Back during the 1918 flu pandemic, they were in higher demand than toilet paper is now.

Can you imagine a world where instead of TP shortages and meat purchase limits, we were experiencing a run on oysters? This scene was reality during the 1918 influenza pandemic, as noted on Instagram recently by Blue Hill owner and chef Dan Barber.

"Stockpiling was ubiquitous, prices skyrocketed, black markets developed. Poachers raided oyster beds—you can often still see the remnants of single-room guard houses built in the middle of the bay where guards with shotguns stood lookout," @chefdanbarber explained in his Instagram post.

Folklore said that oysters, and in particular the briny broth their shells contain, could help prevent the flu. But is it fact or fiction?

Turns out, it's a little bit of both, nutrition and medical experts now agree. While no food or supplement can protect you from bacteria or viruses, certain vitamins and minerals have been proven to bolster your immune system, making it better able to combat any foreign invaders. This includes coronaviruses, like the regular flu and colds.

"Zinc, vitamin C and E, selenium, omega 3s and probiotics are some of the key nutrients important for immunity," says Julie Upton, MS, RD, a registered dietitian in San Francisco, and the co-founder of the nutrition news company Appetite for Health. "They help the fighter T-cells in the immune system fend off infections."

Oysters au Gratin with Spinach and Breadcrumbs

The oyster rush of 1918 was in part due to their size (see Barber's comparison for today's oysters on the left and the usual 1918 size on the right) resulting in a strong source of protein—another immune-supporting nutrient. It was also in part because oysters are the #1 highest-zinc food on the planet, supplying over 500% of your daily needs in a 3-ounce cooked portion. Oysters are also good sources of selenium and omega-3 fats, according to the USDA's nutrition database.

So with beef, pork and poultry in shorter supply these days due to viral outbreaks at meat processing plants across the Midwest, should we be stocking up on seafood like oysters? While it certainly can't hurt to mix up your protein sources and incorporate foods with those immune-supporting nutrients into your daily menu, oysters cannot prevent the coronavirus.

"A diet rich in healthy food can certainly keep your body prepared for a potential infection, there is no replacement for proper hand-washing, physical distancing and following other CDC public health guidelines," Upton says.

The best Rx for your immune system: Eat a well-balanced plant-based diet rich in fruits and veggies, exercise , get enough sleep, don't drink too much alcohol and try not to stress too much. (But if you want to try out some tasty oyster recipes, we've got those too!)