Abnormal levels of cholesterol and fats may be linked to autism in some cases, and adjusting them could prevent onset of the disorder, according to a major study by Israeli and American scientists published this week.
The researchers examined 2.75 million medical records at Boston Children’s Hospital, and found that children with autism are twice as likely than others to have dyslipidemia. The condition is characterized by irregular lipid levels, and often caused by the body experiencing a genetically-inherited difficulty in regulating them.
Blood lipids are fatty substances, such as cholesterol and triglycerides. Common irregularities in people with dyslipidemia include high levels of low-density lipoproteins, sometimes called bad cholesterol and/or low levels of high-density lipoproteins, which are sometimes called good cholesterol.
The research may pave the way to preventing autism in some children by controlling their dyslipidemia, a condition that often goes undetected or untreated, Alal Eran of Ben Gurion University of the Negev told The Times of Israel.
For now, the researchers have only managed to show a statistical link, and while further studies could point to a causal relationship, Eran cautioned that it is too early to recommend specific changes as a way to control or prevent autism.
“We’re not saying we’re going to change clinical practice tomorrow, but we are going to test whether using medication and controlling diet in a way that would push lipid levels within normal ranges could possibly impact behavior and lower the risk for autism,” she said.
Eran said she isn’t suggesting that autism is diet-induced, but rather that if dyslipidemia is present — ordinarily as an inherited condition — but managed well, it may avert autism symptoms. “There is a very strong genetic background that predisposes people to dyslipidemia, and we are interested in the possibility that modulating this could impact the risk for autism,” she said.
Eran, a computational biologist who is part of the BGU-based National Autism Research Center of Israel, is also a research Associate at Boston Children’s Hospital, and collaborated with scientists there and at Harvard Medical School, Massachusetts Institute of Technology, Northwestern University for the study, which is newly peer-reviewed and was published in Nature Medicine on Tuesday.
The team found that 6 percent of autistic children have dyslipidemia compared to 3% of others, Eran said. She acknowledged that the percentages seem to be small, but said that in the search to better understand autism this is a significant finding.
While Eran hopes that the research may lead to fewer children developing symptoms of autism, another leading Israeli autism scholar cautioned against treating the condition as a disease to be eradicated. Judah Koller is “wary of speaking about ways of preventing autism,” he told The Times of Israel, noting that there are objections from many autistic people to suggestions that its incidence should be reduced.
Autism is part of diversity, and preventing it is “not in humanity’s best interests,” said Koller, co-founder of the Autism Center at Hebrew University. “We benefit from people with autism,” he said, noting a significant contribution of people with autism to science and other important fields.
Nevertheless, Koller said that Eran’s research is important. “The amount of data and type of data here makes it worthy of significant attention,” he said, adding that there is good precedent for probing the background to autism.
“The notion of identifying a biological factor, often inherited, that may cause increased chances of autism, isn’t new,” he said. “We know of lots of risk factors such as age of parents, maternal diabetes, low folic acid levels in pregnancy, and psychiatric disorders in parents.”
While he is unenthusiastic about possible use of the research to prevent autism, he is optimistic about its potential to facilitate earlier detection of autism.
As well as exploring whether controlling dyslipidemia can affect the development of autism symptoms, Eran’s team is looking into the relevance of their new findings to diagnosis.
Autism is normally diagnosed based on behavior, at about three to four years, and the genetic causes of most cases have not yet been identified. But Eran said that her team’s findings can prompt careful monitoring of kids who have the condition for signs of autism. “The findings are exciting as they could lead to early detection,” she said.
Koller said that he “hopes future studies show if there’s something actionable here.”
While the data leaves open the possibility that dyslipidemia just happens to occur more in autistic children than others, without a causative connection, Eran believes this is unlikely. “Our evidence suggests it’s not just a random association,” she said.
One observation that leads her in this direction is that her team found mice with lipid irregularities similar to dyslipidemia have higher-than-normal incidence of unusual brain function. She said that affected mice displayed learning difficulties.
But Eran stressed that practical recommendations based on the research would only be made, if justified, after controlled trials are conducted, meaning parents shouldn’t run off to start changing their children’s diets in the hope of reducing chances of autism.
“We are saying that having abnormal lipid levels characterizes a subset of children with autism and abnormal lipid levels raise the risk for autism,” she said. “But we’re not saying people should try to control lipid levels in order to try to prevent autism or to control autism.”