Wednesday, October 27, 2010
High-fructose corn syrup in soda has much more fructose than advertised, study finds
High-fructose corn syrup is often singled out as Food Enemy No. 1 because it has become ubiquitous in processed foods over about the last 30 years – a period that coincides with a steep rise in obesity. One of the primary sources of HFCS in the American diet is soda – in fact, many public health advocates refer to soda as “liquid candy.”
That nickname is more apt than advocates realized, according to a study published online this month by the journal Obesity.
Researchers from the University of Southern California’s Keck School of Medicine went shopping in East Los Angeles and bought 23 cans and bottles of popular beverages. Then they sent them off to a laboratory in Massachusetts that used a technique called high-performance liquid chromatography to determine how much fructose, glucose and sucrose were in each sample. Each beverage was tested three times, and all samples were unlabeled.
Before we get to the results, let’s pause for a quick review on sugars. Fructose and glucose are simple sugars. Fructose is sweeter than glucose and has been shown to do more damage to your metabolism. Sucrose – better known as table sugar – is a 50-50 combination of fructose and glucose. The HFCS used in soda is supposed to contain no more than 55% fructose and 45% glucose, according to the Corn Refiners Assn. (Another popular formulation is 42% fructose and 58% glucose.) This slight difference is the reason why we here at Booster Shots frequently say that HFCS is just as unhealthy as “natural” sugar.
But it turns out that some of the stuff they put in soda isn’t HFCS, it’s RHFCS – Really High Fructose Corn Syrup.
The Keck researchers found that the sweeteners in Coca-Cola and Pepsi contained as much as 65% fructose (and only 35% glucose), and Sprite registered as much as 64% fructose (and 36% glucose).
“The type of sugar listed on the label is not always consistent with the type of sugar detected,” they wrote. “Considering that the average American drinks 50 gallons of soda and other sweetened beverages each year, it is important that we have more precise information regarding what they contain, including a listing of the fructose content.”
To make sure the high-performance liquid chromatography tests were accurate, the researchers also sent samples of pure fructose, pure glucose and pure sucrose. The test detected 9.9 grams of fructose in a 10-gram sample of fructose, 9.8 grams of glucose in a 10-gram sample of glucose, and 9 grams of sucrose in a 10-gram sample of sucrose.
The study included a few other surprises:
Mountain Dew had 13% less sugar than advertised on the label, and Dr. Pepper had 8% less.
Tested samples of Mexican Coca-Cola – which is supposedly made with cane sugar instead of HFCS – contained no sucrose, only fructose and glucose in a 52%-to-48% ratio.
17% of the sweetener in Red Bull was fructose, even though sucrose and glucose are the only sweeteners listed on the label.
We weren’t the only ones surprised by the findings. Here’s what nutritionist Marion Nestle had to say about the study Tuesday on her blog, Food Politics: "I’ve been saying for ages that the sugar composition of high fructose corn syrup (HFCS) is no different from that of table sugar (sucrose)."
Nestle continued: "At most, HFCS is supposed to be 55% fructose, as compared to the 50% in table sugar. Most foods and drinks are supposed to be using HFCS that is 42% fructose. A percentage of 55 is not much different biologically than 50, which is why the assumption has been that there is no biologically meaningful difference between HFCS and table sugar. This study, if confirmed, means that this supposition may need some rethinking."
The USC researchers pointed out that the U.S. Food and Drug Administration allows for some wiggle room on nutrition labels. Sodas are allowed to have as much as 20% more of a nutrient – including sugar and HFCS – than is indicated on the side of the can. Even Cokes and Pepsis with 65% fructose instead of 55% are only 18% higher than advertised.
Source: Karen Kaplan, Los Angeles Times, October 26, 2010
Friday, October 22, 2010
CHICAGO (Reuters) - Marathon runners can train for months to condition for the big race, yet struggle to finish if they exhaust stores of carbohydrates too quickly, a phenomenon known as "hitting the wall."
