In Animals, Exposure to High Fat Diet During Pregnancy Can Affect Offspring’s Neurological Development
New research in non-human primates suggests that exposure to a high fat diet during pregnancy and in early development prior to weaning can increase the offspring’s propensity for anxiety later in life.
The new research echoes 2010 findings about rats. Researcher Staci D. Bilbo and colleagues reported in the journal of the Federation of American Societies for Experimental Biology that in rats, a high fat diet during pregnancy and lactation led to offspring with greater body weight, increased inflammation, and problems with anxiety and spatial learning. Switching to a standard diet after weaning did not eliminate these outcomes.
The recent research by Jacqueline R. Thompson and colleagues, published in the journal Frontiers in Endocrinology in July 2017, suggests that maternal nutrition in the primate during pregnancy and lactation can have long-lasting effects on offspring’s neurological development, altering the brain and endocrine system. These changes occurred even if the offspring began a normal diet after weaning.
65 female Japanese macaques were divided into two groups, one that received a high-fat diet and one that received a normal diet. In the offspring of mothers who ate a high-fat diet, the researchers found impaired development of neurons containing serotonin. The offspring of the high-fat diet group also showed behavioral alterations such as increased anxiety.
The high rates of obesity in the US and other developed nations make these findings particularly important. The researchers suggest that 64% of women in the US who are of reproductive age are overweight, and 35% are obese. Co-author Elinor Sullivan suggested that the findings from the study could motivate mothers to make healthy nutritional decisions, not only for themselves but for their children as well.
Phthalates in Plastics and Creams Cause Epigenetic Changes to Sperm
A recent study suggests that chemicals called phthalates that are used to make plastic flexible and to improve the texture of lotions, creams, and powders have effects on human sperm. Phthalates have become common in our environment since the invention of plastics, and most people have detectable levels of phthalate metabolites in their bodies.
The study, published by Haotian Wu and colleagues in the journal Human Reproduction in 2017, measured DNA methylation in a group of men’s sperm and compared this to levels of phthalate metabolites in the men’s urine.
DNA methylation changes the structure of a DNA strand. Extra methyl groups are attached to the strand, affecting the way it is transcribed, even though the inherited genetic sequence on the DNA strand remains the same. Changes like these to the structure of DNA and histones, which give DNA its helix shape, are known as epigenetic changes.
Wu and colleagues found 131 regions of DNA methylation in the men’s sperm that they could link to at least one of the phthalate metabolites found in the men’s urine.
Sperm takes 72 days to mature. Wu and colleagues suggest that exposure to phthalates in plastics or personal care products during this period may cause alterations to sperm, which could potentially affect the ease of conception or the development of potential offspring. The changes the researchers observed affected genes related to growth, development, and cellular function and maintenance.
In addition to chemical exposure, stressors and drug use can also bring about epigenetic changes to sperm. A father’s offspring may then have altered risk of drug use or other behaviors as a result of these epigenetic changes.
Phthalates, which can disrupt the endocrine system, have previously been found to alter men’s hormone levels and to hurt sperm quality. This is the first study to find that in people, phthalate concentrations measured before conception are associated with DNA methylation in sperm. This was a fairly small study in 48 men, and it remains to be studied whether the changes to sperm affect the offspring’s prenatal and early childhood development.
In addition to their presence in flexible plastics, phthalates may also be found in products such as shaving cream, shampoo, soaps, and detergents.
Gabapentin May Increase Opioid-Related Deaths
The anticonvulsant gabapentin is sometimes prescribed for chronic pain conditions along with opioids. A 2017 article by researcher Tara Gomes in the journal PLOS Medicine reports that compared to opioid prescriptions alone, co-prescription of gabapentin increases the risk of an opioid-related death by 49%. The risk was increased by 60% for those receiving moderate or high doses of gabapentin (those above 900 mg/day).
The increased risk when the drugs are taken together may be because both gabapentin and opioids depress the respiratory system. Opioids also slow the gastrointestinal system, meaning that more gabapentin is absorbed by the intestines than occurs when gabapentin is prescribed alone.
Gomes and colleagues looked at cases of patients who were prescribed opioids and had opioid-related deaths, and matched these with similar patients who had not died while taking prescription opioids during the same time period. The researchers found that having taken gabapentin in the previous 120 days dramatically increased the risk of death from opioid-related causes.
Gomes and colleagues suggest that caution should be used when prescribing gabapentin and opioid drugs at the same time.
