Does how you cook your veggies change how good they are for you?
Melissa Shedden explores the best way to prep your veggies for ultimate nutritional benefit.
Alongside drink water and sleep eight hours, eat more vegetables is solid health advice.
That’s because a diet high in vegetables has been linked to a heap of healthy outcomes, like lowering blood pressure, reducing the risk of heart disease and stroke, preventing some types of cancer, lowering the risk of eye and digestive problems, and having a positive effect on blood sugar, which can help regulate your appetite, reports the Harvard School of Public Health.
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But if you choose to eat them slow cooked versus steamed, fried versus fresh, does it change their nutritional content? Look, does waking up next to Chris Hemsworth versus Luke Hemsworth change things? The answer is kinda, sorta, yep.
We enlisted MasterChef alum, foodie and vegetable lover Sara Oteri, to give us the lowdown on cooking techniques. The passionate home cook, who describes her cooking style as “spontaneous, relaxed, health focused and always delicious” has partnered with Electrolux for a yummo recipe and tips series.
Like rain is to a fresh spray tan, water is to vegetables when it comes to cooking. Water-soluble nutrients, like vitamin C, B vitamins or folate, can leach out of veggies when cooked in water they’re submerged in. That’s when you see the water change colour to green or orange when cooking carrots or broccoli.
For example, according to a review by researchers at the University of California Davis as much as 55 per cent of the vitamin C in vegetables is lost during home cooking (compared with raw). Sara suggests steaming instead to keep the good stuff where you want it.
“Unless you intend on drinking the water too, those vitamins will go down the sink! Steaming however is a far gentler way to cook veggies and retains their nutrients better. Don’t forget, steam is hotter than water, so you’ll often find that veggies cook quicker when steamed also. Winning!”
Look, no one cooking method will preserve 100 per cent of the nutrients and protective phytochemicals in vegetables. So don’t limit yourself to only making friends with salad. Studies actually show the cooking process breaks down tough cellular structure of many vegetables, making it easier for your body to absorb and digest their nutrients.
For example, one study published in the Journal of Nutrition found eating cooked spinach and carrots resulted in higher blood levels of the antioxidant beta carotene, which then converts to vitamin A. But considering only 7 per cent of Australian adults and 5 per cent of children eat the right amount of vegetables – for adults that’s five serves per day, you might want to eat them where you can get them.
“If that’s fresh from the fridge go for it,” says Sara.
Instead of grey green broccoli mush and sad carrot batons, steaming is actually a gentle and controlled way of cooking food, which lets you regulate the temperature and humidity levels, especially if using Sara’s favourite Electrolux steam oven.
“One of my all-time fave and deadly simple recipes is my Firecracker Cauliflower, and as the name suggests, it packs quite the punch. I use the Electrolux steam oven to perfectly cook the cauliflower all the way through, retaining its structure and sweetness. The hit of fiery sriracha, sweet cauliflower flesh and a refreshing coriander yoghurt are a big hit,” she says.
Let’s look to science for a minute. A 2018 study published in Food Science and Biotechnology found microwave cooking caused the least loss of vitamin K in spinach and chard. The researchers concluded: “Cooking may cause changes to the contents of vitamins, but it depends on vegetables and cooking processes.”
But Sara reckons the more easy cooking options you have, the more likely you are to eat veggies. And that’s the whole point. “The more vegetables you can eat, the better you’ll be,” she says.
If boiling your vegetables for too long messes with their nutrient makeup then surely slow cooking must annihilate the good stuff, right? Not the case, because most slow cooking recipes, like stews, casseroles, soups and curries don’t separate the ingredients from the sauce they’re cooked in, which is where all your vegetable vitamins and minerals will party.
Sara says the most sustainable ways to increasing vegetables at every meal is by making the dish vegetarian and then thinking about how to incorporate meat, versus the other way around. “So for example, ‘I’ll make a slow-cooked vegetarian Bolognese but use just 100g of pork mince which will flavour the sauce,’” she says.
Here’s the thing: Stir-frying is much better than deep-frying, but you already knew that. Sauteeing in a healthy cooking oil, like extra virgin olive oil not only maximises those Mediterranean flavours, but increases the absorption of phytonutrients like phenols and carotenes.
For example, a 2015 study linked lightly frying Med vegetables like eggplant, with increases in antioxidants that can protect against cancer. Sara’s favourite veggie to fry is artichokes. “There’s a particular way it’s done in Rome, however I like to use brined artichokes, cover in breadcrumbs, fry until golden and finish with pecorino cheese,” she says.
Dry cooking methods like grilling, roasting and baking retain a greater amount of nutrients than boiling. And if baking your sweet potato into chip form means you’ll eat more vegetables, than that’s a win, says Sara. “I find the most effective way to incorporate more vegetables into your life is to apply an 80/20 rule to your meals.
This means, cook dishes that use 80% vegetables and 20% meat,” she says, not the other way round. Plus, baking your favourite veg will not diminish its fibre content, which helps to promote and maintain a healthy gut.