to my third altered definition of sugar: anything added to food that delivers nothing other than simple carbohydrate calories.
Now I appreciate these 3 definitions of sugar are a little contrived, maybe even controversial. And I don’t expect them to be taken up by others. I just think it’s important to understand the health risks of sugar in its broadest sense. I’m simply putting forward a view of sugar in a wider sense in an attempt to show that there is more to sugar than is generally appreciated. It isn’t just about the granulated stuff you stir in your tea or sprinkle on your food.