Is Mayonnaise Worse Than Butter? A Nutritional Breakdown

October 17, 2025 •

4 min read

While both spreads pack a high caloric punch, a standard tablespoon of butter contains significantly more saturated fat than a similar serving of mayonnaise, which is often made with unsaturated vegetable oils. This fundamental difference in fat composition is key when comparing whether is mayonnaise worse than butter from a health perspective.

Quick Summary

This article provides a nutritional comparison of mayonnaise and butter, analyzing ingredients, fat types, calories, and sodium content. It explores which spread may be the healthier option, emphasizing the role of moderation, ingredient quality, and dietary context rather than a simple 'good vs. bad' conclusion.

Key Points

Saturated Fat vs. Unsaturated Fat: Butter is primarily saturated fat, whereas mayonnaise is primarily unsaturated, often making mayo the more heart-healthy option in this regard.
Comparable Calories: Both mayonnaise and butter are calorie-dense, with similar calorie counts per tablespoon, making portion control the most crucial factor for weight management.
Ingredient Quality Matters: The health profile of mayonnaise is highly dependent on the type of oil used; versions with olive or avocado oil are superior to those made with processed seed oils.
Sodium Content: Commercial mayonnaise can be significantly higher in sodium than unsalted butter, a key consideration for individuals monitoring their salt intake.
Moderation is Key: Given the high fat and calorie content of both spreads, the quantity consumed is more important than which one you choose, as both can be part of a balanced diet in moderation.
Nutrient Differences: Butter contains more fat-soluble vitamins like A, D, and E, while mayonnaise typically contains negligible amounts of these vitamins unless fortified.

A Tale of Two Spreads: Ingredients and Production

At their core, mayonnaise and butter are both high-fat emulsions, but their origins and ingredients are vastly different. Understanding these basics is the first step in determining which spread aligns better with your dietary needs.

The Composition of Butter

Butter is a dairy product, created by churning fresh or fermented cream or milk. This process separates the milk solids and butterfat from the buttermilk. A typical stick of butter is roughly 80% fat, with the remainder being water and milk solids. This fat is primarily saturated fat, which has been traditionally linked to higher levels of LDL ('bad') cholesterol, although modern research suggests the picture is more complex. Some of butter's health benefits include being a good source of fat-soluble vitamins, notably Vitamin A, D, E, and K2.

The Composition of Mayonnaise

Standard mayonnaise is a classic culinary emulsion made from oil, egg yolk, and an acid like vinegar or lemon juice. The egg yolk acts as the emulsifier, binding the oil and acid together into a creamy, stable spread. Unlike butter, the primary fat source in mayonnaise comes from vegetable oils, such as soybean, rapeseed, or sunflower oil. These oils are high in unsaturated fats (monounsaturated and polyunsaturated), including omega-6 fatty acids. However, the type of oil used is critical, as versions made with healthier fats like olive or avocado oil are available. Additionally, commercial mayonnaise often contains added sugars and more sodium than unsalted butter.

Mayonnaise vs. Butter: The Nutritional Breakdown

To get a clearer picture of which spread is the 'better' choice, we must compare their nutritional profiles, particularly regarding fat composition, calories, and other key nutrients. The table below provides a quick comparison based on a 1-tablespoon (14-15g) serving.


Nutrient	Mayonnaise (Regular)	Butter (Salted)
Calories	~90-100 kcal	~102 kcal
Total Fat	~10-11 g	~11.5 g
Saturated Fat	~1.6 g	~7.3 g
Unsaturated Fat	High (Poly & Mono)	Low (Mono & Poly)
Sodium	~88 mg	~82 mg
Cholesterol	~5.8 mg	~31 mg
Vitamin A	Minimal	~11% DV
Vitamin K	Present (oil-dependent)	Present

Unpacking the Details: Fat, Inflammation, and Health

Saturated vs. Unsaturated Fats

The most significant nutritional difference between the two spreads lies in their fat content. Butter is predominantly saturated fat, while mayonnaise is primarily unsaturated. Health organizations previously recommended limiting saturated fat intake to reduce cardiovascular disease risk, although the relationship is now understood to be more complex. Nonetheless, replacing saturated fats with unsaturated fats is still considered a beneficial dietary change for heart health. This gives mayonnaise an edge in fat quality, provided it's made with heart-healthy oils like olive or avocado oil.

