Raw or Cooked Vegetables? Which is better?
The other day I asked the question: “What is better to consume; raw or cooked vegetables?” I had an excellent voter turnout and wasn’t surprised when most people voted raw - I too, used to think that! The correct answer might surprise you.
There is no right or wrong way to eat, there is only the way that is best for YOU. Eating more vegetables will overall have a beneficial impact on your health, regardless of the nitty gritty details on whether they are cooked or not. I myself, eat a combination of raw and cooked depending on how I feel and the time of year. This post will simply breakdown the science on what we know about the pros and cons of raw and cooked vegetables.
Raw Vegetable Pros & Cons:
The proposed befits of eating raw vegetables include that their enzymes are not degraded and some antioxidants (like vitamin C) which are sensitive to being oxidized by heat, remain intact. This is true, as I mentioned on my post about topical vitamin C (read here), heat and air-exposure can begin degrading vitamin C. I was surprised however, to learn that one study only showed a 30% decrease of vitamin C in tomatoes when cooked.
The downside to eating raw veggies is that they require more mechanical breakdown in your mouth (i.e. more chewing) and undergo more fermentation by the microbiome in your digestive system as the bacteria that live there must work at breaking open the tough plant cell walls to access the nutrients. If you have digestive system imbalances, you likely already know the negative digestive symptoms that occur when you eat raw vegetables. This isn’t a problem for everyone, but for some people it can cause a great deal of discomfort.
Another con to raw plant consumption is that all plants contain anti-nutrients or defence chemicals (like phytates, lignins , oxalates and tannins) that impair digestion! As a way to survive in nature, raw plants produce these chemicals to protect themselves from being eaten by predators. What do these plant defence chemicals do?
Let’s take phytates as an example. This defence chemical can bind up minerals like iron, calcium , zinc and magnesium - making them unavailable to humans when they are consumed! Unlike certain animals, humans do not have the enzyme “phytase” that would enable us to breakdown phytate from plant foods. The process of cooking, sprouting or fermenting vegetables can help release the important minerals that these plants contain.
Let’s take oxalates as another example.Ever notice you get a gritty feeling on your teeth from eating raw spinach? This occurs because the oxalic acid (plant defence chemical) in spinach combines with calcium in your saliva to form oxalate crystals that don’t dissolve in water. The non-heme iron that is found in spinach is also LESS bioavailable when spinach is eaten raw! Cooking spinach enables the iron to be released when you eat it and studies show that it can lower the oxalate content by 87%.
Cooked Vegetable Pros & Cons:
The biggest benefits to eating cooked veggies is that some antioxidants actually INCREASE through the cooking process! Carotenoids like lutein, beta-carotene, lycopene and zeaxanthin are key antioxidants for the body and are potentized when cooked! Tomatoes, cabbage, cauliflower, carrots and broccoli have a dramatic increase in carotenoid bioavailability after cooking! One study showed that the lycopene content (i.e. an antioxidant that’s great for eye and prostate health) was 1.3X higher after 2 minutes of cooking and was 1.6X higher after 30 minutes of cooking. Another study looked at cooking potatoes and found that up to 97% of the antioxidant potential was retained! As mentioned previously, cooking inactivates the anti-nutrients and increases some nutrient bioavailability. The downside is that cooking can decrease certain antioxidants like Vitamin C, but on the flip side can increase other antioxidants like lycopene.
From a Chinese medicine perspective, cooking foods is warming to the digestive system and can alleviate the work your body has to do when eating raw vegetables since cooked vegetables are already somewhat broken down. From an immune, fertility and pregnancy perspective, warming foods are supportive of the perinatal timeframe whereas raw (or cooling) foods can lead to stagnation. You can retain some of the water-soluble vitamins from vegetables by consuming the broth or stew that they are cooked in.
I am just scratching the surface here, there were so many articles on this topic when I took a look at the research. The main take-home message is that eating a variety of vegetables, cooked or raw, will have some benefits on either side of the debate. If you are suffering with chronic health problems including digestive issues, joint pain, allergies or other immune related concerns, talk to your ND to help figure out what foods might be at play.
PMID: 22744944 PMID: 15826055