What are mono- and diglycerides?
Mono- and diglycerides are food additives commonly found in a wide range of processed foods, including baked goods, margarine, ice cream, and peanut butter. Chemically, they are types of glycerides, or fatty acids attached to a glycerol molecule. A monoglyceride has one fatty acid chain, while a diglyceride has two. They serve as emulsifiers, a key function that allows for the smooth mixing of ingredients that would otherwise separate, like oil and water. This provides products with a consistent texture, prevents spoilage, and extends shelf life.
Unlike triglycerides, which are a major source of dietary fat and must be listed on nutrition labels, mono- and diglycerides are considered food additives. This crucial distinction means they are often listed in the ingredient list but not accounted for in the nutritional facts panel under total fat, even though they are a form of fat. They are produced through a chemical reaction between glycerol and fats or oils, which can be sourced from either plants (such as soy, palm, or sunflower oil) or animals.
The connection to trans fat
The primary reason for concern over the health implications of mono- and diglycerides lies in their relationship with trans fats. While the FDA banned the use of partially hydrogenated oils (PHOs)—the main source of artificial trans fats—in 2018, this ban did not apply to mono- and diglycerides. The emulsifiers, particularly when produced using hydrogenated fats, can contain small amounts of trans fats.
The '0g Trans Fat' label loophole
Food labeling regulations allow products with less than 0.5 grams of trans fat per serving to be labeled as containing "0 grams" of trans fat. For foods containing mono- and diglycerides, this creates a potential loophole. A consumer eating multiple servings of different processed foods throughout the day could unknowingly consume a higher cumulative amount of trans fats than they realize, as these small amounts add up. Trans fats are widely recognized for their link to increased risk of heart disease, stroke, and diabetes. They raise LDL (“bad”) cholesterol and lower HDL (“good”) cholesterol, promoting inflammation in the body.
Potential health risks and emerging research
While mono- and diglycerides have regulatory approval based on consumption in small quantities, several studies and health concerns suggest moderation is wise. Their presence is often a marker for ultra-processed foods, which are typically high in added sugars, unhealthy fats, and sodium, and have been linked to poorer health outcomes.
- Heart health: Even beyond the trans fat concern, these additives are still a form of fat. A diet rich in processed foods containing them can contribute to a higher overall fat intake.
- Link to cancer: A notable French observational study published in 2024 suggested a correlation between higher intake of emulsifiers, including E471 (the code for mono- and diglycerides), and an increased risk of certain cancers, particularly breast and prostate cancer. It's crucial to remember that this is a correlation and not a causal link, and the study notes that cancer is multifactorial.
- Gut health: Emerging research indicates that synthetic emulsifiers could potentially affect the gut microbiome and intestinal barrier function, though more studies are needed.
- Allergenic concerns: Individuals with allergies to soy or palm, which are common sources for these emulsifiers, may experience a reaction.
Comparison: Mono- and Diglycerides vs. Natural Emulsifiers
| Feature | Mono- and Diglycerides (Food Additive) | Lecithin (Natural Emulsifier) |
|---|---|---|
| Source | Vegetable oils or animal fats | Soybeans, sunflower seeds, or egg yolks |
| Composition | Glycerol with one or two fatty acid chains | A mixture of phospholipids |
| Trans Fat Content | May contain small amounts of trans fat | Typically contains no trans fat |
| Health Reputation | Generally safe by regulators, but linked to ultra-processed foods and some health concerns | Generally considered healthy, with minimal or no health concerns |
| Vegan Status | Can be animal- or plant-derived; must check with manufacturer | Easily sourced from plants like soy or sunflower, making it reliably vegan-friendly |
| Primary Function | Emulsifier, stabilizer, and texture improver | Emulsifier, antioxidant, and flavor protector |
How to avoid mono- and diglycerides
For those who wish to limit their intake, especially due to concerns about trans fats or religious/dietary restrictions (vegan/halal/kosher), a proactive approach is necessary. Always read ingredient labels and be aware that they can be listed under slightly different names, such as "distilled mono- and diglycerides" or "monoacylglycerols". As the source isn't always specified, contacting the manufacturer is the only way to be certain of their origin. The most effective way to avoid these additives is to:
- Choose whole foods: Focus on fresh, unprocessed foods like fruits, vegetables, and unprocessed meats.
- Cook at home: Preparing meals from scratch gives you full control over every ingredient.
- Select organic options: Organic standards may prohibit certain additives or require more transparency, though checking the label is always best.
- Look for natural alternatives: Seek out products that use natural emulsifiers like lecithin.
Conclusion
While regulatory bodies classify mono- and diglycerides as safe for consumption, this status doesn't fully capture the health picture. Their potential to contain trace amounts of trans fats, combined with their prevalence in ultra-processed foods, raises legitimate concerns for health-conscious consumers. Emerging research, like the 2024 French study linking emulsifiers to increased cancer risk, suggests that while not proven causal, caution is warranted. The most prudent approach for those concerned about whether mono- and diglycerides are unhealthy is to reduce consumption of processed foods, cook more meals at home, and choose products that use natural, transparently sourced ingredients. Making these choices empowers individuals to take greater control over their long-term dietary health.
