Autism often linked to early brain autoimmunity

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Autism spectrum disorder rates have increased by about 80 percent in the last 15 years, and an estimated one in 45 children have autism. While both parents scramble and scientists search for answers, one factor increasingly shows up in research: An immune system gone awry attacking the brain — also called autoimmunity.

Research has shown that some children with autism develop autoimmunity to the brain due to antibodies passed to them from their mothers while in utero. One study found one in 10 mothers of children with autism carry antibodies in their blood that reacts to their children’s brains.

Maternal autoimmunity raises autism risk

A mother who already has ongoing autoimmunity (which often may not have been diagnosed) is at a higher risk for having a child with autism.

Studies show children born to moms with autoimmune diseases such as celiac disease, type 1 diabetes, or rheumatoid arthritis, are three times more likely to develop autism.

This is because the mother carries antibodies in her bloodstream that are programmed to target human tissue for attack, including brain tissue. These antibodies then get passed to her fetus.

Obesity and diabetes in moms also raises risk

The factors that predispose a person to triggering autoimmunity are another risk mothers can pass onto their kids, the most common being disorders stemming from high blood sugar: obesity, diabetes, and PCOS (polycystic ovary syndrome). This is because excess sugar is highly inflammatory and raises the risk of autoimmunity.

For instance, maternal obesity almost doubles the risk of a child developing autism, while obesity combined with diabetes quadruples the risk. Maternal PCOS  a hormonal disorder caused by high blood sugar, has also been linked with an increased risk of autism in children due to excess testosterone.

Leaky gut and fetal immune health

Another maternal risk factor that can affect fetal brain health is leaky gut, also known as intestinal permeability. This is a common condition in which the inflamed and damaged gut wall allows undigested foods, bacteria, and other pathogens to escape from the intestines into the bloodstream. These circulating pathogens affect the fetus by stimulating an immune response that may affect the development of the fetal brain.

Many things can cause leaky gut, but the most common is excess sugars and starches, processed foods, and junk foods. Other factors are chronic stress, excess alcohol, antibiotics, NSAIDS, and metabolic imbalances.

Because the gut is the seat of the immune system, a leaky gut triggers a cascade of inflammation that extends beyond the gut and into the brain and body. This raises the risk of brain antibodies developing in the mother and being passed to the fetus.

Immune health affects the developing brain

While some children withstand the assaults of modern life relatively unscathed, the child with autism or whose brain and immune system are predisposed to autism will react to foods, vaccines, viruses, chemicals, or other immune triggers. This imbalance can begin in the womb.

An anti-inflammatory diet is foundational to a healthy immune system and pregnancy. Studies have shown the effectiveness of a gluten-free and dairy-free diet or, more ideally, the immune balancing autoimmune diet.

It’s important to approach conception and pregnancy with immune health in mind. This will not only reduce the risk of autism but also reduce susceptibility to other immune disorders, including asthma, eczema, food intolerances, allergies, and other brain developmental disorders (e.g., Tourette syndromeobsessive-compulsive disorderdepression, ADD/ADHD, etc.)

Girls with autism show different symptoms than boys

By Linsenhejhej (Own work) [CC BY-SA 3.0 (], via Wikimedia Commons

We commonly think of autism spectrum disorders (ASD) affecting mostly boys. While it’s true ASD affects more boys than girls, it turns out that many girls go undiagnosed because their symptoms are much different than that of boys. Girls with autism may behave socially more like neurotypical males than boys with autism. Female autism may also be misdiagnosed as anorexia, obsessive compulsive disorder (OCD), or attention-deficit/hyperactivity disorder (ADHD).

The diagnostic criteria for autism — difficulties with socialization and communication and repetitive, inflexible behavior patterns — come from studies on boys. A 2012 study of 15,000 twins found that girls needed to exhibit more extreme behavioral problems and intellectually disability to receive a diagnosis. This means that many girls on the milder side of the ASD spectrum go undiagnosed.

Girls with autism closer to typical boys

Brain scans, genetic testing, and other measures show that girls with autism disorders not only present differently than boys, but also that the understanding of autism has been overly narrow by primarily studying boys.

For one thing, brain scans show a girl with autism process social information much differently than neurotypical girls, but also differently than boys with autism. Instead, their brain operates very much like that of a neurotypical boy. Furthermore, research assessing friendship quality and empathy showed autistic girls score about the same as neurotypical boys.

Girls are better able to hide autism

Girls often go undiagnosed also because they can excel and suppressing their symptoms and studying and mimicking neurotypical girls. However, it’s an exhausting and stressful process for autistic girls, who show a much greater desire to connect than boys.

Girls also exhibit less repetitive behavior and more typical types of play as children, although researchers can pick out subtle differences — obsessively lining up their Barbies, for instance, or being more engaged in staging a scene than the story line.

Female autism can present as anorexia or OCD

Autistic girls also differ from their neurotypical peers by being extreme in their traits, such as “too sensitive” or “too intense.” Their single-minded intensity is believed to underlie anorexia in some who channel those traits into dieting and body obsession. The extreme aversion to certain tastes and textures common with autism also lends itself to anorexia. It’s estimated about 20 percent of women with anorexia also have autism.

The same can be said for autism and OCD, as obsessive-compulsive behavior, fear of change, and being overly rigid are hallmark traits of both OCD and autism.

Autism can make girls vulnerable to predators

Sadly, the autistic girl’s traits of taking things literally combined with social isolation makes her more vulnerable to sexual predators and abusive relationships.

Autistic girls are more apt to suffer from anxiety, low self-esteem, social isolation, and depression. Although people with mild autism are ten times more likely to be suicidal than the general population, the rate is highest in women — 71 percent of women with Asperger’s report suicidal thoughts.

The role of maternal testosterone in autism risk

Autism risk is linked with higher levels of fetal testosterone. A mother with polycystic ovary syndrome, a hormonal disorder that causes high testosterone, has an almost 60 percent higher risk of giving birth to a child with autism. This is why having a female brain offers protective barriers to this tendency.

However, researchers have found girls with autism have a higher number of genetic mutations than autistic boys. In other words, a girl’s brain may need more genetic and environmental “hits” in order to develop autism.