Attention-deficit hyperactivity disorder (ADHD) affects approximately 11 percent of children aged four to 17—that’s 6.4 million children diagnosed as of 2011. Boys are three to four times more likely to be diagnosed than girls. While there are certain hereditary factors that make some children more likely to develop ADHD more than others, environmental factors are also thought to play an important role.
In a recent study published in the Journal of the Federation of American Societies for Experimental Biology (FASEB), researchers discovered that exposure to the pyrethroid pesticide deltamethrin while in utero and through lactation was linked to the development of several features of ADHD in an animal model. Dysfunctional dopamine signaling in the brain, hyperactivity, attention deficits, and impulsive-like behavior were observed.
“Although we can’t change genetic susceptibility to ADHD, there may be modifiable environmental factors, including exposures to pesticides that we should be examining in more detail,” noted Jason Richardson, PhD.
Male mice were more affected than female mice in the study, similar to what is seen in children. The ADHD behaviors continued through adulthood even long after the pesticide exposure was no longer detected, highlighting the potential long-term effects of pesticide exposure.
The researchers then analyzed data from the Centers for Disease Control and found that children with higher levels of pyrethroid pesticide metabolites in their urine were more than twice as likely to be diagnosed with ADHD, supporting the findings of the animal study. The authors caution that young children and pregnant women are particularly susceptible to pesticide exposure. “We need to make sure these pesticides are being used correctly and not unduly expose those who may be at a higher risk,” said Richardson.
There is something about social connection that enhances our ability to stick with a new habit or practice. The feeling of “we’re in this together” seems to encourage success within a group setting. In a recent study published in the Journal of the Royal Society Interface, researchers found that online dieters who were well connected and participated in an online dieting program were most likely to lose weight when compared to those who participated less.
“Our findings suggest that people can do very well at losing weight with minimal professional help when they become centrally connected to others on the same weight loss journey,” noted Bonnie Spring, PhD.
The researchers found that users who did not connect to others lost about five percent of their body weight over the course of six months while those who were somewhat connected lost almost seven percent and those who were most connected lost over eight percent of their weight.
That’s good news for our Skinny Gut Forum. If you are following the Skinny Gut Diet (or want to be!), the Skinny Gut Forum is a place where you can interact with me and others to get support and encouragement.
Or, why not start a support group of your own? Maybe you have a few friends who want to try the diet. You could create a Facebook group to check in and encourage each other while sharing tips about how to be successful. Clinical studies have found that regular tracking of progress helps people to lose more weight. Report your weekly weight and inches lost in your group to help keep you on track.
If you’ve ever struggled to lose weight or improve your health, I want to let you in on a secret: until now, you have probably been taking the wrong approach. Be sure to watch my Skinny Gut, Vibrant You special on public television throughout the month, and I will show you how to get back on track!
The truth is, you are not entirely responsible for your weight gain or poor health. There is actually a missing piece to the puzzle, and it has to do with the trillions of bacteria inside your gut and whether they are in balance or out of balance. In fact, they are the underlying reason why you still have a hard time losing weight and staying healthy.
In Skinny Gut, Vibrant You I reveal the science behind your inner weight loss secret and provide surprisingly simple ways to help you lose weight and achieve vibrant health. You will learn how to address your internal gut balance so you can finally reach your weight loss goal—plus enjoy the side benefits of fewer digestive problems, a stronger immune system, and even a better mood!
Click here to find out when it will be airing locally, and be sure to tune in to Skinny Gut, Vibrant You all through March on your public television station.
The average age of a girl’s first menstruation has been decreasing in recent years. While there are a number of potentiation causes, consumption of the contributing of sugary drinks is the topic of a recent study published in the journal Human Reproduction. Researchers followed over 5,500 girls aged nine to 14 years and found that those who drank more than 1.5 servings of sugary drinks per day had their first period 2.7 months earlier, on average, than those who consumed two or fewer drinks per week.
“Our findings suggest that frequent consumption of sugar sweetened beverages may be associated with earlier menarche [onset of menstruation],” noted the authors. “A one-year decrease in age at menarche is estimated to increase the risk of breast cancer by five percent … thus, a 2.7-month decrease in age at menarche likely has a modest impact on breast cancer risk.”
