What are the unhealthy ingredients in mayonnaise?

October 26, 2025 •

4 min read

A single tablespoon of commercial mayonnaise can contain up to 90 calories and a significant amount of fat. While a beloved condiment, many store-bought varieties contain numerous unhealthy ingredients in mayonnaise that can undermine a healthy diet.

Quick Summary

This article explores the common unhealthy ingredients found in commercial mayonnaise, including pro-inflammatory seed oils, hidden sugars, excessive sodium, and artificial additives.

Key Points

Processed Seed Oils: Commercial mayonnaise often relies on cheap, heavily processed oils high in inflammatory omega-6 fatty acids, such as soybean and canola.
Hidden Added Sugars: Many popular mayo brands contain unnecessary added sugars or high-fructose corn syrup to enhance flavor, contributing to higher calorie and sugar intake.
Artificial Additives: Preservatives like EDTA, thickeners, and flavor enhancers (MSG disguised as 'natural flavors') are frequently added to extend shelf life and alter texture.
High Calories and Sodium: The high fat content makes mayonnaise calorie-dense, and many brands contain excess sodium, which can contribute to weight gain and high blood pressure with overconsumption.
Misleading 'Light' Labels: So-called 'light' or 'reduced-fat' mayos often compensate for less fat by adding more sugars, starches, and artificial ingredients that may not be healthier.
Homemade is Healthier: Making your own mayonnaise with high-quality oils like avocado or olive oil, and no unnecessary additives, gives you complete control over the ingredients.

The Unhealthy Side of Popular Condiments

Mayonnaise is a global staple, but a significant difference exists between homemade versions and the jarred varieties found in supermarkets. Traditional homemade mayo typically relies on simple ingredients like egg yolks, olive oil, and vinegar. In contrast, commercial manufacturers often use cheaper alternatives and additives to extend shelf life, lower costs, and achieve a consistent flavor and texture. Understanding these added components is key for anyone trying to maintain a healthy and balanced diet.

The Problem with Processed Seed Oils

Perhaps the most significant concern with commercial mayonnaise lies in its oil base. While traditionally made with healthier oils like olive or avocado oil, most mass-produced brands substitute these with cheap, heavily processed seed oils, such as soybean, canola, or sunflower oil. These oils are problematic for several reasons:

High Omega-6 Content: Seed oils are exceptionally high in omega-6 polyunsaturated fatty acids (PUFAs). While omega-6s are essential, the typical Western diet provides an excessive amount, leading to an imbalance with omega-3 fatty acids. This imbalance can contribute to chronic inflammation in the body, which is a root cause of many diseases, including cardiovascular issues.
Heavy Processing: The process used to extract these oils involves high heat, pressure, and chemical solvents. This heavy processing can damage the oil's structure, making it unstable and susceptible to oxidation. Oxidized oils are difficult for the body to process and can create cellular stress.
Potential for GMOs: Many commercially used seed oils, particularly soybean and canola oil, are derived from genetically modified (GMO) crops. While generally regarded as safe, some health-conscious individuals prefer to avoid GMOs in their diet.

Hidden Sugars and Sweeteners

Consumers are often surprised to learn that many mayonnaise brands contain added sugar or corn syrup. This is done to enhance flavor and appeal to the palate. For those managing their weight or blood sugar, these seemingly small additions can add up. The inclusion of unnecessary sugars is a primary reason why some health experts advise caution with condiments. Light or reduced-fat mayonnaises are particularly notorious for substituting fat with added sweeteners to maintain flavor.

Artificial Additives and Preservatives

To ensure a long shelf life and consistent product, commercial mayonnaise is packed with various additives and preservatives. Homemade mayo typically only lasts a couple of weeks, but store-bought jars can last for months. This extended shelf life is a red flag for extra, and often unnecessary, ingredients:

Preservatives: Common artificial preservatives include potassium sorbate and calcium disodium EDTA. While approved as safe in small amounts, some people experience adverse reactions, and calcium disodium EDTA has been flagged as a persistent organic pollutant in some studies.
Flavor Enhancers: Ingredients like monosodium glutamate (MSG) can be listed simply as 'natural flavors'. MSG is a controversial flavor enhancer that some individuals choose to avoid due to potential side effects like headaches and weakness.
Thickeners and Emulsifiers: Modified food starch and other gums are often used as cheap fillers and thickeners to mimic the texture of a high-fat product, especially in low-fat versions. These offer no nutritional value and are often chemically produced.

