Which Is Better – Cooked Or Raw Vegetables?
The debate over which is better for your health – cooked or raw vegetables – has been ongoing for years. As a registered dietitian and certified diabetes educator, I have heard many folks argue that raw vegetables are the way to go as they contain more nutrients, while others contend that cooked vegetables can be just as beneficial. To help you make an informed decision about your diet, let’s take a look at some of the recent research on this topic.
It’s important to note that eating vegetables in either form is always better than not eating them at all. Many vegetables are packed full of vitamins, minerals, antioxidants and dietary fibre, which are important for optimal health. In fact, vegetables and fruits can help lower your risk of chronic conditions like heart disease, certain types of cancers and type 2 diabetes.
And it isn’t only “prevention of disease” that matters.
Because vegetables are full of dietary fibre, they help slow down the absorption of carbohydrates. This is particularly important to keep blood sugar levels stable for type 2 diabetes management.
Plus, the vitamins, minerals, antioxidants and phytonutrients (plant compounds that help combat diseases) found in vegetables help to fight inflammation and promote heart health.
Wondering how much you should be eating? Well, studies have shown that eating 800 grams of fruit and vegetables per day (roughly five servings) offers the most protection against cardiovascular diseases. Furthermore, consuming high levels of fruits and vegetables has been linked with better mental health outcomes like increased optimism, self-efficacy and fewer depressive episodes.
Pros of eating raw vegetables
One of the main benefits of eating raw vegetables is that they retain more water-soluble nutrients than their cooked counterparts. This includes vitamins like C and B, which are essential for good health. Additionally, these vitamins are more bioavailable in their raw form, meaning they are easier for your body to absorb and use.
A review found that people who ate raw and cooked vegetables had a lower risk of developing cancer, particularly those of the upper digestive system and possibly breast cancer. However, these relationships might be more robust for raw vegetables vs cooked vegetables.
The case for raw vegetables is also supported by a survey-based study where eating raw vegetables improved mental health outcomes, including a reduced risk of depression and a higher positive mood.
Keep in mind: Studies, where participants are asked to self-report their food intake and lifestyle habits, aren’t always reliable or accurate. Additionally, the study size of many of these studies is small and may not provide compelling evidence about the benefits of eating raw vegetables. However, they offer some insight into the potential advantages of raw vegetables.
Analysis of data from the UK Biobank cohort, which comprised 399,586 participants – free of any prior cardiovascular diseases – and following them up for 12 years, it was found that higher intakes of raw vegetables (not cooked veggies) were tied to lower cardiovascular disease risk.
However, once we account for socioeconomic and lifestyle factors, the value of raw vegetables decreases significantly. Thus, there’s still some confounding present that likely explains these associations.
Which vegetables are best eaten raw?
Some vegetables are better eaten raw than others. For example, cruciferous vegetables such as kale, broccoli, and cabbage are packed full of vitamins B and C.
Cooking, like steaming, boiling, frying or roasting, can destroy some of the nutrients in these vegetables.
Also, vegetables, like bell peppers and leafy greens, tend to be most vulnerable to the heating process. It seems that the simplest way to offset these nutrient losses is to consume foods rich in vitamin C and B in a raw state (such as in a healthy easy salad recipe) or cook your veggies for only a short amount of time (quickly steaming or blanching them for example).
Pros of eating cooked vegetables
Cooking certain orange and red “beta-carotene rich” veggies (e.g. tomatoes, carrots, and sweet potatoes) can help make pre-vitamin A compound – more absorbable. For example, making tomato sauce, sweet potato wedges or enjoying carrot halwa can help make the nutrients in these vegetables more available to your body.
Did you know that when carrots are stir-fried instead of being eaten raw, the absorption of beta-carotene increases by 6.5 times? And if you consume your fat-soluble vitamins with a healthy cooking oil (like olive oil), you’ll absorb even more of them! We love this vegetable noodle recipe, which is an excellent example of how to get the most out of your carrots through cooking.
For some folks, cooking vegetables is the only way to make them palatable, especially for those with digestive issues. Cooking also offers a vehicle to change the texture of the food and make it easier to chew and digest. It enables the use of other flavours in the process and might be preferred in some cultures.
Do veggies lose nutrients when cooked?
Healthy ways of cooking vegetables can help preserve their nutritional value.
Research has also shown that cooking broccoli (steaming or microwaving and not boiling) can actually preserve and enhance its antioxidant levels.
However, keep in mind that boiling vegetables that contain water-soluble vitamins, like Vitamins B and C, can leach these nutrients out of the veggies. In fact, the retention of vitamin C ranges from 0 to 91% for cooked vegetables like:
- Sweet potato
- Crown daisy
- Perilla leaf
Generally speaking, microwaving retains more vitamin C than boiling, and shorter cooking times are best.
What about other types of vitamins?
Interestingly, the same research (cited above) found that cooked vegetables are higher in fat-soluble vitamins (such as vitamin A and vitamin E) than raw vegetables. But it really depends on the type of vegetable.
For example, microwave cooking seemed to cause the most significant loss of vitamin K among crown daisy and mallow; however, a minor loss of vitamin K was observed in spinach and chard.
It’s an interesting story with spinach. On the one hand, cooking spinach (for one minute) boosts its antioxidant and vitamin K content, and on the other, vitamin C losses in spinach increase when exposed to even short cooking times.
In a nutshell, it’s not a simple answer. Because it depends on the nutrient you’re looking at, the cooking method you choose, and the specific vegetable in question.
What’s more, cooking can help reduce the levels of goitrogen compounds found in cruciferous vegetables like broccoli and cauliflower, which may interfere with thyroid function if consumed in excess. And let’s not forget these goitrogen compounds are mostly deactivated by heat and cooking.
However, the amount you would need to eat to have such an impact – is pretty significant – more substantial than most of us would ever normally eat.
Food for thought
Eating various raw and cooked types is the best way to get the most out of your vegetables. Each cooking method brings changes in nutrient content that can have an impact on their health benefits.
What are your favourite ways to enjoy vegetables? Share in the comments below!