In another study published in the Public Library of Science ONE journal that included over 1,400 women aged, on average, 61, researchers found that those women who were exposed to high levels of chemicals found in everyday household and personal care items experienced menopause two to four years earlier than those women with lower levels of these chemicals.
“Chemicals linked to earlier menopause may lead to an early decline in ovarian function, and our results suggest we as a society should be concerned,” noted Amber Cooper, lead researcher. “Many of these chemical exposures are beyond our control because they are in the soil, water, and air, but we can educate ourselves about our day-to-day chemical exposures and become more aware of the plastics and other household products we use.”
The researchers tested the women’s blood and urine for 111 chemicals from the following categories: dioxins/furans, phthalates, phytoestrogens, polychlorinated biphenyls (PCBs), phenols, organophosphate pesticides, surfactants, and polycyclic aromatic hydrocarbons.
Both of these studies are cause for concern. Although they do not prove causation, they suggest that reducing sugar intake in young girls, and reducing chemical exposure in women is a priority.
Scientists are hard at work researching the effects of probiotics and prebiotics on metabolic abnormalities such as those seen in people with diabetes and related conditions. A recent study published in the journal Diabetes highlights the effects of a Lactobacillus probiotic on blood sugar levels. The researchers engineered the Lactobacillus strain to secrete glucagon-like peptide 1 (GLP-1). Glucagon-like peptide-1 is normally produced in the small intestine and stimulates insulin release to lower blood glucose levels.
People with diabetes are either unable to produce enough insulin (type 1 diabetes) or the body’s cells do not respond properly to insulin (insulin resistance) due to an overabundance of insulin produced in response to continually high blood sugar levels (type 2 diabetes).
In an animal model, the GLP-1–producing probiotic induced the conversion of intestinal lining cells so that they would produce insulin, much like beta cells found in the pancreas. “It’s moving the center of glucose control from the pancreas to the upper intestine,” noted John March, PhDlead researcher. The probiotic reduced blood sugar levels in diabetic rats by up to 30 percent.
This proof-of-concept study will need to be followed up with more study to determine dosage, and later in humans to determine efficacy, but it shows promise that we might soon be able to better control blood glucose levels by targeting the site of glucose absorption.
Some evidence in humans does exist, however. For example, a recent human study published in the British Journal of Nutrition found that people who ate a high-fat, high-carbohydrate diet and also drank a probiotic fermented milk experienced less insulin resistance than those individuals who did not drink the probiotic milk.
Fecal microbiota transplantation (FMT) involves the transfer of fecal material from a healthy donor to the digestive tract of an ill recipient (most commonly, someone with refractory, or difficult to manage, C. difficile diarrhea). Transplanting the gut microbiota from a healthy individual to someone with C. diff has resulted in an impressive 90+ percent cure rate of the disease. Brenda and I have blogged about this topic a few times.
In a recent paper published in the journal Open Forum Infectious Diseases, Neha Alang, MD, and Colleen Kelly, MD report weight gain in a patient who received FMT from a donor who also gained weight shortly after the donation took place, suggesting that the microbes themselves may be to blame for the weight gain.1
“We’re questioning whether there was something in the fecal transplant, whether some of those ‘good’ bacteria we transferred may have had an impact on her metabolism in a negative way,” noted Kelly.
The patient was a 32-year-old healthy, normal weight female who had been unsuccessfully treated for C. diff infection on multiple occasions. Upon discussion of FMT with her physician, she requested that her 16-year-old daughter be the donor. At the time, her daughter’s weight was normal (~140 pounds), but later increased to 170 pounds. The patient improved after the transplant and did not experience a relapse of C. diff.
Sixteen months later, however, the patient had gained 34 pounds and had become obese. She was unable to lose the weight despite dietary and exercise practices. She continued to gain weight—twenty months later she weighed 177 pounds and had developed constipation and indigestion.
