Image credit: Two kinds of rice in spoons via Shutterstock

Carbohydrates can be divided into two major classes: simple carbohydrates and complex carbohydrates.

The simple carbohydrates are colloquially called sugars, and they taste sweet on the tongue. Sugars consist of one or two small carbohydrate units. The individual units are called monosaccharides, a word that means “single sugar,” and of the monosaccharides, glucose is the most ubiquitous. Other common monosaccharides include fructose (“fruit sugar”) and galactose, which is a component of milk sugar. Two monosaccharides chemically bonded together form a disaccharide (“two sugars”), which is also a simple carbohydrate. Common disaccharides include sucrose (“table sugar”), which is made up of glucose and fructose. Lactose (“milk sugar”) is also a disaccharide. The digestive tract can absorb monosaccharides into the bloodstream; disaccharides must be digested into their monosaccharide components before absorption.

Complex carbohydrates, or starches, don’t taste sweet on the tongue. However, starch is made up of long chains of glucose molecules chemically bonded together, and the digestive tract breaks starch into its glucose monosaccharides, which are then absorbed into the bloodstream. As such, while a bite of white rice — which is nearly entirely made of starch — doesn’t taste the same as a spoonful of glucose sugar, the gut quickly breaks the starch from the white rice into glucose, and from that point on, the body can’t tell the difference.

Because it’s such an important fuel to the body cells, glucose is a healthy component of diet. However, the body cells can convert excess glucose into storage fat, so like all calorie-containing components of nutrition, it’s important to consume glucose-containing foods in moderation. Also, the human body responds in a more normal and healthy manner to glucose when it enters the bloodstream slowly; glucose-containing foods that are absorbed very quickly can lead to unhealthy fluctuations in blood sugar. The rate at which the glucose from a food enters the bloodstream is referred to as the food’s glycemic index.

Limited consumption of carbohydrates is the basis for many diet plans. For example, the Atkins diet is based on the theory that overweight people eat too many carbohydrates. The diet plan involves limited consumption of carbohydrates to switch the body’s metabolism from metabolizing glucose as energy over to converting stored body fat to energy (called ketosis). The South Beach Diet is another diet plan that is based on the glycemic index. The diet plan involves replacing “bad carbs” (i.e. carbohydrates with a high glycemic index) with “bad fats” (i.e. carbohydrates with a low glycemic index) and “bad fats” (i.e. trans-fats and saturated fats) with “good fats” (i.e. unsaturated fats and omega-3 fatty acid).

Generally speaking, carbohydrate-containing foods with fiber in them have lower glycemic indices than foods without fiber, meaning that the glucose enters the bloodstream more slowly. This is because fiber slows digestion and absorption of food. While the fiber content of food isn’t the sole determinant of whether that food is healthy, fiber-containing carbohydrate generally leads to a more normal and healthy physiological response than carbohydrate devoid of fiber. For this reason, white rice is nearly identical to a spoonful of sugar, chemically speaking, and is quite different from a spoonful of fiber-rich brown rice.

Two vitamins with which the article notes significant associated potential risk are vitamins E and A. Vitamin E is a fat-soluble antioxidant that exists in nature in several different forms.

The predominant form of vitamin E found in food sources, including leafy greens, nuts, and some oils, is called gamma-tocopherol. The predominant form in manufactured supplements, however, is alpha-tocopherol. Research suggests that alpha-tocopherol may actually block the activity of gamma-tocopherol, which at least partially explains some of the disturbing research findings associated with vitamin E supplementation. For instance, one study found vitamin E supplements increased the risk of prostate cancer in men by 17% [2], while another study found that vitamin E increased the risk of stroke by 22% and 10%, depending upon the type of stroke [3]. Yet a third study associated vitamin E supplementation with increased overall risk of mortality [4].

Vitamin A occurs in food in two major forms: preformed vitamin A and beta-carotene, which the human body uses to produce vitamin A. Like vitamin E, vitamin A is an antioxidant, though it also plays an important part in vision (particularly night vision) and in normal cell division and development. Food sources of beta-carotene include many fruits and vegetables (especially yellow-orange ones), while animal products such as milk and organ meat contain preformed vitamin A. Despite the importance of vitamin A in the diet, however, in supplement form, it is suspected to act as a pro-oxidant (the opposite of an antioxidant). Supplementation with beta-carotene and/or vitamin A has been found to be associated with or cause a number of negative outcomes. For instance, the study that associated vitamin E with increased overall risk of mortality found the same was true of vitamin A. Two studies found that vitamin A and beta-carotene supplements increased the incidence of lung cancer [5,6], while a third found an increased risk of prostate cancer associated with high blood levels of vitamin A [7].

The risks associated with vitamin E and A supplementation are somewhat disturbing. Without significant evidence to suggest that consuming these vitamins in supplement form confers any particular benefit to outweigh the risks, it’s difficult to rationalize recommending vitamin E and A supplements to the general population (those with absorption disorders and other disease processes that may require vitamin supplementation notwithstanding). In light of these findings, consumers using vitamin supplements that haven’t been prescribed or recommended by a healthcare practitioner may wish to discuss their choices with a doctor. Vitamins from food sources, of course, remain an important and healthy component of diet.

