Sugar and natural sweeteners: how different are they, really?

Whether or not we have a sweet tooth, almost all of us consume sugar in some form or another everyday, throughout the day - some naturally occurring like those in fruits and vegetables, some added by the manufacturer to prepared foods (including ketchup, bread, yogurt, breakfast cereal, and baked beans) and some added by us, like table sugar or honey.

The downsides of excess sugar consumption are well-documented: it can increase the risk of heart disease, diabetes, weight gain, cancer, tooth decay, depression, fatty liver disease, and more (1). So, why do we eat it? Well, firstly, because it is delicious! Also, it has short term hedonic effects and activates our brain’s reward systems (2), and, we are biologically programmed to seek it out because naturally sugary fruits helped our ancestors survive when food was scarce (3). While eating sugar is not technically essential because our body can make it for us, the reason we are able to make our own is because it is so important for energy production.

These days there is no real food scarcity problem in the Western world, and sugar in all forms abounds in our diet. We have learned how to isolate it from natural sources, process it, add it to other foods, as well as learning how to manufacture substitutes in the lab. For the average European adult, sugar accounts for 15-21% of daily energy intake (75-105 grams) (4), while adults in the USA reportedly get a whopping 25% of their daily energy from sugar (126 grams), topping the global charts (5)! ​

For reference, the World Health Organization recommend limiting added sugars to <10% of daily energy intake; ten percent of a 2000 calorie diet would be 200 calories, which is 50 grams of sugar per day, or 12.5 teaspoons (6). The American Heart Association is even more austere, suggesting no more than 36 grams (9 tsp) for men and 25 grams (6 tsp) for women per day (7), which is just 5% of daily energy intake, and a lot less than we are currently consuming.

​Are all sweeteners created equal?

You may have read that all sugar ends up the same in our body, so choosing honey over white sugar or agave syrup makes no difference. That is partly true and partly not true. It is true that all sugar (all carbohydrates, actually) end up as glucose, but they are broken down in different ways, so they have different effects on our blood sugar levels. Also, some sweeteners are highly refined, giving us ‘empty calories’, while others are less refined and retain some nutrients.

​Metabolism

The three basic units of sugar are glucose, fructose, and galactose. Glucose can be taken in by every cell in the body and used for energy production. Fructose and galactose need to be converted into glucose in the liver. Galactose isn’t a common sugar (it’s part of lactose, found in milk products), so I’ll focus on glucose and fructose here, which are the most plentiful in the diet.

When you eat a donut, the stomach breaks down the sugar and starches into glucose and fructose, which get absorbed through your intestines into your blood stream. Now there is lots of glucose in your blood (elevated blood glucose levels), so the pancreas releases insulin, which escorts the glucose into the cells, and reduces blood glucose levels. When the cells are full, any excess glucose, plus the fructose, get circulated to the liver. At this stage the liver converts excess glucose to glycogen (short-term glucose storage), or to fat cells (for longer term storage). It also converts the fructose to glucose, and stores that too.​

Glucose causes a spike in blood sugar that we measure with the glycemic index (GI): the more glucose in a food, the higher the GI value, with pure glucose being 100. If your body is constantly receiving high amounts of sugar over a prolonged period, when the insulin comes knocking on the cells with a glucose delivery, the cells stop responding to it (like ignoring a knock at the door because you’ve got enough Girl Scout cookies and you can’t face saying “no, thank you” again). This is called insulin resistance. Eventually, chronically high blood sugar can lead to diabetes: the pancreas stops producing insulin because the cells have stopped responding to it.

High glycemic foods are those with a GI value 70+, low glycemic foods are <55, and everything in the middle (56-69) is medium. The glycemic index isn’t perfect: different people will have different blood sugar responses to the same foods, and the same food items can have different GI values depending on ripeness or how they are prepared. In addition, we rarely eat an ingredient in isolation, and combining foods will affect the overall blood sugar response. For example, a teaspoon of sugar on a bowl of cornflakes is going to spike blood sugar more than a teaspoon of sugar on a bowl of steel cut oats with almonds - the extra fiber, protein and fat in the latter will slow down release of the sugar into the blood stream. That being said, it does provide a guideline for assessing a food’s impact on blood sugar levels.

