This article originally appeared on VICE Italy.

If I had a penny for every time a star chef has bragged about basing their cuisine on seasonal ingredients, I could afford to eat at their fancy restaurants. Over the past few years, sustainability has become the mantra of many high-end restaurants. Gone are the days of imported Maine lobsters or foie gras – it’s now all about local and seasonal food.

This shift has obvious positive effects on the environment. Out-of-season fruits and veggies are grown intensively in greenhouses which require more water and electrical resources. They’re also often transported over long distances, resulting in a higher carbon footprint. Ironically, foods touted as natural “superfoods” – like avocados, nuts and bananas – can be some of the worst offenders.

But Eleonora Lano, dietician and coordinator of the Food and Health project from Slow Food International, an NGO protecting traditional food cultures, said seasonal products are also good for us. “Nature offers the right nutrients when we need them,” Lano said. “For example, in winter we need vitamin C, which is found in oranges, kiwis, the cruciferous family [featuring broccoli and Brussels sprouts].” Similarly, in summer, our skin and eyes are under more stress from the sun, and seasonal foods rich in beta-carotene – like apricots, melons and tomatoes – can help protect us from sun damage.

Lano explained that consuming fruits and veggies grown locally also optimises their nutritional value. “I like to say the countdown starts at the moment we remove the fruit from the tree,” Lano said. “Especially with fruit, many nutritional properties are lost during transport – for example, some vitamins are destroyed with changes in temperature.”

This is why Lano strongly disagrees with the concept of superfoods, a label often slapped onto exotic ingredients, along with a list of miraculous properties unsupported by scientific evidence. “Most of them have a devastating environmental impact, not just because of how they are transported, but also grown,” she said. Avocados, for instance, are devoured by the health-conscious, but have a heavy carbon footprint because they require lots of resources to grow and be transported. They have also been linked to deforestation.

“Eating local can easily cover all your nutritional needs,” Lano said. “A healthy diet is the result of everything we eat – you don’t need a single miracle food to feel good.” Additionally, since most superfoods come from halfway across the globe, they are usually harvested when they’re unripe, before they can develop the properties people buy them for.

“We are so used to eating everything all year round that we forget fish has its own seasons, too,” said Paula Barbeito Morandeira, coordinator of the Slow Fish campaign at the Slow Food Foundation for Biodiversity. Fish seasons depend on the species’ reproductive cycles and should be respected to ensure the sustainable renewal of fish stocks, she explained. 

As well as checking whether the fish you’re buying is in season, you should also pay attention to its origin. “The key questions are: who caught it, where and how,” said Barbeito Morandeira. “If you’re buying it at the supermarket, you should always read the label, or ask the fishmonger directly.”

Sometimes, the packaging does not explicitly state where the fishing has taken place, but it should always have a two-number digit representing an FAO fishing area, a section of the sea defined by the UN Food and Agriculture Organisation. For example, 37 stands for the Mediterranean, 27 for the Northeastern Atlantic Ocean.

Buying local fish also supports traditional fishing communities which have been struggling for years. “They’re often absorbed into industrial markets and forced to sell their catch at unfair prices,” said Barbeito Morandeira. Fishing at an industrial scale is particularly dangerous for impoverished communities in the developing world. As reported by Greenpeace, large fleets from Chinese, Turkish, Russian, Korean and European companies have been overfishing in West African waters for decades, depleting local fish stock and threatening the food security and livelihoods of millions.

“We are allowing entire coastal communities to disappear,” said Barbeito Morandeira. “Fishing policies should be based on the needs of ecosystems and communities, but they are not. The fish supply chain is a complex system unfortunately plagued by widespread illegality.”

Overfishing is a huge environmental issue that’s recently received a fair deal of attention, but farming fish is often problematic too, said Barbeito Morandeira. For instance, salmon is one of the most popular fish varieties in the world, but it takes about 5kg of wild fish in feed to produce 1kg of wild salmon. Diversifying our fish consumption by eating seafood that can be grown with little resources – like mussels, for instance – could prevent millions of wild fish from being taken from the sea.

“The food choices we make have a hidden side,” Lano said. “We don’t often think about it, but we’ll pay for it one day, with interest.”