References

1. (No authors listed). Who should take vitamin supplements? Med Lett Drugs Ther. 2011 Dec 26;53(1380):101-3.
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2. Klein et al. Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA. 2011 Oct 12;306(14):1549-56.
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3. Schurks et al. Effects of vitamin E on stroke subtypes: meta-analysis of randomised controlled trials. BMJ. 2010 Nov 4;341:c5702. doi: 10.1136/bmj.c5702.
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4. Bjelakovic et al. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database Syst Rev. 2008 Apr 16;(2):CD007176.
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5. Omenn et al. Effects of a combination of beta carotene and vitamin A on lung cancer and cardiovascular disease. N Engl J Med. 1996 May 2;334(18):1150-5.
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6. Virtamo et al. Incidence of cancer and mortality following alpha-tocopherol and beta-carotene supplementation: a postintervention follow-up. JAMA. 2003 Jul 23;290(4):476-85.
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7. Mondul et al. Serum retinol and risk of prostate cancer. Am J Epidemiol. 2011 Apr 1;173(7):813-21. Epub 2011 Mar 9.
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Too much body fat, however, is associated with a number of negative health effects, including increased risk of heart disease, type 2 diabetes, arthritis, and apnea.

Fat in the diet can contribute to excess fat on the body, as dietary fat is a dense source of calories. This means that even small quantities of fatty food are very calorie-rich. However, too much body fat comes from too much food in general — regardless of whether it’s made up of fat, carbohydrate or protein — since the body converts excess protein and carbohydrate into stored fat. Further, appropriate quantities of fat are important in the diet; dietary fat serves as a satiety signal, increases the absorption of fat-soluble vitamins, and (depending upon the kind of fat) plays other roles as well.

There are three basic categories of fat in the diet: saturated fats, trans fats and unsaturated fats. For a healthy diet, a growing body of research suggests that you should avoid saturated fats and trans fats, and focus on eating unsaturated fats.

What to avoid: saturated fats

Saturated fats come mainly from animal sources, though there are some plants (avocados and coconut, for instance) that contain saturated fat. Because of their chemical makeup, these fats have high melting points, and are solid at room temperature. Saturated fats contribute to heart disease by increasing low-density lipoprotein, also known as LDL (sometimes called “bad cholesterol”) and should be limited in the diet. According to the American Heart Association, an individual on a 2,000 calorie-per-day diet should limit saturated fat intake to no more than about 16 grams [2].

What to avoid: trans fats

Trans fats are common in the American diet, but they’re not found in nature to any significant extent. Instead, they come about by processing unsaturated oils (including corn and soybean oil). The processes used, called “partial hydrogenation” and “interesterification,” result in the production of plant-based fat that behaves in food like saturated fat. Shortening is an example of trans fat; it’s plant based, but it’s solid at room temperature. Trans fats act strangely in the body: they not only increase LDL, as saturated fat does, they also decrease high-density lipoprotein or HDL. This makes them particularly deleterious components of diet.

In addition to impacting cholesterol, trans fats appear to increase risk of type 2 diabetes. The American Heart Association recommends limiting the amount of trans fat in the diet as much as possible, and sets an upper recommended limit of 2 grams per day [4]. Nutrition labels on foods report how much trans fat is in a serving of the food; whole foods (which don’t have nutrition labels) don’t contain trans fat. One important point to remember is that manufacturers can report that a food contains zero grams of trans fat per serving as long as it contains no more than 0.49 grams per serving. Avoiding trans fat in the diet therefore requires reading ingredient lists as well as nutrition facts; if the words “partially-hydrogenated” or “interesterified” appear in the ingredients, there’s trans fat in the food. The most common sources of trans fat in the diet are processed foods and fast food.

Unsaturated fats are healthy fats

Unsaturated fats, which include both monounsaturated and polyunsaturated fats, come mainly from plant sources, though they’re also found in cold-water fish. Their chemical makeup is such that they have low melting points, and are liquid at room temperature. Some of them are even liquid in the refrigerator or freezer. They confer all the benefits of dietary fat (immune system support, increased fat-soluble vitamin absorption, and so forth) without increasing LDL concentration in the blood. The American Heart Association recommends that 25-35% of daily calories come from fat, the vast majority of which should be unsaturated [3].

Omega-3 fats and omega-6 fats are subcategories of unsaturated fat. They’re both essential in the human diet, but the typical Western diet is much too high in omega-6 fat relative to the amount of omega-3 fat. Generally speaking, omega-6 fat is pro-inflammatory, and increases risk of arthritis, asthma and heart disease when consumed out-of-proportion with omega-3 fat, which is generally anti-inflammatory. Omega-6 fat comes from plant sources, most notably from grains and grain-based oils like corn oil. Omega-3 fat is found in some plant sources (flax is a commonly-cited example), and in fish. Unfortunately, the majority of omega-3 fat in plant sources isn’t a type that humans can use, and has to be converted in the cells into usable omega-3 fats such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Human cells are quite inefficient at this conversion, meaning most of the omega-3 fat from the majority of plant sources isn’t bioavailable. Fatty, cold-water fish are the best source of bioavailable omega-3 fat.