The physicians suggest that, due to her previous history of never being obese and the weight gain that had also occurred in her daughter, the obesity may be a consequence, at least in part, of the bacteria transferred via the fecal microbiota transplantation. Animal studies support the hypothesis that an obese microbiota can be transferred and that it can induce obesity in the recipient.2
Unfortunately, there is no baseline stool evaluation to determine what the before and after microbiomes looked like. Fortunately for us, it is possible to evaluate the microbiome of our stool using an affordable test ($89) from UBiome.
As a result of this case study, the physicians have altered their FMT practice policy to require FMT donors be non-obese. This study highlights the importance of rigorous donor selection, and may discourage FMT recipients from choosing family members as donors. This study is yet one more indication that our microbes are truly in control of our health. Or, on the flipside, perhaps one day we will treat bulimia and anorexia with fecal microbiota transplants.
- Alang N and Kelly CR, “Weight gain after fecal microbiota transplantation.” Open Forum Infect Dis. Winter 2015 2(1): doi: 10.1093/ofid/ofv004.
- Ridaura VK, Faith JJ, Rey FE, et al., “Gut microbiota from twins discordant for obesity modulate metabolism in mice.” Science. 2013 Sep 6;341(6150):1241214.
Although scientists are hard at work studying the human gut microbiome, the complexity of the task is such that we still know very little about the trillions of microbes that live in and on us—and on whom we are intricately dependent. In a recent article published in the Journal of Human Evolution, researchers suggest that by studying the gut microbiome of our ancestors we can more completely understand the nature of our own health.
“We have little information about the ancestral state of our microbiome, and we therefore lack a foundation for characterizing this change,” they note. “The process of industrialization has dramatically reduced our direct interaction with natural environments and fundamentally altered our relationship with food and food production.”
The researchers question whether humans are in “mutualistic symbiosis” with our microbes, or whether the diseases of civilization—heart disease, obesity, type 2 diabetes, asthma, allergies, and osteoporosis, for example—“are out of ecological balance and teetering on dysbiosis?” Indeed. They suggest studying mummified remains in a time-series approach linked to major moments in human development and innovation.
“Although reconstructing the ancestral microbiome by studying our ancestors directly is not without challenges, this approach provides a more direct picture of human-microbe coevolution.”
The more we know about our gut microbes and how they evolved, the better we will understand the current state of our health. I look forward to more studies that help us to understand how our gut microbes evolved—and how that shift has affected our health over time.
Paradoxically, people who are obese have a low intake of essential micronutrients despite having an abundance of stored energy (in the form of fat), according to a recent study published in the Journal of the American College of Nutrition. While this population may be eating more food, the foods they are eating more of are nutrient-poor, energy-dense foods (high-calories, low-nutrients), which may help to explain the paradox.
Using data from the National Health and Nutrition Examination Survey (NHANES), they found that, although the majority of people in the United States lack adequate nutrient intake, overweight and obese adults have about 5 to 12 percent lower intakes of micronutrients than healthy weight people.
“The NHANES data show that a high percent of the population have problems meeting recommended nutrient intake for vitamins A, C, D, and E, and magnesium and calcium,” noted Victor Fulgoni, PhD, one of the researchers.
Overall, dietary supplement users had higher overall nutrient intakes and lower prevalence of micronutrient inadequacy, suggesting that dietary supplements may help with filling the nutrient gaps, the researchers stated.
This is not the first study to find nutrient inadequacies in obese people. In 2005, a study published in the Canadian Journal of Dietetic Practice and Research found that obese children were more likely to not be getting enough vitamins E and D, or enough magnesium and calcium, despite eating more calories, when compared to healthy weight children. If you are overweight or obese, a multivitamin/mineral formula can help you be sure that you are getting the nutrition you need.
Have you ever glanced at the Nutrition Facts label on packaged foods and been confused about what you should be looking for? Do you find it difficult to figure out how much sugar is natural or added in the product you purchased? Does the percent Daily Value total trip you up? Do you know the difference between polyunsaturated fat and monounsaturated fat? (Okay, if you are an avid reader of my blog, you probably do, but you are way ahead of most people.) The fact is the Nutrition Facts label required on all packaged foods is confusing. And I’m not the only one who thinks so.
