SAN ANTONIO, March 27, 2024 – Autism and attention deficit hyperactivity disorder (ADHD) may be preventable if parents avoid toxic exposures and adopt interventions such as environmental house calls, according to a published study led by researchers from The University of Texas Health Science Center at San Antonio (UT Health San Antonio).
Using a validated, self-administered questionnaire now used worldwide to identify individuals with chemical intolerance – the Quick Environmental Exposure and Sensitivity Inventory (QEESI©) – parents and practitioners can determine the risk for each family and learn which exposures to avoid in their own homes where most people spend most of their day, the researchers said.
A population-based survey of nearly 8,000 U.S. adults, using QEESI, found that parents with chemical intolerance scores in the top tenth percentile were 5.7 times as likely to report a child with autism and 2.1 times as likely with ADHD compared with parents in the bottom tenth percentile. The findings build on a 2015 study by UT Health San Antonio that first linked chemical intolerance in patients with the risk of their children developing autism and ADHD.
“This is the first-ever article in the medical literature showing that chemical intolerance in parents can predict the risk of autism and ADHD in their children, and suggests that reducing exposures prior to and during pregnancy could help prevention,” said Claudia S. Miller, MD, MS, professor emeritus with the Department of Family and Community Medicine at UT Health San Antonio. “Up to now, most interventions have been behavioral or medical, after a child is diagnosed.”
Miller is senior author of the study, titled, “Assessing Chemical Intolerance in Parents Predicts the Risk of Autism and ADHD in Their Children,” published March 1 in the Journal of Xenobiotics, a leading toxicology publication, for its special issue on autism. Co-authors include Raymond F. Palmer, PhD, and Rodolfo Rincon, MD and specialist, both with the Department of Family and Community Medicine at UT Health San Antonio; and David Kattari, a statistician with the Marilyn Brachman Hoffman Foundation in Fort Worth, Texas.
The researchers note that the study is observational, and further research is needed using controlled trials to confirm causality and further explore the proposed mechanism behind chemical intolerance.
Still, they wrote, “The implications of this study, if confirmed, could be significant for preventive measures and early intervention strategies in families with parental chemical intolerance. We recommend that all prospective parents be assessed for chemical intolerance at an early age.”
Mast cells and autism
Physician-researcher Miller in 1996 first proposed a two-stage disease process of initiation by exposure and then triggering of symptoms called TILT, for Toxicant-Induced Loss of Tolerance, as the mechanism behind chemical intolerance. She has served as a physician/environmental consultant on exposures. And her published papers have explored the impact of pesticides, the Gulf War, breast and other implants, 9/11, toxic molds, combustion products from fires, and indoor air pollutants in so-called “sick” homes, schools and workplaces, including the EPA’s own headquarters building in Washington, D.C.
The new study comes amid a backdrop of a 317% increase in the prevalence of autism since 2000, now occurring in one of every 36 children in the country, the researchers note, citing data originating from the Centers for Disease Control and Prevention. And the prevalence of ADHD has risen to one in eight children, also according to the CDC.
Miller and colleagues in 2021 discovered a strong association between chemical intolerance and “mast cells,” considered the immune system’s first responders that originate in the bone marrow and migrate to the interface between tissues and the external environment where they then reside.
When exposed to “xenobiotics,” foreign substances like chemicals and viruses, they can release thousands of inflammatory molecules called mediators. This response results in allergic-like reactions, some very severe. These cells can be sensitized by a single acute exposure to xenobiotics, or by repeated lower-level exposures. Thereafter, even low levels of those and other unrelated substances can cause the mast cells to release the mediators that can lead to inflammation and illness.
In their latest study, the researchers determined that the high chemical intolerance scores among parents of children with autism, coupled with the 2021 finding of mast-cell activation as a plausible biomechanism for chemical intolerance, suggest that:
- The QEESI can identify individuals at increased risk.
- Environmental counseling, such as personalized environmental house calls to assess risks at home, may reduce personal exposures to possible triggers such as pesticides, fragrances and tobacco smoke, particularly during pregnancy and childhood.
- The global rise in autism and ADHD may be due to fossil-fuel-derived and biogenic toxicants epigenetically “turning on” or “turning off” critical mast cell genes that can be transmitted trans-generationally.
The researchers conclude that once mast cells are sensitized, diverse xenobiotics that never bothered the person previously and do not bother most people trigger multisystem symptoms that wax and wane over time. And they believe that persistent activation and triggering of mast cells may underlie the brain inflammation in autism.
“The potential role of environmental toxicants in influencing epigenetics and mast cell function is a complex and emerging area of research,” they wrote. “Acknowledging the need for further evidence, we hope this study contributes to an improved understanding of the potential role of environmental factors in the global rise of autism and ADHD.”
The authors created tools for patients, practitioners and researchers, described in their “TILT Tutorial on Chemical Intolerance, Autism, and ADHD”, available along with other resources at https://TILTresearch.org.
