ZOE Science & Nutrition: The Best (and Worst) Oats for Your Health | Prof. Sarah Berry

Release Date: March 6, 2025
Host: Jonathan Wolf
Guest: Professor Sarah Berry, Nutrition Expert at ZOE

Introduction

In this episode of ZOE Science & Nutrition, host Jonathan Wolf delves into the contentious debate surrounding oats. Once hailed as the quintessential healthy breakfast choice, oats are now scrutinized for their impact on blood sugar levels and overall health. To shed light on this controversy, Jonathan is joined by Professor Sarah Berry, a leading figure in human nutritional studies and the chief scientist at ZOE. Together, they undertake a real-time experiment to monitor how different types of oats affect their blood sugar and discuss the broader health implications based on the latest scientific research.

Quick Fire Round

The episode kicks off with a rapid-fire segment where Jonathan poses listener questions to Sarah:

1. Are oats bad for us?
   Sarah: "No."
   [01:53]

2. Are all oats good for us?
   Sarah: "No."
   [01:59]

3. Are the heart healthy labels on oat products sometimes misleading? Is oat milk as healthy as some think?
   Sarah: "No."
   [02:13]

4. Is there a healthy way to enjoy oats?
   Sarah: "Absolutely."
   [02:17]

5. What's the biggest misconception about oats?
   Sarah: "I think the biggest misconception is that all oats are bad for us."
   [02:23]

Understanding Oats: Types and Processing

Professor Sarah Berry begins by elucidating what oats are and the various forms they take post-processing:

• Oat Composition:
  Oats are seeds from the Avena sativa plant, similar to wheat. The edible part comprises the bran (outer layer) and the endosperm (starchy core).
  [04:29]

• Types of Oats:

  • Steel Cut Oats: Least processed, cut into pieces, and take about 30 minutes to cook.
    [06:00]

  • Rolled Oats: Steam-treated and flattened, requiring roughly 20 minutes to cook.
    [06:30]

  • Instant Oats: Pre-cooked and finely ground, cooking in just 2-5 minutes.
    [07:45]

  • Oat Flour and Oat Bran: Finely ground oats and the fiber-rich outer skin, respectively.
    [09:42]

Notable Quote:
"The more processed, the higher the blood sugar response."
– Prof. Sarah Berry [18:07]

Blood Sugar Experiment: Real-Time Analysis

To practically demonstrate the impact of different oat types on blood sugar, Jonathan and Sarah conduct an experiment by consuming a bowl of instant oats and monitoring their blood sugar levels using sensors.

• Initial Observations:

  • Jonathan experiences a headache, indicating a potential blood sugar spike.
    [12:09]

  • Sarah feels satiated and energized due to a balanced meal with added proteins and fats.
    [12:30]

• Blood Sugar Readings:

  • Jonathan's blood sugar spikes to 10.7 mmol/L from a baseline of around 6 mmol/L.
    [12:58]

  • Sarah's levels rise to 8.4 mmol/L, higher than her previous day's numbers.
    [13:12]

Notable Quote:
"It's the structure of the food that affects how quickly blood sugar rises."
– Prof. Sarah Berry [18:07]

Health Implications of Oats

1. Blood Sugar Control:

• Instant Oats vs. Less Processed Oats:
  Highly processed oats like instant oats cause rapid glucose absorption, leading to significant blood sugar spikes. In contrast, steel-cut and rolled oats have lower impacts due to their structure, which slows digestion.
  [13:22 - 19:55]

• Personal Variability:
  Individual factors such as sleep, stress, genetics, and overall lifestyle influence blood sugar responses. Jonathan admits having poor blood sugar control compared to Sarah.
  [16:55 - 17:32]

2. Long-Term Health Benefits:

• Epidemiological Evidence:
  A study following over 500,000 individuals revealed that oat consumers had a 15% lower risk of type 2 diabetes and a 20% lower all-cause mortality rate compared to non-oat eaters.
  [26:27]

