Episode Summary: AMA #67 on Microplastics, PFAS, and Phthalates

Podcast Information:

• Title: The Peter Attia Drive
• Host: Dr. Peter Attia, MD
• Episode: #332 - AMA #67: Microplastics, PFAS, and Phthalates: Understanding Health Risks and a Framework for Minimizing Exposure and Mitigating Risk
• Release Date: January 20, 2025

Introduction

In Episode #332 of The Peter Attia Drive, Dr. Peter Attia hosts AMA #67, focusing on the growing concerns surrounding microplastics, PFAS, and phthalates. This episode delves into the prevalence of these chemicals, their health implications, routes of human exposure, and strategies to minimize risk. The discussion is informed by extensive research and fieldwork conducted by Dr. Attia and his team.

Setting the Stage: The Complexity of the Topic (00:39 - 06:10)

The episode begins with an overview of the heightened public interest in microplastics and related chemicals, driven by media coverage and increased consumer awareness. Dr. Attia emphasizes the nuanced nature of the topic:

"This is a very nuanced topic. If I could answer this in a word, I promise you I would, and I would never try to go through the 75 pages of notes that our team has assembled to help me think about this topic."
- Unknown Analyst (00:39)

He acknowledges the extensive preparation required for this AMA, highlighting the complexity and the incomplete nature of current scientific understanding. The goal is to provide listeners with a framework to make informed, risk-based decisions regarding these chemicals.

Defining the Key Terms (07:00 - 12:20)

Dr. Attia begins by clarifying the terminology to ensure listeners have a clear understanding:

• Microplastics: Typically defined as plastic particles smaller than 5 millimeters, though most current studies classify them as less than 1 millimeter. Dr. Attia prefers discussing micro-nanoplastics (MNPs), which are smaller than one micrometer.

  "Micro nanoplasticles or MNPs are completely ubiquitous. They're found anywhere that we have looked for them, which is to say we find them in water, we find them in food, we find them in fruit, on fruit, in vegetables, on vegetables, in meat, in the air."

- Unknown Analyst (07:00)

• BPA (Bisphenol A): A chemical used in making polycarbonate plastics. Although BPA usage has decreased over the past 15 years, it has been replaced by other bisphenols like BPS and BPF, whose safety profiles are not well-established.

• Phthalates: Chemicals used to make plastics more flexible. They are prevalent in personal care products, fragrances, and various household items. Unlike BPA, many phthalates are still allowed in food contact applications.

Dr. Attia also touches on PM2.5 (Particulate Matter ≤2.5 micrometers), explaining their significance in respiratory health:

"If inhaled, it has the potential at least to become systemic... it is small enough that it could actually get across a cell barrier at the innermost part of the lungs and enter the systemic circulation just as though it had been injected into you."
- Unknown Analyst (10:35)

Prevalence and Public Awareness (12:20 - 14:21)

Addressing why microplastics have become a focal point in recent years, Dr. Attia points to two main factors:

1. Increased Production and Use of Plastics: Since the 1950s, plastic production has surged, leading to greater environmental accumulation.
2. Heightened Scientific and Public Attention: The number of scientific publications on microplastics has dramatically increased, akin to the rapid growth seen in Bitcoin-related research from 2010 to 2020.

He questions whether the apparent rise in microplastics is due to actual increases or merely increased detection and reporting.

Routes of Human Exposure (14:33 - 16:31)

Dr. Attia outlines the primary ways humans are exposed to microplastics:

• Inhalation: Breathing in plastic dust and fibers from the environment.
• Consumption: Ingesting microplastics through contaminated food and beverages, including seafood, salt, water (both tap and bottled), fruits, vegetables, meat, milk, beer, and wine.

He distinguishes between larger microplastics (≥5 mm), which are unlikely to be absorbed by the body, and smaller MNPs that can potentially enter systemic circulation.

