Marks Daily Apple
Serving up health and fitness insights (daily, of course) with a side of irreverence.
18 Apr

Should You Chew Your Child’s Food?

mommabirdBy now, you’ve probably seen the Alicia Silverstone pre-mastication video. It’s totally safe for work (maybe not for lunch, but your mileage may vary), but some viewers will find it a bit unsettling: Silverstone feeds her baby pre-chewed food directly from her mouth, just like a bird. I found it pretty fascinating and not at all upsetting. Before you recoil in disgust and/or horror, think about how people weaned babies before Magic Bullets, Vitamixes, Gerber baby food, and even mortar and pestles hit the scene. That’s right – they chewed their food for them. In a paper entitled “Premastication: the second arm of infant and young child feeding for health and survival,” Gretel Pelto speculates that pre-mastication was likely common practice among pre-agricultural groups and confirms that it continues today across every continent (PDF).

As to why this practice arose in humans but not other mammals, it’s the neoteny. Humans are born completely helpless, and remain so for several years (some would suggest “decades”). Newborn babies have no teeth and don’t even develop a decent set until about a year or later. This isn’t an issue at first, since they have access to plenty of delicious, nutritious breastmilk that goes down smooth. But because breastmilk is fairly low in iron (albeit a highly bioavailable form designed specially for infants), once kids run out of their pregnancy iron stores, they need a more reliable source of the mineral in addition to the milk. Nowadays, kids get iron-fortified rice cereal or baby vitamins or something silly like that, but before all that stuff, kids needed to eat iron-rich foods when the iron supply dwindled. What’s simpler and more effective for a hard-working hunter-gatherer who needs to feed her child some adult, iron-rich food – chopping up and crushing a strip of venison liver on a wooden plank with stone knives, or chewing it up and transferring it directly to the kid’s waiting mouth?

Okay, so there’s historical and evolutionary precedent for it, but is there any reason to chew your kid’s food today rather than whip out the food processor? Are there any extra upsides?

Free Mechanical Digestion

Since babies are rather limited in the tooth department, they can’t chew their food effectively, which is how most animals – humans included – mechanically digest their food. That’s why “baby food” is pureed; it’s a more socially acceptable (and financially lucrative) way of pre-chewing their food for them. And since the greater surface area of mechanically digested food bits exposes more of them to enzymatic action, pre-chewed food is more easily digested by babies (and adults).

Chewing your kid’s food is definitely cheaper than buying baby food, and it’s more time-efficient than making it in a blender or food processor.

Oral Enzymatic Pre-Digestion

Infants are born equipped with the enzymatic machinery to handle the simple sugars, animal fats, and animal protein in breast milk. They are not ready to digest a whole lot of other things, particularly dietary starch (which is often “baby’s first food” regardless). In humans who have it, salivary amylase predigests starch during the chewing process, initiating the conversion of starch into more easily assimilable carbohydrate derivatives like maltose (a disaccharide of two glucose units) and dextrin (a polysaccharide). Infants don’t come equipped with much salivary amylase right out of the box, so when a parent who wields the full array of salivary enzymes pre-masticates their food, the infant digests the food better. To get an idea of what kind of enzymatic digestion this pre-mastication is providing, let’s check the numbers:

In adults, salivary amylase (which predigests starch) is present in concentrations of 70-300 U/ml. Infants are born with “negligible” amounts, attain “appreciable levels” by 3 months, and reach 85% of adult salivary amylase levels by five months (PDF). Since Alicia Silverstone feeds her kid a vegan diet, presumably rich in fruits and starches, pre-mastication is a sound tactic.

There’s also lingual lipase, which breaks down long-chain triglycerides into glycerides and free fatty acids. Infants have lingual lipase at birth, but they have very little gastric (gut) lipase. Since babies absorb far less dietary fat than adults (65-80% versus more than 95%), a little extra lingual lipase activity provided by the pre-masticating parent combined with the kid’s lingual lipase could improve absorption rates. Hey, maybe that’s what’s causing infant obesity – a wave of pre-mastication sweeping the nation!

Unless you’re drooling into your Vitamix, the parent who pre-masticates may be giving her kid a digestive advantage.

