Monday, January 30, 2012

Sugar Alcohols

In my most recent post I discussed sugar imposters.  AKA: sugar substitutes, or non-caloric sweeteners.  However, I left out one large group that deserves its own posting.  They are the sugar alcohols.  These products are made by hydrogenating carbohydrates.  This is different from the hydrogenation process used to turn liquid fats into solid fats such as margarine.  However, both process do require the addition of a hydrogen molecule, and the breaking of a double bond.  Sorry if this is making you reach far back into your high school chemistry years.  There are approximately 10+ sugar alcohols available for use as a food additive, the ones listed below in bold are the ones you will most frequently run into on a nutrition label.

  • Erythritol: Discovered in 1848, it naturally occurs in some fruits and fermented foods.
  • Glycerol: Typically used as a filler in baked goods as well as a thickener in viscous foods.
  • HSH: Hydrogenated Starch Hydrosylate, used as a humectant in order to retain moisture in foods.
  • Isomalt: Naturally found in beets, and used widely in sugar sculptures because it does not crystalize as quickly as sugar.
  • Lactitol: Non active ingredient in many medications, but an active ingredient in some laxatives.
  • Maltitol: Widely used in candy, chocolates, and chewing gum.
  • Mannitol: Found in almost all plants, and occurs during fermentation.  Used in medications needed to affect the brain, as it is capable of crossing the blood/brain barrier.  Sometimes used as a filler in illegal drugs such as heroin and cocaine...
  • Sorbitol: Used as a thickener in many food and cosmetic products.
  • Xylitol: Most easily tolerated of all SAs.  May aid in increasing bone density, preventing ear/upper respiratory infections, as well as controlling yeast infections.

Unlike the other sugar substitutes, sugar alcohols are not as sweet as sugar.  Products that use other artificial sweeteners, often add SAs in order to mask the flavor of the other sweeteners.  Because they are poorly absorbed by the body, and typically contain between 1/8 to 1/2 the calories of sugar, SAs contribute very few calories to the diet.  This means they also cause only small changes in blood sugars which can make them appealing to people with Diabetes.  However, since they are poorly absorbed in the intestines, overconsumption of foods made with SAs may lead to gas, bloating, and diarrhea.  People who have undergone any form of gastric bypass surgery should be especially wary of these side effects.

Sugar alcohols do not brown, and are not suitable for baking when used alone.  This is why they are most often seen in candy products, chewing gum, and mouth wash.  These products are used world wide, and do not appear to cause cancer.  People with diabetes, especially those taking insulin do need to be aware that these products will increase their blood sugar.  There is some evidence that excess intake of sorbitol by people with diabetes may increase their chances for nerve/small blood vessel complications.

As with most things dealing with food, I say if you want to eat it, eat the real thing.  These sweeteners have their place, most notably in chewing gum and breath mints.  But if you notice that a large proportion of your pantry contains foods with these or other artificial sweeteners in them, it may be time to take a step back and reevaluate your diet.  As I mentioned in the previous post, artificial sweeteners contain no important nutrients, so just like sugar, they should be consumed minimally.

Wednesday, January 25, 2012

Sugar Impostors

I had a recent request to do a post on sugar substitutes.  While there is a lot of conflicting research and information on the subject, I'm going to try and give the basic facts without too much personal bias.
  • Sucralose (Splenda): Discovered by European scientists looking for new ways to use sucrose (sugar).  One researcher was told to test the new compound and thought he was told to taste it, thereby discovering its sweet property.  It is 600X sweeter than table sugar, and is poorly absorbed in the intestinal tract, therefore it provides almost no calories to the diet.  While it tastes the most like sugar of any of the substitutes, the chemical process of creating it leaves it looking nothing like sugar.  Splenda is probably the most commonly recognized sugar substitute, and while it contains Sucralose, it also contains absorbable carbohydrates in the form of dextrose and maltodextrin.  1 cup of Splenda contains 96 calories from 32g of carbohydrate VS. 1 cup of sugar = 770 calories, 200g carb. While the FDA and Canada consider Sucralose safe for consumption (1.1mg/kg/day), new studies from Duke University show that it may reduce the level of good bacteria in the intestinal tract, which can in turn lead to an increase in body weight in rats. 
  • Saccharin (Sweet 'N Low): Discovered in 1879 by researchers at Johns Hopkins University.  This product was created with the intention of using it as a sugar substitute for people with diabetes.  One of the chemists licked his hand at dinner and connected it to the compound he had been working with that day. It did not become widely used until the sugar rations during both World Wars.  Studies in the 1970s showed an increase in the incidence of bladder cancer in male rats.  However, the metabolism of this sweetener is different in rats than in humans; further studies have shown no CONSISTENT evidence that saccharin may cause bladder cancer in humans. In 2000 the US National Toxicology program removed it from its list of possible carcinogens.
  • Aspartame (Equal, NutraSweet): Discovered in 1967 when James Schlatter accidentily licked his finger while working on an anti-ulcer drug.  Created by the combining of Aspartic acid and Phenylalanine.  Both are amino acids-or the building blocks of protein.  It is 200x sweeter than table sugar.  It still contributes 4 calories per gram, but so little is needed to sweeten a product that the calories ingested are negligible.  In 1980 the FDA worked with the Public Board of Inquiry and determined that Aspartame does not cause brain cancer.  Between this time and the mid 1990s both the US and the EU approved aspartame for use in dry goods and sweetened beverages.  People with PKU should not consume products with Aspartame as its metabolism will cause a buildup of phenylalanine in the blood.  Metabolism of aspartame also creates formaldehyde, however this happens with other "natural" foods as well.
  • Acesulfame Potassium (Sunnet, Sweet One) Discovered in 1967 by Karl Clauss, once again the silly scientist licked his finger on accident.  It is created by the combining of acetoaceitc acid and potassium; forming a crystal.  It is 200X sweeter than table sugar and is heat stable, meaning it can be used in baked goods.  It has not been proven to cause cancer by the FDA...and has been approved for use in the US, EU, Australia, Canada, and many other countries.  People with renal failure should avoid this product due to the potassium.