"The epithelial barrier is the first line of defense... there’s an epithelial layer on the outside of your body... and there's an epithelial layer on the inside of your body."
- Unknown Analyst (14:33)

Quantifying Consumption (16:42 - 19:12)

Estimating the exact amount of microplastics humans consume is challenging due to variability in diet, location, and water sources. However, studies provide a general range:

• Estimated Consumption: Between 10 and 300 micrograms per week.
• Specific Study Findings:
  • A 2021 study estimated an average of 4 micrograms per week from seafood, tap water, bottled water, and beverages.
  • A 2023 Korean study suggested consumption between 140 and 310 micrograms per week, aligning with the higher end of U.S.-based estimates.

Dr. Attia emphasizes that some widely publicized figures, such as consuming a "credit card worth of plastic" weekly (assumed to be 5 grams), are significantly exaggerated and not supported by scientific evidence.

"The soundbite that humans consume a credit card worth of plastic [5 grams] has been largely debunked... I don't think any serious person believes that we're consuming 5 grams."
- Unknown Analyst (19:12)

Elimination from the Body (20:07 - 22:14)

Understanding how microplastics are processed and eliminated by the body is crucial for assessing health risks:

• Elimination Mechanisms:

  • Respiratory System: Larger particles (>10 microns) are expelled through coughing and sneezing.
  • Digestive System: Approximately 99% of ingested microplastics are eliminated via stool within 24 to 72 hours.
  • Urinary System: A smaller fraction is excreted through urine.

• Absorption: Only a minimal percentage (0.3% to 1.7%) of ingested microplastics cross the gastrointestinal epithelium, with absorption highly dependent on particle size. Particles smaller than 2.5 microns can potentially be absorbed both through the gut and lungs, entering systemic circulation.

"The majority, to the tune of 99% of ingested microplastics, are going to be eliminated through stool."
- Unknown Analyst (20:07)

Dr. Attia highlights that the body's natural defenses are effective at removing most microplastics, especially larger particles, thereby mitigating potential health risks from exposure.

Ongoing Concerns and Health Implications

While the majority of microplastics are efficiently eliminated, the small percentage that may enter systemic circulation raises concerns about potential long-term health effects. This includes:

• Immune System Interactions: The possibility of microplastics interacting with immune cells.
• Chronic Inflammation: Potential for inducing inflammatory responses.
• Bioaccumulation: Although minimal, persistent exposure might lead to accumulation over time.

Dr. Attia underscores the importance of further research to fully understand these implications and to develop strategies for minimizing exposure where necessary.

Framework for Minimizing Exposure and Mitigating Risk

Concluding the discussion, Dr. Attia proposes a pragmatic approach for individuals to assess and reduce their exposure to microplastics, PFAS, and phthalates:

1. Assess Your Environment: Identify sources of exposure in your home and community, such as types of plastics used and water sources.
2. Make Informed Choices: Opt for alternatives to products containing these chemicals, such as using glass or stainless steel containers instead of plastic.
3. Stay Informed: Keep abreast of the latest research and regulatory changes concerning these chemicals.
4. Advocate for Change: Support policies and initiatives aimed at reducing plastic production and promoting safer alternatives.

"The bottom line is that if you're encountering a microplastic that's less than 2.5 microns, you could absorb it both in your gut or via your lungs."
- Unknown Analyst (20:07)

By adopting these strategies, individuals can effectively manage their risk and contribute to broader efforts to address the environmental and health challenges posed by these ubiquitous chemicals.

Conclusion

AMA #67 offers a comprehensive exploration of microplastics, PFAS, and phthalates, balancing current scientific understanding with practical advice. Dr. Attia and his team provide valuable insights into the complexities of these issues, empowering listeners to make informed decisions about their health and environment.

Notable Quotes:

• "This is a very nuanced topic... there are a hundred things I'd rather be doing than going through this."
  - Unknown Analyst (02:50)

• "The epithelial barrier is the first line of defense..."
  - Unknown Analyst (14:33)

• "The majority, to the tune of 99% of ingested microplastics, are going to be eliminated through stool."
  - Unknown Analyst (20:07)

Note: This summary is intended to provide an overview of the key discussions and insights from AMA #67. For a more detailed understanding and access to the full conversation, listeners are encouraged to subscribe to The Peter Attia Drive and explore the available membership benefits.