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The Five Ways Sweeteners May Be Making You Sick

Sophie Jackson is a freelance writer who has written for national newspapers and magazines.

Are Artificial, Low-Calorie, Non-Nutritive, or "Natural" Sweeteners Making You Sick?

Headaches, stomach upsets, nausea, mouth ulcers, low blood sugar—all these problems have been linked with the consumption of sweeteners. If you have recently been feeling unwell and do not know the cause, it may be because you are one of the many people who unwittingly suffer from an intolerance to sweeteners.

I can personally testify to the negative effects of consuming sweeteners which invariably make me violently nauseous. Their effect has made me very cautious of what I consume.

Learning what causes the problem is the first step to solving it. Below are five ways sweeteners can make you ill and the symptoms of sweetener intolerance.

Packets of artificial sweetener: Are they making you sick?

Packets of artificial sweetener: Are they making you sick?

Do Sweeteners Cause Headaches?

There is a lot of debate as to whether sweeteners cause headaches and migraines. Much of the information is anecdotal, though at least two scientific studies have indicated that migraines are triggered by the consumption of sweeteners—namely aspartame and sucralose (also known as Splenda).

Splenda and Migraines

Ironically, Splenda is often named as a "safe" sweetener for migraine sufferers. This is not necessarily the case. A study from 2007 demonstrated that one female patient suffered migraines as a direct result of consuming Splenda. Her migraines were also worse when triggered by the sweetener. When she completely removed sucralose from her diet, her migraines stopped.

Aspartame and Migraines

Another study, from 2009, indicated that aspartame was a migraine trigger, especially in children and adolescents.

Why Do Sweeteners Cause Headaches?

There are a number of theories as to why sweeteners may cause migraines. Aspartame is known to break down into formaldehyde when it is ingested, and many migraine sufferers react badly to formaldehyde. Aspartame also affects neurotransmitters, over-exciting brain cells and potentially destroying them. In certain individuals, this triggers migraines.

Do Artificial Sweeteners Increase or Decrease Obesity?

One of the known risk factors for migraines is obesity. Sweeteners have been marketed as a means of combating obesity; however, a number of studies, including one conducted by Yale University, have shown that sweeteners can increase obesity rather than decrease it.

John Hopkins University studied 24,000 people in 2014 and found that those who were obese drank higher quantities of diet drinks than those who were a healthy weight. The reasons behind this seemingly odd correlation are still being explored, but there is growing evidence that consuming sweeteners does not prevent you from getting fat.

Scroll down for a more in-depth discussion of the link between sweeteners and obesity.

Headache sufferer cradles his throbbing head

Headache sufferer cradles his throbbing head

Do Sweeteners Cause Digestive Issues or IBS?

If you are a sufferer from IBS (irritable bowel syndrome), you may be already aware that your symptoms worsen after consuming products with sweeteners. Even if you do not suffer from IBS, you may have experienced stomach cramps, nausea, vomiting or diarrhoea as a result of drinking or eating sweeteners.

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I can personally testify to the discomfort and sickness caused by consuming sweeteners. My first bad experience came after drinking lemonade that contained aspartame. I threw up after consuming it. Over the years, I have tried other sweeteners with similar effects. The awful nausea many of these sweeteners caused me has made me very cautious of what I consume.

Limited research has been done on why sweeteners cause these problems in some people, despite the fact that many IBS sufferers have been able to link an increase in their symptoms with sweetener consumption. It may be that sweeteners have a negative effect on the good bacteria in the gut, which is more noticeable in IBS sufferers.

Whatever the reason, many IBS sufferers are finding that avoiding sweeteners has made a huge improvement to their symptoms.

Problems Associated With Common Sweeteners

Table showing the side-effects associated with the commonest sweeteners.

NameUsed inBelieved to Cause


Diet drinks, sugar-free ice cream and sauces, lollypops, yoghurts

Migraines, stomach upsets, nausea, dizziness, tiredness


Sugar substitutes, diet drinks, sugar-free cakes/sweets

Migraines, depression, stomach upsets, nausea


Diet drinks, toothpaste, sugar substitutes

Stomach upsets, raised blood sugar


Soft drinks, jelly, jam, fruit juice drinks

Stomach upsets, nausea, low blood sugar, low blood pressure

How Do Sweeteners Affect Blood Sugar?

For people suffering from blood sugar problems, going sugar-free and consuming only products that contain sweeteners might seem like a logical choice. The reality is not so simple. Sweeteners might not only raise your blood sugar, but they could also lower it too far, resulting in hypoglycemia.

Stevia Lowers Blood Sugar

This is the case with stevia. Stevia is a popular sweetener used by many people, including diabetics. Stevia lowers the blood sugar, which for some, is a reason for consuming it; however, when already restricting diet to keep the blood sugar low, Stevia can be a step too far. The sweetener may cause blood sugar levels to drop too much, making a person seriously ill.

What Diabetics Should Know About Sweeteners

This is of especial concern for diabetics who must constantly monitor their blood sugar. When their levels drop too low, the solution is to reach for something sweet to give a sugar boost. If that product happens to be a drink or food flavoured by stevia, or certain other sweeteners, the anticipated effects will not be felt. The blood sugar will not rise significantly, and, in the case of stevia, the blood sugar may drop even lower.

