How does excessive sugar consumption impact oral and general health?

Substituting sugarChris Harper examines the impact of excessive sugar consumption on oral and general health, and suggests some alternatives to refined sugar.

In this article, I will highlight the dietary modifications that both you and your patients can make to your diet to extensively cut your intake of free sugars.

That said, attempting to provide comprehensive dietary advice in the space available here would be impossible and beyond my remit. One aim of this article is, I suppose, to try to spark a greater interest and debate about sugar and diet as a whole. Hopefully it will inspire others who may want to research the topic more for themselves.

What follows are little snippets of my normal dietary advice. Also, a larger debate to give you a few ideas about things to research further.

Alternatives to refined sugar

Quite possibly the simplest way to make a positive impact on your diet is to do a swap. Swap refined sugar out of recipes and swap foods containing refined sugar for healthier options. When deciding what to use instead of refined sugar, many choices stand on offer. These range from natural sweeteners, such as coconut sugar, to artificial, chemically derived options, such as aspartame.

Some of these choices have well understood pros and cons. Scientific debate surrounds the others. These therefore require a bit more effort from the individual to decide whether to use them.

Natural sweeteners

This category contains many potential options that you can use instead of refined sugar in your recipes. For example, one simple swap to do – and one that my wife regularly bakes with– is coconut sugar.

Coconut sugar, derived from the sap of the coconut palm, is a natural, unrefined sweetener. While it is metabolised by oral bacteria in a similar way to refined sugar, it has a much lower glycaemic index. This results in much less of a blood sugar spike and crash. It also contains small amounts of various minerals. Refined sugar has no nutritional value at all.

Honey and syrups

Various natural liquid sweeteners are alternatives to refined sugar during cooking. Examples include honey, maple syrup, date syrup, brown rice syrup, and agave syrup.

Similar to coconut sugar, all can be metabolised by oral bacteria. This increases the risk of caries. However, they also do have some slight nutritional value. Though be warned, that not all of these natural sweeteners are created equal. You should avoid some entirely. For example, people thought that agave syrup was healthy.

Recently nutritionists shunned the syrup because of concerns about its potential impact on the liver.


Stevia is another natural sugar alternative, this one derived from plants in the Asteraceae family. It comes recommended by many nutritionists because it has a GI of zero. Also, it isn’t metabolised by oral bacteria, meaning no increased risk of caries.

However, as always, be mindful that some forms of stevia are better than others. It depends on which species of plant it was derived from and how heavily processed it is.

You need little stevia, as it is 200-300 times sweeter than refined sugar.


Xylitol is a sugar alcohol derived from the bark of birch trees. It has a GI of seven, meaning very little impact on blood glucose levels. It doesn’t contain fructose, so also avoids the potential impact on the liver seen with some other sweeteners.

Xylitol also has a very interesting property for dentists. Whilst it cannot be metabolised by oral bacteria, they still ingest it. This results in disruption in the metabolic cycle of bacteria such as strep mutans. This even causes cell death thereby actually reducing the risk of developing tooth decay (Nayak et al, 2014).

There is, however, a slight caveat to the use of xylitol. As it is a sugar alcohol, if used in large quantities, it has the potential to cause gastrointestinal disturbances. Therefore, it is not recommended for people with a history of irritable bowel syndrome (IBS).

Artificial sweeteners

Artificial sweeteners are chemicals that do not occur naturally but are instead man-made. The aim is to give food the illusion of sweetness but without tooth decay and an increased blood glucose level.

This sounds brilliant. It is possible that one day we will find the perfect artificial sweetener that will make most of this article irrelevant. However, I choose to avoid all artificial sweeteners because I am not convinced that the debate about their suitability for human consumption is over at this point.

Many artificial sweeteners fall into the category of sugar alcohols, which like xylitol, can cause GI disturbances for many people if consumed in large quantities.

The problem

You could argue that this isn’t necessarily a big problem as any particular food will only require a very small quantity of an artificial sweetener.

However, this could become a problem that creeps up on our society. Especially if many food manufacturers choose to reduce the high sugar content currently in their produce simply by replacing much of it with one of these compounds. Many people will suddenly be consuming artificial sweeteners many times every day.

There has been a large-scale debate for many years about other potential adverse side effects of artificial sweeteners, with the headline concerns being the potential for neurotoxicity and a possible increased risk of various cancers linked to artificial sweetener use.