PTSD Increases Risk of Lupus
A new large 2017 study in the journal Arthritis and Rheumatology reports that post-traumatic stress disorder (PTSD) in women triples their risk of developing the autoimmune disease lupus. The study included 54,763 civilian women whose health data was tracked over a period of 24 years.
Not only did PTSD increase lupus risk, but any traumatic event doubled lupus risk compared to women who were not exposed to trauma.
The researchers, led by Andrea L. Roberts, were taken by surprise at the strong links between trauma and lupus. Trauma was more of a risk factor for lupus than smoking.
Diet Drinks May Worsen Glucose Control, Making Type 2 Diabetes More Likely
Many people substitute diet drinks containing artificial sweeteners for sugary drinks in the hopes of reducing their diabetes risk. However, new research suggests that artificial sweeteners alter the gut’s response to glucose in a way that could actually worsen diabetes risk.
At the 2017 meeting of the European Association for the Study of Diabetes, researcher Richard Young described a small study in which he and his colleagues compared the effects of artificial sweeteners to those of placebo in healthy adults. Seventeen participants consumed an amount of artificial sweetener equivalent to what would be found in 1.2 to 1.5 liters of diet beverage per day for two weeks, while 16 participants received placebo.
Young and colleagues determined that glucose absorption and glycemic response increased in the participants who consumed the artificial sweetener. Those who consumed the sweetener absorbed 20% more glucose than those in the placebo group. While before the study the two groups had similar blood glucose levels, these rose by 24% in those who consumed the artificial sweetener.
Consuming artificial sweetener also seemed to affect the gut peptide GLP-1, which limits the rise in blood glucose after meals. The two groups had similar GLP-1 responses before the study, but after consuming artificial sweetener, participants showed a 34% reduction in GLP-1 response to glucose absorbed in the intestines.
Changes like these could increase the risk of type 2 diabetes. Young explained that artificial sweeteners may reduce the body’s ability to control blood sugar levels, leading to high glucose, and possibly predisposing those who consume artificial sweeteners to type 2 diabetes. Young and colleagues have previously found that switching from sugar to artificial sweeteners does not predict a lower risk of type 2 diabetes.
This study was the first of its kind in humans. Larger studies will help to clarify the effects of artificial sweeteners on glucose control.
Exercise in Childhood Decreases Depression Symptoms Two Years Later
A 2017 study in the journal Pediatrics found that higher rates of moderate to vigorous physical activity at ages six and eight was linked to fewer symptoms of depression at age 10.
The study included 795 six-year-olds who were tracked for four years. Their physical activity was measured by accelerometry, the same type of technology found in smartphones and other consumer products that can track a person’s daily steps. Depression symptoms were assessed via interviews with the children and their parents.
While exercise seemed to reduce depression symptoms, sedentary behavior did not predict later depression.
Minimizing Cardiovascular Risk in Bipolar Disorder
At the 2017 meeting of the American Association of Child and Adolescent Psychopharmacology, researcher Ben Goldstein gave an overview on cardiovascular risk and bipolar disorder. He noted a study by Nicole Kozloff and colleagues in the Journal of Affective Disorders in 2010 that indicated that onset of cardiovascular disorder occurred an average of 17 years earlier in those with BP I (at age 40-45 years) compared to controls (at age 55-60 years). Several risk factors made onset of cardiovascular disorder more likely, including diabetes, obesity, and the metabolic syndrome (which consists of any three of the five following symptoms: high cholesterol, triglycerides, blood sugar, blood pressure, and waist circumference).
Risk factors include pathophysiological and behavioral mechanisms and certain medications. Pathophysiological mechanisms include inflammation, oxidative stress, and autonomic and endothelial dysfunction.
Behavioral mechanisms include poor diet, exercise, sleep, and increases in tobacco and alcohol use.
Medications could also contribute, with the most to least problematic for weight gain including, among atypical antipsychotics: clozapine, olanzapine, risperidone, quetiapine, aripiprazole, ziprasidone, and lurasidone. Among mood stabilizers, worst to best for avoiding weight gain are: valproate, lithium, carbamazepine, oxcarbazepine, and lamotrigine.
Goldstein has data from retinal vascular photography (RVP), whereby blood vessels can be observed directly. As opposed to in adults, in youth large vessels are more problematic and arteriolar to venous ratio is abnormally higher in bipolar children compared to normal controls. This ratio is lower in bipolar adults, also reflecting increased cardiovascular risk.
