Artificial sweeteners appear to fool appetites; Sucralose may harm friendly gut bacteria
If you surf social media, you may have seen warnings about peanut butter and pets.Those messages, which claim that peanut butter can kill pets, certainly caught my eye!
But I soon learned that the risk isn't from peanut butter itself.
Instead, peanut butter sweetened with xylitol can be fatal to your critters.
Xylitol is a type of pentose or “sugar alcohol” extracted from plant materials for use as a natural, somewhat lower-calorie sweetener. (It has about one-third fewer calories than cane sugar.)
While Xylitol is safe for humans, just two pieces of gum or candy sweetened with Xylitol would throw a 13-pound dog into severe hypoglycemia (low blood sugar), while 10 pieces would cause liver failure.
The numbers and varieties of artificial sweeteners in prepared foods has risen rapidly over the past few decades.
Aside from risks to your pets, do people run risks if they consume artificial sweeteners routinely?
And if you're hoping that artificial sweeteners will help you avoid weight gain, does that strategy really work?
Two new studies shed light on some surprising risks of high-intensity artificial sweeteners, including saccharin, aspartame (NutraSweet), and sucralose (Splenda).
Surprising news about artificial sweeteners and your appetite
As we reported earlier this year, artificial sweeteners may mess with blood sugar regulation.
For more on those studies, see Do Artificial Sweeteners Help or Hurt?.
And there's growing evidence that artificial sweeteners may actually leave you hungrier, causing you to consume more calories.
A new study from Australia's University of Sydney sheds new light on those possible adverse effects of artificial sweeteners.
For the first leg of the study, fruit flies were fed a diet laced with artificial sweetener (sucralose) for periods of five days or more.
The flies on the artificially sweetened diet consumed 30% more calories than fruit flies who were given a naturally sweetened diet.
According to lead researcher Greg Neely from the University of Sydney's Faculty of Science: “When we investigated why animals were eating more even though they had enough calories, we found that chronic consumption of this artificial sweetener actually increases the sweet intensity of real nutritive sugar, and this then increases the animal's overall motivation to eat more food.”
The team re-ran the study using mice, to gauge the effect of artificial sweeteners on mammals.
Just like the fruit flies, the mice who ate a sucralose-sweetened diet for seven days showed significant bumps in food consumption.
As study co-author Peter Herzog said, “These findings further reinforce the idea that ‘sugar-free' varieties of processed food and drink may not be as inert as we anticipated. Artificial sweeteners can actually change how animals perceive the sweetness of their food, with a discrepancy between sweetness and energy levels prompting an increase in caloric consumption.”
While early research has shown that artificial sweeteners can boost appetite rather than satisfy it, this is the first study to look at how artificial sweeteners stimulate appetite.
For the first time, researchers identified a complex network of neurons that responds to artificially sweetened food by telling the animal it hasn't eaten enough energy.
“After chronic exposure to a diet that contained the artificial sweetener sucralose, we saw that animals began eating a lot more,” said Professor Greg Neely.
“Through systematic investigation of this effect, we found that inside the brain's reward centers, sweet sensation is integrated with energy content. When sweetness versus energy is out of balance for a period of time, the brain recalibrates and increases total calories consumed.”
The research team also found that in mice, artificial sweeteners led to hyperactivity, insomnia and poor-quality sleep, all of which correspond with a mild state of starvation (this matches earlier human studies).
Diet sodas in pregnancy linked to weight gain in infants
There is growing evidence that life-long obesity may begin in our earliest days.
According to the Centers for Disease Control, childhood obesity has more than doubled in children and quadrupled in adolescents in the past 30 years.
The percentage of obese children ages 6–11 in the United States rose from 7% in 1980 to nearly 18% in 2012.
Pregnant women who use artificial sweeteners to avoid sugar should think twice.
New research suggests they may render their unborn children vulnerable to weight problems and related health conditions.
Childhood obesity is linked to higher risk for heart disease, high blood pressure, bone-joint problems, and higher rates of pre-diabetes.
Scientists from four Canadian universities found that artificial sweetener use by pregnant mothers tends to increase a child's body mass index (BMI) and may even lead to a higher risk of early childhood obesity.
According to Meghan Azad, lead author of the Canadian study: “Our study provides the first human evidence that maternal consumption of artificially sweetened beverages during pregnancy is associated with differences in infant body weight.”
“Given the current epidemic of childhood obesity and widespread use of artificial sweeteners, further research is warranted to confirm our findings and investigate the underlying biological mechanisms, with the ultimate goal of informing evidence-based dietary recommendations for pregnant women.”
For the study, researchers measured the mother's consumption of artificially sweetened beverages during pregnancy for over 3,000 mother-infant pairs.
Their analysis linked use of artificially sweetened beverages during pregnancy to higher infant body mass index by the age of 1 year.
After adjusting the data for maternal obesity and the quality of their diet, daily consumption of artificially sweetened beverages was still associated with a two-fold higher risk of an infant becoming overweight.
According to Azad: “We know that prenatal nutrition plays a key role in ‘programming' fetal development and infant weight gain, but the impact of artificial sweetener consumption during pregnancy has not been extensively studied. Some animal research suggests that consuming artificial sweeteners during pregnancy can predispose offspring to develop obesity, but this had never been studied in humans.”
Sucralose may not be as “inactive” as thought
Sucralose is the chlorine-based artificial sweetener better known as Splenda.
Research in humans suggests that sucralose doesn't get digested, so it shouldn't have much effect on human health (Brusick D et al. 2009; Brown AW et al. 2011).
But studies in rodents raise concerns that our bodies may in fact metabolize sucralose in ways that could harm health.
Susan Schiffman, Ph.D., of North Carolina State University co-authored two studies that linked sucralose to a number of problems (Abou-Donia MB et al. 2008; Schiffman SS et al. 2012).
These were among the problems Sucralose created in rodents:
- Reduced beneficial bacteria: Sucralose altered the amount and quality of beneficial gut microbes adversely, in ways associated with weight gain and obesity. These effects resulted from amounts equivalent to those approved for use in food, and some were seen at even lower levels.
- Interfered with drug-metabolization pathways: Sucralose interfered with enzymes in ways that would limit absorption of therapeutic drugs, such as those for cancer and heart disease.
- Exerted undesirable metabolic/immune effects: Sucralose altered insulin and blood sugar levels in ways associated with higher risk for type 2 diabetes, heart disease, metabolic syndrome, and obesity.
And when it's subjected to high temperatures, as in baking, Sucralose breaks down into potentially toxic compounds called chloropropanols.
Given the mounting concerns about artificial sweeteners, it may actually be healthier to use sugar in moderation.
The American Heart Association recommends limiting consumption of added sugars to less than 100 calories or 6 added teaspoons a day.
But it's hard to calculate how much you're getting when sugars are added to so many packets in processed foods.
Even the limits suggested by the American Heart Association may not be strict enough to protect against the heart, metabolic, and inflammation problems linked to added sugars.
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