TPV Podcast, Episode 365: Does Paleo cause heart disease?

Posted on August 16, 2019

On this week’s episode, Stacy and Sarah dig into a study that was recently published, looking at how long-term adherence to a Paleo diet affects the gut microbiota and TMAO. Take a step back from the media headlines, learn about the study, the findings, and how to use this information to inform your dietary choices. All of this and more in episode 365. Enjoy!

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The Paleo View (TPV), Episode 365: Does Paleo cause heart disease?

- (0:40) Welcome
  - Welcome back to The Paleo View listeners!
  - Stacy is home and is so excited to jump into this week’s very science-y topic!
    - Snuggling her pets and sleeping in her own bed, Stacy is so happy
    - Stacy also shared an update on a family that she visited with while in Texas
      - Their daughter has alopecia and her hair is starting to grow back after following an AIP approach and working with her family to heal her body
      - Sarah shared her feelings on how significant this is and what this specific case shows us about the autoimmune protocol
  - This week’s show sponsor is Just Thrive probiotics
    - Both Stacy and Sarah’s family uses this product
    - Get 15% off with code PALEOVIEW15
    - Visit: https://thriveprobiotic.com/thepaleoview
- (11:13) The Study that Sparked the Discussion
  - Recently, a human study was published looking at how long-term adherence to a Paleo diet affects the gut microbiota and TMAO
    - Mainstream news picked it up the day it was published
      - Using headlines like, “Study linking Paleo diet to increased heart disease risk strengthens diet industry concerns”
    - There are a few physician-focused websites that publish news to keep doctors up to date on the medical literature
      - The headline was, “Paleo diet increases the risk for heart disease”
    - Sarah’s inbox and The Paleo View’s inbox was flooded with questions
    - It is common in these situations for mainstream media to pick up on any anti-fad diet study
      - The standard response from our community is to find some reason why this study is irrelevant
  - TMAO is often linked with red meat consumption
    - It is thought to be one of the mechanisms behind the link between increased cancer risk and increased cardiovascular disease risk and high red meat consumption
  - The reason why Sarah wants to dedicate an entire episode to this study is that it was very well done
    - It has some results that we need to pay attention to
    - Sarah doesn’t see this study as a nail in the coffin on the Paleo diet
    - Instead, Sarah sees this as a very serious warning about a very particular type of implementation of Paleo
      - We need to make sure we are incorporating all the key principles of Paleo, instead of combining Paleo with other dietary approaches
  - This study shows us that there are problems with the longterm implementation of a low carb Paleo diet
    - Really what it is telling us is that root vegetables and fruit are awesome
  - The study was performed in Australia and they took people who self-reported following the Paleo diet for over a year
    - The controls were following the national dietary recommendations of Australia
      - These are similar to the recommendations made by the USDA/MyPlate
    - Within the Paleo group, they further divided them into two subgroups
      - The people who followed Paleo very strictly were called strict Paleo
      - The other group was called pseudo-Paleo
        
        These people were consuming about one serving of grains or dairy per day
        
        In the real world, most of us who have been following Paleo for a longtime fall closer to that pseudo-Paleo group
        
        Strict Paleo is often the challenge Paleo group or is utilized by those who are using it for therapeutic purposes
    - They had these people do a three-day weighed diet record
      - Measure and record everything they were eating
      - They then did urine tests to measure nitrogen and the Goldberg cut point
        
        If those urine tests didn’t match the dietary records they were eliminated from the study
      - They eliminated anybody who had been on antibiotics, cholesterol medication, blood pressure-lowering medication, previously diagnosed with cardiovascular disease, anyone with any kind of GI disorder, or anyone who has had surgery on their GI tract
        
        They were eliminating anyone who would predictively be an outlier
    - They then did a series of measurements (TMAO, blood work, stool analysis)
      - The two measurements that turned out to be different between the Paleo and pseudo-Paleo group was the amount of TMAO in their blood and what was happening in their gut microbiome
    - Sarah explained more about why TMAO was a focal point in this study
      - Studies that pool all of these studies together show that if you have higher TMAO in your blood you have a higher risk of cardiovascular disease
        
        23% increased risk
        
        And 55% increased risk of all-cause mortality
        
        Which is a general marker of health and longevity
  - The interesting thing that Sarah notes, is that there has also been a lot of research that fails to show a causal link
    - The majority of the science from the last few years makes this picture of TMAO as an indicator or a symptom as opposed to the direct link between high red meat consumption and heart disease
  - How we get TMAO:
    - Some we absorb directly from food
    - Most of the TMAO is made by our gut bacteria when they metabolize choline, lecithin, and carnitine
    - So it is a multi-step process
      - Sarah shared more on this process and how TMAO is created
  - Researchers have discovered over the last few years that how much TMAO is in your bloodstream is far more correlated to your gut microbiome than to how much carnitine you ingest
  - There are certain bacteria that have been shown to be TMA producers
  - There is now this really interesting picture being painted with all the scientific literature showing that TMAO is potentially, rather than a causal link between red meat consumption and cardiovascular disease and cancer, that it’s an indicator of a gut microbiome that is conducive to disease development
    - As we start to look at TMAO it is probably less related to red meat consumption, so much as a dysbiosis in the gut
      - One of the best pieces of evidence for this is that fish is really really high in TMAO
        