At the campaign website of MyPlate, which replaced the Food Pyramid to help consumers eat better, there are a number of nutrition education tips in an easy-to-follow, convenient format. One of the ten tips to making food choices for a healthy lifestyle in Choose MyPlate: 10 tips to a great plate focuses on “foods to eat less often”: these include foods high in solid fats, such as ice cream, pizza, ribs, sausages, bacon and hot dogs. Instead, choose lean, protein-rich foods such as soy, fish, skinless chicken and fat-free or 1% dairy products. Eat foods that are naturally low in fat such as whole grains, fruits and vegetables.

References

1. Obesity and Overweight for Professionals: Data and Statistics: U.S. Obesity Trends. Centers for Disease Control and Prevention. Accessed 2011 Nov 15.
2. Saturated Fats. American Heart Association. Accessed 2011 Nov 15.
3. Know Your Fats. American Heart Association. Accessed 2011 Nov 15.
4. Trans Fats American Heart Association. Accessed 2011 Nov 15.

This news may surprise those who look to vitamin and mineral supplements as a mechanism for maintaining — and even improving — health. However, while it would be easy to sensationalize the research findings, the reality is that there are many limitations that prevent drawing meaningful conclusions — ones that could be used to inform behavior — from the study.

The first limitation is that the study was neither randomized nor placebo-controlled.

These are major limitations, despite the fact that the study was strong elsewhere (it took place over a long period of time, and included tens of thousands of participants). Because the study was not randomized, there is no way to determine whether the multivitamin supplements were responsible for increased death rate, or whether women who took multivitamin supplements had another characteristic that made them more likely to die (but which was not effected by the supplements). For instance, perhaps women who feel ill, tired, or otherwise less fit than they once did are more likely to take supplements. Perhaps their perceptions of failing health are accurate. In such a hypothetical scenario, the very women most likely to die due to failing health would also be those most likely to start taking supplements in an effort to improve their quality (and quantity) of life.

Another major limitation associated with interpreting the results of this study in a broad sense (i.e. supplements increase risk of death) is that the study included both women who used supplements as recommended and those who used supplements in inappropriately high dosages. For instance, the researchers report that use of iron supplements leads to a risk of death (hazard ratio) of 1.10 (compared to a baseline risk of 1), or an absolute risk increase of 3.9%. However, these numbers do not isolate the women who were using iron in dosages recommended by the National Institutes of Health. Per the NIH, women age 51 and older should get 8 mg of iron a day from food or supplements. Many study participants were taking supplemental iron in quantities much greater than those recommended, with some participants taking upwards of 400 mg daily. Iron toxicity is a real risk, and increases the likelihood of heart disease and other organ failure. As might be expected, the women taking the highest doses of iron had the greatest hazard ratios (the greatest likelihood of dying). While the researchers did evaluate the hazard ratios of women on different iron doses separately, large ranges were clumped together for analytical purposes. For instance, all women taking low dose iron were analyzed as a single group, where “low dose” meant anywhere from 0 to 50 mg per day. This incorporates those taking iron per the NIH guidelines and those taking as much as 6-times the NIH-recommended quantity into the same group.

Current scientific evidence does not conclusively support the use of multivitamin and mineral supplements in otherwise healthy individuals to any conclusive extent, though there are certainly cases (such as calcium supplementation in older women and multivitamin supplementation in the case of chronic malabsorption) in which supplements are medically indicated and widely used. Further, even a cursory review of the literature reveals a multitude of inconsistencies and ambiguities in the field of supplement research. One study suggests that folic acid decreases risk of breast cancer [2], while another suggests it has no effect [3]. One suggests that selenium helps reduce risk of prostate cancer [4], while a later study refutes that assertion [5]. In a particularly boggling turn, one study suggests that vitamin E decreases risk of heart disease [6], while a second suggests it has no effect on heart disease [7], and a third notes that supplementation with vitamin E increases overall mortality rate, and should be avoided [8].

While it’s tempting — and in many cases, appropriate — to make personal health decisions on the basis of scientific research, it’s important to remember that a single study, taken alone, is never anything more than interesting. Those who are already taking multivitamin supplements shouldn’t stop on the basis of these data, though individuals taking “megadoses” of particular vitamins or minerals — meaning doses much larger than those recommended by the NIH — should discuss their supplementation decisions with a physician. Those considering starting a multivitamin supplement should bear in mind that the safest and best way to get vitamins and minerals is from food, in the context of a healthy, balanced diet.