Assessing Chemical Intolerance in Parents Predicts the Risk of Autism and ADHD in Their Children
Raymond F. Palmer, Rodolfo Rincon, David Kattari, Claudia S. Miller
First published: March 1, 2024, Journal of Xenobiotics
https://www.mdpi.com/2039-4713/14/1/22
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JOURNAL
Journal of Xenobiotics
METHOD OF RESEARCH
Observational study
ARTICLE TITLE
Assessing Chemical Intolerance in Parents Predicts the Risk of Autism and ADHD in Their Children
ADHD stimulants may increase risk of heart damage in young adults
While likelihood of cardiomyopathy grows over time, the overall risk remains low
AMERICAN COLLEGE OF CARDIOLOGY
Young adults who were prescribed stimulant medications for attention-deficit/hyperactivity disorder (ADHD) were significantly more likely to develop cardiomyopathy (weakened heart muscle) compared with those who were not prescribed stimulants, in a study presented at the American College of Cardiology’s Annual Scientific Session.
The study found that people prescribed stimulants such as Adderall and Ritalin were 17% more likely to have cardiomyopathy at one year and 57% more likely to have cardiomyopathy at eight years compared with those who were not taking these medications. Cardiomyopathy involves structural changes in the heart muscle that weaken its pumping ability. It can cause a person to tire easily and limit their ability to perform daily tasks, and it often worsens over time.
However, researchers said that the overall risk of cardiomyopathy remained relatively low even when stimulants were used long-term. They said the findings do not necessarily point to a need for clinicians to change their approach to screening patients or prescribing stimulants.
“The longer you leave patients on these medications, the more likely they are to develop cardiomyopathy, but the risk of that is very low,” said Pauline Gerard, a second-year medical student at the University of Colorado School of Medicine in Aurora, Colorado, and the study’s lead author. “I don’t think this is a reason to stop prescribing these medications. There’s very little increased risk of these medications over the long term; it’s a real risk, but it’s small.”
ADHD is one of the most common neurodevelopmental disorders in children, affecting about 1 out of 10 American children aged 3 to 17, and can continue into adulthood. It is typically treated with behavioral therapy initially, which may be combined with stimulant or non-stimulant medications to help control behaviors that interfere with daily life and relationships. Stimulant medications can elevate blood pressure by causing the heart to beat faster and with greater force.
Most previous studies assessing the safety of stimulant medications have focused on the first year or two of use and found no evidence of harm to the heart. Since many patients are prescribed these medications in early childhood and continue taking them into adulthood, this new study was designed to assess their potential to cause harm over a longer period of time, Gerard said.
Using the TriNetX research database that includes information from about 80 hospitals across the U.S., researchers analyzed data from people diagnosed with ADHD between 20-40 years of age. Individuals with the presence or absence of a prescription for stimulant medications along with rates of cardiomyopathy that could potentially be linked to stimulant use were included. Those with heart damage caused by other known factors, such as cancer treatments, were excluded.
For the analysis, the researchers paired each person who had been prescribed stimulants with an individual who had not been prescribed stimulants but was as similar as possible in all other respects, such as age, sex and other health conditions. Overall, 12,759 pairs were created and were followed for at least 10 years. Of these pairs, people prescribed stimulants were found to be significantly more likely to develop cardiomyopathy throughout the 10-year follow-up period, with the gap growing larger each year except the last two, when it narrowed slightly.
Despite the significant gap, the overall prevalence of cardiomyopathy was still quite low in both groups. After being prescribed stimulants for 10 years, 0.72% (less than three-quarters of one percent) of patients developed cardiomyopathy, compared with 0.53% (a little over half of one percent) among those who were not prescribed stimulants.
To put the numbers into context, Gerard said, “You can have almost 2,000 patients on these medications for a year and you might only cause one of them to have a cardiomyopathy that they otherwise would not have had, but if you leave them on it for 10 years, 1 in 500 will have that happen.”
At these levels, researchers said the study does not suggest that aggressive testing for cardiovascular risk is warranted before prescribing stimulants, given that the potential benefits of testing must be balanced against the risks and costs. They suggest that further studies could help to identify subgroups of patients at greater risk who may benefit from future screening approaches.
Gerard said that it could also be helpful to study potential differences among different types of ADHD medications and different types of cardiomyopathies.
Gerard will present the study, “ADHD Stimulant Use Associated with Increased Risk of Cardiomyopathy in Young Adults,” on Sunday, April 7, at 2:15 p.m. ET / 18:15 UTC in Hall B4-5.
ACC.24 will take place April 6-8, 2024, in Atlanta, bringing together cardiologists and cardiovascular specialists from around the world to share the newest discoveries in treatment and prevention. Follow @ACCinTouch, @ACCMediaCenter and #ACC24 for the latest news from the meeting.
The American College of Cardiology (ACC) is the global leader in transforming cardiovascular care and improving heart health for all. As the preeminent source of professional medical education for the entire cardiovascular care team since 1949, ACC credentials cardiovascular professionals in over 140 countries who meet stringent qualifications and leads in the formation of health policy, standards and guidelines. Through its world-renowned family of JACC Journals, NCDR registries, ACC Accreditation Services, global network of Member Sections, CardioSmart patient resources and more, the College is committed to ensuring a world where science, knowledge and innovation optimize patient care and outcomes. Learn more at ACC.org.
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