The Skinny On Artificial Sweeteners

I am frequently asked about the sweeteners that can be used along with a low carbohydrate diet.  I am a strong proponent of a high fat, moderate protein, very low carbohydrate diet, and I use this dietary approach in my medical practice daily.  What follows is a reprint of my article about sweeteners that can be found on my low carb website.  

So what is the "Skinny on Sweeteners?" There are a number of sweeteners available that can be used with cooking; however, many of them are not appropriate for use with a low carbohydrate diet.

With an understanding that weight gain or weight loss is controlled by the hormone insulin, our overall goal is to lower the insulin levels in the blood stream.  Glucose (a carbohydrate in its most simple form) stimulates insulin to rise.   A Low carbohydrate diet works because insulin levels are significantly lowered throughout the day.  Elevation in cholesterol, elevation in triglycerides and stimulus for production of uric acid also occur because of surges in the hormone insulin. The most common stimulus for insulin to rise is the body’s recognition of the presence of carbohydrates or sugars.

First, and foremost, we must understand how these carbohydrates or sugars are labeled or named so that we can identify them in the food products we eat.  Most sugars are labeled with the ending “ose". 

Sucrose, fructose, glucose, dextrose, lactose, and maltose are very common sugars you’ll see in the ingredient list of many products containing carbohydrates. All of these types of sugars will stimulate a significant insulin rise and lead to weight gain, elevation in cholesterol and triglycerides. 

Other very commonly used names that you will find containing the sugars above are: white and brown sugar, succanat, corn syrup, high fructose corn syrup, honey, malt syrup, cane juice, cane syrup, rice syrup, barley syrup, maple syrup, molasses, turbinado, and fruit juice concentrate.  Beware of products that contain "no added sugar" because they will often contain sugar concentrates in the form of concentrated grape or apple juice.

Fructose is sometimes promoted as a suitable sweetener for patients with diabetes or people who are wanting to follow a low-carb diet; however even though it does not cause a significant insulin rise, it is rapidly absorbed by the liver and converted into glycerol which leads to increased triglyceride and cholesterol levels.  Even though fructose occurs naturally in regular fruits and some vegetables, it is usually only present in small amounts. The fiber in these fruits or vegetables balances out the fructose content.  Today, fructose is added commercially to many foods in a highly refined purified form as high fructose corn syrup. Be careful because this form of fructose is found in soft drinks, ice teas, fruit drinks, jams, jellies, desserts, baked goods and even in many baby foods.  This form stimulates an extremely powerful stimulus in the liver to form triglycerides and leads to fatty liver disease, a form of non-alcoholic cirrhosis (J Am Diet Assoc, Lustig RH, 2010 Sep; 110 (9):1307-21).

Artificial Sweeteners
Most artificial sweeteners fall into a class that is referred to as “non-nutritive” meaning that they have no nutrient value to the human body. They provide a sweet taste to the senses without raising the blood sugar. These sweeteners can be useful in cooking and in maintaining blood sugars; however, it is important to realize that many of them still stimulate an insulin response.

Aspartame
The most popular artificial sweetener in use today is aspartame (NutraSweet™, Equal™).  Aspartame is calorie and carbohydrate free; however, it is not the ideal sweetener. Because of its chemical instability, it breaks down under heat into its chemical constituents - namely phenylalanine and aspartic acid. This makes it notably unsuitable for cooking or for storage for more than a few days. 

Second, in light of its safety profile maintained by the manufacturer, a number of people of experience side effects including headache, stomach upset, migraine and exacerbation of depression (Neurology October 1, 1994, vol. 44: 1787). Most people enjoy without problem, however.

Acesulfame Potassium
A second popular sweetener has been identified by the food and beverage companies called acesulfame potassium (Ace-K™, Sunette™). This sweetener is not fully absorbed by the gut, and yields no calories, nor does it raise blood sugar.  It also contains no carbohydrates.  To many palates, it has a slightly bitter savor, so it is often combined with aspartame to eliminate the bitter aftertaste.  The problem with acesulfame potassium is that there are a number of studies revealing it significantly increases insulin response without raising blood sugar.  Studies show that the insulin response is as remarkable as if a person ingested an equivalent amount of glucose (Horm Metab Res. 1987 Jun; 19(6):233-8.).  It appears thatacesulfame potassium works directly on the pancreas to stimulate insulin release (Horm Metab Res. 1987 Jul; 19(7):285-9).

This product appears to be one of the most popular artificial sweeteners currently used in a number of low-carb products. It can be found in many of the protein bars and protein shakes on the market.   It is also found in Coke Zero™, Pepsi One™ and a number of other diet sodas.  I have found in my private medical practice that this sweetener significantly limits weight loss.

