Raw versus cooked food
There are different opinions on whether our vegetables and fruit are best for us eaten raw or cooked. It seems to me both options have things in their favour.
Some vitamins are sensitive to heat, for example, cooking tomatoes for just two minutes decreases their vitamin C content by 10%. However when you cook tomatoes – whether you roast them slowly or make a cooked sauce – it helps to break down the plant cell walls, allowing us to better absorb the antioxidant lycopene.
A study published in The British Journal of Nutrition found that a group of 198 subjects who followed a strict raw food diet had normal levels of vitamin A and relatively high levels of beta-carotene (an antioxidant found in dark green and yellow fruits and vegetables), but low levels of the antioxidant lycopene.
So while cooking may cause the loss of some valuable nutrients, like vitamin C, there are some vegetables which offer useful health benefits when they’re cooked. Steaming or boiling asparagus, cabbage, carrots, mushrooms, peppers, and spinach, among other vegetables, supplies more antioxidants like beta-carotene, which we convert to vitamin A, from carrots and ferulic acid from asparagus to the body than they would raw. All these nutrients help to safeguard our cells from environmental damage, are heart friendly and may protect us from certain cancers.
Some vegetables certainly benefit from being eaten raw including broccoli and watercress. When these veg are heated an important enzyme is damaged, which means the potency of helpful anti-cancer compounds called glucosinolates, are reduced. Similarly, cooking makes the herb garlic less potent because heat reduces the amount of health-promoting allicin so it’s best to add your garlic just before you finish cooking rather than at the start.
Cooking is important to our diets as it helps us digest food without expending huge amounts of energy. It softens food that our small teeth, weak jaws and digestive systems aren’t equipped to handle. We might hear that cooking kills vitamins and minerals in food as some nutrients are sensitive to heat there are others, like the fat-soluble vitamins A, D, E and K which are unaffected by heat, but whether you choose to eat your fruit and vegetables raw or cooked you should still try to get the most out of them.
Only prepare your fruit or veg just before you need them.
You will increase your absorption of fat-soluble vitamins by eating your veggies with a little oil, a spinach salad with vinaigrette dressing, roast vine tomatoes with a drizzle of olive oil or quickly stir-fry spring greens.
Choose cooking methods which use the minimal amount of water or preferably no water at all, like roasting to avoid losing water soluble vitamins like the B group and vitamin C.
Don’t forget frozen vegetables and fruit are not to be sneered at because they are frozen quickly after picking which means they retain more nutrients than some supposedly ‘fresh’ produce.
Store fruits like tomatoes at room temperature rather than in the fridge – this optimises the ripening process and increases levels of valuable lycopene.
Buy local produce as some vitamins are lost during transportation and storage.
But the important thing to realise is balance. Balancing raw foods with cooked foods is the best strategy as far as diets are concerned. Choose the middle of the two extremes ? don’t eat just raw foods and don’t eat just cooked foods — eat them both in equal harmony whenever possible. And remember for those watching their weight, eating some fruit and veg raw can help fill you up because raw fruit and veg tend to be bulkier and have a higher water content.