How does diet affect our DNA?

PAMELA: (00:01):

Welcome everyone to week four! I will keep an eye out for Amanda. Hopefully, she can join tonight. Before we get started, congratulations on making it through all four weeks! I think everyone who started is still here. I know Amanda, even if she won't make it tonight, she'll review stuff. And Josh has been reviewing the recordings and he says, hello, even though he hasn't been able to make it to the live sessions. He's the one with a child that needs some medical attention. But let's get started on our last week, diet and aging. As with every week we review where we're at in the program, and today I'm just going to do a brief reminder of disclaimers. I'm not a medical doctor consult your doctor for problems--you all know the drill by now!

PAMELA: (00:58):

We're going to cover how diet affects internal aging as well as external aging. And we're going to go over weeks four's action plan and the meal plan. So today our learning objectives will be to learn how diet affects our DNA. What roles do telomeres play in the aging of our DNA? You don't need to know what telomeres are. I'm going to explain that in the module. How does diet affect skin health? That relates to telomeres, as well as other factors. Can a plant-based diet make us more attractive? We're going to appeal to vanity toward the end, and we're going to do some Q & A.

PAMELA: (01:46):

So let's get started talking about diet and aging and what the connection is there. Some simple facts right now. Firstly, diet does affect the structure of our DNA, specifically the length of our telomeres. And I will again, get to what those are. When I say it affects the structure of our DNA, obviously if I eat certain foods, I'm not going to morph into a lion or a gorilla or something like that! It affects our DNA in more subtle ways, but it certainly does affect how our DNA operates, which I will be showing you. A whole food plant-based diet has been shown to improve DNA function. And as you might guess, this improvement is associated with longer life, and better skin health. And there are many studies that show this, I'll go into some of those studies. And we're going to talk about how the same mechanisms that we've talked about in previous weeks that cause heart disease, insulin resistance and contribute to cancer growth.

PAMELA: (02:52):

Recall that last week when we were talking about protein and how it stimulates the production of Insulin-like Growth Factor-1 that affects the rate of cancer growth, how all of this also ties into overall longevity as well as skin health. So let's get into the good stuff! In every human cell, we've got 46 chromosomes--strands of DNA that are wound together. And at the tips of these strands are caps called telomeres. If you think about when you tie your shoes, your shoe laces are strings, and then they have the plastic caps at the end. Those keep the shoe laces from coming unraveled as you use them. It's the same idea with our DNA. And this is why I included this picture here on the left. This is a chromosome, a couple strands of DNA wound together. And these green knobs, these caps at the end are our telomeres.

PAMELA: (03:52):

Each time a cell divides, what happens is that a bit of the telomere is lost. After enough cell divisions, the telomere is gone and the cell either stops dividing, or what normally happens is the cell dies. So telomeres are kind of like a lifeline--when they are gone, our cells are gone and ultimately we are gone after enough time. This is the aging process. One of the issues with telomeres is that they regulate cell growth so that we don't want them to overregulate and not allow enough cell growth and replication. We also don't want them to underregulate cell growth, which is when cancer can happen. And that's that second point on screen there. In younger people telomeres are long and they're healthy. The normal process of aging is for these telomeres to shorten as we age, that's just a normal aging process.

PAMELA: (04:53):

The current scientific thinking is that if we can keep our telomeres long, we can actually prolong our life. So this is my animation for today. It's very basic. It's just showing the progress of a chromosome and how the telomeres get shorter over time. And eventually, the chromosomes die.

PAMELA: (05:12):

How do we lengthen our life when it comes to telomeres? In 2013, a series of randomized controlled studies were done that show that a plant-based diet can significantly improve telomere length in adults. The controlled study involved 400 women. They divided the subjects into an exercise group and an exercise and portion-controlled diet group. So neither of these was eating a plant-based diet. They were eating the standard American diet. One group was exercising. The other was exercising and restricting calories. There was another control group that made no changes, changes to their lifestyle at all, they were simply sedentary. And over the course of a year, they measured telomere activity in these groups and found that none of the groups had any significant change lengthening or shortening in their telomeres over the course of just one year. Another study that was done as kind of a replication of that first study added on a fourth group. The fourth group was exercise plus plant-based diet. So the fourth group wasn't restricting their calories. They were exercising and they were eating a plant-based diet. And over the course of the year, again, that group did show significant lengthening in their telomeres. So I know that was a little discombobulated. Did everyone get that? Does that make sense? Okay. I'll take silence as a yes!

DAISY: (06:48):

Yes, I was trying to say yes.

PAMELA: (06:55):

Okay. Thank you. Perfect. Thanks. So portion control, diet and exercise did not have the same lengthening effect in these adults. Now the following things have had a positive association with telomere length--no real surprise here: higher fruit and vegetable consumption, lower butter consumption. Later studies also included other dairy foods, foods high in fiber and vitamin content, low saturated fat. So all kind of predictable at this point. There's another study that was done that I thought was particularly of interest when we talk about diet. This is a year long study. It didn't involve exercise. It followed what people were eating over the course of a year. So it examined the intake of a variety of foods on telomere length in a multiethnic group of individuals. And in this yearlong study of what these individuals ate, it was shown that two food groups over and above the others actually did more damage to the DNA than any of the other food groups.