A recent study published in the Annals of the New York Academy of Sciences journal compared four labeling systems and found that the Nutrition Facts label was the least useable of the four. The label took more time to understand and led to nutrition choices that were no different than those chosen randomly. Of all four labels, the NuVal Nutritional Scoring System was the most useable. NuVal scores food on a scale of 1 to 100. The higher the score, the better the nutrition. Simple as that.
“Food shoppers typically have a limited amount of time to make each food choice, and they find the Nutrition Facts labels to be confusing and difficult to use,” noted Peter Helfer, lead researcher. “One product might be low in fat, bur high in sugar, while another product may be just the opposite. Nutrition Facts labels can highlight nutrition conflicts, but fail to resolve them. Even educated and motivated shoppers have difficulty picking out the most nutritious product with these labels.”
I am hopeful that this study will help influence the Food and Drug Administration, who are currently working on updating the current label. They have already proposed some changes, including adding an “added sugar” category, but even with the proposed changes, the label is still confusing to many.
A number of studies have linked stress during pregnancy to premature birth and low birth weight, eczema, asthma, skin condition, and general illness as well as anxiety, attention-deficit hyperactivity disorder (ADHD) and impaired cognitive and psychomotor development.1 The reasons for these associations is not completely understood. Some researchers believe that gut microbes play a role.
Intestinal microbes affect the development of an infant’s immune system, development of the gastrointestinal tract, and hormone function. Infants receive their gut microbes largely from their mother—especially if they are delivered vaginally and breastfed—and to a smaller extent from their environment. Compromised development of a healthy balance of gut bacteria during infancy can have long-lasting negative health effects.
In a recent study published in the journal Psychoneuroendocrinology, researchers found that women who experience stress during pregnancy are more likely to have babies with an imbalance of gut bacteria and worse gastrointestinal problems and allergic reactions when compared to women with less prenatal stress.1
Fifty-one mother-infant pairs were involved in the study. Stress levels during pregnancy along with salivary cortisol levels were measured. Cortisol, known as the stress hormone, is secreted under conditions of stress and so is a biological marker of stress. Those women with either high stress levels as measured by questionnaires or high cortisol levels were more likely to deliver babies with greater gut bacterial imbalance.
Fecal samples were collected up to five times beginning at seven days after birth up to four months after birth. Mothers with high stress and high cortisol levels had babies with higher amounts of Proteobacteria, which is comprised of a number of pathogenic species, and lower amounts of lactic acid bacteria (a group including the beneficial Lactobacillus) and Actinobacteria (a group including the beneficial Bifidobacterium). These children also experienced greater gastrointestinal symptoms and allergic reactions. Even breastfeeding, which is known to help promote the growth of beneficial bacteria in the gut due to its prebiotic content, was not enough to protect from the negative effects of stress.
“We think that our results point towards a possible mechanism for health problems in children of mothers who experience stress during pregnancy,” noted Carolina de Weerth, lead researcher. “Giving other bacteria would probably benefit these children’s development.”
The researchers suggest that cortisol may be affecting gut microbes in three main ways. First, cortisol may be interfering with bile production which can have an effect on gut bacteria. Second, cortisol may cross the placenta and increase fetal cortisol levels, which might affect the development of the gastrointestinal tract and impact gut bacteria. Third, cortisol may be transferred to the infant from breast milk. Cortisol is not the only mechanism, however, since prenatally stressed women without elevated cortisol also had babies with gut imbalance. The researchers suggest that the effects of stress on the endocrine and immune systems might be to blame. These mechanisms require further study.
Indeed, this study points to the need for a diet high in plant-based foods that feed the beneficial bacteria in the gut, supplementation with pre- and probiotics, and stress-reduction therapies such as meditation during pregnancy. Lactobacillus and Bifidobacterium bacteria are sensitive to environmental disturbances, and yet are well known to be crucial to the development of a healthy gut microbiota in children. Replenishing this population of bacteria—and preventing its depletion—during pregnancy, infancy, and beyond is crucial.
- Zijlmans MAC, Korpela K, Riksen-Walraven JM, et al., “Maternal Prenatal Stress and Infant Intestinal Microbiota.” Psyconeuroendocrinol. 2015;19 Jan: online ahead of print.