cron-web.org

[A1CR]

[Posted on behalf of MR]

All:

CRONie_BL wrote:
> > There have also been other studies linking natto consumption with
> > bone health, including this one [1]

It's worth noting that (1) found natto to be of benefit in only a very
small proportion of people: "In a monovariate analysis, no significant
differences in indices for dietary intake, including Ca and vitamin D
intake, were observed. The stiffness index in the B allele group [BB
homozygotes for vitamin D receptor (VDR) polymorphism --
only 5% of the population], however, was slightly lower than in the bb
groups when there was no Natto intake ... A logistic regression test,
including the interactional effect of Natto intake and VDR RFLP,
indicated that the B allele group was a risk factor of bone mineral loss
and that Natto was effective in maintaining bone stiffness *in this
group*. Although the present study was cross sectional and requires
longitudinal investigation, Natto may improve the bone health of people
*who have a low affinity receptor* for vitamin D.

Another issue, discussed in the past, is that natto is both quite high
in soy isoflavones, and that they are present in the unusually
bioavailable aglycone form (vs the form in tofu and soybeans). Granted
the limited evidence that tofu may accelerate brain aging (see links
appended), I suggest avoiding natto as a food whose benefits are not yet
clearly established & that may have much less acceptable risks.

> 1. J Nutr Sci Vitaminol (Tokyo). 2002 Jun;48(3):207-15
> Usual dietary intake of fermented soybeans (Natto) is associated with
> bone mineral density in premenopausal women.
> Katsuyama H, Ideguchi S, Fukunaga M, Saijoh K, Sunami S.

Tofu-dementia discussion:

http://lists.calorierestriction.org/cgi-bin/wa?A2=ind0009&L=crsociety&P=R1363
http://lists.calorierestriction.org/cgi-bin/wa?A2=ind0012&L=crsociety&P=R11954
http://lists.calorierestriction.org/cgi-bin/wa?A2=ind0408&L=crsociety&P=R39250
http://lists.calorierestriction.org/cgi-bin/wa?A2=ind0408&L=crsociety&P=R30610
http://lists.calorierestriction.org/cgi-bin/wa?A2=ind0107&L=crsociety&P=R14951

[MR]

Correcting a mistake:

MR:

>> >>There have also been other studies linking natto consumption with
>> >>bone health, including this one [1]
> >
> >
> > It's worth noting that (1) found natto to be of benefit in only a very
> > small proportion of people: "In a monovariate analysis, no significant
> > differences in indices for dietary intake,... were observed.
> > The stiffness index in the B allele group [BB
> > homozygotes for vitamin D receptor (VDR) polymorphism --
> > only 5% of the population], however, was slightly lower than in the bb
> > groups when there was no Natto intake ... A logistic regression test ...
> > indicated ... that Natto was effective in maintaining bone stiffness *in this
> > group*. Although the present study was cross sectional and requires
> > longitudinal investigation, Natto may improve the bone health of people
> > *who have a low affinity receptor* for vitamin D.

I believe that they likely aactually meant "the pooled group of all
persons bearing the B allele, including the heterozygotes" - esp as this
allele is, perversely, dominant ... in that case, it's still a minority
(25%) of the population, but a much more substantial one.

Also note the cross-sectional, rather than prospective, design, further
weakenign any claim of association & thus benefit.