A new formula by a marathon runner and student at Harvard and MIT gives elite runners and marathon enthusiasts a more exact way to calculate just how many carb calories they need to take to stay in the 26.2 mile race.
"About 40 percent of marathon runners hit the wall," said Benjamin Rapoport, a student in the Harvard-MIT Division of Health Sciences and Technology, whose study appears in the Public Library of Science journal PLoS Computational Biology.
Essentially, that means the runner has burned up all of the carbohydrates stored in his liver and leg muscles, forcing him to slow down dramatically as the body starts to burn fat.
"You feel like you're not going anywhere," Rapoport said in a statement. "You can't will yourself to run any faster."
He said many runners believe hitting the wall is inevitable, that it is just part of a marathon.
"That is not true at all," Rapoport, who has run 18 marathons, including a personal best of 2 hours 55 minutes at this year's Boston Marathon, said in a telephone interview.
"What I came up with was essentially a set of formulas," he said.
"People need to know really three things: how much they weigh, what their target marathon time is and their maximum oxygen intake capacity," he said. "That is a measure of a person's aerobic fitness."
Aerobic capacity, also known as VO2max, is a measure of how much oxygen the body can transport to the muscles and consume during aerobic exercise.
Measuring exact VO2max requires a treadmill stress test at maximum effort, but an informal way to estimate aerobic capacity is to divide your maximum heart rate by your resting heart rate and multiply by 15, Rapoport said. To find your maximum heart rate, simply subtract your age in years from 220 beats per minute.
The result, he said, is a number that tells runners how many excess carb calories they need to take in before a race.
He said many runners also supplement their stored carbohydrates by taking gels and sports beverages as they are running, but a runner can carry much more fuel in their legs and liver, if they know the right amount.
Until now, runners have had to guess at what that was. The new calculator will make that easier, Rapoport said.
Rapoport has built an online calculator to help runners estimate their aerobic fitness pace and race goals which can be found at endurancecalculator.com/ .
"It's my gift to my fellow runners," he said.
Source:Reuters News Thu, Oct 21 2010. By Julie Steenhuysen
Thursday, October 21, 2010
Eating whole grains instead of refined grains may have benefits for your waistline, a new study suggests.
Adults who ate three or more servings of whole grains per day, and limited their refined grains to less than one serving per day, had 10 percent less belly fat than those who did not follow this diet, study researcher Nicola McKeown, a scientist with the USDA Human Nutrition Researcher Center on Aging at Tufts University, said in a statement.
The findings held true even after the researchers accounted for other facts that may have influenced the results, such as the participants' smoking, alcohol intake, fruit and vegetable intake, percentage of calories from fat and physical activity.
The study involved 2,834 men and women, ages 32 to 83, who filled out questionnaires about their diet. The participants also underwent body scans to determine their fat distribution — researchers measured how much fat was around the belly, so-called visceral fat, and how much was found in other parts of the body under the skin, known as subcutaneous fat.
Visceral fat is thought to be worse for you than subcutaneous fat. Previous work has linked belly fat with the development of metabolic syndrome, a cluster of symptoms including hypertension, unhealthy cholesterol levels and insulin resistance, which can develop into cardiovascular disease or Type 2 diabetes.
However, eating lots of whole grains didn't have the same benefits if people also consumed a lot of refined grains as well. Those who ate more than four servings of refined grains per day did not show improvements in their visceral fat volumes even if they also consumed whole grains, McKeown said.
"This result implies that it is important to make substitutions in the diet, rather than simply adding whole grain foods. For example, choosing to cook with brown rice instead of white, or making a sandwich with whole-grain bread instead of white bread," McKeown said.
The researchers noted the study only shows an association, and future work in a larger, more diverse population will be needed to confirm the findings.
This study was funded by the National Heart Lung and Blood Institute, the USDA and a research grant from the General Mills Bell Institute of Health and Nutrition.
Source: The American Journal of Clinical Nutrition, 11/2010.
Wednesday, October 20, 2010
The season in which babies are born could affect their susceptibility to food allergies early in life, new research indicates.
