Arctic Sunday Social
INSPIRE & ENJOY
Raw or Not Raw?
To cook or not to cook? This week at Arctic Social we investigate the super hot topic of going RAW or not. I.e. there’s a big crowd out there these days that swear on going raw being best…but is this right? And if so, why?
Eating your fruit and vegetables raw is indeed sometimes the healthier option. After all, some vitamins are sensitive to heat; for example, cooking tomatoes for just two minutes decreases their vitamin C content by 10%. However, whilst there might be a decrease in vitamin C, cooking tomatoes helps break down the plant cell walls, allowing us to better absorb the antioxidant lycopene. Equally, cooking some other vegetables makes it easier for our bodies to benefit from their protective antioxidants, specifically ferulic acid from asparagus, and beta-carotene, which we convert to vitamin A, from carrots.
Eating raw or lightly cooked foods requires more energy to chew and digest, while ingesting cold foods uses calories to warm the food and us up. But there’s more to it than that. Cooking food helps us ingest more calories, too.
The calorific value of cooked vs. raw foods is the subject of ongoing work by the evolutionary biology department at Harvard University. A paper published recently in the American Journal of Physical Anthropology, for instance, details new evidence that fats in foods yield more calories when cooked. They have also found that cooking makes more energy available to us in starch and protein.
Some vegetables that many experts believe are better raw include broccoli and watercress (both members of the cruciferous family). When these vegetables 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.
On the flipside, some items are indigestible when raw…in particular some starches. Nowadays starch is most commonly associated with items that we generally don’t consider eating raw, such as rice or wheat flour. But it is also present in plenty of salad ingredients. Peas, for instance, are delicious raw – so on the starch front we have to pick and choose.
Starch is made up of long chains of glucose that we can’t metabolise, but cooking reorganises the structure, as it swells with water in a process known as gelatinisation. Once gelatinised, says Carmody (part of the Harvard research team), “our enzymes – primarily salivary amylase in our saliva and pancreatic amylase in our small intestine – can then attack the glucose”. Different types of starch will provide varying amounts of calories when cooked. “In the research that we’ve done,” says Carmody, “it looks like you’ll get anywhere between 20 to 40% more calories based on cooking.”
In terms of protein power, (something we love so much at Arctic that we named one of our juices such), cooking untangles the protein, allowing digestive enzymes to cut into them and break them down. This process is called denaturation, and breaks down the protein into a form that allows it to be absorbed in the small intestine. According to findings, cooked protein provides around 10 to 20% more energy than raw.
One might expect that, relative to other activities, digesting cooked foods as opposed to raw can’t amount to saving that much energy. However, as a guideline, Carmody points out that, “typically in western society, we spend about 15% of our total energy budget digesting food, which is about the same as what we spend in locomotion – walking around, running, all the activities that we do.” So eating raw rather than cooked food, she says, is comparable to having gone for that jog!
When we analyze the pro/con raw debate it seems that the jury is still out on a definitive answer. There’s no doubt that there are some benefits of going raw, but equally with the very same food, there might be some advantages with gentle cooking. It seems we need to pick and choose what we eat ‘raw’ carefully in order to maximize the benefits. Comparing the healthfulness of raw and cooked food is complicated, and there are still many mysteries surrounding how the different molecules in plants interact with the human body. Whatever side of the argument you come down on, one thing most agree on is balance is key, and generally the more green the better!