Does butter increase IGF-1? Exploring the Surprising Research

October 3, 2025 •

4 min read

According to findings published in a 2022 meta-analysis, while some dairy products like milk and yogurt were associated with increased IGF-1 levels, high consumption of butter surprisingly showed an inverse relationship. This challenges the long-held notion that all dairy products uniformly affect hormonal pathways and raises the key question: Does butter increase IGF-1?

Quick Summary

Studies suggest high consumption of butter is linked to lower IGF-1 levels, distinguishing it from milk and yogurt, which are associated with increases. The difference is attributed to butter's high-fat, low-protein composition, affecting the complex IGF-1 signaling pathway.

Key Points

Inverse Association: A 2022 meta-analysis found a negative correlation between butter consumption and circulating IGF-1 levels, contrary to milk and yogurt.
Composition Is Key: Butter's high-fat, low-protein nature differentiates it from protein-rich dairy products, which are typically associated with increased IGF-1.
Butyrate's Influence: Short-chain fatty acids like butyrate, found in butter, may play a role in lowering insulin levels, which can influence IGF-1 signaling.
Contrast with Milk and Yogurt: Unlike butter, studies consistently link the protein and other factors in milk and yogurt to a rise in IGF-1.
Overall Diet Matters: The effect of any single food, including butter, on IGF-1 should be considered within the context of a person's total dietary pattern.
Not a Green Light: The finding that butter may not increase IGF-1 doesn't negate other health considerations related to saturated fat and overall caloric intake.

The Complex Link Between Dairy and IGF-1

Insulin-like growth factor-1 (IGF-1) is a hormone with a powerful anabolic effect, crucial for growth and development. However, chronically elevated levels in adults have been linked to increased risks for certain cancers, prompting interest in how dietary factors can influence its concentration. Research has long focused on the role of dairy products, primarily milk and milk proteins, in this dynamic. Multiple studies have consistently shown that high intake of milk and dairy proteins, especially whey and casein, increases circulating IGF-1.

This effect is largely attributed to the amino acid composition of dairy protein, particularly leucine, which stimulates the mTORC1 pathway, a regulator of cell growth. Given this established link, it's natural to assume that all dairy, including butter, would have a similar, if not identical, effect on IGF-1. However, this assumption fails to account for the vast nutritional differences between dairy products.

Why Butter Differs from Milk

Understanding the composition of butter is key to unraveling its unique effect on IGF-1. Butter is predominantly milkfat, typically consisting of 80-82% fat, with minimal protein and lactose. In contrast, milk and yogurt contain significant amounts of protein, including whey and casein, along with carbohydrates (lactose). This fundamental difference in macronutrient profile is the primary reason for butter's distinct impact on hormonal regulation, a departure from the effects of protein-rich dairy items.

Research Says: Butter May Decrease IGF-1

In a landmark 2022 meta-analysis published in the journal Aging Cell, researchers examined the association between diet and IGF-1 levels using data from the NHANES III study. They found that while milk, cheese, and yogurt were all linked to higher IGF-1 concentrations, the consumption of butter showed the opposite effect. The analysis found that high consumption of butter was associated with decreased serum levels of IGF-1. This finding, which aligns with previous observations of saturated fat intake, suggests that the type of dairy product, rather than the category as a whole, dictates its specific hormonal impact.

Potential Mechanisms Behind the Butter-IGF-1 Relationship

The inverse relationship between butter and IGF-1 is likely driven by several complex mechanisms. While some saturated fatty acids (SFAs), like palmitate, may impair IGF-1 function in certain contexts, other components of butterfat or the overall dietary context seem to be at play. One potential mechanism involves butyrate, a short-chain fatty acid found in butter. Studies in animal models suggest butyrate can influence IGF-1 by suppressing insulin levels. Given the close relationship between insulin and IGF-1 signaling, a reduction in insulin could lead to lower IGF-1. Furthermore, research has identified that butyrate can regulate the expression of IGF-binding proteins (IGFBPs), which modulate the availability and activity of IGF-1. This complex interplay highlights that focusing solely on fat content without considering the specific type of fat and other constituents is a flawed approach to dietary analysis.