  • Stevia (Truvia, Purvia): While it is new to the United States, people in the EU, Canada, East Asia, and South America have been using it in its natural leaf form as well as in a liquid and crystal form for years.  Paraguay indians have been using this herb for centuries, and the Japanese have used it in everything from sugar free gum to pickled vegetables.  There was some controversy in the US in 1985-1987 as to whether it was mutagenic...apparently a study showed that it may alter the DNA of salmonella bacteria.  Extracts are 200-300x sweeter than table sugar VS the herbal leaves which are only 10-25x sweeter.  As of 2008 it became approved for use as a food additive in the US and is generally recognized as safe.  If you want to use an artificial sweetener, this is the one I would go with.  Make sure to experiment with it when baking, as it does not caramelize or brown the same way sugar does.
For more information on artificial sweeteners check out these websites:
Mayo Clinic
Baking with out sugar
Family Doctor

What do I think... Artificial sweeteners are just that, artificial.  Our body does not need them and just like sugar they do not add any vitamins, minerals, or antioxidants to our system.  They also do not make food taste good.  Often times, products that are made with sugar substitutes also have to add extra fat and other chemical compounds to make them taste decent.  Would you rather eat 4 mediocre cookies made with Splenda for 150 calories, or 2 really good cookies made with sugar for 150 calories?  I know which I would choose.  There are some studies coming out that show people who consume artificial sweeteners actually eat more.  They trick the body into thinking it is receiving calories, and when they are not there, it craves more.  There is also very little evidence to support its efficacy in weight loss.  Weather or not they cause cancer, headaches, or ADHD, I recommend people avoid these products and limit their intake of refined sugars.  When you eat a sweet treat, go for the real thing and truly enjoy it.

Wednesday, January 11, 2012

Nitrates and Nitrites

Like many American kids I grew up eating turkey or ham and cheese sandwiches.  And if I was lucky, mom occasionally bought me a Lunchables.  Which is funny looking back; even in grade school I didn't think they tasted that good.  It must have been the novelty of it...and their great marketing.  In college I continued to make deli meat sandwiches, mostly out of convenience and cost.  But over the past several years it dawned on me... I HATE deli meat (except for the occasional roast beef and very rarely salami).  This is probably a good thing since most deli meats are preserved with sodium-nitrate.  Nitrates are a naturally occurring nitrogen compound found in vegetables.  Leafy greens and root vegetables are especially high in them: cauliflower, collards, broccoli, spinach, potatoes, beets, turnips...  When plants die and decompose, they release these nitrates into the ground.  This is a good thing and part of the reason why smart farmers rotate crops.  Corn is notorious for depleting the nitrogen in soil, where as soy beans replenish it.  Veggie nitrates are natural.

As I mentioned above, most processed meats (deli meat, bacon, sausage, ham) are preserved with sodium nitrate.  Tap water is another sources of nitrates since farms often use nitrate containing fertilizers which run off and contaminate ground water aquifers.  Consuming excess nitrates found in processed meats has been shown to increase a child's chances for leukemia if they consume 12+ hotdogs in 1 month; they have also been linked to colon cancer in adults.  While most kids are not eating 12 hotdogs/month, they probably are eating hotdogs, deli meat, hamburgers, sausages, bacon and pepperoni pizza at least once per day at school.  To avoid these nitrates opt for nitrate free products such as those from Applegate farms and specific products by Hormel.  The American Meat Industry will tell you that nitrates are safe, however I'm not convinced.  But to be fair, here is a link to what they have to say.

No studies have shown a link between the nitrates in water and cancer.  However, there is a link between these nitrates and methemoglobinemia or "blue baby syndrome."  The nitrate is converted into a nitrite in the colon and is absorbed into the blood stream reacting with iron and hemoglobin in the fetal blood causing it to become methemoglobin.  Methemoglobin is unable to cary oxygen and this can result in breathing difficulties, low blood pressure, and developmental delays.  This is easily avoidable by either breastfeeding or using only filtered water to mix formula.

You may be wondering how I got on this topic?  Ryan and I made pasta bake the other night with Trader Joe's High Fiber pasta.  I compromised since Ryan wasn't in the mood for whole wheat.  The next day I looked at the ingredients and noticed that it contains Thiamine Mononitrate.  AAAHHH not a nitrate!!! Being the inquisitive RD that I am, I did a little research.  Thiamine Mononitrate (TM) is a synthetic form of the vitamin B1 or thiamine.  Thiamine is important in many different bodily functions and plays a roll in vision, hair/skin integrity, and the nervous system.  Processed grain products have been fortified with B vitamins for many years as a way to prevent dietary deficiency.  However, studies now show that TM does not actually prevent or reverse Thiamine deficiency; only natural sources do.  B vitamins are water soluble and when consumed in excess the body eliminates them in the urine.  However, TM is fat soluble and the body has difficulty removing it.  This can lead to accumulation in the liver and other fatty tissue.  The nitrates in TM may also accumulate in the kidneys.  This accumulation can cause problems such as kidney stones.  For healthy individuals I would recommend they try and avoid foods with TM in it.  People with liver or kidney disease should absolutely avoid this food additive.  To ensure adequate intake of Thiamine focus on consuming these foods: Pork, Tree Nuts (peanuts don't count), Sunflower and Sesame Seeds, and fish.