        People will get 300x more TMAO in their blood after eating fish than after eating beef, even if they have a microbiome that produces TMAO
        
        And fish is uniformly beneficial and reduces the risk of heart disease
  - Sarah has seen in relation to this new scientific study is arguments that say, “TMAO probably doesn’t cause heart disease, therefore Paleo causing high TMAO is nothing we need to worry about”
    - This isn’t something Sarah agrees with
      - High TMAO, especially when it is not timed with TMAO rich foods, generally is an indicator of something going wrong with our gut bacteria that needs to be paid attention to
      - The way that this study was designed to measure high TMAO food consumption is not taking into account seafood, which is something worth paying attention to
- (27:40) Testosterone Deficiency
  - What is happening in this particular new study looking at strict Paleo and pseudo-Paleo adherence is not that TMAO is going up because the Paleo people are eating more fish
    - But rather that the TMAO is going up as a result of a shift in the gut microbiome
  - The study also took a deeper look into the gut microbiome
    - They found overall big trends
    - However, the study did find that two particular genres of probiotic bacteria were really low in the Paleo and pseudo-Paleo groups
      - Bifidobacteria
      - Roseburia bacteria
    - This is something really important to pay attention to
    - Bifidobacteria are some of our main vitamin producers
      - They are important for inhibiting pathogen colonization in the gut
      - They help to modulate our immune responses
      - They modulate the gut barrier
      - They can reduce inflammation
      - They can improve glucose intolerance
      - Low bifidobacteria is associated with a ton of different health problems
    - We get bifidobacteria from fermented dairy and sauerkraut
      - They love starch loving bacteria, especially fermented starch
    - There is a little less known about roseburia bacteria and fewer species
      - We do know that they are very important for maintaining gut barrier health
        
        So if you have low roseburia you have a leakier gut
      - They are very important immune regulators, especially at reducing inflammation
      - Low roseburia is also associated with many health conditions:
        
        Cardiovascular disease
        
        Autoimmune disease
        
        IBS
        
        Neurological disease
        
        Allergies
        
        Asthma
      - They are really important members of a healthy gut microbiome
        
        The levels of this bacteria were tanked in the study
        
        Another genus had taken their place, called Hungatella
        
        This strain isn’t as well studied as bifidobacteria or roseburia
        
        But hungatella are TMAO producers
        
        They are absolutely associated with TMAO
        
        And this is probably why given that these people following Paleo were also consuming more red meat than the controls
        
        So they were consuming the precursors at the same time as they were shifting their gut bacteria towards a TMAO producing bacteria type
        
        Their gut bacteria was making more TMAO
        
        We don’t super understand if high hungatella might be linked with disease but we do know that the low roseburia and low bifidobacteria is potentially a problem
  - As this study looks at high TMAO and all these different measurements of what these people are eating and we have this shift in the gut bacteria
    - We have all of this really fascinating correlation analysis to try to understand what aspect it was of the study diet that was actually causing these shifts
    - While TMAO itself was mostly aligned with red meat consumption, the shift in the gut microbiome that was driving TMAO production was actually most closely related to total carb consumption as well as resistant starch consumption
    - In the control group, those people were mostly eating grains as their carb source
    - In the Paleo and pseudo-Paleo group, they were mostly eating non-starchy vegetables
      - Hardly any roots and tubers
      - Hardly any fruit
      - So both groups were only consuming 90ish grams of carbs a day, but getting quite a bit of fiber
        
        They were consuming 6 to 7 servings of vegetables a day
        
        As you dig into the details of what they were eating, they were not eating as much resistance starch
      - This indicates that this particular implementation of Paleo in this particular study is a low carb Paleo template
        
        Less than 100 grams of carbs a day
        
        Close to 30 grams of fiber
      - This is where the change in the gut microbiome is really predictable
        
        Both roseburia and bifidobacteria thrive in starchy conditions and are very sensitive to the types of carbohydrates we consume
        
        Out gut bacteria have an amazing ability to digest carbohydrates
        
        Sarah shared more on this process
        
        If we don’t feed our bifidobacteria the right type of food it can’t survive
        
        This is why this is such a sensitive species
  - There is this whole other fascinating to Sarah link with TMAO and what is happening in a low carb diet and the gut bacteria
    - This whole other life form is called Archaea
      - These are normal residents of the gut
      - They are the main methane producers
        
        These particular methane-producing Archaea use compounds like TMAO and TMA to produce methane
      - The diet factor that most strongly correlates with Archaea in the gut is carbohydrate consumption
        