Transplantation of “Good” Oral Bacteria

Over 700 species of oral bacteria have been identified from human mouths, and the oral microbiome of any given individual may house from 30 to more than 100 different species. While oral bacteria can trigger the development of dental caries and periodontal disease, it’s not all “bad.”  For example, many strains of oral bacteria taken from healthy children actually provide protection against harmful oral pathogens and are being developed as oral probiotics. Other strains have been shown to directly influence the immune response in gum tissues, as well as protect the host from oral pathogen-induced apoptosis and inflammation.

I wasn’t able to pull up any explicit references to pre-mastication as a transplantation method for “good” bacteria, but there is evidence that mouth to mouth contact between mother/father and offspring can transfer pathogenic cavity-causing bacteria to the child. If the “bad” can be transferred, why not the “good”?

Development of the Immune System

Saliva contains the very same antibodies found in breastmilk, like immunoglobulin A, immunoglobulin G, and immunoglobulin M. These help establish the budding immune system and provide passive resistance to pathogens, including bacterial infections and viral infections. There’s very little research on the impact of saliva-borne immunoglobulins on infant health, but we do know that breastmilk-borne immunoglobulins are crucial to the development of an infant’s immune system, so it seems likely that pre-mastication is also helpful (especially since both breastmilk and pre-chewed food enter a child through the same orifice).

Perhaps it’s even a way for non-breastfeeding mothers to give their child a leg up.

Are there any downsides?

Transfer of “Bad” Oral Bacteria

As I just mentioned, a parent with dental disease caused by bacteria could transfer the same bacteria to their child by pre-chewing his food. If the bacteria takes hold early enough, it could be difficult to dislodge it. The same could just as easily be said for the early transfer of good bacteria, though, so it’s impossible to say who “wins.”

It all depends on the oral health of the pre-masticator.

Transfer of Saliva-Borne Disease

Transfer of saliva-borne diseases is a possibility. Those include hepatitis G, herpes, TT-virus (which is widespread and seems pretty harmless), hepatitis B (although the hepatitises are present in low amounts in saliva), and there’s mixed evidence that pre-mastication can and has transferred HIV from caregiver to child, although that probably requires an open sore or wound in the mouth.

Again, it depends on the health of the caregiver.

Pre-mastication appears to be a valid, viable way for Ma (or Pa) to deliver food to a baby’s maw. There are some impressive potential health benefits, it might save money, and it could even bolster immunity. The potential downsides, however, must be considered. Overall, I don’t think it’s necessary for parents, and the social pariahism you’re likely to face may not be worth the trouble, but I certainly find it intriguing.

How about you, folks? Would you – or have you already – pre-chew your kid’s food?

You want comments? We got comments:

Imagine you’re George Clooney. Take a moment to admire your grooming and wit. Okay, now imagine someone walks up to you and asks, “What’s your name?” You say, “I’m George Clooney.” Or maybe you say, “I’m the Clooninator!” You don’t say “I’m George of George Clooney Sells Movies Blog” and you certainly don’t say, “I’m Clooney Weight Loss Plan”. So while spam is technically meat, it ain’t anywhere near Primal. Please nickname yourself something your friends would call you.

  1. If that’s your cup of tea go for it, but really aren’t we all about living Primal in a MODERN world?! I’ll stick with my blender and spoons. :)

    I enjoy making for for my baby and its still easy and cheap using a blender! And i don’t have to worry about passing on a cold virus I may not know i have.

    Very interesting article to say the least though! ;)

    Joanne - The Real Food Mama wrote on April 18th, 2012
  2. Have to admit, this is a new one on me. I am not repulsed though. My daughter (who turns 40 this summer) was an “Adele Davis” baby. I had a mentor that helped me in the breastfeeding department as nursing was just then becoming more popular–we lived in a teeny tiny Iowa village where my husband taught high school. I was the only pregnant lady that whipped around town at 9 months preggers on a man’s bicycle (the old ladies on the block were shocked about that) and then all around town with my baby strapped into a seat on the back later on. I told my daughter last week I used to feed her spoons of cod liver oil and had one of those small grinders that I used to make her food. I was considered a bit odd, but she NEVER ever had an ear infection or any of the other common maladies of kids then, except colds now and then. I kind of remember we ate paleo-ish back then in the middle 70’s. Didn’t have money to buy lots of snacks and crap food. If moms want to do what Alicia is doing–go for it! Mark’s info sounds compelling.

    Janet wrote on April 18th, 2012
  3. Great dialogue here! It’s lovely to live a modern life where the choices are endless and there’s not just one “right” way to have to go about doing anythihg. Do what’s right for you and yours!

