PART 3

Seed Oils, Olive Oil, Avocado Oil, and the Modern Fat Debate

Few topics in nutrition have generated as much debate in recent years as dietary fats.

For much of the twentieth century, public health messaging encouraged reducing saturated fat intake while increasing the use of vegetable oils.

These oils, commonly referred to as seed oils, include products derived from soybeans, corn, sunflower seeds, and canola.

Today they are among the most widely used cooking oils in the world.

However, increasing attention has turned toward how these oils are produced, how they are consumed, and how they interact within modern dietary systems.

From a systems perspective, the discussion extends beyond individual oils and into the structure of food production itself.

A Changing Health Profile

There is also a noticeable shift occurring in clinical environments.

Where bowel cancer was once predominantly associated with individuals over the age of 50, clinicians are increasingly observing cases presenting earlier.

In some instances, patients are now presenting in their 40s.

This shift raises a broader question.

What has changed within the system over the past several decades?

Dietary patterns, food processing, and fat consumption are all part of that discussion.

While no single factor explains the trend, the structure of modern food systems is increasingly under scrutiny.

The Rise of Industrial Seed Oils

Seed oils became widely adopted during the twentieth century as industrial processing methods allowed large volumes of oil to be extracted efficiently.

These oils offered several advantages.

They were inexpensive
Widely available
Highly scalable
Suitable for processed food manufacturing

As global food production industrialised, seed oils became embedded within the system.

They are now present in a wide range of foods including:

Packaged snacks
Fast food
Baked goods
Sauces
Ready-made meals

In many cases, they form a foundational component of ultra-processed foods.

Processing, Stability, and Heat

A key point of debate relates to how oils are produced and how they behave under heat.

Some seed oils undergo intensive processing, including chemical extraction, refining, and high-temperature treatment.

These processes can influence how stable the oil remains when used in cooking, particularly at high temperatures.

In contrast, oils such as olive oil and avocado oil are often mechanically extracted through pressing methods.

Extra virgin olive oil, in particular, is minimally processed and retains naturally occurring compounds such as polyphenols.

These compounds are often studied for their role in oxidation stability and broader metabolic interactions.

From a systems perspective, the method of production becomes as relevant as the ingredient itself.

Olive Oil and Traditional Systems

Olive oil provides an interesting contrast within the modern fat discussion.

It has been a central component of traditional dietary systems, particularly within Mediterranean regions, for centuries.

Unlike many industrial oils, olive oil is typically produced through mechanical processes rather than chemical extraction.

It is also consumed within a broader dietary pattern that includes:

Whole foods
Plant diversity
Lower reliance on ultra-processed products

This context matters.

Because oils are not consumed in isolation.

They are part of a wider system of inputs.

Avocado Oil and Alternative Fats

Avocado oil has gained popularity as a modern alternative cooking fat.

It shares some similarities with olive oil in that it can be mechanically extracted and offers relatively high heat stability.

As with olive oil, its role in the diet depends on how it is used and what broader dietary pattern it sits within.

The discussion is therefore not simply about choosing one oil over another.

It is about understanding the system in which those oils are consumed.

The Broader Dietary Pattern

From a Craig Astill systems perspective, focusing on individual ingredients alone can miss the larger issue.

Modern diets are increasingly dominated by ultra-processed foods.

These foods often combine:

Refined carbohydrates
Industrial oils
Additives
Stabilisers
Flavour enhancers

Within highly engineered formulations.

It is this broader dietary environment that may exert the greatest influence on gut health, inflammation, and long-term metabolic outcomes.

Craig Astill frames this clearly:

“Individual ingredients matter, but dietary systems matter more.”

The Structural Shift

The growing debate around fats may reflect a deeper shift in how societies think about food.

Attention is moving away from isolated nutrients and toward entire systems.

Soil health
Agricultural practices
Food processing
Microbiome diversity
Dietary patterns

These layers interact continuously.

And over time, they shape human health outcomes.

The increasing prevalence of metabolic conditions and earlier onset of diseases may not be explained by a single ingredient.

They may reflect cumulative system pressure.

A Systems-Level View

From a long-cycle perspective, the renewed focus on gut health and dietary fats may signal the early stages of a broader transition.

A shift away from purely industrial food design.

Toward systems that better align with human biology.

Craig Astill summarises this relationship:

“Biology does not respond to isolated inputs. It responds to the total system.”

Because in the end, food is not just fuel.

It is information.

And that information begins long before the plate.

In the soil, in the system, and in the structure of how food is produced.

For More information feel free to Reach out.