References

1. Mursu et al. Dietary Supplements and Mortality Rate in Older Women: The Iowa Women’s Health Study. Arch Intern Med. 2011 Oct 10;171(18):1625-33.
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2. Rohan et al. Dietary folate consumption and breast cancer risk. J Natl Cancer Inst. 2000 Feb 2;92(3):266-9.
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3. Zhang et al. Effect of combined folic acid, vitamin B6, and vitamin B12 in women: a randomized trial. JAMA. 2008 Nov 5;300(17):2012-21.
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4. Duffield-Lillico et al. Selenium supplementation, baseline plasma selenium status and incidence of prostate cancer: an analysis of the complete treatment period of the Nutritional Prevention of Cancer Trial. BJU Int. 2003 May;91(7):608-12.
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5. Lippman et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the selenium and vitamin E cancer prevention trial. JAMA. 2009 Jan 7;301(1):39-51. Epub 2008 Dec 9.
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6. Knekt et al. Antioxidant vitamin intake and coronary mortality in a longitudinal population study. Am J Epidemiol. 1994 Jun 15;139(12):1180-9.
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7. Lee et al. Vitamin E in the primary prevention of cardiovascular disease and cancer: the Women’s Health Study: a randomized con- trolled trial. JAMA. 2005 Jul 6;294(1):56-65.
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8. Miller et al. Meta-Analysis: High-Dosage Vitamin E Supplementation May Increase All-Cause Mortality. Ann Intern Med. 2005 Jan 4;142(1):37-46. Epub 2004 Nov 10.
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Saccharin is the oldest of the artificial sugars that’s still in use today. It was discovered in the late 19th century, completely by chance, when a chemistry student who was working with coal tar derivatives licked his fingers and found they tasted sweet [1]. Saccharin is about 500 times sweeter than sugar, and the human body can’t break it down to provide the cells with energy, which is why it contains no calories. While some research suggests that it can cause bladder cancer in lab rats, no research has linked saccharin to cancer in humans. Saccharin-containing foods once carried warning labels, but scientists have since determined that rats have specific features of their urinary system (which humans lack) that make them susceptible to bladder cancer from saccharine [2]. Warning labels have been removed from foods as of 2000. Sweet’N Low is a brand of artificial sweetener made from granulated saccharin, dextrose and cream of tartar.

Aspartame is another non-nutritive sweetener that was discovered serendipitously by Jim Schlatter in 1965, as he was attempting to synthesize an ulcer drug [3]. Aspartame is a modified dipeptide, whose full name is aspartyl-phenylalanine methyl ester. Equal is an example of an aspartame-based sweetener.

Like saccharin, aspartame is sweeter than table sugar (by a factor of about 200), and it’s not possible for the human body to break aspartame down, which explains its lack of calories. The reason artificial sweeteners are sweeter than table sugar is that they bind more tightly to sweetness receptors on the human tongue, which then sends a signal to the brain. Chemicals that don’t bind very tightly — like table sugar — send signals of mild sweetness. Chemicals like aspartame and saccharine bind much more tightly, meaning they stay in the sweetness receptor (and continue to trigger signals) for a longer period of time.

The sweetness receptor is a complex called a G-protein coupled receptor comprised of proteins encoded by the genes TAS1R2 taste receptor, type 1, member 2 (TAS1R2) and TAS1R3 taste receptor, type 1, member 3 (TAS1R3) [4].

While there’s no evidence linking aspartame to cancer or other major health problems in most people, it’s not safe for individuals with the disease phenylketonuria (PKU). PKU is a genetic, meaning inherited, disorder in which affected individuals can’t break down phenylalanine. Phenylalanine is one of the amino acids, which are components of protein. Because those with PKU can’t break phenylalanine down, it accumulates in the bloodstream, and negatively impacts brain development in babies and children. Babies with PKU (a disease that hospitals routinely test newborns for) must be kept on a phenylalanine-free diet in order to avoid impaired physical and mental function. Adults with PKU don’t have to follow as strict a diet, but generally benefit from diets with low phenylalanine. Because aspartame contains the amino acid phenylalanine, aspartame-containing foods carry a warning label.

Sucralose is yet another non-nutritive sweetener. Its chemical structure is quite similar to that of table sugar, but key differences (e.g. the presence of chlorine atoms, where table sugar has none) prevent the human body from breaking it down for energy. Like the other non-nutritive sweeteners, sucralose is much sweeter than table sugar. No research has yet linked sucralose to cancer or other major health problems, but as the newest of the popular non-nutritive sweeteners, it may be some time before long-term effects of routine consumption — if there are any — reveal themselves. Splenda is an example of a sucralose-based artificial sweetener.

While there isn’t reason to believe that non-nutritive sweeteners cause cancer, there is some research evidence to suggest that they aren’t as benign as manufacturers claim. Many individuals who use these calorie-free sweeteners do so in an attempt to avoid the weight gain associated with excess sugar consumption, since the body can convert sugar — but not non-nutritive sweeteners — into fat. However, research suggests that there are sweetness receptors in the gut as well as in the mouth [5], and that artificial sweeteners can bind to these receptors. Further, research reveals that when calorie-free sweeteners bind to gut sweetness receptors, physiological responses mimic those expected in the case of sugar binding to the same receptors: the cells take up glucose [6], and the gut releases digestive hormones [7]. In short, it appears that the human body has an ability to sense the sugar — and therefore caloric — content of foods based upon the binding of key nutrients in those foods to receptors in the gut, but that these receptors are fooled (just like receptors in the mouth) by substitute chemicals. This can disrupt the body’s ability to determine whether a given quantity of food is sufficient to meet energy needs [8]. Compare, for example, the quantity of salad necessary to stimulate a feeling of fullness to the quantity of cheesecake necessary to do the same; the average individual consumes a much greater quantity of salad than of cheesecake, because the gut senses the caloric density of the cheesecake and sends satiety signals after consumption of a smaller quantity.

By disrupting the body’s ability to equate sweetness with calories, it appears that non-nutritive sweeteners can “teach” the body that sugar contains no calories. This can result in consumption of more total calories, which can lead to increased weight gain. In the end, consumption of sugar in moderate quantities may be more compatible with weight-loss or weight maintenance goals than consumption of artificial sweeteners.