Finnish scientists studied just under 6,000 children born between 2001 and 2006 in southeast Finland. About 1,000 were tested for sensitization to food allergens up to the age of 4.
Researchers say the incidence of an allergic response to certain foods varied according to season of birth, ranging from 5% for infants born in June and July to 9.5% for those entering the world in October and November.
The study says 11% of children whose 11th week in the womb occurred during April or May were sensitive to food allergens as babies and toddlers.
Pollen has something to do with this, apparently, according to the researchers from the University of Oulu in Finland.
Readings of ambient pollen for the children born between 2001 and 2006 showed that levels of birch and alder pollen peaked during April and May.
The researchers conclude that children whose first three months of fetal development ended in April or May were three times more likely to become allergic to milk and eggs than kids in the same stage of development in November and December.
Slideshow: Are Your Allergies Out of Control?
Antibodies to Allergens
Previous research has shown that children born in the fall or winter are more prone to wheezing and eczema, and that they have higher levels of antibodies to allergies than kids born in spring and summer, the study researchers say.
The reason could be that fetuses start to produce antibodies to allergens around the 11th week of development and antibodies to specific allergens by 24 weeks of gestation.
An allergic type response apparently is necessary for a pregnancy to continue, and in some cases this continues after birth, according to the researchers.
The study is published online in the Journal of Epidemiology and Community Health.
The population studied comprised all 5,973 children born between April 1, 2001, and March 31, 2006; records came from the Finnish Population Register Centre.
The researchers conclude that kids whose early gestational period falls in the pollen season for broad-leafed trees are “more prone to sensitization to food allergies than other children.”
They concede that the issue is controversial and say that 18% of all children tested had developed food allergies by age 4, and that this varied by season.
“We found a higher incidence of positive results in food allergy tests among children born in October or November than among those born in other months,” and that the “incidence of such results was particularly high and especially pronounced for milk and egg among children who had their 11th gestational week in April or May, the season during which the concentrations of pollen from birch and alder are highest in the area concerned,” which was in the southeast area of Finland.
The researchers say their study is the first to examine an association between environmental pollen concentrations during the first trimester of pregnancy and the incidence of a positive result in food allergy tests.
Source : WebMD 10/19/2010
Tuesday, October 19, 2010
People who reported skipping breakfast during childhood and adulthood had more risk factors for heart disease than their peers who ate morning meals throughout their lives, Dr. Kylie J. Smith of the University of Tasmania and her colleagues found.
Some studies have found that people who don't eat breakfast tend to have worse eating behaviors and are less active than people who do, while some research has linked skipping breakfast with weight gain. There is also some evidence that people who don't eat in the morning are more prone to high cholesterol.
To investigate the long-term effects of not eating breakfast, Dr. Smith and her team analyzed data from the Childhood Determinants of Adult Health study, in which participants were surveyed in 1985, when they were 9 to 15 years old, and again in 2004-2005.
According to a report published online October 6th in the American Journal of Clinical Nutrition, children were categorized as not eating breakfast if they said they didn't eat anything before school, while adults were considered to have skipped breakfast if they didn't eat between 6 and 9 a.m.
Among nearly 2,200 study participants, about 1,400 didn't skip breakfast at either time point; 224 only skipped breakfast in childhood; 515 only skipped breakfast as adults; and 86 skipped breakfast in both childhood and adulthood.
The researchers found that people who consistently didn't eat breakfast had waists that were nearly 2 inches (or 5 centimeters) larger, on average, than people who ate breakfast as children and as adults. They also had higher insulin levels and higher levels of total and LDL cholesterol.
The researchers did not look at whether skipping breakfast had anything to do with developing cardiovascular disease, for example whether people were more likely to have heart attack or stroke. Nevertheless, the researchers conclude, "Promoting the benefits of eating breakfast could be a simple and important public health message."
Source:Am J Clin Nutr. Posted online October 6, 2010
Friday, October 8, 2010
Daily supplements of capsinoids - non-pungent compounds in sweet pepper – may boost weight loss by promoting energy use after a meal, suggests a new study from UCLA.