    Paula wrote on April 18th, 2012
  4. Ever since my brother-in-law idily wondered aloud “I wonder what cave people fed their babies…” while I was feeding our 8 monthish daughter (she’s now nearing 11 years), my husband & I have fed our kids prechewed food. Not so much with the first born, we were still beliving what the ‘experts’ told us. Prechewed food makes sense. Especially since our kids never had a highchair.When they were tiny,I would sit at the table & nurse them & try to eat my own meal before it cooled. As they grew older they would sit on our laps as we ate & eventually would forage off our plates. I was determined to ‘get it right’ with our last child. He didnt get any baby cereals (anti grain for babes by that time, nursed the full 2 years, & wasnt going to introduce ANY solids till he was at least 6 months. His first food was fresh corn on the cob at 5 months when he grabbed it off my plate & started eating it! They are all healthy, robust, energetic kids. People still think we are strange sometimes – but that’s fine!!

    mamaof3 wrote on April 18th, 2012
  5. I never did this (nor would I want to) but I did play loosey goosey with sharing food and utensils and ended up getting my kid off to a terrible start in the dental department.

    I do hope whoever is doing anything like this or even more common things like letting your baby stick their hands in your mouth, etc. takes into consideration the state of their own oral health. Anyone with signs of dental disease should err on the side of caution and not share bacteria.

    We resolved our issues and are on the straight and narrow but it was a lot of work, extra expense, stress all around and boy does it feel crummy to have messed up your kid’s teeth. We’re lucky kids get another set for a do-over.

    misterworms wrote on April 18th, 2012
  6. My wife’s parents fed her and her sister meat this way when they were very young, and it’s common in their culture (SE Asia). It works so well that we have carried the torch and fed our son this way until he could chew such food on his own. We’ll do the same thing with our daughter, who is only just now eating solids of any kind.

    That said, we don’t do it “birdie style,” nor do folks from my wife’s homeland – one simply removes the food from one’s mouth and feeds the child by hand.

    It’s not a big deal, either way. Healthy parents feeding healthy children – you gotta do what you gotta do – who cares what anyone else things? I’m not going to put jerky in a blender or spend five minutes chopping it up into dust when I can chew it and feed my kid, as needed.

    Kyle wrote on April 18th, 2012
  7. I’m going to pass on this one. Sure, we’re all challenging social norms here, but I’m a Primal girl living in a modern world. To that end, I am going to live in a way that maintains my health and happiness without giving up every modern convenience.

    Using a BabyBullet someday will probably be one of those modern conveniences.

    After all, I’m not going to up and quit my job, find a secluded place in the forest, snuggle down into a cave, and live as a hunter-gatherer for the rest of my life.

    Not that the thought isn’t tempting sometimes…

    Deanna wrote on April 18th, 2012
  8. Yes. I chewed food for all three of my babies. I also breastfed them as long as possible. After all, that is the way we were designed to exist. Technology and social dysfunction has impacted our existence greatly…and not always necessarily for the better.

    Heather wrote on April 18th, 2012
  9. Haha, I totally get it, and more power to those of you who go this way – but personally, I think I’ll stick with a food processor ;-)

    mental floss wrote on April 18th, 2012
  10. Thank you for posting this article. When I saw the report of this topic on my local news channel, and their aghast reactions, I was very peeved. I had been thinking of birds, as shown above, though mostly wolves. Wolves actually regurgitate meat already swallowed. It just makes me shake my head more at our race and why seem to think we’re so different(which we are, but not in everything!)than our fellow animals.

    I, personally, would pre chew food for my child. If the need was there, I would.

    Cindy wrote on April 18th, 2012
  11. I never considered this do not have children yet but this was so interesting Mark! I am not sure how I would feel about it…. I can say this though if the apocalpse happened and electricity ceased you can bet your arse I would try this if I had a little one…. on a side note hasn’t this sort of thing occured with very sick adults in past times?

    LexxyV wrote on April 18th, 2012
  12. This may be a bit off topic but I chew chicken before I give it to my 21 year old cat.

    empi wrote on April 18th, 2012
  13. Canines do this, too, as do birds and others. Makes tons of sense to me. Don’t have human kids but pups I have raised doing this occasionally with, bonded that much closer. (If you don’t have the rough-and-tumble, smootchie-wootchie relationship I have had with my dogs, you night want to put it on a plate.)