References

1. Wotiz. The discovery of saccharin. J. Chem. Educ. 1978 55(3): 161.
2. Whysner et al. Saccharin mechanistic data and risk assessment: urine composition, enhanced cell proliferation, and tumor promotion. Pharmacol Ther. 1996;71(1-2):225-52.
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3. Mazur, R.H. (1984). Discovery of aspartame. In Aspartame: Physiology and Biochemistry (L. D. Stegink and L. J. Filer Jr., Eds.). Marcel Dekker, New York, pp. 3–9.
4. Li et al. Human receptors for sweet and umami taste. Proc Natl Acad Sci U S A. 2002 Apr 2;99(7):4692-6. Epub 2002 Mar 26.
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5. Jang et al. Gut-expressed gustducin and taste receptors regulate secretion of glucagon-like peptide-1. Proc Natl Acad Sci U S A. 2007 Sep 18;104(38):15069-74. Epub 2007 Aug 27.
   View abstract
6. Mace et al. Sweet taste receptors in rat small intestine stimulate glucose absorption through apical GLUT2. J Physiol. 2007 Jul 1;582(Pt 1):379-92. Epub 2007 May 10.
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7. Kokrashvili et al. Taste signaling elements expressed in gut enteroendocrine cells regulate nutrient-responsive secretion of gut hormones. Am J Clin Nutr. 2009 Sep;90(3):822S-825S. Epub 2009 Jul 1.
   View abstract
8. Egan et al. Taste cells of the gut and gastrointestinal chemosensation. Mol Interv. 2008 Apr;8(2):78-81.
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Researchers at Princeton University examined the effect of HFCS and other sweeteners on the eating habits and weight gain of Sprague-Dawley rats, which are commonly used in nutrition studies because of their metabolic similarity to humans. In the first phase of the study, some male rats were given plain water to drink, while others consumed either water sweetened with HFCS or water sweetened with table sugar (sucrose). In all instances, rats had free access to rat chow. The rats were examined for weight gain and body changes after eight weeks. The scientists found that HFCS-consuming rats gained more total weight than sucrose-consuming rats. This was despite the fact that the two groups of rats consumed approximately equal total daily calories, and that the HFCS rats consumed fewer calories from HFCS than the sucrose rats consumed from sucrose. A little HFCS, it appears, goes a long way toward influencing weight gain.

In the second phase of the study, the researchers examined the effect of HFCS-sweetened water on the body weight and general constitution of male rats over the course of 6 months. Rats with free access to rat chow and plain water gained less weight, while rats with free access to rat chow and HFCS-sweetened water gained more. The fat pads on the HFCS-fed rats were much heavier than those of the rats who had access to only food and water, and specifically, the fat pads in the abdomen were much larger.

The investigators found similar long-term results in female rats, and additionally noted that among the females, access to long-term HFCS-sweetened water had a greater impact on total body weight gain and fat gain than access to long-term sucrose-sweetened water, echoing the results of the first phase of the study.

HFCS is a common additive to processed foods, and occurs in everything from packaged desserts to fast food meals to condiments like ketchup. Many nutrition researchers have speculated in recent years that it’s no coincidence that the American obesity rate has increased tremendously since the advent of HFCS in the American diet. However, there has been debate among scientists as to whether the increased obesity rate was due to increased caloric intake or was specific to HFCS.

On the surface, HFCS appears quite similar to sucrose. Sucrose is a disaccharide, made up of the smaller sugars glucose and fructose, chemically bonded together.

Because of its chemical makeup, sucrose contains 50% glucose and 50% fructose. Digestive enzymes in the intestine break sucrose into glucose and fructose, which are absorbed separately into the bloodstream. There are several types of HFCS, but the most prevalent in processed food is HFCS-55, which consists of 55% fructose and 42% glucose [2]. The chemical difference between HFCS and sucrose is significant because glucose stimulates the release of insulin and has been linked to higher circulating levels of leptin [3], and there’s a significantly higher proportion of glucose in sucrose than in HFCS-55.

Consuming a meal high in fructose (one sweetened with HFCS, for instance) results in lower circulating insulin and leptin, which can cause a reduced sense of satisfaction and stimulate overeating. Moreover, high fructose diets can induce leptin resistance, accelerating high-fat induced obesity [4].

A recent study demonstrated this by offering different groups of rats either plain water or water sweetened with a variety of compounds, including both sucrose and HFCS [5]. The rats that drank sweetened water, regardless of sweetener type, consumed more total calories than those that drank plain water. This result suggests that consumption of sweetened beverages may increase the risk of obesity, as appetite doesn’t completely accommodate for calories consumed in the form of liquid. Further, however, rats consuming HFCS-sweetened water had the greatest final weight and fat mass, despite the fact that all the rats drinking sweetened water took in approximately the same number of total calories. This suggests once again that HFCS influences fat accumulation to a disproportionately large extent per calorie consumed, compared to other sweeteners.

While researchers haven’t completely elucidated the mechanism through which HFCS promotes rapid fat gain — particularly in the abdominal region — accumulating evidence suggests that avoiding HFCS in the diet might help reduce the risk of obesity and obesity-related disease.

