Sunday, November 20, 2011

The Nutrition Debate #32: Artificial Sweeteners

I’ve been avoiding this topic because I was afraid I was going to learn “the bitter truth” as I researched and studied synthetic sweeteners. You may feel the same way after learning about them. But increasing public awareness about human nutrition and health issues is why I write this column, so here goes.

An artificial sweetener is a food additive that is not natural and that duplicates the effect of sugar (sucrose) in taste, texture and “mouthfeel.” The primary compounds used as sugar substitutes in the United States are sucralose (e.g., Splenda), aspartame (e.g., Equal, NutraSweet), and saccharin (e.g., Sweet’n Low). The good news is none of these products contain any fructose. The bad news: 1) the little yellow, blue and pink packets all contain bulking agents which are mostly sugars, and 2) the effect on the body’s hormonal system of a high-intensity artificial sweetener is as bad or worse than “natural” sugar, as in refined sugar cane, even allowing that cane sugar is 50% fructose!

Not a big deal? You say it’s just a little. Not so. Splenda, for example, is usually just 5% high-intensity artificial sweetener (sucralose) and 95% bulking agents, specifically dextrose (D-glucose) and maltodextrin, a polysaccharide containing from 3 to 20 glucose molecules in a chain. The body easily and quickly metabolizes both of these sugars as energy, while most (85% to 95%) of the non-nutritive sucralose passes unchanged out of the body through the feces or, after some is absorbed into the blood, through the kidneys as urine. Reviewing then, that’s 5% non-nutritive sweetener and 95% nutritive sweeteners, all basically absorbed and metabolized as glucose.

How much energy are we talking about in the 95% part? Each 1 gram packet of Splenda contains almost a gram of carbohydrate (3.36 calories). That compares to 10.8 calories in a 2.8 gram packet of sugar, 15 calories in a level teaspoon of table sugar or 25 calories in a heaping teaspoon. The 5% sucralose part is non-nutritive (zero calories), but sucralose, the artificial “sugar,” is about 600 times sweeter than sucrose (table sugar). That’s a lot of sweetness.

Is this important? If you’re diabetic or pre-diabetic and need to limit or restrict sugars, then “sure.” We know that glucose induces an insulin response, and we are trying not to wear out our pancreas which produces insulin. There is in addition, however, also the well-established scientific fact that the taste of sweetness, perceived in the mouth by the salivary glands, induces an insulin response. As such, even a high-intensity artificial sweetener that contains no glucose (I know of none) would induce an insulin response. Chronic high insulin levels in the blood (hyperinsulinemia), which occurs when there is little glucose to transport, leads to insulin resistance, and eventually to Metabolic Syndrome and Type 2 diabetes. Wide use of artificial sweeteners, in this respect, could be worse for your health than real sugar.

An Equal packet, containing the artificial sweetener aspartame, is made with dextrose (D-glucose), acesulfame potassium, starch, silicon dioxide, maltodextrin and an unspecified flavoring. Equal tablets contain the sugar lactose.

Sweet’n Low is a compound of granulated saccharin, dextrose and cream of tartar. In Canada, Sweet’n Low is made from sodium cyclamate because saccharin has been banned there since the 70’s. In the U. S., cyclamate was banned in 1970.

A similar and closely related sugar substitute is a natural sweetener from the herb stevia. Four years ago Cargill and the Coca Cola Company introduced the stevia-based product Truvia. It is made from rebiana, an extract of stevia, pus erythritol, a sugar alcohol, and natural flavors. More recently, Pepsico and the Whole Earth Sweetener Company introduced PureVia. It contains the stevia extract, plus dextrose, cellulose powder and natural flavors. These extracts are relatively new to the market and are used both as tabletop sweeteners and as food ingredients, especially in beverages.

Other natural sweeteners include the sugar alcohols. Maltitol and sorbitol are often used in tooth paste, mouth wash, and in foods such as “no sugar added” ice cream. Erythritol is gaining momentum as a replacement for these other two sugar alcohols in foods as it is much less likely to produce gastrointestinal distress when consumed in large amounts. Xylitol is an especially non-fermentable sugar alcohol that is tooth friendly and is used in chewing gum. Possessing approximately 40% less food energy than sucrose, xylitol is another low-calorie alternative to table sugar.