Sucralose
Sucralose (Splenda™) is actually derived from regular sugar in such a way that the body doesn't recognize it, and it is not absorbed. It contributes no calories or carbohydrates to the body in its pure form. Amazingly, it remains stable in heat and has become ideal for cooking and baking.  It is available as a bulk sweetener and actually measures equivalently to table sugar.  Be aware, however, Splenda™ is not carbohydrate free. Because of the maltodextrin used to make it bulk in nature, it contains about 0.5 g of carbohydrate per teaspoon, or about 1/8 of the carbohydrate of sugar. It does cause some insulin release and may lead to weight gain or difficulty with weight loss when used in excess (J Clin Oncol [Meeting Abstracts] June 2007 vol. 25no. 18_suppl 15127).  1 cup of Splenda™ is equivalent to 2 tablespoons of sugar, or 12-15 grams of carbohydrate in 1 cup of Splenda™.

Saccharine
Saccharine (Sweet’N Low™, SugarTwin™) is another unstable chemical when heated, however, it does not react chemically with other food ingredients and thereby stores well. It was used for quite some time as one of the original sweeteners.  It does not increase glucose or blood sugar, but it does stimulate an insulin response and can be problematic in weight loss (Am Jour Physiol - Endo April 1980 vol. 238 no. 4 E336-E340). It is often combined with other sweeteners to preserve their shelf life.

Cyclamate
Cyclamate (SugarTwin™, Sucaryl™) is a sweetener available in Canada that is often combined with saccharine and is similar to sucralose. However, there is some controversy over this substance as it is known to cause bladder cancer in rats. There has been no human occurrence in its 30 years of study (Ann Oncol, October 2004, 15(10): 1460-1465.doi: 10.1093/annonc/mdh256). This product is currently banned in the US because of the notable potential for cancer. Cyclamate is stable in heat and therefore is an alternative for cooking and baking.

Stevia
Stevia is a non-caloric natural sweetener which contains no carbohydrate. He is to rise from a South American plant and has been widely available for use in Asia for many years. It comes from a shrub called Stevia rebaudiana that has very sweet leaves. Stevia is in extract, a white powder that is derived from these leaves.  It can be found today commercially in extract, powder, or in a powdered green herbal leaf. It has an intense sweet taste which actually does have the potential to be slightly bitter.  Stevia has two faults. First, it is so very sweet that it is hard to know just how much to use when cooking. Second, he often has a slight bitter taste as well as a sweet one. Therefore, stevia is often combined with fructooligosaccharide (FOS). FOS is a sugar, but it is such a large molecule that humans cannot absorb it. It does not raise blood sugar and it does not stimulate insulin release.  Stevia does not increase blood sugar and appears to improve insulin sensitivity in the pancreas (Metabolism, 2003 Mar;52(3):372-8.). FOS is only half as sweet in table sugar; therefore, it makes it a perfect partner for stevia.  

Sugar Alcohols
Sugar alcohols are also called polyols.  These are a class of long-chain carbohydrates that are neither sugar nor alcohol. Included in this group are maltitol, sorbitol, mannitol, xylitol, erythritol, lactitol, and hydrolyzed starch hydrolysates (HSH).  These sweeteners give the texture and sweetness of sugar to corn syrup and can be used to make crunchy toffee, chewy jelly beans, and slick hard candies, moist brownies and creamy chocolate.  However, they are incompletely absorbed by the human intestine.  This causes problems, as side-effects of these long-chain carbohydrates include gas, bloating and diarrhea for a significant portion of people. The other issue is that there seems to be notable variability in people's ability to absorb these long-chain carbohydrates.  In other words, these sweeteners affect people differently and may actually increase the blood sugar and insulin release in varying degrees among individuals. 

Maltitol, sorbitol and xylitol seemed to be worse offending culprits in this class of artificial sweeteners. They cause an insulin response of about half that of normal sugar (American Journal of Clinical Nutrition, Vol 65, 947-950).  Maltitol and sorbitolhave also been shown to increase cholesterol (International Journal for Vitamin and Nutrition Research, 1990 Vol. 60 No. 3 pp. 296-297). Erythritol is absorbed and excreted unchanged and appears to have no insulin response (Food and Chemical Toxicology Volume 36, Issue 12, December 1998, Pages 1139-1174). Erythritol also seems to inhibit fructose absorption (http://rave.ohiolink.edu/etdc/view?acc_num=osu1180462637).

So, in summary, which sweeteners will not cause weight gain or cholesterol changes?  From the research that is presently available, aspartame, Stevia, anderythritol have no weight gain or cholesterol changes associated with them. Splendais a great sweetener, but excessive quantities will limit your ability to loose weight. All of the other sweeteners listed above have significant insulin response when ingested and will make it more difficult to lose weight.  I have found that combinations of Stevia, Splenda and erythritol seem to provide adequate texture and remove any aftertaste that may be found when using them individually.