We know that cooking is crucial to our diets and something that humans adopted more than 250,000 years ago. It helps us digest and soften the food that our teeth and digestive systems aren’t quite equipped to deal with. And while we might hear from raw ‘foodies’ that cooking kills vital vitamins and minerals (and potentially alters the nature of enzymes that aid our digestion), the flip side to that coin is that raw vegetables are not always the best. So what’s the answer? how should you be eating your veggies? Is it raw or cooked? How do we get the most out of our vegetables that benefit optimal nutritional health?
A leading US nutritional scientist Dr Michael Greger, MD, explains: “It’s not what you eat, it’s what you absorb.” Because here’s the thing; whilst some nutrients may be lost in the cooking process, others become more available for your body to use.
Reasons to eat cooked;
There are numerous vegetables and fruits that contain calcium, for example – some more than others, but cooking vegetables usually always increases the amount of calcium available in the vegetable for the body to absorb, and this difference can be huge. For example, cooked spinach has 245 mg/cup of calcium, while raw spinach only has 30mg/cup!
A study published in The British Journal of Nutrition last year found that a group of 198 subjects who followed a strict raw food diet had normal levels of vitamin A, but high levels of beta-carotene which plays an important role in vision, reproduction, bone growth and regulating the immune system.
However, the same subjects also presented low levels of the antioxidant lycopene. Lycopene is the red pigment found predominantly in tomatoes and other rouge fruit and veg such as red pepper, beets, red cabbage, guava, watermelon etc. Several studies show that a high intake of lycopene lowers the risk of cancer and heart attacks. Rui Hai Liu, an associate professor of food science at Cornell University who has researched lycopene, says that it may be an even more potent antioxidant than vitamin C! He found that cooking actually boosts the amount of lycopene in tomatoes by as much as 35%.
The cooking process also aids the body’s uptake of some nutrients that are bound by cell walls. Steamed carrots, spinach, mushrooms, asparagus, cabbage, peppers and many other vegetables also supply more antioxidants, such as carotenoids and ferulic acid, to the body than they do when raw.
Research has shown that steaming your vegetables yields a higher rate of vitamins and minerals than boiling does as this is where a lot of the good stuff gets lost! – although, that said if you were to re-use the water to cook your rice or pasta then you can probably gain some of the lost nutrients back.
Cooking vegetables not only taste better for the most part but it also helps with our ability to chew, digest and improve the overall energy of foods. Plus, there is some evidence out there to suggest that the evolution of cooking our food has a direct correlation with the evolution of the human brain due to its calorific yield!
Reasons to eat raw;
To be considered raw, food can’t reach above 40-49ºc when heated and contains no less than 70% of food that hasn’t been cooked or processed. People eating a raw food diet consume a lot of fresh, fruits, vegetables, nuts, seeds, and sprouted grains and legumes.
Many people advocate going raw to cure certain types of auto-immune diseases and cancers, but one major benefit to going raw is that you’re essentially eliminating all known processed foods. So for those who are watching their weight, this is ideal. it’s well documented too that eating a phytonutrient rich diet has been scientifically proven to reduce the risk of certain chronic diseases, such as heart disease, stroke, cancer, and auto-immune disease. Many of these beneficial compounds can be destroyed by the cooking process. Cooking vegetables also raises the acidity levels which is an environment cancerous cells thrive in. Eating raw vegetables may also help boost mental health and relieve symptoms of depression.
Vitamin C for example, is easily degraded through exposure to heat (oxidation) and through cooking in water (dissolved), and as much as 55% of Vitamin C in vegetables is lost during the cooking process.
Some foods eaten raw can be considered super foods for their nutritional punch. Polyphenols for example, are a group of chemicals found in raw carrots. Specific polyphenols have been shown to have antioxidant properties and to reduce the risk of cardiovascular disease and cancer. Research too shows that some veggies, including broccoli, contain three times the amount of the cancer-fighting compounds called ‘sulforaphanes’. Onions contain ‘antiplatelet’ agents which protect against heart disease. Raw garlic is an anti-carcinogenic.
There is argument too, that cooking vegetables eliminates vital enzymes known for their digestive and health benefits, and for the most part this is true. However, if we are eating a healthy whole food plant based diet, our bodies should be well equiped to making these enzymes anyway.
It’s well established that people who generally eat more vegetables and fruits are less likely to suffer from chronic diseases. So whichever way you prepare them in order to consume more, do whatever feels right for you; listen to your body. Ultimately raw food is not a long term game. Yes, in the short term, it can be quite remarkable with amazing results for sick people, but there are studies that show that the long term side effects of a raw food diet can potentially lead to nutritional deficiencies.
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. The bottom line is to eat your veggies and fruits no matter how they’re prepared. The consensus among most nutrition experts is that you need both raw and cooked veggies to get the most vitamins and minerals.
For your health & wellness
Dr Martyn Williamson