Because most of the cells of the body can’t use fructose, the majority of it ends up in the liver, and because there is only so much short-term glucose storage needed, most of it ends up as fat cells in the form of triglycerides, more LDL cholesterol, and fatty deposits on the liver. So, while fructose doesn’t have much of an impact on blood sugar levels, it does impact blood lipid levels unfavorably, increasing the risk of cardiovascular disease, obesity, and also diabetes (8).

In nature, fructose comes from fruits and vegetables, and poses minimal harm because it is packaged with water and fiber and other nutrients that slow down digestion and absorption. However, isolated fructose is used as an added sweetener in a broad array of foods in the US (9), making it hard to avoid. Fructose consumption can also lead to leptin resistance (10): leptin is the satiety hormone, so resistance to leptin means that the brain doesn’t get the message that it’s full, so we keep eating beyond our needs.

​Raw vs. refined

Aside from the glucose vs. fructose consideration, some sweeteners are more highly refined, removing all of the minerals and other nutritious components. The closer a sweetener is to nature, the more nutrients it is likely to have. To be clear, while some sweeteners are a good source of magnesium (for example), that doesn’t mean we should consume lots of them for their magnesium content - there are plenty of magnesium-rich foods that don’t contain sugar! But, if you are considering using a sweetener with no nutrients or one with some trace minerals, a few extra nutrients are more beneficial than none.

Beyond the nutrition conversation, refinement also impacts the flavor and texture. The less refined, the more complex a flavor the sweetener is likely to have. Highly refined options tend to be pure white or clear, compared with darker tones among less refined products. Some sweeteners work better for some applications than others - you can’t simply substitute them all 1:1 in a recipe, unfortunately. Some are a little sweeter than sugar, some are less sweet. Some are granulated like sugar, but some are liquid. If you want to use a syrup instead of sugar in a recipe, you’ll need to reduce the liquid content elsewhere in the recipe, and this can take some tweaking. Some have a very strong flavor (e.g. molasses), while others are more subtle. These things will all impact whether you use them! 

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Baker’s Dozen

​White sugar (AKA table sugar)

Basic white granulated sugar comes from sugar cane or sugar beets; the juice of these plants is extracted, boiled down, and centrifuged, revealing large sugar crystals. A dark syrup is left behind, known as molasses (see below). The sugar crystals are further refined, removing color and nutrients, and filtered (typically with bone char) to achieve pure white fine sugar crystals. White sugar has no nutritional value beyond providing energy (AKA empty calories), but it is the standard for baking, and it’s what all other sweeteners are compared against. This highly refined sweetener is 100% sucrose (50:50 glucose and fructose), with a GI of 65 (medium).

​Brown sugar

Brown sugar (AKA evaporated cane juice, raw sugar) is essentially the same as white sugar, but only partially refined. Because the refinement process isn’t completed, some of the color and micronutrients are retained. Brown sugar is typically more moist in texture and has a more complex flavor, as it still has some of the molasses. It is marginally less sweet than white sugar, with a GI value of 64 (medium), and low levels of some minerals.

​Honey

Available raw or partially refined, honey is produced by bees and is a minimally-refined natural sweetener. It is slightly sweeter than table sugar, meaning less can be used. Honey contains trace minerals, as well as antioxidants and some amino acids; it also has antimicrobial properties and is an effective first line defense against coughs (ref). There are also highly filtered honeys on the market - these will have lower levels of these beneficial components. Honey is around 38% fructose, with a GI around 50 (low). This means that it slightly better for blood sugar than table sugar, with less fructose, a slightly sweeter taste, and some bonus nutrients.

​Maple syrup

Maple syrup is the sap of the maple tree, tapped straight from the trunk and cooked down to a syrup; it is a minimally-refined natural sweetener. It can also be further cooked down until all the water evaporates, leaving maple sugar behind. Maple sweeteners are almost twice as sweet as table sugar, so less can be used (e.g. 2/3 cup of maple sugar = 1 cup of table sugar) in a recipe. Maple syrup is almost entirely sucrose (50:50 glucose and fructose), like table sugar, but has a lower GI value of 54 (low) due to its water and micronutrient content. It provides high levels of B2 and manganese, as well as zinc and calcium.

