Raw versus Cooked Fruit and Vegetables
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By chef Nancy Berkoff, EdD, RD
It’s often interesting to talk about “what’s better for you: cooked or raw fruits and vegetables?” The answer, which has been debated since, well, people have been cooking, is generally “it depends.”
Our blog column is too short to get into details about raw versus cooked philosophies. We’ll try to have a fast, “food for thought” column, rather than attempting to get into the very fine points. Several generalities on this topic could be:
- Prepare fruits and vegetables the way you enjoy them, so you will be willing consume them on a regular basis!
- Over processing (boiling for extended periods of time, for example) is rarely a positive for fruit and vegetable enjoyment or for nutrient value; Overcooked Brussel sprouts never won any flavor or vitamin awards.
- Nutrition is not meant to be an “always or never” routine. Fresh spinach salad one day, steamed garlic spinach the next day… each menu item offers some type of and level of nutrition. “Cooking” may mean up to only 118 degrees for some and roasting over a wood fire for others; raw may mean plucked from the tree and eaten or microwaved for thirty seconds and cooled; each technique provides some level of nutrition.
Way back when, there may have not been a great deal of choice whether fruits and vegetables were cooked or processed, or not. If you lived in an area that had year-round crops, you could have some guarantee that fruits and vegetables would be available throughout the year, no processing needed. If you lived in a limited-growing climate, then fruits and vegetables needed to be cooked or processed to ensure a steady food supply.
If we listen to food technologists, we understand that the way fruits and vegetables are cooked or warmed does make a difference in nutrient availability and absorption. Some nutrients will be better absorbed if veggies or fruit are prepared or eaten with a small amount of healthy fat. The fat soluble vitamins, A, D, E, and K, and nutrients found in plants, especially beta-carotene, lycopene, and carotenoids, are better absorbed when a bit of fat is included. So, for example, vegetables or fruit in a salad, served with a small amount of dressing, avocado, or nuts can help with absorption of fat-soluble nutrients. As a rule of thumb, we are speaking about a teaspoon or so of fat per serving. Larger amounts of fat don’t improve the amount of absorption.
Heat breaks down cell walls, releasing nutrients. For example, cooked or heat processed (sun-drying would be one technique) tomato products tend to have higher levels of available lycopene than raw tomatoes. Vegetables like carrots, sweet potatoes, spinach, broccoli, mushrooms, zucchini, asparagus, cabbage, and peppers supply more carotenoids or flavonoids to the body when cooked or warmed than when eaten raw. Oxalates and phytates are substances found in many fruits and vegetables, and can impede the ability to absorb calcium and iron. Light cooking or heating helps to break down these substances, allowing the body to absorb more calcium and iron.
Water soluble vitamins, Vitamin C and all the B vitamins (B6, B12, folic acid, thiamin, riboflavin, niacin, etc.) are heat sensitive. Fruits and vegetables eaten for these vitamins may supply more nutrients if consumed raw. Broccoli and cauliflower, chard, peppers, beets, and radishes contain nutrients that may “leech out” if exposed to a lot of cooking liquid or prolonged heat. If it is desirable to cook these fruits or vegetables, try to use the cooking water (which may contain some of the nutrients lost from the cooked vegetables). Soups, vegetables stews or borscht are ways to obtain water soluble vitamins, as is using the cooking water to prepare rice, grains, pasta or beans.
Both mushrooms and spinach benefit from gentle cooking or heating to release nutrients. The B vitamins found in mushrooms, and the calcium and Vitamin K found in spinach are better absorbed when these veggies are quickly blanched or sautéed.
Of course, this information needs to be considered in the context of regular intake. A menu plan that contains a variety of fruits and vegetables on a regular basis should contribute to health. Varying preparation techniques are helpful, as well… a spinach salad one day, vegan creamed spinach the next day. If fruits and vegetables are more of an “I should really do this” with small portions on an occasional basis, rather than “I really look forward to this” with multiple portions throughout the week, than, hopefully, the maximizing of nutrients will be a consideration.
