Don’t Got Milk?
January 29, 2008 by Kristina Chew, PhD
Filed under Health
The Journal of Autism and Developmental Disorders has published a study about thin bones in boys with autism spectrum disorders by researchers from the National Institutes of Health and the Cincinnati Children’s Hospital Medical Center. Researchers x-rayed the hands of 75 autistic boys who are between the ages of 4-8 and found that, compared to boys of the same age who do not have autism, the autistic boys had significantly thinner bones. A “lack of exercise, a reluctance to eat a varied diet, lack of vitamin D, digestive problems, and diets that exclude casein, a protein found in milk and milk products,” were all cited as reasons that autistic boys might have poor bone development. From an NIH press release:
The researchers then measured the thickness of the bone located between the knuckle of the index finger and the wrist and compared its development to a standardized reference based on a group of boys without autism.Dr. Hediger said that the research team measured cortical bone thickness. She added that this procedure was done as a substitute for a conventional bone scan, which measures bone density. Bone density is an indication of bones’ mineral content. Less dense bones may indicate a risk of bone fracture.
The researchers used the measure of bone thickness because many of the boys were unable to remain still long enough for the conventional scan, which requires individuals to lie immobile for an extended period of time. To successfully complete the bone scan, many of the boys would have required sedation — a step the researchers were reluctant to take for an early study.The hand X-ray, Dr. Hediger explained, offers an approximate indication of bone density. She added, however, that because the researchers were unable to use a conventional bone scan, the results of the current study should be confirmed by additional studies using conventional bone scans.
The investigators found that the bones of the boys with autism were growing longer but were not thickening at a normal rate. During normal bone development, material from inside the bone is transferred to the outside of the bone, increasing thickness, while at the same time, the bones are also growing longer.
The researchers particularly noted that only nine of the boys in the study were on casein-free diets, which are a type of “special diet” that some families of autistic children have tried. These diets have been popularized by parents including celebrity Jenny McCarthy who wrote about her son’s “recovery from autism” as being largely due to a special casein-free, gluten-free diet, and by Karyn Seroussi, who also attributed her son’s gains to a special diet. The researchers noted that the boys on casein-free diets had bones that were 20 percent thinner than normal for children their age and urged parents whose children are on such diets to consult with a dietician. Other reasons cited for autistic children’s deficiencies in calcium and vitamin D are aversions to food (neophobia), digestive problems that interfere with the absorption of nutrients, and a tendency to stay indoors and not get sufficient physical exercise.
My son has been casein-free for the past 8 years. I’ve been working on him taking calcium supplements and he eats lots of vegetables and fruits and shrimp; dairy products do seem (this is anecdotal) to disagree with his stomach (as is the case with other family members). He does get a lot of physical exercise, eats a fairly varied diet (he does not live on sushi alone), and he spends so much time outside once spring and summer start that he is completely tanned by June (so am I). Time to work on more tofu……
Photo courtesy of radarxlove via Flickr
I’d be curious as to the prescription drugs, supplements, etc. the children are on (if any). I suppose if enough of the children were on similar drugs the connection would’ve been mentioned. My son takes some prescription medication, and while there is clearly a benefit (from his perspective, not just ours), the possible side effects scare me. Both of my children have decent diets and we are outside a lot, though the young one was failure to thrive and had a lot of early health issues.
Very interesting. I wonder if that’s something else I need to worry about? There again, they’re still growing…..last time I checked. I’ll be interested to hear follow up work on this as there are too many variables to calculate and separate to draw any conclusions.
Cheers
“he added, however, that because the researchers were unable to use a conventional bone scan, the results of the current study should be confirmed by additional studies using conventional bone scans.”
If they get additional confirmatory evidence, or even without, I would be personally interested in whether the results are similar or different for girls with autism, since women are at higher risk for osteopenia and osteoporosis than men (or so say the girls’ pediatrician and my GP.) Eleanor can’t drink milk or intake much dairy, not as in discretionary, but can’t without additional enzymes or additional supplementation, so we know that she is already at some risk for lower bone density.
The mechanism by which bone mineralization is regulated is via NO. Bone strain causes release of NO, that NO activates cells which deposit bone mineral where the NO levels are highest. More bone strain (less stiff bones), more deposition of mineral making the bones more stiff.
http://adr.iadrjournals.org/cgi/content/abstract/13/1/93
http://www.ebmonline.org/cgi/content/full/227/2/88
TH loves milk. We all do. We’re strictly of Northern European ancestry around here, and as a family, we go through several gallons of milk a week. Our middle son has bones like mine (I think), dense and tough, although he did have a broken humerus from falling off of a playscape at school when he was two. But TH (our son who has Asperger’s or HFA)–his arms feel like little bird wings to me, they’re so fragile feeling. His whole torso feels like that. But I don’t think it’s a vit D thing because his legs are very strong and powerful. I think it’s the hypotonia. He has no upper-body strength and can’t even do one pushup or control himself enough to balance on a bike. His new year’s resolution is to do one pushup a day, and it’s a huge struggle for him even to stretch his body out all the way.
