Cherries are a vibrant fruit, but for people managing blood sugar, the question of whether this sweet fruit is safe to consume is a common concern. While all fruits contain natural sugars, they do not affect blood glucose levels in the same way. The impact of cherries is nuanced, involving a complex interplay of their carbohydrate structure and unique bioactive compounds. This article explains how cherries influence the body’s glucose response.
Glycemic Score and Carbohydrate Content
The primary measure for a food’s impact on blood sugar is the Glycemic Index (GI), which ranks foods based on how quickly they raise blood glucose levels. Fresh cherries are generally considered a low-GI food, with scores typically ranging from 20 to 25, among the lowest of many common fruits. This indicates that the carbohydrates are digested and absorbed relatively slowly, leading to a gentle, gradual rise in blood sugar rather than a sharp spike.
A more practical measure is the Glycemic Load (GL), which accounts for both the GI and the serving size. The GL for a standard serving of fresh, sweet cherries (about one cup) is very low, typically around 4 or 5, confirming a minimal effect on glucose management.
A one-cup serving of fresh cherries contains approximately 22 to 25 grams of total carbohydrates, with 18 to 20 grams coming from natural sugars (primarily fructose, glucose, and sucrose). This serving provides roughly 17.7 grams of total sugars and around 3 grams of dietary fiber. Tart or sour cherries contain slightly fewer carbohydrates (closer to 19 grams) and less sugar (around 13 grams), making them an even more favorable choice. The low GI and GL scores are attributed to the fiber content and the specific composition of their natural sugars.
Bioactive Compounds and Blood Sugar Regulation
Cherries contain non-carbohydrate components that contribute to their favorable blood sugar profile, often resulting in a lower impact than their sugar content might suggest. Dietary fiber, present at about three grams per cup, slows the rate at which sugars are absorbed from the digestive tract into the bloodstream. This delayed absorption helps maintain a steadier blood glucose curve after consumption.
The primary blood sugar modulators in cherries are the plant pigments called anthocyanins, which give the fruit its deep red color. These antioxidants are believed to interfere with glucose metabolism through several mechanisms. Research suggests that anthocyanins may improve the body’s sensitivity to insulin, the hormone that helps cells absorb glucose.
In laboratory studies, exposure to anthocyanins extracted from cherries was shown to increase insulin production by as much as 50 percent. These compounds may also directly inhibit digestive enzymes that break down complex carbohydrates, thereby slowing the release of glucose into the circulation. Anthocyanins can also help reduce the amount of glucose released by the liver and may decrease glucagon production, a hormone that raises blood sugar levels.
Practical Consumption: Types, Serving Sizes, and Timing
The form in which cherries are consumed drastically alters their blood sugar impact. Fresh cherries, both sweet and tart, are the best choice because they retain all their natural fiber, which buffers sugar absorption. Tart cherries generally have a lower sugar and carbohydrate content than sweet cherries, providing an advantage for glucose control.
The blood sugar response changes significantly when the fruit is processed. Dried cherries are a concentrated source of sugar and carbohydrates because the water has been removed; a small quarter-cup serving can contain 32 grams of carbohydrates. Cherry juice removes the beneficial fiber, leading to a faster spike in blood sugar, with a one-cup serving of tart cherry juice containing about 37 grams of carbohydrates. Canned cherries are often packed in heavy syrup, adding extra sugar that should be avoided.
For individuals monitoring glucose, a standard serving size for fresh cherries is one cup (roughly 12 to 15 cherries). To minimize any potential blood sugar spike, cherries should be paired with a source of protein or healthy fat, such as nuts or yogurt. Eating them as part of a meal, rather than as a standalone snack, can also help slow overall digestion and glucose release.