The strings are called "Phloem Bundles" which transport nutrients to the insides of the fruit.
Most people agree that banana is a great fruit to consume. However, a lot of us have a bone to pick with it because of the weird strings we have to keep removing off of every banana ever, just to get to the good bit. But, did you know, banana strings are great for your health just like other weird parts of veggies and fruits? Yeah, me neither. Apparently, the strings have a name and they're called "Phloem Bundles"—a fact we'd probably know if we paid attention in biology class.
According to The Healthy, we've been eating banana all wrong because these strings we love to hate are just as nutritious as the rest of the fruit—they are said to be rich in potassium, Vitamin A, Vitamin B6, and fiber. Phloem is said to be found in all plants and is generally responsible for the transport of nutrients to all regions of the fruit or vegetable. Explaining the significance of the strings is Rebecca Lee, a registered nurse and founder of Remedies For Me, a repository for natural remedies. "Phloem bundles are made up of living cells and allows for food products and sugar to get to all the different parts of the plant."
Likewise, phloems act as veins or arteries in a human body wherein they transport necessary nutrients throughout the fruit for it to grow properly. Speaking to Reader's Digest, Dr. Elizabeth Trattner AP DOM, Doctor of Chinese and Integrative Medicine, highlights the importance of the strings. "It’s not gross or disgusting it just helps the banana grow and become delicious. It is fine to eat and although its structure is a little different than the inside it can be consumed." The phloem bundles also serve another important purpose—they let us know if a banana is ready to be eaten. In case all the nutrients haven't been distributed evenly through the fruit, phloem bundles stay on more tightly, signaling that the fruit isn't ripe yet. On the contrary, when the strings can be removed easily, you can begin chomping down on the fruit.
In conversation with Insider, Nicholas D. Gillitt, Ph.D. in physical/inorganic chemistry and the VP of nutrition research and director at the Dole Nutrition Institute, also emphasized the importance of strings on bananas. "Phloem bundles are necessary for the adequate disposition of nutrients throughout the plant," he adds. That doesn't change anything for most of us of course as we'd still want to be rid of the strings forever. When quizzed about the possibility of this ever happening through research, Gillitt notes that it is "potentially possible" but that it is totally unnecessary and adds that "it is a much more important extension of resources to spend research money on breeding disease-resistant or increased nutrient content varieties."