The High-Calorie Trap and Excessive Sodium

The high fat content, largely from refined oils, makes mayonnaise very calorie-dense. A single tablespoon can add 90 calories to a meal, and since mayonnaise is used generously in many dishes like salads, sandwiches, and dips, those calories can accumulate quickly and contribute to weight gain. Additionally, many store-bought brands contain excessive sodium. Too much sodium can contribute to high blood pressure and other cardiovascular issues.

Comparison: Homemade vs. Store-Bought Mayonnaise


Feature	Homemade Mayonnaise	Store-Bought Mayonnaise (Conventional)
Oil Base	High-quality, healthy fats like avocado or olive oil	Cheap, highly processed seed oils like soybean or canola
Omega-6 Content	Low to moderate, depending on oil choice	Very high, promoting an imbalanced omega-6 to omega-3 ratio
Sweeteners	None, unless a touch of honey or sugar is added	Frequently contains added sugars or corn syrup
Additives	None	Contains artificial preservatives, thickeners, and flavor enhancers
Preservatives	None; requires refrigeration and has a short shelf life	Artificial preservatives allow for long-term storage
Ingredient Transparency	Full control over all ingredients	Often contains vague terms like 'natural flavors'

Making Healthier Choices

Being mindful of the ingredients in your mayonnaise is an important step toward a healthier diet. For the most control, making your own mayonnaise at home is the best option. However, if that is not feasible, here are some tips for navigating the store shelves:

Read Labels Carefully: Look for brands that use high-quality oils like avocado or olive oil and have a shorter, more recognizable ingredient list.
Avoid 'Light' Mayo: Don't be fooled by 'light' or 'low-fat' labels. Always check the ingredients, as they often contain added sugars and starches.
Explore Alternatives: Consider using healthier creamy spreads like mashed avocado, hummus, or Greek yogurt as substitutes for mayo.
Control Portion Sizes: Given the high-calorie nature, using mayonnaise sparingly is always a wise decision.

Conclusion

While mayonnaise can be part of a balanced diet, the quality of ingredients varies drastically between brands. Common commercial mayonnaises often contain inflammatory seed oils, added sugars, and a cocktail of artificial additives designed to increase shelf life and mimic texture cheaply. By becoming a diligent label-reader, choosing brands with healthier oils, or opting for a homemade version, you can reduce your intake of these potentially unhealthy ingredients and enjoy your favorite condiment with greater peace of mind.

For more detailed information on the health implications of fats, refer to educational resources like those from the National Institutes of Health.

Note: While some ingredients may be generally recognized as safe (GRAS), individual sensitivities and the overall cumulative effect of a diet high in processed foods should be considered.

This is not medical advice. Consult a healthcare professional for personalized dietary recommendations.

Frequently Asked Questions

The primary unhealthy ingredient is typically the oil base. Most commercial brands use highly processed, refined seed oils like soybean or canola oil, which are high in pro-inflammatory omega-6 fatty acids.

Not necessarily. To make up for the reduced fat, manufacturers often add more sugar, starches, and other artificial ingredients to maintain the taste and texture, which can negate any potential health benefits.

Manufacturers add sugar to commercial mayonnaise to enhance the flavor and create a taste profile that appeals to a wider audience. This is an unnecessary addition that contributes to higher sugar consumption.

Common additives include preservatives such as potassium sorbate and calcium disodium EDTA to extend shelf life, along with thickeners and stabilizers like modified food starch and natural flavors (which can mask MSG).

The most effective way is to make your own mayonnaise at home using healthier oils like avocado or olive oil. If you buy from the store, carefully read labels and choose brands with simple, recognizable ingredients and high-quality oils.

You can use healthier alternatives like mashed avocado, hummus, Greek yogurt, or pesto to achieve a creamy texture in your dishes while boosting nutritional value.

Yes, excessive consumption of omega-6 fatty acids, without a proper balance of omega-3s, can lead to chronic inflammation in the body. The typical Western diet, heavy in processed foods and seed oils, already contributes to this imbalance.