Episode Transcript
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Speaker 1 (00:09):
Hey, everybody, welcome to another edition of Wisdom Wednesdays. So
today we are going to talk about protein intake because
I've just done a series on anti aging and I've
mentioned before that I think that the recommended guidelines, particularly
for older adults, are suboptimal, and there was a study
(00:29):
that was recently published that set out to determine just that,
and so let's dive into the details of the study.
It was a twelve week randomized control trial in older
adults and their average age was around sixty years old. Now,
they all had type two diabetes and signs of sarcopamia,
which is that loss of muscle mass and strength and
(00:52):
bone that is associated with aging, and what they find
was really significant. Twenty six participate were split into two groups.
One group consumed a higher protein diet, which was about
one point two to one point five grams of protein
per kilogram of body weight per day a've reached over
(01:13):
the period, and the other group had a lower protein
diet around not pointing it to one grams per kilogram
and that not point eight, you might remember, is the
Recommended Daily Alliance or RDA. So they were consuming the
RDA or slightly more and after twelve reeks. The results
(01:35):
were pretty down clear appendicular lean mass, so that's the
amount of lean mass in your arms and legs dropped
by almost two kilos. It was just over one and
a half kilos actually in the lower protein group. But
in contrasted increase by a kilo in the high protein group,
(01:56):
So that's a two kilo swing or almost five pounds,
which is really really significant in twelve weeks. And on
top of that, physical function was better in the high
protein group. They had improvements in handgrip strength, in gate speed,
and balanced test performance, and these are all very important
(02:20):
tests as you age. Interestingly, though, there weren't any differences
in a sit to stand or a timed up and
go test between the two groups, and it may just
have been that it was a little bit short for that.
But here's the kicker. Our muscle tissue is constantly being
broken down and built back up because we don't have
(02:42):
a big storage capacity for amino acids, and we need
a constant supply of amino acids. Your organs all need
amino acids. They are the building blocks of life. And
the key player in building muscle and maintaining your muscle
is something called muscle protein synthesis. So for muscle mass
(03:02):
to increase, muscle protein synthesis needs to exceed the rate
of muscle protein breakdown. And as we age, this process
becomes less efficient, and that's a phenomenon that is known
as anabolic resistance. So we actually become slightly resistant to
building muscle as we age. And what this means is
(03:24):
when an older adult eats protein, their body doesn't ramp
up muscle protein synthesis as much as a younger person's
body would. In fact, older adults may need nearly twice
as much protein per meal to get the same response,
and yet we have these very low recommended guidelines. And
(03:45):
what we also know from studies is that as people
get older, they tend to eat less and eat less
protein and to put numbers on it, and young adults
can achieve maximum protein synthesis according to studies with a
male containing around not zero point two five grams of
protein per kilogram of body weight, so about a quarter
(04:06):
of a gram of protein per kilogram of body weight,
But older adults need more like zero point four grams
of protein per kilogram of body weight. That's per meal,
and that's a big, big difference and that brings us
back to this study. So the lower protein group, the
one that lost muscle, was consuming the RDA as I
(04:27):
said earlier, which is that it's actually the RDA is
the minimum needed to prevent deficiencies. That's what it was
established as. It's not designed to be optimal, but people
think it's a recommendation. What is clear is it's not
the minimum needed to prevent deficiencies in older adults. It
(04:47):
may be in younger adults, but not older so it's
not surprising that muscle mass and grip strength declined in
that group, and it's not a one off result. There's
another randomized trial in older adults showed that consumers I
mean one point five grams per kilogram of protein per
day resultant in significantly higher muscle protein synthesis over a
(05:07):
twenty two hour period compared to consuming the RDA of
zero point eight grams per kilogram, and long term observational
studies show the same thing. People sticking to just the
RDA tend to lose muscle over time, and you do
not want to lose muscle as you age. And in fact,
(05:28):
going back to the data here, a metaaly meta analysis
published in twenty twenty concluded that protein integrates averaging one
point three grams per kilogram today led to greater muscle
mass gains than sticking with the RDA. So the evidence
is becoming really clear and we need to change these recommendations,
(05:49):
particularly for older adults. So how much is ideal based
on this and other research? I would say at least
one point two grams per kilogram per day, but really
you should be looking at I think one point six
grams per kilogram per day up to two grams per
kilogram today, and that's not just my opinion, that's looking
(06:11):
at lots of different studies that might be optimal one
point six grams per kilogram of body weight to two
grams of kilogram of bodyweight per day if you're an
older adult who wants to maintain their muscle mass. And
then obviously adding in strength training is really really key.
And one study of people aid is fifty to seventy
(06:32):
those who consumed one point six grams per kilogram of
bodyweight per day of protein over twenty four weeks gained
more muscle than those consuming one point two grams per kilogram.
So that really tends to suggest that one point six
should be your bottom number here and why we don't
have enough long term studies and older adults at higher intakes.
(06:56):
The younger adult studies show a clear dose response. More protein,
even up to three and a half grams per kilogram
per day equates to more muscle mass. So the takeaway
here is very clear if you're an older adult, and
we know that anabolic resistance can start to kick in
at the age of forty or fifty for people, so
(07:17):
if you're over the age of forty, I think to
be see if your protein intakes should be a minimum
of one point six grams per kilogram per day and
up to two or it may be even more, particularly
if you're doing resistance training and you want to avoid
scyclopedia which I think we should be avoiding like the plague.
(07:38):
That's it for this week, folks, catch you next time.