Given the huge loss of life expectancy in bipolar disorder, primarily from cardiovascular disorders, Goldstein urges greater and earlier attention to reducing the pathophysiological, behavioral, and pharmacological mechanisms for poor health. These should be pursued in parallel with attempts at mood stabilization. Read more
A Calculator of Risk for Bipolar Disorder in Youth
Daniella Hafeman of the University of Pittsburgh described a risk calculator for predicting an individual’s risk for bipolar disorder, which is available at www.pediatricbipolar.pitt.edu. Possible factors included in the risk calculation include a parent’s early age of onset of bipolar disorder, mood shifts early in life, a child’s anxiety or depression symptoms, later affective mood shifts, and new onset of subthreshold mania.
Editor’s Note: A “poor man’s” assessment of risk can also be of help to a family or clinician. There are four components. The first is genetic. Having one parent with bipolar disorder is a potent risk factor, and can be further magnified if the other parent also has a mood disorder. If three or more first degree relatives or three or more generations of first degree relatives have a mood disorder, this further increases risk four- to six-fold.
Perinatal vulnerability is another factor. Beyond these genetic vulnerabilities, a history of maternal toxoplasmosis or a viral infection during pregnancy, or the infant being noticeably underweight at birth can contribute to bipolar risk.
Childhood adversity also contributes to vulnerability to early onset of bipolar illness. A history of psychosocial stress in the child’s early years, such as abuse or abandonment, can be an added risk factor.
Prodromal or preliminary symptoms are also a risk factor. The development of an anxiety or depressive disorder, a disruptive behavioral disorder, or a bipolar not-otherwise-specified diagnosis (BP-NOS, used to describe manic symptoms of short duration) further increases risk. In studies by David Axelson and Boris Birmaher, 50% of children with an initial diagnosis of BP-NOS developed full-blown bipolar I or II illness upon several years of followup if there was a family history of bipolar disorder. About one-third converted to full bipolar disorder if there was no family history of bipolar disorder.
Thus, if a child has three or all four types of risk factors, their risk would be substantial. In this case, one might consider attempts at prevention. This could include a good diet rich in omega-3 fatty acids, regular exercise, joining a school sports team, developing good sleep habits, playing a musical instrument, and engaging in something akin to family focused therapy. Family focused therapy emphasizes psychoeducation, good communication skills, and problem solving. Attending to and treating parents’ symptoms and building a support system for both parents and the child can also help.
While these endeavors are not a guarantee to prevent the onset of more severe illness, they are all health-promoting in general and have few downsides.
Even Light Exercise Prevents Future Depressions
A 2017 article in The American Journal of Psychiatry suggests that regular leisure-time exercise of any intensity can protect against future depressions.
The study by Samuel B. Harvey and colleagues followed a group of 33,908 healthy adults for 11 years. The researchers found a link between regular leisure-time exercise and reduced incidence of future depression (but not anxiety). This link occurred regardless of the intensity of the exercise, and most of the effect occurred at low levels of exercise. Analysis suggested that 12% of future cases of depression could be prevented if all participants fit one hour of physical activity into their week.
A small part of the benefit came from the social and physical health benefits of exercise.
Harvey and colleagues suggested that from a public health perspective, increasing population levels of exercise modestly could lead to a substantial decrease in depressions.
Editor’s Note: Alongside maintenance treatment, in the form of antidepressants for unipolar depression or mood stabilizers and atypical antipsychotics for bipolar disorder, exercise could provide some benefits in preventing future depressions.
Reduced Functional Connectivity of Amygdala Linked to Autism in Pre-School Boys
A 2016 study in the Journal of the American Academy of Child and Adolescent Psychiatry found that preschool-aged boys with autism have weaker functional connectivity of the amygdala than typically-developing children of the same age. Researchers led by Mark D. Shen used resting-state functional connectivity magnetic resonance imaging (MRI) to measure how connected the amygdala was to other regions of the brain in 72 young boys (average age 3.5).
The boys with autism had weaker connectivity between the amygdala and regions linked to social communication, language deficits, and repetitive behaviors. These areas include the medial prefrontal cortex (mPFC), bilateral temporal lobe, striatum, thalamus, cingulate cortex, and cerebellum.
The weaker the connectivity between these regions, the more severe the boys’ autism symptoms were. They showed impairments in overall cognitive ability and both verbal and nonverbal ability.
