Nectarines are in season right now and are one of the most delicious seasonal fruits you can eat. Essentially a peach without fuzz, the nectarine is beyond sweet and heavily fruity scented, not to mention healthy. But one of the biggest concerns when it comes to nectarines is their glycemic index score and effects on blood sugar. Given the fact they are extremely sweet fruit, are nectarines high glycemic or low?
What is the glycemic index?
The glycemic index (GI), or the glycemic index scale, is a numerical system that measures how much foods affect blood sugar. More exactly, the glycemic index measures how much and how fast the digestible carbohydrates in a food raise blood sugar levels. The glycemic index assigns a number or score to foods based on their effects on blood sugar, or glycemic effects. The lesser the glycemic effects, the lower the GI score. Conversely, the more pregnant the glycemic effects, the higher the GI score.
The glycemic index scale ranges from 0 to 100. GI values between 0 and 55 mark a low glycemic index, or low GI score. Values from 56 to 69 represent a moderate glycemic index, or moderate GI score. Values ranging from 70 to 100 mark a high glycemic index, or high GI score. Low-glycemic foods affect blood sugar the least and are preferred and overall better for health, while high glycemic foods affect blood sugar the most and are best consumed infrequently and in small amounts.
Glycemic index of nectarines
The glycemic index score of nectarines is estimated at 40 which is a low GI score. This makes nectarines a low glycemic fruit. It also means that eating nectarines in normal food amounts will not spike blood sugar levels, despite the fruit being extremely sweet due to its natural sugar content.
However, that does not mean nectarines don’t raise blood sugar levels at all, but that the rise in blood sugar is gradual and not excessive. The limited sugar content in a serving of the fruit and the presence of indigestible dietary fiber to control the rate of sugar absorption into the bloodstream are what contribute to the low glycemic index score of nectarines. Find out more about how nectarines raise blood sugar.
The glycemic effects of nectarines are relative to intake
An important aspect to consider about the glycemic effects of nectarines is that they are relative to intake. More exactly, how much of the fruit you eat at once will determine how much it will raise your blood sugar levels. If you were to eat nectarines in normal food amounts, then the glycemic index score of the fruit would still apply and the fruit would still have limited effects on blood sugar as it’s a low GI score food.
But if you were to eat excessive amounts of the fruit in one sitting, then you’d get your fill of sugar and then the glycemic index value would no longer apply – the high intake would determine a significant rise in blood sugar levels, despite the fruit being a low glycemic food under normal conditions, aka reasonable intakes.
Do all nectarines have the same glycemic index?
The nectarine as a fruit came to be by chance: it appeared spontaneously on a peach tree some centuries ago and was subsequently picked up for cultivation (find out more about what is a nectarine). From then and until now, different varieties of the fruit have been bred from that first fruit and we now have at least a few dozen different cultivars. But all the different types of nectarines are essentially the same fruit and, as a result, have roughly the same nutrition and the same health effects, including the same GI score and glycemic effects.
While there are typically differences in nutrition between the same types of fruit, including sugar content and fiber content which determine glycemic score and effects on blood sugar, these are typically negligible. Which means the different varieties of the fruit will have roughly the same glycemic index score and glycemic impact.
It’s more likely for ripe vs underripe nectarines to produce somewhat more measurable differences in blood sugar levels rather than two ripe nectarines of different varieties (e.g. yellow fleshed nectarines vs white fleshed nectarines or purple nectarines vs yellow mango nectarines or green honeydew nectarines). This is because the content of sugar and other digestible carbohydrates vs indigestible carbohydrates differs more significantly between a ripe and an underripe or unripe fruit than between ripe fruits.
Can you lower nectarine glycemic index even more?
Diabetics in particular are quite concerned with the effects of foods on blood sugar. Given the need for better blood sugar control in diabetes, it’s natural to question if you can have nectarines if you are diabetic since they are particularly sweet fruit. While you can definitely eat nectarines with diabetes if you keep to a reasonable intake, is there a way to reduce the glycemic impact of the fruit even more?
In theory you can lower the glycemic effects of nectarines even further. One way to do this is to have small amounts of the fruit at once, say 50 grams or 100 grams servings. Another way to do this is to make sure your eat the fruit with skin so you get all the fiber you can get to help better control the rate of sugar absorption into the bloodstream.
But the best way to lower the effects of nectarines on blood sugar is to eat the fruit with a food that is a source of lean protein and also has some fat. For example, you can have a small nectarine with a small piece of cheese, whether it’s some Brie or a lower-calorie, low-fat ricotta cheese or cottage cheese. Or pair it with say 5-8 raw nuts such as almonds, cashews or walnuts. Or eat a small nectarine after a meal that is low in carbohydrates, but provides lean protein such as chicken or turkey.