> exercise your jaw. This can help build wider mouths (new bone growth!) and open up your airways.

Do you have a citation for that? Jaw bone pretty much stops growing in your late teens.

Increasing bone density is not the same as actual bone growth. By that rational doing deadlifts would stimulate your leg bones to continue grow which is obviously untrue.

I suspect it does actually cause your leg bones to adapt, however not by getting longer. Just how often are powerlifter's skeletons examined for adaptations? See the research into the arm bones of British archers who pulled a +100lb bow. https://www.forbes.com/sites/kristinakillgrove/2015/09/30/br...

Agreed, your bone tissue effectively has mini piezoelectric sensors, the more mechanical pressure you apply on them the more you signal for tissue 'reinforcement', this leads to an increased _density_ (not growth) of the bone tissue in that region.

Bone _growth_ during childhood and early adulthood is mostly hormone regulated AFAIK.

There is nothing that I know that supports that earlier claim that chewing hard things makes your jaw bone 'grow'.

Dunno whether it does, but if it does, I bet South Africa Biltong chewers must have strong masculine square jaws fit to bite off any competition then.'

Hmmmm. Biltong.

I'm drooling.

If I understand correctly from the various articles on this topic, there is a theory (with some evidence) that the lack of difficult chewing in childhood while the jaw is developing, leads to smaller mouths and tooth or breathing issues. Nestor's book does not make the claim that chewing tough foods as an adult makes a difference. What he does refer to extensively is a doctor that has an expander device to enlarge the jaw (which does work in adulthood).

He actually does make this claim very specifically. In his conclusions chapter, one of the main headings is "Chew", where he states: "the bones in the human face don't stop growing in our 20s, unlike other bones in the body." And then goes on to recommend eating "foods that require an hour or two a day of hard chewing".

I seem to recall that earlier in the book he describes some research that documented this effect, but I don't have a reference.

Sounds like a good way to get TMJ. Probably a good thing to run past your dentist first.

Lookup the term "mewing" - apparently jaw changes after age 25 are difficult but apparently not impossible.

I'd recommend watching this interview between John Mew (orthodontist) and Bret Weinstein too: https://youtu.be/JYpPu-NrYSI

I remember seeing this but I still don't know if it's a hoax or not.

I wonder if that could help with tinnitus?

The source is the book. He talks about it at depth and the scientists he worked with to come to that conclusion.

> exercise your jaw. This can help build wider mouths

I have bruxism. My doctor told me specifically to not chew excessively.

Also, despite the bruxism over a period of >20 years, I don't have a wide mouth :(

Chewing hard stuff will make your jaw muscles stronger, but the reason you most likely have bruxism is due to a habit of chewing and its an automated reflex. Do you chew gum?

I rarely chew gum, and my doctor said I should avoid it.

Compared to what?

Do you have an evil twin that doesn't have bruxism?

The top review has me concerned, it claims the book says plants exchange oxygen for carbon dioxide and that deoxygenated blood appears blue, both of which are incorrect. Does the book really say that?

> Chew tough stuff, exercise your jaw.

One of the primary reasons I like to eat meat (am nearly vegetarian and happy that way) or chew gum its good for your brains -- other than respectively B12 and fresh breath.