Navigating the Dairy Aisle: A Comparative Look

To better understand the differences between butter and other dairy products in the context of IGF-1, it's helpful to compare their nutritional profiles and associated research findings. It's crucial to remember that overall dietary patterns and the presence of other nutrients, such as fiber, also significantly influence IGF-1 levels.


Feature	Butter	Milk	Yogurt	Cheese
Primary Macronutrient	Fat (approx. 82%)	Water, Protein, Lactose, Fat	Water, Protein, Lactose, Fat	Protein, Fat
Protein Content	Minimal	High	High	High
Associated IGF-1 Effect	May decrease IGF-1 levels	Increases IGF-1 levels	Increases IGF-1 levels	Inconsistent; potentially neutral or no association
Key Contributing Factor	High fat content; presence of butyrate	Insulinotropic proteins (whey, casein)	Insulinotropic proteins (whey, casein)	Varies; fermentation may alter effects

Considerations for a Balanced Diet and IGF-1

While butter's effect on IGF-1 may be less concerning than that of milk or yogurt, it doesn't mean butter should be consumed without restraint. Saturated fat intake is a significant consideration for cardiovascular health, though recent perspectives have softened the once-rigid stance against it. A balanced approach that focuses on whole foods, including a variety of protein sources (both plant and animal), healthy fats, and complex carbohydrates, is essential for maintaining optimal health. Factors beyond diet, such as exercise, sleep, and stress management, are also critical for regulating IGF-1 and overall well-being. For example, resistance training can stimulate IGF-1 production for muscle repair, while chronic stress can suppress it. A balanced diet that includes certain plant-based foods, which are associated with lower IGF-1, may further mitigate potential risks.

Conclusion: Does Butter Increase IGF-1?

Despite the broader association between dairy consumption and increased IGF-1, the evidence suggests that butter behaves differently. Research indicates that high butter intake may actually be linked to lower IGF-1 levels, a distinction likely due to its high-fat, low-protein profile. This differentiates it from other dairy staples like milk and yogurt, which have insulinotropic protein compositions that stimulate the IGF-1 pathway. While butter's unique effect is an important insight, it should be viewed within the context of a balanced, whole-foods diet. Consumers should consider the overall impact of their dietary patterns, mindful of the potential effects of different food sources on hormonal health.

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Frequently Asked Questions

Butter's composition is the main reason for its differing effect. It contains very little protein, the primary component in milk and yogurt that drives the increase in IGF-1 levels via the mTORC1 pathway. Butter is mostly fat, which affects the body's hormonal systems differently.

Not necessarily. The relationship is complex and depends on the specific type of fatty acid and its interaction with other nutrients. While some saturated fatty acids may have a negative association, butterfat contains other compounds like butyrate, which could play a unique role in the observed effect.

Butyrate is a short-chain fatty acid found in butterfat. Research suggests it may have a role in inhibiting insulin, and because insulin is linked to IGF-1 production, this could potentially lead to lower IGF-1 levels. Butyrate's effects are still under investigation.

Research on cheese and IGF-1 is inconsistent. Some studies show no association between cheese consumption and IGF-1 levels, contrasting with milk and yogurt. This could be because the fermentation and processing of cheese alters the hormonal impact of the dairy proteins.

Not necessarily. While the IGF-1 finding is interesting, butter is still high in saturated fat and calories. A balanced diet considering all macronutrients and health factors is more important than focusing on a single, potentially isolated effect.

Research suggests that reducing overall dairy intake, particularly milk and yogurt, may contribute to lower IGF-1 levels, especially in individuals consuming a higher-protein, Western-style diet. Plant-based diets are also associated with lower IGF-1.

Many factors influence IGF-1. Total protein intake, particularly from animal sources, is linked to higher IGF-1. A higher intake of fiber and certain micronutrients like zinc and magnesium can also influence IGF-1 levels.