• Cholesterol Reduction:
  Oats contain beta-glucan, a fiber proven to reduce total and LDL cholesterol levels. Consuming at least 3 grams of beta-glucan daily is necessary for these benefits, a claim supported by both FDA and EFSA health guidelines.
  [28:58]

Notable Quote:
"The food matrix, or the structure of what we eat, significantly influences our blood sugar response."
– Prof. Sarah Berry [18:07]

Concerns About Oat Products

1. Oat Milk:

• Processing Issues:
  Oat milk typically contains about 10% oats, which are highly processed to create a liquid form. This process involves heating, grinding, and adding enzymes to break down carbohydrates into simple sugars, making it similar to consuming sugar directly.

• Health Implications:
  While oat milk can reduce cholesterol if consumed in large quantities (around a liter daily), this is impractical for most people. Additionally, the high sugar content and added ingredients like oils and stabilizers negate some health benefits.
  [38:41 - 40:59]

Notable Quote:
"Oat milk is mainly water, and the oats have been degraded, making it less healthy than traditional oat forms."
– Prof. Sarah Berry [41:22]

2. Pesticides in Oats:

• Glyphosate Exposure:
  Oats can absorb glyphosate, a pesticide used to dry grains before harvesting. While organic oats typically have lower levels, conventional oats may contain trace amounts. Regulatory bodies have set strict limits to ensure safety.

• Health Risk Assessment:
  Current evidence suggests that occasional consumption of non-organic oats is unlikely to pose significant health risks. However, choosing organic oats is recommended when possible to minimize exposure.
  [34:18 - 38:30]

Notable Quote:
"Unless you're eating oats in excessive quantities daily, the glyphosate levels are generally safe."
– Prof. Sarah Berry [36:50]

Personalization and Recommendations

1. Optimal Oat Consumption:

• Choosing the Right Oats:
  Opt for steel-cut or whole rolled oats with minimal processing. Check packaging for minimal ingredients and longer cooking times, indicating less processing.

• Balancing the Meal:
  Enhance satiety and stabilize blood sugar by adding proteins, healthy fats, and additional fiber. Examples include adding nuts, seeds, yogurt, or nut butters.
  [43:07 - 44:03]

2. Alternative Breakfast Options:

• For individuals with poor blood sugar control, alternatives to oats include chia seeds, which can be soaked overnight and paired with similar additions to maintain nutritional balance without causing significant blood sugar spikes.
  [49:04 - 49:45]

Notable Quote:
"The key is to balance oats with protein and fat to create a more stable blood sugar response."
– Prof. Sarah Berry [43:07]

Final Takeaways

Jonathan Wolf concludes with several key insights from the episode:

• Avoid Instant Oats: Instant oats can cause significant blood sugar spikes, akin to consuming sugary drinks.

• Choose Less Processed Varieties: Steel-cut and large rolled oats are preferable due to their lower impact on blood sugar.

• Read Labels Carefully: Look for oats with minimal ingredients and longer cooking times to ensure lower processing levels.

• Be Cautious with Oat Milk: While environmentally friendly, oat milk may not offer the same health benefits as traditional oat forms due to high processing and added sugars.

• Consider Organic Options: When possible, choose organic oats to reduce pesticide exposure, though occasional non-organic consumption is generally safe.

Conclusion

This episode of ZOE Science & Nutrition effectively demystifies the health implications of consuming oats by combining real-time experimentation with comprehensive scientific analysis. Professor Sarah Berry emphasizes the importance of understanding the different types of oats and their processing levels to make informed dietary choices. While oats offer significant health benefits, particularly for heart health and cholesterol management, their impact on blood sugar varies based on preparation and individual biology. By choosing less processed oat varieties and balancing meals with proteins and fats, individuals can harness the benefits of oats while minimizing potential drawbacks.

Notable Quote:
"It's essential to look at the food in its totality rather than isolating individual components."
– Prof. Sarah Berry [29:54]

For more insights and personalized nutrition advice, consider exploring ZOE's membership offerings to tailor your diet to your unique biological responses.