Equally, not all sweeteners are good for diabetics, or people watching their blood sugar. Sorbitol and xylitol, for instance, though used in sugar-free products, actually can raise the blood sugar levels. Meaning their consumption needs to be monitored as carefully as eating products containing sugar.

Symptoms of Low Blood Sugar

Even non-diabetics can experience problems with their blood sugar as it rises and falls during the course of a day. Symptoms of low blood sugar in a non-diabetic include hunger, shakiness, feeling sleepy, feeling anxious, dizziness, confusion, sweating, trouble speaking, feeling irritable, and, at the worst end of the spectrum, fainting. The medical recommendation for when suffering a sugar low is to consume 15 grams of something containing a carbohydrate (sugar is a carb). This could be fruit juice, glucose tablets, or a hard candy.

What to Do

If you have experienced any of the symptoms above and consume sugar-free products, cutting them out of your diet may alleviate the problem. However, you should also consider seeing your doctor as frequent episodes of low blood sugar can be a sign of further health problems.

Sweeteners in Fruit Juice Drinks and Hard Candy

Unfortunately, many fruit juice drinks, unless listed as 100% pure juice, now contain sweeteners instead of sugar, making them useless for low-blood-sugar sufferers. The same can apply to some forms of hard candy.

Stevia's Effects on Blood Pressure

Few people are aware of the effect that certain sweeteners can have on blood pressure. Stevia, which is marketed as a natural sweetener made from the stevia plant, has long been known to act as a vasodilator—that means it widens the blood vessels, causing the blood pressure to drop.

This trait of stevia is often advertised as a benefit, and for some people it is. However, for those with naturally low blood pressure, or who are taking medications to reduce their blood pressure, the long-term effects of regular consumption of stevia could be serious. Medical News Today recommends that anyone with chronic low blood pressure or those taking medications to reduce blood pressure should speak to their doctor before consuming stevia.

Conversely, a recent review of 37 studies on the effects of consuming artificial sweeteners organised by the University of Manitoba, discovered that there was a link between sweeteners and an increased risk of high blood pressure. Dr. Meghan Azad, Assistant Professor at the university, stated:

"Caution is warranted until the long-term health effects of artificial sweeteners are fully characterised. Given the widespread and increasing use of artificial sweeteners and the current epidemic of obesity and related diseases, more research is needed to determine the long-term risks and benefits of these products."

Check the Label

This low sugar jam contains sweeteners and has a warning about possible side-effects of consuming them.

This low sugar jam contains sweeteners and has a warning about possible side-effects of consuming them.

The Battle of the Bulge

For many people, the consumption of sweeteners is part of a plan to lose weight or to keep weight off. Yet, more and more evidence is indicating that sweeteners are as much to blame for obesity as traditional sugar.

Do Sweeteners Help You Lose Weight?

In the same review of studies that discovered sweeteners could be linked to high blood pressure (see above), it was noticed that, despite claims, sweeteners were not helpful in weight loss programmes. "We found that data from clinical trials does not clearly support the intended benefits of artificial sweeteners for weight management," stated Dr. Ryan Zarychanski of the University of Manitoba.

Mounting Evidence

It seems counter-intuitive that diet drinks and foods could actually be making you fat, but the evidence for such a correlation is increasing. In the 1980s, the San Antonio Heart Study examined 3,682 adults over a seven- to eight-year period, looking at their gender, race and diet, and recording their BMI over the period. Those participants who drank artificially sweetened products had a higher BMI at the end of the study than those who did not drink low-calorie beverages. A similar study by The American Cancer Society produced the same results. (For both studies, see here.)

The reasons for this trend are complicated. It is known that sweeteners increase the appetite (follow the link above for studies) and that people who consume a diet drink before a meal will eat more than a person who has drunk water, or a naturally sweetened drink. Other experts contend that the link between diet products and obesity is psychological, with people feeling that as they have "been good" by drinking a low-calorie product, they can eat more.

Though the exact explanation for why sweeteners cause weight gain is still debated, one thing is clear—despite an increasing number of people opting to consume diet products and using artificial sweeteners, obesity is still on the rise.

The stevia plant is used to produce the commercial sweetener of the same name.

The stevia plant is used to produce the commercial sweetener of the same name.

Cutting Sweeteners

The use of artificial sweeteners is on the rise, but evidence suggests that in some people, they can be the trigger for serious health concerns. Experts argue on their safety and whether they actually have any benefit. The information out there can be confusing and contradictory.

I hope this article has given you some insight and maybe offered an explanation for what is triggering any health problems you are having. Cutting sweeteners from your diet could be the key to better wellbeing, but in practice, it can be a time-consuming and challenging process. Sweeteners can be found in any product and do not have to be listed as an allergen.

At the current time, many who are adversely affected by artificial sweeteners suffer in silence, possibly unaware of what is causing their ailments. As science catches up and provides evidence of the problems sweeteners can cause, this will hopefully change. Until then, the onus is on the individual to check every label on the products they buy.

What about you?

This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

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