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