References

1. Bocarsly et al. High-fructose corn syrup causes characteristics of obesity in rats: increased body weight, body fat and triglyceride levels. Pharmacol Biochem Behav. 2010 Nov;97(1):101-6. Epub 2010 Feb 26.
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2. White JS. Straight talk about high-fructose corn syrup: what it is and what it ain’t. Am J Clin Nutr. 2008 Dec;88(6):1716S-1721S.
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3. Teff et al. Dietary fructose reduces circulating insulin and leptin, attenuates postprandial suppression of ghrelin, and increases triglycerides in women. J Clin Endocrinol Metab. 2004 Jun;89(6):2963-72.
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4. Shapiro et al. Fructose-induced leptin resistance exacerbates weight gain in response to subsequent high-fat feeding. Am J Physiol Regul Integr Comp Physiol. 2008 Nov;295(5):R1370-5. Epub 2008 Aug 13.
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5. Light et al. The type of caloric sweetener added to water influences weight gain, fat mass, and reproduction in growing Sprague-Dawley female rats. Exp Biol Med (Maywood). 2009 Jun;234(6):651-61. Epub 2009 Apr 9.
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In the United States and Europe, people take it for granted that when they turn on the faucet, clean water will flow out. Indeed, a single flush of a toilet in the West uses more water than most Africans have to perform an entire day’s washing, cleaning, cooking and drinking [2].

Securing access to safe water worldwide is vitally important. Clean water is essential for agriculture, food and energy production, recreation and reduction of poverty. More than 2 million people, most of them children, die every year from water-borne diseases. And time is of the essence: by 2020, more people could die of water-related diseases than those that have died due to HIV/AIDS [2].

In the 1990s, researchers figured out a simple, free and effective way to clean polluted water and kill disease-causing organisms, including E. coli, Vibrio cholera (which causes cholera, an infection of the small intestine), Salmonella (which causes typhus) and Yersinia enterocolitica (which causes diarrhea) [3]. Solar water disinfection, known as SODIS, is a method of disinfecting water using only sunlight and transparent polyethylene terephthalate (PET) plastic bottles (think: clear 2-liter soda bottles).

The first study to evaluate the effect of the SODIS method on health was investigated by the Royal College of Surgeons of Ireland. Carried out in Kenya, research showed that 16-24% of diarrhea-type illnesses and 86% of cholera occurrences were avoided [4]. Since then, many scientific studies have confirmed the effectiveness and reliability of the SODIS method.

The SODIS procedure is incredibly simple: contaminated water is filled in a transparent PET-bottle and exposed to the sun for 6 hours (or 2 days under very cloudy conditions). During exposure, ultraviolet (UV) radiation from the sun kills disease-causing pathogens. Moreover, infrared radiation heats the water. The combined exposure to UV plus heat in the SODIS process has a synergistic effect on microbial inactivation.

However, scientists don’t yet understand how UV kills germs. Researchers currently think that the bacteria die because cellular respiration — the process in which nutrients are converted into useful energy in a cell — is damaged by UVA radiation so severely that it can’t be repaired.

The SODIS method together with washing hands particularly effective at preventing diarrheal diseases. A systematic study found that while better better sanitation facilities prevented 32% of diarrhea cases, treatment of drinking water in the home (e.g. SODIS method) prevented 39% of diarrhea cases [5]. Incredibly, hand washing was the most effective, preventing almost half (45%) of all diarrhea cases.

The SODIS method is used around the world in places like India, Cameroon, Bolivia, Kenya, Nepal and Nicaragua. So why then are people in developing countries going without clean water? According to a 2008 report by Urs Heierli of msd consulting GmbH, a Swiss company focused on market-based development interventions, it’s difficult to persuade the poor to use SODIS and to ensure that those who have been persuaded continue to use it [6].

The World Health Organization (WHO), UNICEF, and the American Red Cross all recommend the SODIS method as a way to treat drinking water in developing countries. Indeed, it is an ideal way solve one of the world’s most vital issues: making clean water.

References

1. Water Facts. Water.org Accessed 2011 Jul 8.
2. Dying for A Drink of Clean Water. The Washington Post. 2005 Sep 20.
3. SODIS: Microbiology. sodis.ch Accessed 2011 July 8.
4. SODIS: Health. sodis.ch Accessed 2011 July 8.
5. Fewtrell et al. Water, sanitation, and hygiene interventions to reduce diarrhoea in less developed countries: a systematic review and meta-analysis. Lancet Infect Dis. 2005 Jan;5(1):42-52.
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6. Heierli, U. Marketing safe water systems: why it is so hard to get safe water to the poor – and so profitable to sell it to the rich. Bern, Switzerland, Swiss Agency for Development and Cooperation (SDC). 2008.

The 2010 Dietary Guidelines for Americans focuses on balancing calories with physical activity, and encouraging Americans to consume more healthy foods such as vegetables, fruits, whole grains, fat-free and low-fat dairy products, and seafood, and to consume less sodium, saturated and trans fats, added sugars, and refined grains.

Secretary Vilsack said [2]:

With so many food options available to consumers, it is often difficult to determine the best foods to put on our plates when building a healthy meal. MyPlate is an uncomplicated symbol to help remind people to think about their food choices in order to lead healthier lifestyles. This effort is about more than just giving information, it is a matter of making people understand there are options and practical ways to apply them to their daily lives.