A daily dose of 9 milligrams of the capsinoid dihydrocapsiate was associated with a significant enhancement in energy expenditure after a meal, compared with a lower dose of 3 milligrams or placebo, according to findings published in Nutrition & Metabolism .
“In this small double-blinded, randomized, placebo controlled trial, we found that the consumption of a nonpungent capsiate supplement by overweight and obese subjects significantly increased post-prandial energy expenditure when combined with a high protein, very low calorie diet on an outpatient basis,” wrote researchers, led by David Heber MD, PhD, from the Center for Human Nutrition at the University of California at Los Angeles.
“The increase is estimated to be equivalent to an increase in daily energy expendtiture of approximately 100 kcal for a 100 kg individual,” they added.
The study supports the potential weight management actions of capsinoids, sister compounds to the more famous and more pungent compound capsaicin. While the ingredient has been reported to also produce thermogenic effects like capsaicin, capsinoids are not said to produce the gastrointestinal side effects of its more pungent relative.
The new study used Ajinomoto Inc’s dihydrocapsiate capsules of 1 mg. The FDA issued a GRAS letter of no objection to Ajinimoto in early 2009 for the company's capsinoid ingredient.
Dr Heber and his co-workers recruited 33 healthy men and postmenopausal women with BMIs between 27 and 35 kg/m2 who completed an outpatient protein-rich very-low calorie diet (VLCD) providing only 800 kcal per day.
The volunteers were then randomly assigned to receive one of two doses of dihydrocapsiate (3 mg or 9 mg) or placebo for four weeks. Metabolic rates after eating and at rest were measured by the UCLA researchers.
Results showed that, while resting metabolic processes were not affected, the high dose of dihydrocapsiate was associated with a statistically significant increase in energy expenditure after a meal.
“These data provide evidence for postprandial increases in thermogenesis and fat oxidation secondary to administration of dihydrocapsiate,” said the researchers.
“Further studies are needed to assess the impact of the predicted differences in energy expenditure related to dihydrocapsiate supplementation on weight loss and weight maintenance in free-living populations,” they concluded.
The research taps into the burgeoning weight loss and management market, estimated to already be worth $7bn (€5.2bn) globally. With 50 per cent of Europeans and 62 per cent of Americans classed as overweight, the food industry is waking up to the potential of products for weight loss and management.
The slimming ingredients market can be divided into five groups based on the mechanisms of action - boosting fat burning/ thermogenesis, inhibiting protein breakdown, suppressing appetite/ boosting satiety (feeling of fullness), blocking fat absorption, and regulating mood (linked to food consumption).
Source: Nutrition & Metabolism
2010, 7:78, doi: 10.1186/1743-7075-7-78
“Effects of dihydrocapsiate on adaptive and diet-induced thermogenesis with a high protein very low calorie diet: a randomized control trial”
Authors: T.Y.A. Lee, Z. Li, A. Zerlin, D. Heber
Tuesday, October 5, 2010
Nutrition experts have examined the diets of typical U.S. children and they don't like what they see: Almost 40 percent of the kids' calorie consumption comes from solid fat and added sugars.
These so-called "empty calories," mainly in soda, pizza and desserts, are fueling the obesity epidemic among young people and putting them at risk for developing weight-related illnesses, such as diabetes and heart disease, the U.S. government researchers said.
"Product reformulation alone is not sufficient -- the flow of empty calories into the food supply must be reduced," said dietitians Jill Reedy and Susan M. Krebs-Smith, from the U.S. National Cancer Institute's division of cancer control and population sciences in Bethesda, Md.
The findings are published in the October issue of the Journal of the American Dietetic Association.
The researchers examined data from the National Health and Nutrition Examination Survey and calculated solid fats and added sugars using the USDA MyPyramid Equivalents Database, according to a news release from the journal publisher and the American Dietetic Association.