So, the bitter truth is “there’s no such thing as a free lunch.” Bitter is better. (Butter is better too.) Weaning myself off Splenda isn’t going to be easy. I take it in my coffee and in my iced tea every day. But bitter will be better for my health.

© Dan Brown 11/20/11

Sunday, November 13, 2011

The Nutrition Debate #31: Carbohydrates and Sugars

Are all carbohydrates sugars? Are all sugars carbohydrates? What is a carbohydrate? And what is a sugar? This is not chemistry class, but I think we all need to know the answers to these basic questions if we are going to guard our health. So, I’ll try to keep it simple and interesting. After all, we all have to eat, and making wise choices requires us to be well informed. There’s a lot of misinformation going around so listen up.

All carbohydrates are saccharides. The word saccharide comes from the Greek word meaning sugar. Carbohydrates are divided into four types: monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Monosaccharides and disaccharides are smaller compounds, composed of one or two molecules, and are commonly referred to as sugars. These compounds very often end in the suffix –ose. Examples include glucose (as in blood sugar), sucrose (as in table sugar), fructose (fruit sugar), and lactose (milk sugar).

Polysaccharides store energy (e.g. glycogen and starch) and as structural components (cellulose in plants). The term carbohydrate is often used to mean any food that is rich in complex carbohydrates such as cereals, bread, rice or pasta, or simple carbohydrates, such as candy, jams, jelly and ice cream.

Glucose, fructose and galactose are the three monosaccharides. They are the simplest carbohydrates in that they cannot be broken down into smaller molecules. They are the major source of fuel for metabolism, being used as an energy source (glucose being the most important). When not immediately needed for energy, they are converted into its storage form, glycogen, mainly in liver and muscle cells.

The disaccharides include sucrose (composed of one glucose and one fructose molecule), lactose (composed of one glucose and one galactose molecule) and maltose (two glucose molecules bonded in a special way). Oligosaccharides and polysaccharides are just longer chains of monosaccharides bound together. Oligosaccharides contain between three and ten monosaccharides and polysaccharides contain greater than ten monosaccharide units.

The human diet contains many foods high in carbohydrates: fruits, sweets, soft drinks, breads, pastas, beans, potatoes, rice and cereals. Carbohydrates are a common source of energy in living organisms; however, no carbohydrate is an essential nutrient in humans. Carbohydrates are not necessary building blocks of other molecules, and the body can obtain all its energy from protein and fats.

The brain and neurons generally cannot burn fat for energy, but use glucose or ketones. Humans can synthesize some glucose (in a process called gluconeogenesis) from specific amino acids, from the glycerol backbone in triglycerides, and in some cases from fatty acids. Glucose is a nearly universal, accessible and preferred source of calories. It is used first, either directly or indirectly from glycogen in storage. Polysaccharides are also a common source of energy. Many organisms can easily and quickly break down starches into glucose.

A commonly held belief among the general public, and even among nutritionists, is that complex carbohydrates (polysaccharides, e.g. starches) are digested more slowly than simple carbohydrates (sugars) and thus are healthier. However, there appears to be no significant difference between simple and complex carbohydrates in terms of their effect on blood sugar. Some simple carbohydrates (e.g. fructose) are digested very slowly (and very differently from glucose), while some complex carbohydrates (starches), especially that in processed food, raise blood sugar rapidly.

It is not sufficient, therefore, to buy foods that trumpet “whole grain ingredients.” The primary ingredients of these foods (those listed first) may be “bleached all purpose flour” (a highly processed food), sugar, dextrose, molasses, sucrose or HFCS (all highly processed sugars), before any “whole grains” are added. When you see grain sprinkled on the surface of that loaf of bread, just realize that it’s been brushed with HFCS to give it a nice brown color and make it sticky.

Always a wiser choice is to choose whole, unadulterated foods from the meat, dairy and produce aisles. Avoid the center of the store; shop the perimeter. Avoid food sold in a box or a bag, except perhaps flash frozen fish and veggies, in which case always check the ingredients list. Avoid anything refined or heavily processed. In other words, eat real food.

N.B.: For the record and for those who would doubt my authority of make some of the claims herein, this column has been largely cribbed – much of it lifted verbatim – from the Wikipedia entry “Carbohydrate.” Credit them. Check it out.

© Dan Brown 11/13/11

Sunday, November 6, 2011

The Nutrition Debate #30: Is Fructose a Liver Toxin? Is it Really Poison?