PAMELA: (08:06):

And those two were 1) eating fish--non-fried fish over the course of the year, did six years worth of damage to the telomeres. So what that means is over the course of the year, eating fish as a regular part of their diet, the damage that was done to the length of their telomeres would translate into six years worth of life lost at the end of their life. Hopefully that makes sense! 2) Processed meat--the damage done to their DNA over that year was 14 years worth of DNA damage. Now they didn't see the same DNA damage with other groups, for example they didn't see that kind of damage with dairy. They did not see that kind of damage with fruits and vegetables. In fact, they saw some positive changes with fruits and vegetables, but these two groups I thought were pretty interesting. The fish to me was particularly interesting. Now, I can argue that dairy has its other issues! But as far as telomere damage, these are the two big food groups that did the most damage. Some foods that protect telomeres--

DAISY: (09:18):

Any specific fish or fish in general?

PAMELA: (09:21):

Fish in general. It just said non-fried fish. It was a variety of fish that they ate. They didn't fry it though, because they specified non-fried fish and did not say types of fish. So I can dig more into that Daisy. But as I recall, when I was reading this study and I read these sources a bunch of different times, there was not one specific type, like it wasn't only salmon or only grouper or what have you. It was different types of fish. Okay. So these foods protect telomeres: flax, spinach, mushroom, various oats. These are standouts, but other foods will also protect your telomeres.

JULIE: (10:02):

Pamela, how many people were involved in this study?

PAMELA: (10:05):

In that particular study? I do have it in here, let me find it.

Speaker 2 (10:11):

It was one year long...

PAMELA: (10:14):

Oh, so I didn't write down the number of people. I will put that in the group, in the Facebook group.

Speaker 3 (10:20):

It's not that important. I just was curious.

PAMELA: (10:23):

It's a good question! I thought I had it written down because there are some other studies here where I wrote down the number of people involved. I don't have that in this one. *writing* How many people in this study... I will find out for you!

JULIE: (10:35):

I'm just surprised that fish came up.

PAMELA: (10:40):

Yeah, me too! And not dairy! I would've suspected dairy, but you know, in this particular study it didn't happen that way. Any other questions before we go on?

DAISY: (10:54):

The flax. Are you talking about flax seed like we talked about last week? The seeds? Okay. That's it.

PAMELA: (11:04):

And these are just a few foods. I literally Googled "foods that protect telomeres." I found articles on sources that I trust. And so I plucked from there, but you could probably find a thousand other sources that have broccoli or collards or whatever they're going to have. So these are some of the ones that stood out repeatedly.

PAMELA: (11:27):

How do these foods protect our DNA though? Without getting too deep into it and getting into levels of microbiology that even I don't understand, I can explain some of this to you. And it has to do with an enzyme called telomerase. You may guess by the name that telomerase is associated with lengthening of telomere in our DNA. So telomerase is an enzyme that was discovered by a scientist, Elizabeth Blackburn. Actually this enzyme was discovered before 2009, but he discovered it in a 5,000 year old tree in 2009!

PAMELA: (12:06):

And there are a couple of species of tree that are exceptionally long lived. In fact, this particular tree is estimated to have been around when the Egyptian pyramids were first being built. That's how mind-blowing this is. That's how long-lived this tree is! Telomerase is also of course found in humans and other animals, any animal or non-animal that has telomeres is going to have telomerase. What it does is it helps rebuild and strengthen our telomeres. So I'm going to explain this. Actually let me show everyone's face while I'm explaining this, because this does get a little geeky! But I think it's interesting. So you saw the picture of the chromosome earlier when a cell divides, our DNA comes unraveled and each half of the DNA makes a copy of itself. They recoil and then each new group of DNA goes into two cells rather than one.

PAMELA: (13:07):

So that's just the process of cell division, where our DNA makes a copy of itself. The new copies go off into a new cell. The old copies stay in the cell that they're in and that's how we continue to exist. Our cells divide all the time. They die out. They get reborn through cell replication. And that's just a natural process. What happens though, is that the mechanism by which our DNA copies itself, not all the genetic material can get to the exact ends of each DNA strand. And what telomerase does is it literally transports genetic material to the tips of our DNA and helps rebuild the ends that are not rebuilt during normal cell division. So that's why this enzyme is so important. It literally helps rebuild parts of our DNA that would otherwise be lost as our cells divide. So hopefully that wasn't too geeky in microbiology, but that's why it's so important to mention!

PAMELA: (14:11):

There have been some studies done starting in 2008 and this one was actually funded by the Department of Defense. It involved Elizabeth Blackburn the scientist who discovered this enzyme in the tree, and a man named Dean Ornish who is pretty well known in the plant-based world for his pioneering research. And this study that they did in 2008 was just three months, but they wanted to see whether three months of intensive lifestyle changes--meaning we're going to change your diet, we're going to up your exercise and everything is going to be very controlled for these three months. And this was for men with low-grade prostate cancer. They wanted to see if these interventions would affect their telomerase activity. And if so, how that would translate potentially into reversing their cancer or at least keeping it at bay. So in this study they did find that a whole food plant-based diet and exercize combined had a very positive association with, telomerase activity. It was a pilot study, so further research was recommended-- and further research was indeed done, which brings me to our skin section! Because I know everybody wants to know that! Before I go into that, does anyone have any questions about what I just explained? Was it like, wow, this is just over my head. I don't care about this. Or was it interesting? Or, you know?

DAISY: (15:43):

I thought it was a little little over my head, but I got the essence of it!

PAMELA: (15:50):

Okay. Great, good feedback! Thank you!