The top sources of energy for 2- to 18-year-olds were grain desserts, pizza and soda, they found. Sugar-sweetened drinks (soda or fruit drinks) provided nearly 10 percent of total caloric intake. Half of the kids' empty calories came from these six foods: soda, fruit drinks, dairy desserts, grain desserts, pizza and whole milk.
Energy sources varied depending on age. The top five sources of energy for toddlers (2- to 3-years old) included whole milk, fruit juice, reduced-fat milk, and pasta and pasta dishes. The top five choices among 4- to 8-year-olds also included pasta and reduced-fat milk, the investigators found.
Energy sources also varied by race and ethnicity, the dietitians noted. Among black children, fruit drinks and pasta and pasta dishes were the primary energy sources, while Mexican American kids' top sources included Mexican mixed dishes and whole milk. Blacks and whites consumed more energy from soda and fruit drinks than from milk, whereas Mexican American children obtained more energy from milk than from sugary drinks, the data showed.
Added sugar is especially damaging, according to Dr. Rae-Ellen W. Kavey, a pediatric cardiologist at the University of Rochester Medical Center, who wrote an accompanying commentary in the journal. Health consequences include accelerated atherosclerosis and early cardiovascular disease, Kavey said in the news release.
"Reducing consumption of sugar-sweetened beverages should be considered a critical dietary approach to reducing cardiovascular risk in childhood," Kavey added.
A second study in the journal found that vending machines in middle schools attract students mainly to buy snacks and beverages, even if healthier choices are offered.
Source: FRIDAY, Oct. 1 (HealthDay News)
NEW YORK (Reuters Health) - Getting too little sleep might prevent dieters from losing as much body fat as they otherwise would have, a small study suggests.
The findings, published Monday in the Annals of Internal Medicine, add to evidence that sleep habits play a role in weight regulation. They also suggest that people embarking on a weight-loss plan may want to make sure they are catching enough shut-eye each night, researchers say.
The study included 10 overweight men and women who lived in a sleep lab for two separate two-week periods. During both, they were kept on the same calorie-restricted diet; but for one period, the participants slept for 8.5 hours per night, while during the other, they got 5.5 hours.
Researchers found that the dieters lost the same amount of weight under both conditions -- just under 7 pounds, on average. But during the sleep-restricted period, they mainly lost muscle rather than fat.
When participants got 8.5 hours of sleep, more than half of their weight loss came from shedding fat; when they got 5.5 of sleep, only one-quarter of their weight loss came from fat -- translating to a 55 percent reduction in fat loss.
Instead, the majority of people's weight loss during the sleep-restricted period came from lean body tissue, which refers to muscle and any other body tissue that is not fat.
"So they lost the same amount of weight, but the composition was different," said senior researcher Dr. Plamen Penev, an assistant professor of medicine at the University of Chicago.
Successful dieters always shed a certain amount of muscle, Penev noted in an interview, but ideally one wants to limit that loss in favor of shedding excess body fat. Insufficient sleep, the current findings suggest, might interfere with that.
The study has a number of limitations. Besides its small size, it also looked only at short-term weight loss. More research is needed to see how sleep duration might affect dieters' body composition over time, Penev said.
It's also unclear how well these findings from a tightly controlled sleep-lab setting might translate to the "real world," according to Penev.
Still, the findings do add to a body of research linking sleep habits to body weight. A number of studies have found that self-described "short sleepers" -- typically defined as those who get less than 6 hours of sleep each night -- tend to weigh more or gain more weight over time than people who get seven to eight hours of sleep per night.
Those studies do not, however, prove that sleep differences are the reason for the weight differences. Small sleep-lab studies such as the current one help researchers zero in on the effects of sleep itself.
Lab studies have suggested, for example, that sleep loss may alter people's levels of the "hunger hormones" leptin and ghrelin. Leptin is secreted by fat cells; low blood levels of the hormone promote hunger, while increases tell the brain that body is full and encourage calorie burning. Ghrelin is secreted by the stomach to boost appetite.