So…in his case, I’d say underuse as a secondary outcome of hypotonia.
Hello friends -
This discussion shouldn’t just be about the milk. All of the autistics had lower bone density, it is just that those on the diet were worse.
“The boys in the study who were on a casein-free diet had the thinnest bones. In fact, the 9 boys who were on a casein-free diet had bones that were 20 percent thinner than normal for children their age. Boys who were not on a casein-free diet showed a 10 percent decrease in bone thickness when compared to boys with normal bone development.”
We have no way of knowing if the CF component of a diet was responsible; perhaps they were on CF because they had even larger problems with absorption than the children who weren’t on the diet. In many cases, kids on the diet are further ‘along’ the spectrum than those whose parents won’t be bothered to try dietary restrictions. These children will be getting less exercise than their PDD-NOS peers; and in fact, exercsie has been shown to be a good predictor of bone health in younger cohorts.
What we should be taking from this is that every child with autism should have their levels of vitamin D and calcium checked, as well as a good number of other essential nutrients. Of course, a regular pediatrician probably isn’t aware of this.
Take care!
- pD
More physical activity to build up kids who are low-tone—–Charlie is muscular and very strong. The researchers seem to have been careful to note that only some autistic children were on the casein free diet and indeed noted that these children had the lowest bone thicknesses in the group studied. Certainly some cultures have done fine without milk.
The lack of exercise is not just “because they don’t play outside” as much, which is not always the case. That’s because autistic boys do not use their muscles (especially upper body) as much as typical peers, who are constantly pushing, pulling, carrying, punching, hanging, AND participating in organized sports or other intense workouts.
“All of the autistics had lower bone density, it is just that those on the diet were worse.”
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Actually, all the autistic young males, i.e., boys, ages 4-8.
I take your point that the results carry across the group, but I also note the researchers caveat that they did not use the standard procedure to measure bone density.
Still want to know if there is a difference in girls, and whether/how these differences carry beyond the age cohort into adulthood.
Follow-up on Leila’s point—-when our kids do participate in sports activities, sometimes (much of the time?) less is expected. Some times this is fine, if a child is just not ready developmentally and physically to perform certain activities (throwing, catching, running—it’s just recently that Charlie has been able to run or walk when we requested these). But other times teachers, coaches, etc. allow themselves to have lower expectations for autistic kids. Charlie has been on 14 miles bike rides with his dad—-people are still surprised to hear that he rides his bike on the street and not just on a bike trail or parking lot.
My little guy’s only been casein-free for a month, but he had muscle weakness before then, which makes physical activity harder for him than it might be for others. Maybe it’s not because of autism therapies, but the autism itself?
Interestingly enough, my now 18 yos had bone scans/x-rays done at 4 years of age. They found his bones were so small that they felt a specialist was necessary, immediately. He’s fine now…but he isn’t autistic, never was. Maybe it happens to autistic children more often, maybe not, but it’s definitely more common than just spectrum kids and the article doesn’t mention stats of NT children. Sometimes I think these studies do more harm than good.
Taking note of some of the comments, I thought that maybe these excerpts from the full text paper might be of interest.
My read is that they would like to follow up some of what appears to be preliminary or speculative with more direct measures and a larger sample size.
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(…)”Compared with the 2000 CDC references for height-forage, weight-for-age, and BMI-for-age (Kuczmarski et al. 2000), the boys with autism or ASD were significantly taller, heavier, and had higher BMI than average.
Compared with the 2000 CDC references for height-forage, weight-for-age, and BMI-for-age (Kuczmarski et al. 2000), the boys with autism or ASD were significantly taller, heavier, and had higher BMI than average. Nearly 19% were classified as at risk of overweight and 27% overweight, according to CDC screening criteria (Table 1).
Fewer than expected were moderately underweight (9.3% with BMI\15th percentile), and none were severely underweight (\5th percentile). In terms of factors that might affect bone development, 9.3% were taking hypoallergenic supplements without calcium, 6.7% antiepileptic drugs, 13.3% drugs that are considered appetite suppressants, and 12% casein-free diets (gluten-/caseinfree or casein-free). Of the boys on casein-free diets (n = 9), only 3 (33.3%) were taking supplements that provided calcium. In addition, 3 boys were on diets that were dairy-restricted (e.g., no milk), although not necessarily casein-free.