    Brindle

    brindle wrote on April 18th, 2012
  14. Haha love it… I might have to experiment!

    Alby wrote on April 18th, 2012
  15. ick

    joe wrote on April 18th, 2012
  16. I think the iron in breastmilk is undervalued here. It is almost 100% digestible, so even while low, it’s still high enough to keep a baby healthy (unless the mom is deficient) well past 6 months. We did baby-led weaning (or baby-led solids) and we didn’t have to chew any food for our daughter. She didn’t start ingesting food until around 9-10 months, but that was perfectly normal and her iron levels were more than sufficient. Babies can gum food and suck on meat at an early age, if given the opportunity. To each his own, but I wouldn’t chew up food to give to my kids. They can handle it on their own and we practice extended (aka normal) breastfeeding, so there are no worries in the iron department.

    Kate wrote on April 18th, 2012
    • +1!

      We did much the same with both my kids. Although I did sometimes pre-masticate for my son (older child), I didn’t much with my daughter.

      Karen C. wrote on April 18th, 2012
  17. Its how my dad says that his mom fed him 80 years ago during the depression on the farm, so when I heard the story, I thought nothing of it.

    lynn wrote on April 18th, 2012
  18. if you couldnt chew it up cause you were sick, or had cold sores or something, would you ask someone else to chew and spit in your child’s mouth?

    is this a parent only thing, or would you allow someone else to do it for you?

    how about pets? can you get your dog to chew your child’s food?

    is there an acceptable line of ick, or is there no bounds?

    could your other children do it for each other? what about in laws or step parents?

    joe wrote on April 18th, 2012
  19. I didn’t give my child food until she started to ask for it. Then I let her choose from the healthy options I provided. She had teeth by the time she started asking for food. And she chose chicken and beef liver mostly, and it was pretty easy to chew for her with just a few teeth. I didn’t cook it much, just a touch on the outside. She didn’t ask for muscle meat or other hard to chew foods until much later when she had a mouth full of teeth. She was on her own by then. I did do the pre-mastication thing once or twice but it really wasn’t necessary in our case.

    Amy wrote on April 18th, 2012
  20. Great article, Mark. Very informative. If I were to start the baby-period all over again, I would definetly consider this way of feeding my baby. I think the benefits are more than we asume. In the GAPS-diet Dr. Natasha Campbell-McBride recommends to give the baby a little of whey in the food to help the digestion.

    Anne-Marie Van den Bossche wrote on April 18th, 2012
  21. The controvery around this is bizzare. I’ve breastfed my baby and started her on minimal solids at 6mos and found the best and easiest way to expose her to a wide variety of foods with different textures and spices was by chewing it for her. It is way faster and cleaner than the food processor. Also, I wanted her to have as “real” an experience of eating as possible. Eating puree does not prepare her for texture and taste as well because she’d have been eating mush. She is 2.5yrs now and eats everything and anything and chows at each meal and loves spices and eats Paleo. Glad you addressed this, Mark. From one proud Paleo mom whose raising a Paleo child who has NEVER eaten baby food.

    Kristen wrote on April 18th, 2012
  22. I think the real travesty here is feeding her kid a vegan diet. There just will not be enough beneficial fats to sustain sound cognitive development…

    Premastication, meh. I never thought it was that crazy because it makes sense for all the reasons listed here. I DO think it might be crazy to announce it to the world, however…we’re all so judgmental :)

    Apple wrote on April 18th, 2012
  23. I did pre-chew for both of my babies. It wasn’t something I had ever read about. It was something my husband and I saw in nature’s design and didn’t question. It made sense on so many levels. My babies loved the food and thrived on being part of meal times as their personal readiness dictated. Great article Mark.

    stephanie wrote on April 18th, 2012
  24. It’s an interesting idea.
    Could a similar effect be achieved through adding digestive enzymes to the food instead? Similarly to how there’s baby probiotics now.

    JMH wrote on April 18th, 2012
  25. Lost in these comments is the fact that Silverstone is feeding her baby a *vegan* diet. We should email-bomb her, telling her what a horrible idea that is.

    jake3_14 wrote on April 18th, 2012
  26. I lived with a family in a developing country for a year as an exchange student back in the early 90’s. Pre-mastication was a normal practice, when the food required it (tough vegetables, for example). The people had a belief that it made the child love the mother more (sealed the bonding). Using a small wooden spoon or a thumb to mash up banana or boiled rice was also common and even more widely accepted. Breast feeding went on probably longer than here in the States–until the kid had teeth and could manage most solid foods on his/her own. No one ever said, “hey, the kid obviously needs more iron now so lets start chewing meat for them.” It was more about gradually expanding the range of foods the kid consumed and, as stated, the folk belief about bonding.