Fructose is ubiquitous in the food supply. It is 67% of the natural sugar found in an apple as well as 50% of table sugar (sucrose), 55% of high fructose corn syrup (HFCS) in sweetened soft drinks, and 42% of the HFCS used in many baked goods, For a fuller exposé, take a look at the last column, #29, “Fructose: Formerly Known as Fruit Sugar,” also archived on my blog at www://

The amount of all sugars is increasing each year in the American diet. Since 2000, however, the amount of fructose has leveled off and even declined slightly, precipitating the Corn Refiners’ Association recent TV ad campaign to repair the image of HFCS. In it, a pretty young woman says, “I learned, whether it’s corn sugar or cane sugar, your body can’t tell the difference. Sugar is sugar.” I agree. HFCS is essentially not much worse than (table) sugar made from sugar cane or beet sugar. HFCS and sucrose are basically the same, and both are equally bad for you.

The problem is not with the glucose component of sucrose. Once absorbed through the wall of the small intestine, glucose goes to virtually all the cells of the body and is used for energy or it is stored mostly in the muscles and liver as glycogen, a ready form of quick energy. Either way – used quickly or stored and used later – it is metabolized (broken down and “burned”). Glucose is the preferred and most commonly and readily used form of energy.

Fructose is different. It cannot be metabolized by the body for quick energy. Once it enters the bloodstream it goes directly through the portal vein to the liver and is stored there. Scientists, noting that the liver’s function is to filter out toxins, think that fructose is toxic. Remember, before modern agriculture, fruits were available seasonally and were far less sweet because they had not been hybridized. In addition, refined processed sugars were nonexistent. When we eat large doses of sugar the liver becomes overloaded with fructose. Is fructose toxic to the liver? Not in the sense of an acute toxin. It is, these scientists claim, a “chronic hepatotoxin.” In the words of Robert H. Lustig, MD, presenter of UCSF’s YouTube video, “Sugar: The Bitter Truth” in their Mini Med School for the Public series, fructose is “alcohol without the buzz.” No wonder that excess fructose consumption over a long period of time is frequently thought to be a cause, and is certainly associated with, non-alcoholic fatty liver disease (NAFLD), also on the rise.

Lustig adds: “Fructose increases de novo lipogenesis (fat formation), triglycerides and free fatty acids in most adults.” Fructose is a carbohydrate, but “it is metabolized like fat,” he says; therefore, “a high sugar diet is a high fat diet”.

In addition to Dr Lustig’s work, a 2005 a scientific paper titled “Fructose, insulin resistance and metabolic dyslipidemia,” from the Clinical Biochemistry Division, Department of Laboratory Medicine and Pathobiology, Hospital for Sick Children, University of Toronto, Toronto, Canada, concludes: “An important but not well-appreciated dietary change has been the substantial increase in the amount of dietary fructose consumption from high intake of sucrose and high fructose corn syrup...” A high flux of fructose to the liver, the main organ capable of metabolizing this simple carbohydrate, perturbs glucose metabolism and glucose uptake pathways, and leads to a significantly enhanced rate of de novo lipogenesis and triglyceride (TG) synthesis...” Fructose-induced insulin resistant states are commonly characterized by a profound metabolic dyslipidemia... Thus, emerging evidence from recent epidemiological and biochemical studies clearly suggests that the high dietary intake of fructose has rapidly become an important causative factor in the development of the metabolic syndrome. There is an urgent need for increased public awareness of the risks associated with high fructose consumption...”

Dr. Lustig’s video presentation includes a slide entitled “Fructose is Not Glucose,” with five bullets, summarized here:

1. Fructose is 7 times more likely than glucose to form Advanced Glycation End Products (AGE’s).
2. Fructose does not suppress Ghrelin, the hunger hormone.
3. Acute fructose does not stimulate Insulin (or Leptin: The brain doesn’t see that you ate, so you eat more).
4. Hepatic fructose metabolism is different. (rather than forming glycogen, de novo lipogenesis occurs).
5. Chronic fructose exposure promotes the Metabolic Syndrome.

But Dr. Lustig says that because fructose is a chronic toxin, not an acute toxin, the USDA/FDA “won’t touch it.” That may be, but personally I think Cargill and Archer Daniels Midland may have some influence in Washington as well.

© Dan Brown 11/6/11