Blue Bonnet is not actually butter. It’s a vegetable oil spread made primarily from soybean oil, palm oil, and palm kernel oil. At 40 calories and 4.5 grams of fat per tablespoon, it’s lower in calories and saturated fat than real butter, but that doesn’t automatically make it a healthy choice. The answer depends on what you’re comparing it to and how much you use.
What’s Actually in Blue Bonnet
The original Blue Bonnet spread starts with soybean oil, followed by palm oil and palm kernel oil. It also contains monoglycerides (an emulsifier that helps blend oil and water) and several preservatives: potassium sorbate, sodium benzoate, and calcium disodium EDTA. It’s a heavily processed product, not a whole food.
One tablespoon gives you 40 calories, 4.5 grams of total fat, 1 gram of saturated fat, and 105 milligrams of sodium. For comparison, the same amount of real butter has about 100 calories, 11.5 grams of fat, and 7 grams of saturated fat. So Blue Bonnet cuts your calories by more than half and your saturated fat by about 85%.
Since the FDA banned partially hydrogenated oils, margarine sold in the U.S. can no longer contain added trans fats. This was the main health concern with older margarine formulas, and it no longer applies to Blue Bonnet.
How It Compares to Butter for Heart Health
The American Heart Association recommends limiting saturated fat to less than 6% of your daily calories, which works out to about 13 grams on a 2,000-calorie diet. A single tablespoon of butter eats up more than half that limit. Blue Bonnet, with just 1 gram of saturated fat per tablespoon, leaves you much more room.
Clinical feeding studies bear this out. When researchers replaced 10% of calories from butter with tub margarine (the category Blue Bonnet falls into), LDL cholesterol dropped by a meaningful amount, with no change in protective HDL cholesterol. Stick margarine, by contrast, showed no improvement in LDL and actually lowered HDL slightly. So the format matters: soft tub spreads consistently outperform both butter and stick margarine in cholesterol studies.
The AHA’s broader guidance emphasizes replacing saturated fat sources with unsaturated plant-based fats. Their position is clear: higher saturated fat intake promotes less healthy cholesterol profiles, which can lead to plaque buildup in arteries over time.
The Palm Oil Question
While Blue Bonnet is lower in saturated fat than butter, it’s not as clean a swap as using liquid oils like olive or canola. Palm oil and palm kernel oil, its second and third ingredients, are among the most saturated plant fats available. Palm kernel oil in particular is roughly 80% saturated fat.
There’s also an emerging concern about how these oils are processed. Many modern margarines use a technique called interesterification to achieve a spreadable texture without trans fats. Preliminary research has found that interesterified palm-based fat blends can raise blood triglyceride levels for several hours after eating, compared to the same fats in their natural form. Elevated post-meal triglycerides are a recognized risk factor for cardiovascular disease. The science here is still limited, and researchers have noted there isn’t enough data to draw firm conclusions yet, but it’s a question mark that liquid plant oils don’t carry.
Better Than Butter, Worse Than Olive Oil
Blue Bonnet sits in a middle tier. It’s a clear step up from butter if your main concern is saturated fat and calories. But it’s a processed blend of refined oils with preservatives, not something that appears on any “optimal diet” list. The AHA’s dietary guidance specifically highlights liquid plant-based oils (olive, canola, and similar options) as the preferred fat sources, not margarine spreads.
If you’re spreading something on toast or using a fat for cooking, here’s a practical way to think about it:
- Best option: Olive oil, avocado oil, or canola oil when the recipe allows it. These are liquid, minimally processed unsaturated fats with the strongest evidence for heart health.
- Middle ground: Blue Bonnet and similar tub spreads. Lower in saturated fat than butter, but processed and made partly from palm oils.
- Most saturated fat: Butter, at 7 grams per tablespoon. Fine in small amounts, but easy to overdo.
How Much You Use Matters Most
A tablespoon of Blue Bonnet on your morning toast isn’t going to make or break your health. The real issue is cumulative intake across the day, especially if you’re also getting saturated fat from cheese, red meat, and baked goods. At 1 gram of saturated fat per serving, Blue Bonnet gives you flexibility that butter doesn’t.
That said, no spread is a health food. The most heart-protective dietary patterns, according to the AHA’s 2021 guidance, are built around fruits, vegetables, whole grains, legumes, nuts, fish, and liquid plant oils. Spreads of any kind are a minor player. If you enjoy Blue Bonnet and use it in moderation, it’s a reasonable choice. If you’re optimizing, drizzle olive oil instead.