The MyPlate icon emphasizes the fruit, vegetable, grains, protein and dairy food groups; the pie-shaped sections are larger for vegetables and grains, and smaller for fruits and proteins. To help consumers build healthier diets, the campaign website ChooseMyPlate.gov provides resources and tools for dietary assessment, nutrition education, and other user-friendly nutrition information.

Obesity increases a person’s chance of developing a number of health problems, including type 2 diabetes, heart disease, high blood pressure, and some cancers. To combat the U.S. obesity epidemic, the ChooseMyPlate.gov resources and tools empower people to make healthier food choices for themselves, their families and their children.

First Lady Michelle Obama said [2]:

This is a quick, simple reminder for all of us to be more mindful of the foods that we’re eating and as a mom, I can already tell how much this is going to help parents across the country. When mom or dad comes home from a long day of work, we’re already asked to be a chef, a referee, a cleaning crew. So it’s tough to be a nutritionist, too. But we do have time to take a look at our kids’ plates. As long as they’re half full of fruits and vegetables, and paired with lean proteins, whole grains and low-fat dairy, we’re golden. That’s how easy it is.

Since 1992, American consumers have been following the food guide pyramid. The pyramid was divided into six sections: basic foods were at the base and included bread, cereal, rice and pasta. Two middle sections consisted of vegetables and fruit; two top sections consisted of milk, yogurt and cheese, and meat, poultry, fish, dry beans, eggs and nuts. In an effort to simplify the design and promote physical activity, the food pyramid was updated in 2005 to MyPyramid. However, many people found it complicated (MyPyramid has 12 sets of possible recommendations) and confusing (food group pictures were replaced by colored vertical bands that represent different food groups).

MyPlate updates and simplifies the food guide, ending 19 years of United States Department of Agriculture (USDA) food pyramid diagrams. The MyPlate icon is a visual cue to make half your plate fruits and vegetables. In addition, ChooseMyPlate.gov offers the Ten Tips Nutrition Education Series, which provides consumers and professionals with high quality, easy-to-follow tips in a convenient, printable format (perfect for posting around the house or work). There you will find a wealth of suggestions (in sets of 10) that can help you get started toward a healthy diet, including:

• Choose MyPlate: 10 tips to a great plate
• Add more vegetables to your day: 10 tips to help you eat more vegetables
• Focus on fruits: 10 tips to help you eat more fruits
• Make half your grains whole: 10 tips to help you eat whole grains
• Got your dairy today? 10 tips to help you eat and drink more fat-free or low-fat dairy foods
• With protein foods, variety is key: 10 tips for choosing protein
• Build a healthy meal: 10 tips for healthy meals
• Healthy eating for vegetarians: 10 tips for vegetarians
• Smart shopping for veggies and fruits: 10 tips for affordable vegetables and fruits
• Liven up your meals with vegetables and fruits: 10 tips to improve your meals with vegetables and fruits
• Kid-friendly veggies and fruits: 10 tips for making healthy foods more fun for children
• Be a healthy role model for children: 10 tips for setting good examples
• Cut back on your kid’s sweet treats: 10 tips to decrease added sugars
• Salt and sodium: 10 tips to help you cut back

Later this year, the USDA will unveil an exciting “go-to” online tool that consumers can use to personalize and manage their dietary and physical activity choices. Over the next several years, USDA will work with First Lady Michelle Obama’s Let’sMove! initiative and public and private partners to promote MyPlate and ChooseMyPlate.gov as well as the supporting nutrition messages and “how-to” resources.

References

1. Dietary Guidelines for Americans, 2010. United States Department of Agriculture Center for Nutrition Policy and Promotion. 2011 Jan 31.
2. First Lady, Agriculture Secretary Launch MyPlate Icon as a New Reminder to Help Consumers to Make Healthier Food Choices. United States Department of Agriculture Center for Nutrition Policy and Promotion. 2011 June 2.

The result of this movement to bring science into the kitchen is Molecular Gastronomy, the application of biological and chemical knowledge to cooking. Molecular Gastronomy is a discipline practiced by both scientists and food professionals to study the physical and chemical processes that occur while cooking.

BioMed Central, an open access STM (Science, Technology and Medicine) publisher of research, is introducting a new journal called Flavour, which will allow people to read the latest and highest quality scientific research in the field of Molecular Gastronomy. Flavour reflects the growing interest in the developing new science of molecular gastronomy and will publish high-quality, peer-reviewed research on topics related to flavor, while also encouraging contributions from chefs and other food professionals who are exploring the role of science in the kitchen. Flavour offers a “new taste” of journal and seeks to create a shared forum for the publication of evidence-based research in an open access context that will make it accessible not only to researchers but also the wider community of chefs, policy makers and the public.

Flavour is giving away 10 free copies of Peter Barham’s Science of Cooking. Simply register for article alerts from Flavour before 1st July to be entered into the drawing.

Focusing on flavor generation and perception, and its influence on behavior and nutrition, Flavour is now accepting submissions and will publish research relating to all contexts — whether it be everyday cooking, haute cuisine or government policy on healthy eating.

