Fiber: Independent Benefits or Just a Proxy for Healthy Foods?

**Danny Lennon** (0:00)
Before we get into today's episode, this is just a quick note to let you know that what you're about to hear is a segment that we've taken from one of our larger question and answer style premium exclusive episodes that we do now and again for our premium members. So you are going to hear a segment of that covering the topic of today, which covers the very interesting topic of whether the health impacts we see associated with fiber come from its independent effects, or is it simply acting as a proxy for other healthy food groups? And how do we disentangle that from research? But like I mentioned, this is from a larger Q&A episode for our premium subscribers, in which we got into many other really interesting topics, including for a match dose of red meat, does the exposure frequency matter for MTHFR gene mutations? Which type of supplementation might be useful? How do we compare typical over-the-counter fish oil supplements versus the pharmaceutical-grade products we see in the main studies? And then what are the health impacts of plant-based saturated fats like coconut products?
Do we need to consume whole grains within the context of an otherwise healthy diet? And then could AI pose a threat to doing rigorous nutrition science? All of these were covered in our full-length Q&A episode. If you're interested in listening to that episode in its entirety, with all of those seven questions covered, then please check out information in the description box about how to become a premium subscriber. That will also support our work. It'll give you access to the full back catalogue of all our premium exclusive episodes that we publish every month. And of now, there are currently more than 50 of those that you can go and listen to. And you also get study notes to all our regular podcast episodes as well. So check that out if that could be interesting to you.
But in the meantime, please enjoy this particular segment from our most recent Q&A episode. I hope you find it interesting.
Hello and welcome to another episode of Sigma Nutrition Radio. My name is Danny Lennon and with me is Dr. Alan Flanagan. Alan, how are things?

**Alan Flanagan** (2:19)
I'm very well, thanks. I'm having a nice, slow summer, so everything's good.

**Danny Lennon** (2:24)
Good. Well deserved after probably many months of chaos and work that we'll probably hopefully see soon once some of your publications see the light of day. They're in the works, but yeah, at the moment, it's a bit of a waiting game for some of them. They're at various different stages.

**Alan Flanagan** (2:40)
Exactly. I always find that the first 98% of the process of writing up and vetting it on your own end before you submit is okay. And the last 2% is so painful that it makes you question whether the previous 98% is or any of it is in fact worth it. Yeah, there's really something about that last yard of getting it over the line that is never really enjoyable. I can't see how anyone enjoys it.

**Danny Lennon** (3:08)
But the good thing is, I guess, from your experience, you'll probably end up forgetting about all that pain pretty quickly and then think, oh, great, let's do the process all over again.

**Alan Flanagan** (3:17)
Let's just repeat this. There's a real case of Stockholm Syndrome, I think, in research. You just can't get away from.

**Danny Lennon** (3:24)
No, you're very much committed to helping the endeavor that is science. So I salute you for that.
Today, we've collected a whole range of questions from listeners that we're going to work our way through. We've picked out what we think are going to be the most interesting, that tie into some concepts that we've discussed on some previous episodes, as well as build off some of them as well. And we'll work through these and hopefully give some answers that might be of utility. And we'll also add some notes related to these afterwards if you want to go back and check over anything that we end up do discussing. But to get going, we may as well just jump in and start working our way through. The first question that we're going to tackle here, Alan, relates to potential independent effects of fiber. And of course, we've discussed fiber on a range of different episodes, as well as looking at overall healthy dietary patterns that tend to be high in fiber. And so this question touches on something that I think we see claims in a variety of places that speak to this. So Sam asks, it seems to me that a perfectly reasonable way to interpret the strong relationship between fiber intake and its various beneficial health outcomes is that fiber is fundamentally a composite of or surrogate for total fruit, vegetable, legumes, and whole grains. I'm not sure why we would necessarily assume that fiber itself in isolation from those foods would have nearly the same effects. Before maybe I get you to chime in this, I think there's probably two distinct things going on here. One, the kind of final thing that I presume would be very much in agreement with is that fiber in isolation isn't going to have the exact same effect as an exposure of all these different food groups that were mentioned because they contain other things than fiber. But I think what the question is really getting at is, and this is something that some people tend to hypothesize as well and say maybe the benefits per se of fiber are overblown, or they're just simply a proxy for these other things that are causing that benefit. And the fiber itself maybe isn't the thing that is as important for that health outcome.