(…)
even unadjusted for covariates, there was a noticeable progressive widening of the gap between the medians for boys with autism/ASD and the reference (Fig. 1)
(…)Second, although a low dietary intake of calcium and vitamin D from dairy sources appeared to be a significant factor limiting bone development in our study, it is probable that physical inactivity and/or lack of sunlight exposure also contributed. However, neither of these variables was measured in this study, and future studies should address these issues. One of the benefits to measuring the second metacarpal of the hand, though, is that it is not a major weight-bearing bone and should show less variation due to physical activity differences compared with the reference than other long bones”(…)
I wasn’t actually making the discussion about milk. My point was that TH is practically a case control within himself for the non-issue of milk and the relevance of hypotonia in the etiology of lower bone mass.
TH is huge…tall and slender, but off the charts for height and weight–and head circumference. But he’s part Swedish and German and has uncles and cousins close to 7 feet tall.
So, of the 9 that were on CF, 3 of them were taking calcium supplements and still had a lower bone density? Also, it says there were 3 on “dairy-restricted”, which could show a lack of calcium and vitamin D intake.
When my son was at his most restricted, around age 5, he had a blood test to check for nutrition., He came out fine. He eats a lot more variety now. But now I”m worried about his bone density too., My husband broke a lot of bones as a kid and continues to rebreak his toes all the time. He assumed because he wasn’t properly supervised (starting at age 3) and became a daredevil.
I’m curious about Charlie’s bone density in the wake of this study—-but I can’t deny that he is growing healthy, tall, and strong.
He has not broken any bones, despite some falls from his bike—two of which led to a visit to ER. (And we still take him out on the bike….)
MJ had 3 arm fractures (both left and right) before the age of five, pre diagnosis. One severe enough for a rod placement. I always attributed them to developmental coordination disorder (clumsiness), but maybe he was susceptible too. He is low toned also, but in my experience as a pediatric PT that does not increase the risk for fractures-only dislocations. Lack of bone density from under use would not, I believe, show in hand x-rays as it does in the long bones of the legs in children who do not walk for example severe cerebral palsy or spina bifida. I think this is a really interesting study.
This is a really great conversation. I agree, children who thrive on a GFCF diet ALREADY have issues with absorption and faulty digestion. To make bone at least 19 nutrients are needed—including calcium, magnesium, phosphorus, boron, silica, vitamin A, K, D, B6, B12, fluorine, etc. If a child has poor absorption, their bone density will be lower. Nutrition boosters can be of benefit for these children. There are hypoallergenic products (FDA approved as medical foods) that can be useful for the picky eater or undernourished child on the spectrum. They contain free amino acids, free fatty acids, vitamins and minerals, so they are easily absorbed and don’t require any digestion. digestion–they’re a stepping stone to build on until the child is adequately nourished. I find them really useful for some of my ASD clients.
Also, acid-alkaline balance plays a role in bone health. People on the spectrum have typically higher needs for antioxidants. If they don’t get them, they tend to have acidic blood which gets neutralized by potassium from extracellular spaces and calcium, phosphorus and small amounts of magnesium from bone. So even if the child gets enough nutrients, they can still be used to alkalize the blood which must remain at a constantly neutral pH. It’s easy to check pH with a simple dip stick first thing in the morning.
I have had bone (and other) problems because I simply don’t get out much: not enough light. Our house doesn’t get much light inside either. And of course this country isn’t a very bright one to begin with, especially in winter. I now take supplements for this (calcium and vitamin D).
@Liz Lipski,
Thanks so much for all that information—-this might seem like a small point, but one thing I tend to keep in mind regarding supplements and kids on the spectrum is rather practical: The challenge of getting the child to take the supplements. We specifically taught my son to swallow pills and capsules; I know other parents mix supplements into various foods (apple sauce, pudding) but I’ve never had any luck with that method. Best wishes and thank you again.
Dear Kristina,
I also really appreciate your blog—your comments are excellent and the discussion is lively.
Getting kids, especially kids on the spectrum, to take supplements is a huge challenge. The products I work with don’t taste like anything that most kids would want to typically eat. they don’t have a lot of sugar or great flavorings, and amino acids are a bit bitter. On the other hand, some kids with ASD really like the products because they don’t make them feel sick.
I’m not trying to insert a commercial in here—want to be very respectful, or this blog will be a circus. If you’d like, email me privately with your address and I can ask the company to send you a sample. It’ tastes best cold.
Best,
Liz