There are plenty of myths about jackfruit and its glycemic effects being perpetuated by today’s media. The top myth is that it’s good for diabetes because it has a low glycemic index score as a result of a high fiber content and, as such, doesn’t raise blood sugar (too much). And it’s the ripe fruit we’re talking about, the one most people eat raw. But how can a fruit with over 23 g of carbohydrates per 100 g, 19 g of which are simple sugars and only 1.5 g dietary fiber, not raise blood sugar? The truth is it does raise blood sugar which means that it can’t have a low glycemic index score, or a low glycemic load.
Real glycemic index and load values of jackfruit
Glycemic index of ripe jackfruit: 63 (average score, moderate value)
Glycemic load of ripe jackfruit: 15 (average score, moderate value)
Glycemic index of unripe jackfruit: variable, but low to moderate, depending on the amount of digestible and indigestible carbohydrates available (which differs according to fruit maturity)
The lowest glycemic index of unripe jackfruit reported: 11 (low) – when eaten raw
That would make the glycemic load of unripe jackfruit: 2.5 – 3 (low) – when eaten raw
Note: Cooking the unripe jackfruit raises its glycemic index and load score.
Why the difference in glycemic values? The ripe and unripe fruit have different carbohydrate profiles which is why they elicit different effects on blood sugar. Normally, a food high in digestible carbohydrates, including sugars, raises blood sugar levels rather quickly. Whereas a food high in indigestible carbohydrates, such as dietary fiber or resistant starches, delays digestion and the rate of sugar absorption into the bloodstream. In the case of jackfruit, if it’s ripe, it has more digestible carbohydrates (23.25 g per 100 g to be exact), most of which are sugars (19.08 g) and very little indigestible dietary fiber (1.5 g per 100 g). If it’s unripe, a lot of its carbohydrate content is taken up by indigestible dietary fiber and resistant starches which means, if eaten raw, it will have lesser effects on blood sugar.
In other words, the amount of digestible carbohydrates in the ripe fruit is much greater than the amount of indigestible carbohydrates (such as dietary fiber). And the amount of indigestible carbohydrates in the unripe fruit is much greater than the amount of digestible carbohydrates. And since carbohydrate type and content determine how a food affects blood sugar, it’s only natural to have different glycemic index and load values for the ripe vs unripe jackfruit.
For the most part, there is a clear preference for ripe jackfruit. And most sources reference the ripe fruit when presenting the benefits of jackfruit for diabetes, high blood pressure or other health aspects. In some parts of the world, however, the unripe jackfruit is consumed too. But only rarely is it eaten raw (it would have to be tender to lend itself to raw consumption). Unripe jackfruit, when eaten, is usually cooked. Cooking serves the purpose of making the fruit more readily digestible. What this means is that it breaks down the carbohydrates, facilitating their digestion. Which also means a rise in glycemic score and more pregnant effects on blood sugar. So if you were thinking that the unripe jackfruit is better for your blood sugar, know that it would have to be eaten raw. Because cooking would bring it closer to ripe jackfruit glycemic values (to what extent exactly, it is difficult to estimate).
Jackfruit glycemic index: 63 (ripe fruit), as low as 11 (unripe fruit)
The glycemic index (GI) is a scale that measures how the carbohydrates in a food raise blood sugar levels. Below 55 is a low GI. Between 55-69 is a moderate GI. Between 70-100 is a high GI. The average GI of ripe jackfruit is 63, which is moderate. Some laboratory experiments put the GI of the ripe jackfruit at 57 (low GI), while others put it at 73 (high GI).
The different values may be explained by the use of different jackfruit varieties at various stages of ripeness which would mean potentially significant variation in nutritional profile, especially carbohydrate profile. The riper the fruit, the more digestible the carbohydrates and the faster they raise blood sugar (most of them are sugars anyway). The less ripe the fruit, the less digestible the carbohydrates and the slower they raise blood sugar. This also explains why unripe jackfruit has been found to have a GI as low as 11 (being unripe, the carbohydrates are more complex, more resistant to digestion which explains its lesser glycemic effects).
Jackfruit glycemic load: 15 (ripe fruit), as low as 2.5 – 3 (unripe fruit)
The glycemic load (GL) is a scale that measures how fast the carbohydrates in a given serving of food raise blood sugar. Below 10 is a low GL. Between 10-19 is a moderate GL. Over 20 is a high GL. On average, ripe jackfruit with a glycemic index of 63 and roughly 23.25 g of carbohydrates per 100 g will have a glycemic load of 63 X 23.25/100 = 14.64, estimated at 15 (moderate GL). There are also reports that put the GL score at 16 or 18 which is slightly higher, but still moderate.
Unripe jackfruit has been found to have a GL as low as 2.5 – 3, but only when eaten raw. Cooking the unripe fruit would make the complex carbohydrates more readily digestible. This would cause more pregnant effects on blood sugar and an increase in the GL score. Overall, diabetics or anyone needing to monitor their blood sugar would benefit most from eating foods with as low a GI and GL as possible. Of course, modest amounts of moderate GI foods such as ripe jackfruit, ripe bananas, mango or cantaloupe can be enjoyed occasionally without side effects, especially considering they often have a low GL score.