Calorie Density and Portion Control

For weight management, both spreads are calorie-dense, with comparable calorie counts per tablespoon. This means that regardless of your choice, portion control is paramount. Easily adding 100+ calories per serving, these condiments can significantly increase a meal's total energy intake if used without care. Whether you are spreading it on toast or mixing it into a salad, a little goes a long way.

The Sodium and Additive Factor

One area where commercial mayonnaise often falls short is its sodium content. While unsalted butter is very low in sodium, mayonnaise can contain a significant amount per serving. For individuals managing their blood pressure, this is an important consideration. Furthermore, cheap commercial mayonnaise is often made with highly processed vegetable oils high in omega-6 fatty acids, and sometimes, added sugars.

The Inflammation Debate

Mayonnaise's high omega-6 fatty acid content has raised concerns about inflammation. While omega-6s are essential, the modern Western diet often has an imbalance of too many omega-6s compared to anti-inflammatory omega-3s. However, the link between dietary omega-6 and inflammation is a subject of ongoing debate in the scientific community. The source of the oil is critical; mayonnaise made from healthier oils can help mitigate these concerns.

Making a Healthier Choice

To make an informed decision between mayonnaise and butter, consider these factors:

Ingredient Quality: Read the labels. High-quality mayonnaise made with olive or avocado oil offers a better fatty acid profile than butter or low-quality mayo made with highly processed seed oils.
Fat Type: If focusing on reducing saturated fat, mayonnaise generally has a better profile, but the unsaturated fats should come from healthy sources.
Moderation: Given their high-calorie density, the amount you use is more important than the product itself. A balanced diet can accommodate small amounts of either spread.
Cooking vs. Spreading: The application matters. Butter can brown and add flavor when heated, while mayo is more neutral and often used as a cold spread or binder.
Sodium: For those watching sodium intake, unsalted butter or a homemade, low-sodium mayonnaise is the safer bet.

For more information on the nuances of dietary fats, resources from organizations like the American Heart Association provide valuable context beyond this specific comparison.

Conclusion: It Depends on the Jar and the Portion

Ultimately, whether mayonnaise is worse than butter is not a simple yes or no answer. In terms of saturated fat content, most mayonnaises offer a more favorable profile than butter. However, generic commercial mayonnaise can be high in sodium and made with processed oils rich in omega-6 fatty acids. Butter provides beneficial vitamins but is much higher in saturated fat and cholesterol per serving. The 'healthier' choice is highly dependent on the quality of the mayonnaise ingredients, the quantity consumed, and your overall dietary goals. For most people, consuming either spread in moderation is unlikely to have a major negative impact, as long as it fits within a balanced nutritional plan. The best approach is to read labels, be mindful of portion sizes, and choose products with higher-quality, less-processed ingredients whenever possible.

Frequently Asked Questions

The calories per tablespoon for regular mayonnaise and butter are very similar, both typically falling around 100 kcal, though this can vary by brand and fat content.

Mayonnaise, especially versions made with olive or avocado oil, contains more unsaturated fat and less saturated fat than butter, which is generally considered better for heart health. However, moderation is key for both.

For weight loss, neither is inherently better due to their similar high-calorie density. The most important factor is portion control, as either can quickly add unwanted calories.

Some commercial mayonnaises made with high levels of processed seed oils rich in omega-6 fatty acids could contribute to inflammation if consumed in excess as part of an imbalanced diet. Healthier oil options can mitigate this risk.

Standard mayonnaise does not contain milk or dairy, as it is made from oil, egg yolk, and acid. This makes it a suitable option for those with dairy allergies.

The sodium content is very different; unsalted butter has virtually no sodium, while regular salted butter contains some. Commercial mayonnaise, however, often contains significantly more sodium per serving than butter.

For cooking, the choice depends on the application. Butter is preferred for tasks requiring a specific flavor profile or browning. Mayonnaise, with its neutral flavor, higher heat tolerance, and emulsifying properties, is often a better choice for certain spreads and coatings, like on grilled cheese.