The city of Revere sends peanut butter and canned tomatoes to the town of Winthrop. Winthrop sends carrots and apples to Revere and East Boston. Neighbors have always helped one another. Now, the deep needs created by the pandemic have sparked the resurgence of this old idea from one municipality to the next.

It started with a surplus of bananas. Winthrop realtor Derek Brodin got a call from his sister-in-law in the produce business. She had 6,000 cases of bananas but no buyer. He had connections in four communities.

“No one could take 6,000 cases but they could take 50. And I realized that if we didn’t do something with that valuable resource, that it was going to go in a dumpster,” said Brodin. “So when I reached out to partners — East Boston, Winthrop, Revere, Chelsea, they said, ‘Yeah, sure, we’ll take 200, and, oh by the way, we have 50 cases of apples that we might be able to give to you, or 20 bags of potatoes.’”

Winthrop football coach and Parks and Recreation Director Sean Driscoll is part of the effort. This time of year he’s usually lining up summer camps. Instead — along with Matthew Rodes from Winthrop’s Senior Center — he was tasked with starting a food pantry. They now have what Driscoll calls a “playbook” for networking their food supply.

“If somebody has a lot of pears, and we have too many apples but they have a lot of pears, we make the switch,” Driscoll said. “For instance, we have frozen pancakes, somebody needs frozen pancakes, we’ll send it there and they’ll send us back some frozen lunches that they gave out.”

It comes down to neighbor helping neighbor, an old fashioned way to help meet an enormous new need: 38 percent of Massachusetts residents now struggle to get enough food. That's up 300 percent from before the pandemic.

“The underlying issue and challenge that we face is food insecurity, and this is something that we’ve heard from our residents from the beginning of this crisis,” said Revere Mayor Brian Arrigo.

Last week, the East Boston YMCA, which participates in Brodin’s sharing network, distributed more than 13,000 meals. Food sharing creates efficiencies and prevents waste, according to James Morton, president and CEO of the Greater Boston YMCA, which runs nearly 60 food delivery sites and also partners with the Greater Boston Food Bank and Project Bread.

“This kind of sharing is elevating the power of partnership. We learned how to do this best during the time of crisis,” Morton said. “I’m hoping this stays with us.”

As he’s moved among communities, Brodin has witnessed the growing need.

“Sometimes it’s just overwhelming, when you hear these cases of people who are literally living day to day by the food that they receive,” he said.

The nonprofit Feeding America estimates nearly 40 percent of people now using food pantries didn’t need food assistance before the pandemic. Sean Driscoll sees evidence of that trend in Winthrop.

“We have a lot of airline and hotel workers that, you know, live in Winthrop, because its so close to the city and some of the bigger places, that have gotten laid off and are still waiting for some unemployment stuff. And we have a lot of people reaching out saying that, ‘Hey I’m a little stuck for food, can you get us through a week?’” Driscoll said.

At Cummings Elementary School in Winthrop, volunteers sort the food donations from private donors and companies. They have been receiving a weekly truckload of produce — an anonymous donation from a local resident. The produce is shared among the four communities.

And it’s not just food being shared. When Winthrop had more diapers and baby food than the community needed, they sent the extra to Revere. When people were coming for food without masks, Brodin said the East Boston Neighborhood Health Center stepped in to help add masks to the food bags.

“We’re stronger as one during these tough times, so with that going on, anytime we can help out another community that turns around and helps us. So it’s kind of like the old-school barter system,” Driscoll said.

Arrigo said the old-school approach is the way to govern through a crisis as well. He says more than ever, mayors are turning to each other.

“We’re all in this position where we’re flying the plane, building the plane, and drawing the blueprints all at the same time and it’s really unprecedented, we’re all going through it at the same time. And it’s really important for us to share information and share resources,” Arrigo said.

This mutual aid effort is now in its ninth week, and organizers say there’s no sign of the need slowing down.