​Molasses

In the process of refining sugar cane into sugar, a dark brown syrup called molasses (or black treacle in the UK) is left behind. It is less sweet than sugar because most of the sweetness has been extracted, but what is left behind is a mineral-rich syrup, containing manganese, magnesium, iron, potassium and calcium, as well as high levels of vitamin B6. Molasses has a strong flavor that lends itself to certain recipes (e.g. gingerbread), but it isn’t an easy substitute for sugar in most cases. It has a GI value of 55 (medium), similar to the other liquid sweeteners above. Molasses is 30-40% sucrose, with around 10% glucose and 10% fructose, so the sugars are roughly 50:50 glucose and fructose.

​Coconut palm sugar

Another natural sugar, this is similar to maple sugar in its processing - the coconut palm is tapped, and the sap is boiled until no water remains. In terms of sugar content, it is mostly sucrose, with smaller amounts of glucose and fructose, and inulin (a fiber). The GI value of coconut sugar is 54 (low), in line with the other natural sweeteners we’ve discussed. Because it is minimally processed, it contains minerals like iron, zinc, calcium and potassium, plus some antioxidants. Coconut sugar looks and tastes similar to brown sugar, with a subtly sweet flavor.

High fructose corn syrup (HFCS) & glucose-fructose syrup

This highly refined sweetener is made from corn, typically genetically modified. The corn is processed into corn starch, then into corn syrup, then enzymes are used to convert some of the glucose into fructose, making the syrup sweeter. The result is usually 55% fructose, but there are versions with less (45% fructose) and with more (>90% fructose). Because it’s highly refined, HFCS has no additional nutrients.

In Europe a similar product is called glucose-fructose syrup (indicating more glucose than fructose). Corn is not as widely farmed in Europe, so glucose-fructose syrup is sometimes made from wheat. The European Union limits production of this sweetener (to 5% of all EU sugar production), so it is not very common (11), but in the US there are no production limits and HFCS is ubiquitous. HFCS has a GI of 58 (medium), slightly lower than table sugar due to its slightly higher fructose content.

​Brown rice syrup

This liquid sweetener is made by exposing cooked brown rice to enzymes that break down the starches into individual sugar molecules. Due to this refinement process very few nutrients remain, but one thing that does stick around is arsenic: arsenic is a toxic chemical present in most rice and rice products, even if they are organic, because there is arsenic in the fields where rice is grown. One study found significant levels of arsenic in all products containing organic brown rice syrup, including infant formulae and other foods marketed for young children (12). The sugar composition is mainly maltose, which is three glucose molecules linked together, so it is almost entirely glucose when broken down, giving it a high glycemic index value of 98. It is sometimes used as a vegan substitute for honey, contains minimal fructose, and it is slightly less sweet tasting than regular sugar.

​Agave syrup

The sap of the agave plant is extracted and refined. The sap contains fibers called fructans which can be good for insulin regulation and metabolism, but these are almost entirely broken down into fructose during refinement, which includes heat and enzymatic processing. This process renders the syrup almost devoid of nutrients, except possibly some antioxidants. The majority of the sugar in agave syrup is fructose - typically 75-85%, which is much higher than table sugar. This gives the syrup a very low GI value of 15, which is where it gets its health halo: marketing focuses on the low impact that it has on blood sugar. Unfortunately, fructose has deleterious effects on the metabolism and satiety signaling over time, so while it is not likely to cause significant problems with occasional use, regular use should be avoided.