        We know that Archaea are fruit and starch lovers
    - Sarah dug deeper into the picture being painted by the results from this study
      - All of the things that would fix this gut microbiome and reduce TMAO production is to eat starchy roots and tubers and fruit
    - When you dig into these details this study makes a very strong case for high starchy vegetable consumption not being sufficient to support the gut microbiome
      - It is not enough to get fiber from non-starchy vegetables
      - We need the type of fiber that is in fruit and resistance starch in root vegetables that is going to support a healthy gut microbiome that is going to reduce the risk of disease
      - This study very cleverly used TMAO as a marker of those gut microbiome changes
        
        It is the mainstream media that is then making the leap to it actually impacting cardiovascular disease risk
  - Stacy said that it is shocking to see another study supporting this idea that vegetables are good for you
  - Sarah is really starting to see the evidence accumulate for problems associated with long-term low carb approaches
    - We need a diversity of fruits and vegetables and need to not be afraid of the carbohydrates in starchy vegetables
    - Even if you can’t do nightshades there are plenty of wonderful options
    - We need to not be fruit-phobic
    - The science is mounting up that we actually do best with moderate carbs, moderate fat, moderate protein
      - These approaches that are driving macronutrient extremes and even macronutrient imbalance have problems associated with them
  - Why have these diets lasted so long as weight loss approaches?
    - It is because it is a set of rules that result in ditching hyper-palatable foods and trick you into reducing your caloric intake
  - When we can formulate a much healthier option that embraces whole food sources of carbohydrates without demonizing them
    - It this uphill battle against the amount of misinformation that is out there on the internet that needs to be fixed
    - Sarah’s call to action (besides everyone going home and eating a sweet potato) is to contribute to this conversation of avoiding carb phobia
      - The manufactured food carbohydrates are clearly bad, but we don’t need to lump these super nutrient-dense roots, tubers, starchy vegetables and fruit and demonize them with cupcakes
  - Stacy shared her thoughts on how we as humans are drawn to very dogmatic ideals
    - The truth of the matter is that not all carbs are the same
- (49:42) Closing Thoughts
  - If you found this show fascinating, go back and check out the insulin show for more on gut health and overall human health
    - It will help to make a lot of sense of the study
  - Stacy shared examples of cases when kids are put on extreme diets and does it make sense to put kids into these dogmatic bubbles?
    - If you answered no, then why does it make sense to put yourself into these bubbles?
    - Is it just purely weight loss, or are you really thinking about health?
  - Studies like this always make Stacy go back to the mentality of, just focus on health
    - Colorful, rainbow foods exist for a reason
    - There is so much science to support why it is healthy for you
  - Stacy reminds people that none of us are perfect
    - Making healthy choices every day is something we need to be mindful of, and that is hard
    - It can be overwhelming, but there are things you can do to make it easier on yourself and to be excited
      - Take your kids with you to the grocery store and let them pick out vegetables and fruits that they love
      - When you get home from the store cut them up and have them on hand in the fridge
      - We as adults can do this to
  - This is the kind of thing where it is easy to get frustrated and overwhelmed with mixed messages and not sure what to do and to feel like you can’t win
    - And this isn’t the case
    - If good quality gluten-free oats agree with you and your family, enjoy them
      - Add some antioxidant-rich fruits, mix in some yogurt if that agrees with you because these things are feeding your gut in a good way
      - It is about balance, and if we just relaxed into real food a little bit it would come easier and more natural to us
  - Sarah agrees with Stacy
    - Gluten-free oats are a gut microbiome superfood
      - These won’t agree with everyone
    - There are a list of foods that we define as not being Paleo, but they are great for the gut microbiome and when prepared correctly are nutrient-dense whole foods
    - Sarah identifies with the label Paleo, but she thinks of Paleo as a diet that looks to Paleoanthropology in terms of understanding human biology and then confirms with contemporary studies with a biological systems approach
      - It has a rooted in science approach
  - This study is a really good illustration of the importance of taking this really thorough broad look at what foods do for us and don’t do for us
    - And also understanding that one of the biggest problems that we have run into over the last 50 years is this idea that we have to just make a list of yes foods and no foods
      - We define all of these diets by what you cut out, not based on what you eat
      - When people are troubleshooting they cut out more
      - It isn’t what you don’t eat that makes a diet healthy, it is what you actually put in your face that makes your diet something that supports your body or not
      - Sarah thinks it is important for this community to stop with the memes, the soundbites, and the lists and the rules
        
        Start embracing a broader education around health topics that help us really understand what is in foods that help our bodies and what is in foods that may potentially undermine our health
        
        We need to start looking at the gray and not just the black and white so that we can start making informed choices
        
        Look at universal truths as opposed to arbitrary rules
        
        Dig in and understand
  - If you want to help your gut health, be sure to check out Stacy and Sarah’s favorite probiotic
    - 15% off with code PALEOVIEW15
    - Visit: https://thriveprobiotic.com/thepaleoview
    - Stacy feels a difference when she remembers to take her probiotic every day
  - Thank you Sarah for taking the time to do all of this research
  - Thanks for listening everyone! We will be back next week!