In their study, Penev and his colleagues found that under the sleep-restricted condition, participants reported greater hunger during the day compared with the 8-hour sleep condition -- even though they consumed the same number of calories during both periods. They also had higher blood levels of acylated ghrelin, one form of the appetite-boosting hormone.
This, Penev said, raises the question of whether, outside the tight control of the lab, the sleep-deprived dieters would have eaten more.
"The study suggests that if you are trying to lose weight by restricting your calories, it may be more difficult if you are sleep deprived," Dr. Shahrad Taheri, of the University of Birmingham in the UK, told Reuters Health in an email.
As for how much sleep is enough, "I don't think at this stage we can recommend a specific number of hours of sleep, as sleep is very individualized," said Taheri, who co-authored an editorial published with the study.
"But what we can do," Taheri added, "is pay more attention to our daily routines of eating, physical activity, and also sleep."
Penev agreed that there is no one-size-fits-all prescription for sleep. He suggested that people try to notice how much sleep they generally need to feel refreshed the next morning; for some people that may be 6 hours, for others it may be 8.
Both Penev and Taheri said that more studies are needed in real-world settings. According to Penev, a study might, for instance, follow patients at a weight-loss clinic to see how their typical sleep habits correlate with their weight-loss success.
As for why fewer hours in bed may cause the body to preferentially lose muscle over fat, Penev said he and his colleagues can only theorize. Their guess is that the extra waking hours increase the need for glucose (sugar) in the brain and other parts of the nervous system -- and they get that extra fuel from breaking down muscle.
Source:Mon, Oct 4 2010
By Amy Norton
WASHINGTON (Reuters) - Researchers who persuaded slender volunteers to gorge themselves on sweets to gain weight said on Monday they have overturned the common wisdom that adults cannot grow new fat cells.
As they gained weight, the volunteers added new fat cells on their thighs, while fat cells on their bellies expanded, Michael Jensen of the Mayo Clinic in Rochester, Minnesota and colleagues found.
"It sort of inverts the old dogma that we don't make new fat cells when we are adults," Jensen said in a telephone interview.
Doctors have long believed that, in adults, fat cells just get bigger and bigger when people gain weight.
Understanding why this happens on one part of the body and not another may explain why gaining weight in the lower part of the body does not appear to carry as many health risks as gaining belly fat, Jensen said.
"Those people who make new leg fat cells, it may be protecting them," he said.
Writing in the Proceedings of the National Academy of Sciences, Jensen and colleagues said they recruited 28 healthy men and women and fed them controlled meals, asking them to eat until they were more full than usual for two months.
The volunteers also agreed to have their body fat sampled.
To boost weight gain, the volunteers were encouraged to slurp milkshakes, chocolate bars and energy drinks.
In the two months the volunteers gained about 2 kg (4.4 pounds) of upper body fat and about 1.5 kg (3 pounds) of fat on the hips and thighs.
"We found that a gain of only 1.6 kg of lower-body fat resulted in the creation of 2.6 billion new adipocytes (fat cells) within eight weeks," Jensen's team wrote.
There were some unexpected findings.
"We thought the women would be the ones who gained on the thighs but it turned out it was pretty even on the two sides, to our surprise," Jensen said.
The volunteers shed their extra pounds easily, Jensen said.
"When you take normal, healthy weight people and you overfeed them and make them gain weight, almost as soon as they stop overeating the weight just falls off," he said.
"These were all people who never had a history of weight problems. Most of us have trouble when we gain it. We don't lose it so easily," Jensen said.
Jensen is unsure what the findings may mean for most Americans. More than two-thirds of the U.S. public are overweight or obese and the Organization for Economic Cooperation and Development says residents of most developed countries are catching up fast.
"Our next step is to try to understand better what are the genetic and environmental factors that cause the leg fat cells to be able to proliferate," Jensen said.
Scientists have learned that fat cells are not just passive storage facilities for extra calories, but produce hormones and other compounds with important biological effects. This may help explain why extra pounds raise the risk of diabetes, heart disease and some cancers.
Source: Mon, Oct 4 2010
By Maggie Fox, Health and Science Editor