​Date syrup

A staple of Middle Eastern cuisine, where it is called silan or date honey, date syrup is made by boiling down dates, then pressing and straining the mixture. It is fairly easy to make at home (recipes abound) or it can be found at stores carrying specialty products. Because it is minimally processed it retains many minerals: it has significant amounts of potassium and magnesium, plus phosphorous, calcium, iron and zinc. Date syrup is high in antioxidants (higher than fresh blackberries) and also has antibacterial potential: one study suggests that it might even be better than manuka honey at killing pathogens (13). The sugars in date syrup are 40% fructose, plus some fiber, giving it a GI value around 50 (low). It has a rich flavor profile and is less sweet tasting than sugar or honey.

​Date sugar

Date sugar is just desiccated whole dates, sometimes mixed with oat flour or maltodextrin to manage moisture. Because of this it doesn’t really dissolve or melt, which limits the applications of this substitute, although it is good for sprinkling applications and in some recipes. It also retains more of the trace minerals mentioned above (potassium and magnesium, plus phosphorous, calcium, iron and zinc), plus some fiber. It looks like brown sugar and can be used to replace it 1:1.

​Yacon syrup

Made from the roots of the yacon plant, it has a caramel flavor and is half as sweet as table sugar. The juice from the root is extracted and evaporated, similar to maple syrup, making this product minimal refined. It has an appearance and earthy flavor profile similar to molasses. Culinary uses are quite limited, but some people like it in place of other liquid sweeteners in beverages. In terms of carbohydrate composition, yacon syrup is half fructans (a prebiotic fiber) with the rest being a mix of fructose, sucrose and glucose. The GI value is widely cited as being 1, suggesting it has essentially no effect on blood sugar, but the University of Sydney, who are the originators and keepers of the glycemic index, found the GI to be 40 (14). Although the discrepancy is large, this value is still very low - second only to agave syrup - and with minimal fructose content. Yacon syrup may also have a beneficial effect on the gut microbiome due to the high fructans content: our good microbes ingest these fibers and produce short chain fatty acids, which are good for bowel health and may prevent weight gain, plus fructans may help reduce appetite (15).

​So, which one is right for you?

The most important take away - for everyone - is that moderation is the most important factor when it comes to sugar and health. Quality is important for all the reasons discussed, but no sweetener is good for us in large quantities. Pay attention to added sugars in packaged foods, because these could well be a major source of sugar in your diet: sugar (often HFCS) is added to 74% of packaged foods in the USA, including pasta sauces, bread, ketchup, yogurt, salad dressings, yogurt, peanut butter, breakfast cereal, fruit juice and more (15). So, even if you seldom eat candy, cookies, or pastries, and you don’t drink soda or energy drinks, most of us are still getting a steady stream of sugar from the rest of the foods we eat. Aim for fewer than 50 grams per day, which is 12.5 tsp, with half that amount being even better for your health (16). Taking a break from sugar completely for a few weeks can reset your sugar cravings and your taste buds!

• If you are watching your blood sugar closely, avoiding high glucose sweeteners (like brown rice syrup) is important, and lower glycemic index options, like date sugar or yacon syrup, will be better.

 

• If you have high blood lipids (triglycerides and LDL cholesterol), you probably want to avoid high fructose options (like agave), and read food labels to make sure you’re not unwittingly consuming high fructose corn syrup.

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• If you’re following a low FODMAPs diet, you will want to avoid sweeteners with excess fructose (HFCS, agave, honey), as well as those with fermentable oligosaccharides like fructans or inulin (e.g. yacon syrup). Stick with simple table sugar or other sweeteners with mainly sucrose (like maple syrup).

​If you are generally healthy and aren’t following a special diet, you don’t have to worry too much about picking the ‘right’ sweetener - in moderation, none of these is going to do you any harm, but you might want to stick with the more natural, less refined options. The less processed a sweetener is, the less of an impact it will have on your blood sugar and your liver. The sweeteners with additional nutrients are arguably a better choice, if all else is equal: for example, if choosing between white sugar or date sugar on your oatmeal, date sugar would be the more nutritious and flavorful option; if making meringues, sticking with regular sugar is probably going to be your best bet. I encourage you to try some of the options on this list if they are new to you - having a variety of sweeteners in the kitchen will allow you to play with the options in different applications and find out what you like. Plus, variety is always good, from a nutritional perspective.

Comparison Chart

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