    Blato wrote on April 18th, 2012
  27. oh sure, i’ve pre-chewed food for my kiddo if it was tough or a bit too dry. he’s got good chompers at 3 yrs, so there’s no more need!

    kate wrote on April 18th, 2012
  28. I would DEFINITELY do it. Think of all the saved time, dishes and cleanup time!!

    dr.maapkra wrote on April 18th, 2012
  29. I remember my mother pre-chewing my meat as a toddler, I thought she was the only one who did this. I didn’t continue the practice with my own daughter.

    Suzanne wrote on April 18th, 2012
  30. I breast fed for six months and with the last two I didn’t worry about food until they took an active interest in what was going on at the table which was just around the time they were getting teeth oddly enough. I simply mashed stuff up with a fork and put it on a plate for them. They were happy healthy kids with no overt signs of iron deficiency.

    I question the wisdom of dropping solid food into a child’s mouth before the equipment is there to chew it.

    Sandra wrote on April 18th, 2012
  31. Well, this was interesting. I lived in the bush of Alaska for 14 years. I did have a baby while I was “outside” civilization and I did chew her food as the other mothers were doing. Mainly soft dried fish. She would wait while I chewed it and if it seemed like I was taking too long or might eat it myself she would poke my cheek. She is 40 now and living in Alaska. She also has beautiful teeth. And an MBA ;D

    On a side note – I read a book about owls last year. The zoos had almost no success raising abandoned baby owls but only realized when a domesticated owl mother produced copious saliva when giving her baby food that the parent was giving the baby owl something critical. They did an analysis on the saliva to find the critical enzyme to keep their baby owls alive.

    Carole Gonzalez wrote on April 18th, 2012
  32. Just had to chime in (as an anthropology major) and say that a lot of cultures pre-chew the food children eat while they are being weaned. Not sure why it’s so shocking to American, but…

    Autumn wrote on April 18th, 2012
  33. I am both intrigued and disgusted by this article. Do you prechew and mama bird it or put it in a bowl and serve it with a spoon? Baby humans are lots of work! :)

    DeAnna wrote on April 18th, 2012
    • I prechewed as needed and put it on her plate and let her eat it. Didn’t prechew everything, just things she couldn’t eat yet. She loved it!

      Kristen wrote on April 18th, 2012
  34. Thank you, I see no problem with feeding your child in that manner. It is her child and her decision… I have fed my child in that manner but not a lot. My daughter who is now 18 years did not receive her 1st antibiotic until she was 3.5-4 years old.. I breast fed her until after her 1 year birthday. She is a really healthy young lady.. I think all of these actions have been to her benefit…We are giving our best effort to the PALEO way of life…

    MJ Deckbar wrote on April 18th, 2012
  35. Ewww! Nope, it never, ever crossed my mind. I would have to be hard pressed and in some dire straights to do that to my child.

    WendyD wrote on April 18th, 2012
  36. Hmmm I can grok this …
    The other article a while ago about eating dirt … noooo

    WildGrok wrote on April 18th, 2012
  37. EXACTLY how I fed my kids (11 and 7)….cannot believe that this is even a social issue…

    Sarah wrote on April 18th, 2012
  38. I did this with both of my children….no blender required! With a a bonus of enzymes for those early eaters! yep, breast milk IS the best – my kids started eating at around 9 months….chewed up mama-food, that is!

    Sarah wrote on April 18th, 2012
  39. Hello

    I was too lazy to pre cook separate food my kids, but wqhy should we.

    I did the same chew if I was out and guess what my kids eat everything. Curry the works.

    May look feral but its practical and the kids dont choke and they get some of germs which I think is good for the immune system.

    Thats my take

    Sarah Hackett wrote on April 18th, 2012
  40. Yes, I have chewed my children’s food. No mouth to mouth transfer, but I did breastfeed all three of my children for an extended period of time as well as give birth naturally with NO medications and NO interventions at all. I think Silverstone is using this to stay in the “spot” light, but it isn’t strange in most cultures.

    Ginger wrote on April 18th, 2012

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