The current scientific research appears to suggest that these fears are not substantiated and suggest that at appropriate levels, artificial sweetener consumption isn’t correlated with either of these risks (Lohner et al, 2017). I am yet to be convinced because I don’t think we have good enough long-term data to make global statements at this time.

Weight gain

One risk that does seem to be coming to the surface is that, rather perversely, artificial sweetener consumption appears to be linked to weight gain for many people (Yang, 2010). The two main hypotheses for this are that people who choose a ‘diet’ food or drink item may then fool themselves into thinking it is okay to allow themselves a calorific reward for making this perceived healthy choice.

Therefore they consume more than if they had not chosen an item artificially sweetened in the first place.

The second hypothesis, is one that I agree with. By continually bombarding our sweetness taste receptors we become accustomed to overly sweet foods. Therefore we only crave those foods that tend to be high in calories.

I have found that by reducing my consumption of sugar and sweet foods in general, my tastes have changed. I can far better appreciate a larger range of tastes that in the past didn’t satisfy me. If I happen to try a commercially produced sweet treat now, they seem overly sweet. My palate is more sensitive than it was a year ago.

The added benefit of this is that if my wife is baking and following a recipe that asks for a certain amount of something like coconut sugar, she can put in less than half the amount than what the recipe calls for and still create something very satisfying.

Healthy snacks

Snacking is often regarded as the nemesis of those attempting to maintain a healthy diet, watch their weight, or reduce their risk of tooth decay. This idea is understandable when you consider that it is often very challenging indeed to find anything in the snacks aisle of a supermarket that doesn’t contain significant quantities of refined sugar.

I agree with the opinions of a growing number of nutritionists that the regular consumption of good snacks can help to maintain physical and mental energy levels.

The key is to avoid buying snacks you have in the past and instead choose things like seeds, nuts, cheese, oatcakes, or crackers (and be sure to check the labels for sugar and salt levels).

Healthier puddings

Flick through almost any baking cookbook and you will see that putting the words ‘healthy’ and ‘pudding’ together might seem like an oxymoron in its truest form. However, choosing to reduce your sugar intake doesn’t automatically mean choosing to forgo the third course in a meal. It just requires a bit of lateral thought to find options that are satiating while not leaving you at high risk of both caries and a metabolic crash an hour later.

As discussed earlier, it is possible to substitute refined sugar for one of a variety of other alternatives. Or if you want to take this idea further you can eliminate any of these sweeteners at all just by rethinking how you create your puddings.


Understanding the role sugar has on both dental and general health is complex. People don’t give it enough emphasis in either the undergraduate or postgraduate dental fields.

We need further research to deepen our knowledge about the long-term implications of sugar. As well as many of the available alternatives. There are some simple ways you can reduce your personal sugar intake. You can also help your patients to do the same.


Abou Neel EA, Aljabo A, Strange A, Ibrahim S, Coathup M, Young AM, Bozec L, Mudera V (2016) Demineralization-remineralization dynamics in teeth and bone. Int J Nanomedicine 11: 4743-4763

Liley AW (1972) Pathophysiology of gestation. Volume 2. New York Academic Press, New York

Lohner S, Toews I, Meerpohl JJ (2017) Health outcomes of non-nutritive sweeteners: analysis of the research landscape. Nutr J 16(1): 55

Nayak PA, Nayak UA, Khandelwal V (2014) The effect of xylitol on dental caries and oral flora. Clin Cosmet Investig Dent 6: 89-94

Solomon TPJ, Haus JM, Cook MD, Filion J, Rocco M, Kashyap SR, Watanabe RM, Barkoukis H, Kirwan JP (2010) A low-glycemic index diet combined with exercise reduces insulin resistance, postprandial hyperinsulinemia, and glucose-dependent insulinotropic polypeptide responses in obese, prediabetic humans. Am J Clin Nutr 92(6): 1359-1368

Tasevska N, Jiao L, Cross AJ, Kipnis V, Subar AF, Hollenbeck A, Schatzkin A, Potischman N (2012) Sugars in dient and risk of cancer in the NIH-AARP Diet and Health Study. Int J Cancer 130(1): 159-169

Yang Q (2010) Gains weight by ‘going diet?’ Artificial sweeteners and the neurobiology of sugar cravings. Yale J Biol Med 83(2): 101-108.

This article first appeared in Oral Health magazine. You can read the latest issue here. 

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