The journal is seeking articles on the psychophysical, psychological and chemical aspects of flavour as well as those taking brain imaging approaches. Since the editors take flavour to be the experience of eating food as mediated through all the senses, they welcome articles that deal with not only taste and aroma, but also chemesthesis (the chemical sensibility of the skin and mucus membranes), texture and all the senses as they relate to the perception of flavor.

Some of Flavour’s main interests include:

• Mechanisms of taste and flavor
• How flavor affects liking and satisfaction gained from eating
• Relationships between satiety and perceived quality of foods
• Choice behaviour with respect to food quality and satiety
• Multi-modal integration and multi-sensory perception of flavor
• How all senses play their role in our perception of flavor
• How ingredients are changed by different cooking methods and in the mouth
• Aroma release mechanisms in the mouth
• Sensitivity to stimuli originating inside the body
• The evolution of our organs of taste
• The psychology and neuroscience of food preferences and habit formation

The new journal will be edited by Peter Barham from the University of Bristol and author of the best selling Science of Cooking, and Per Moller from the University of Copenhagen. Peter is a researcher of Molecular Gastronomy, polymer physics and penguins; Per’s research focuses on psychophysics and neurophysiology of the senses and on the neuropsychological phenomena regulating food sensation, reward and appetite.

Dr. Jens Kondrup from the Department of Human Nutrition, University of Copenhagen, Denmark, believes Flavour’s high-level scientific content can bring about advancements to aid people that are sick [1]:

Many patients with cancer and other long lasting diseases lose weight and suffer severely from malnutrition. The main reason is inadequate food intake and it appears that changes in sensory requirements play a major role. Flavour can become a very useful journal for the necessary scientific development in this area.

Claus Meyer, co-founder of the restaurant Noma in Denmark (voted S.Pellegrino’s World’s Best Restaurant 2010) is also excited about the possibilities for Flavour [1]:

It is possible, it might even be very smart, to combat obesity, global warming and the over-exploitation of our planet, with deliciousness as a weapon. I am sure that Flavour will give us crucial insight into the pleasure giving qualities of food.

References

1. A new Flavour of journal is cooking up a storm. BioMed Central Blog. 2011 May 3.

It has long been known that peanut allergies are heritable, but the gene responsible for this heritability was unknown. Filaggrin is a protein that is expressed primarily in the skin, where it binds to keratin and plays an important role in forming the protective and impenetrable barrier that makes skin such a vital organ. Mutations in the filaggrin gene have already been identified as risk factors for eczma, asthma and other allergies, which is what prompted Drs. Sara Brown at the University of Dundee in the UK and Yuka Asai at McGill University Health Centre in Montreal, Quebec, Canada, and colleagues to consider it as a candidate gene for peanut allergies.

The researchers analyzed blood or saliva from 71 white English, Dutch, and Irish people known to have peanut allergies based on an oral challenge and 1000 healthy English controls. To confirm their results, they repeated the study with 390 white Canadians who had peanut allergies and 891 white Canadian healthy controls. They looked for loss-of-function mutations — those that completely inactivate the protein — in the filaggrin gene (FLG) that are most prevalent in the European population. They found that these mutations are “strongly and significantly associated with peanut allergy.” Twenty percent of the people with peanut allergies harbored a loss-of-function mutation in the filaggrin gene in both the European and Canadian populations, compared to 5 – 10% of the control populations.

It is still unclear how nonfunctional filaggrin might allow peanut allergies to arise. Eczma is a hypersensitivity reaction in the skin that results in inflammation, and is thus very much like an allergy. It has been suggested that impairment of the epidermal barrier — as would occur if filaggrin function is disrupted — could allow allergens to penetrate into the body, causing a local inflammatory response like eczma as well as a more systemic response like asthma. Studies performed in mouse models support this hypothesis. This explains tactile peanut allergies, and to make the story even neater, eczma is a known risk factor for peanut allergies. In fact, eczma is a stronger risk factor than these loss-of-function mutations in the filaggrin gene. As for oral exposure to peanuts, some patients with eczma have increase intestinal permeability … but it is not yet known if filaggrin plays a role here. Filaggrin has not been found in the gastrointestinal tract, but it is present in the oral mucosa and possibly as far down as the esophagus.

The authors suggest that these mutations might be associated with other food allergies. As the “most significant genetic risk for peanut allergy that has been identified to date,” looking into that possibility certainly seems warranted.

Researchers at the North Carolina Agricultural and Technical State University have recently developed an enzymatic treatment that reduces two of the most potent peanut allergens in roasted peanut kernels, Ara h 1 and Ara h 2 [2]. Ninety percent of those with peanut allergies react to these two proteins. Jainmei Yu, who has been working on developing hypo-allergenic peanuts since 2005, plans to begin clinical trials as a first step of getting them. Hopefully they will be successful, and peanut butter and jelly sandwiches will become a school lunchroom staple once again.

References

1. Brown et al. Loss-of-function variants in the filaggrin gene are a significant risk factor for peanut allergy. J Allergy Clin Immunol. 2011 Mar;127(3):661-7.
   View abstract
2. Yua et al. Enzymatic treatment of peanut kernels to reduce allergen levels. Food Chemistry. 2011 Aug;127(3):1014-22.