Well, it’s finally March and that can only mean one thing: St. Patty’s Day is approaching, and Shamrock Shake season is almost half-over. This shake begins its annual month-long availability on Valentine’s Day—Feb. 14—and finishes sales on St. Patrick’s Day—March 17. Soon, the seasonal treat will be coming up on its 50th anniversary, after debuting on menus in 1970. This iconic green dessert has been mentioned in popular culture for many years, and many consumers make it part of their spring tradition. Everyone knows it’s a dessert and a health splurge, but how much of a health splurge is it, really?
Let’s get down to the basic ingredients. Shamrock Shakes are made from vanilla soft-serve ice cream, special “Shamrock Shake” syrup, and whipped topping. According to the ingredients list found on the McDonald’s website, this special syrup is composed of (1) High Fructose Corn Syrup, (2) Corn Syrup, (3) Water, (4) Sugar, (5) Natural Flavor, (6) Xanthan Gum, (7) Citric Acid, (8) Sodium Benzoate (which is a preservative), (9) Yellow 5, and (10) Blue 1. Without even going into the additives found in the ice cream and whipped cream, this syrup ingredient list contains a few informational holes.
To even the most nutrition-savvy student, this list really only gets us halfway to the goal of knowing what goes into our Shamrock Shakes. We can confidently recognize about 75 percent of the ingredients, at most. Of course, water and sugar are ubiquitous in our daily life. We’ve heard of citric acid, and probably consume it every day in fruits such as oranges, lemons, tomatoes, and grapefruits, but also in vegetables such as broccoli, carrots, potatoes, rhubarb, and beans. In this case, citric acid is most likely being utilized as a preservative. We can also safely assume Yellow 5 and Blue 1 are the dyes that give us the green color of the shake. And we’ve all heard of high fructose corn syrup and corn syrup. However, even the ingredients we recognize raise a bit of uncertainty. What’s the difference between “high fructose” corn syrup, and plain corn syrup? What’s the purpose of having two preservatives: citric acid and sodium benzoate? What sort of biological effect do Yellow 5 and Blue 1 have on the body? And what in the world is my personal pet peeve ingredient name: “Natural Flavor”? Honestly, is there a more ambiguous ingredient? There’s really no way to even know what this may be. Another descriptive qualifier would certainly be nice, such as “Natural Mint Flavor.” That way, we’d expect peppermint or spearmint extract in our shake. Without the qualifier, however, we really have no idea what the company means by “Natural Flavor.”
Of course, McDonalds is certainly not the only culprit in this ambiguous ingredient list game. In most of the food industry, it’s difficult to read labels and immediately know what ingredients are healthy, unhealthy, or non-impactful. For Shamrock Shakes, there’s a good mix of ingredient toxicity, ranging from “not too bad” to “yeah, this is pretty bad”:
- High Fructose Corn Syrup & Corn Syrup – Corn syrup is 100 percent glucose (which is a type of sugar) while high fructose corn syrup is a mix of glucose and fructose (another type of sugar). The difference between these two sugars is how they are metabolized by the body. Glucose is metabolized in brain, liver, muscle, and fat tissue, and directly increases your blood sugar and insulin levels. Fructose is primarily metabolized by the liver, and primarily affects fats in the blood. Although there are metabolic differences between these two sugars, no sugar is “good” sugar, and therefore, the 2015-2020 U.S. Dietary Guidelines recommend no more than 50 g of sugar per day. A small Shamrock Shakes has 63 g of sugar; a large: 113 g of sugar.
- Xanthan Gum – This polysaccharide operates as a thickening agent. However, it also operates as a laxative, so if you know you have digestive issues, you may do well to avoid any foods with this ingredient, including Shamrock Shakes.
- Citric Acid & Sodium Benzoate – Both compounds are treated as preservatives in the Shamrock Shake and alone, are not hazardous to your health. However, these two compounds are often found together on ingredient labels. This is particularly concerning, because the combination of sodium benzoate and citric acid creates benzene rings: a known carcinogen. Yikes.
- Blue 1 – The jury’s still out on this food colorant. Preliminary research at the Slovak University of Technology reveal this compound (commonly called “Brilliant Blue”) may inhibit cellular respiration at high concentrations.
- Yellow 5 – Also known as tartrazine, this compound doesn’t seem to affect most people, but does cause some increased hyperactivity in some with attention deficit disorder. And no, this increased hyperactivity is not just due to the large amount of sugar in your shake.
So if you’re only getting your Shamrock Shake fix once a year, you’re probably fine. It’s very high in sugar, and the additives aren’t great, but your body can handle one splurge per season. However, if you’re just looking for a green March beverage to be festive and celebrate the month, green tea would be a much better option.