Holiday side dishes are not only delicious but also nutritious. They are rich in micronutrients such as vitamins and minerals. Learn the importance of how to prepare these vegetables, such as using fat to promote absorption of fat-soluble vitamins, and the nutritional benefits of green and orange vegetables. Holiday side dishes like green beans and carrots are packed with essential micronutrients. Proper cooking methods, such as cooking with oil, can promote nutrient absorption and make these dishes delicious and nutritious.
Author: Julie Pollock, associate professor of chemistry at the University of Richmond.
When it comes to holiday meals, turkey or ham is often the first thing people think of, but the sides are key to balancing the plate. Colorful vegetables like green beans, lettuce, roasted carrots and mashed sweet potatoes are packed with important micronutrients. But how you prepare these side dishes will determine whether you get the most nutritional value from every bite this holiday season.
As a biochemist, I know that food is made up of many chemicals that are critical to the growth and function of the human body. These chemicals are called nutrients and can be divided into macronutrients (such as carbohydrates, fats, and proteins) and micronutrients (such as vitamins and minerals).
Vegetables are rich in micronutrients needed for the body's metabolism (or the conversion of food into energy) and the formation and maintenance of cells and tissues. These micronutrients can be divided into three categories: minerals, water-soluble vitamins, and fat-soluble vitamins.
The green vegetables on your table—lettuce, kale, spinach, green beans—are rich sources of magnesium and calcium. The body requires these two primary minerals for muscle movement and bone health.
Magnesium is required for many enzymes that play important roles in DNA synthesis and repair, protein production, and metabolic function. Cellular processes, especially accurate DNA synthesis, are important in protecting the body from diseases such as cancer. Calcium helps regulate the pH in the body, affects metabolism, and strengthens nerve impulses. Nerve impulses are important to the senses and memory.
Green vegetables are also a source of iron – you’re right, Popeye! Iron is particularly important for the oxygen-binding proteins hemoglobin and myoglobin that transport and store oxygen in the body. In addition, the body needs iron to help produce energy, protect against oxidative damage, and make hormones.
Orange vegetables--carrots, squash, sweet potatoes, and squash--contain some amounts of calcium and iron, as well as plenty of potassium. Potassium is important for muscle movement, nerve impulses, and maintaining low blood pressure. Although not a colorful vegetable, white potatoes also contain a lot of potassium.
Vitamin C is an important water-soluble vitamin because of its antioxidant effects. Antioxidants protect cells from certain types of damage caused by reactive molecules called free radicals.
In addition, vitamin C can also enhance immune response and is a necessary substance for the synthesis of collagen, the main protein of the skin. While consuming high amounts of vitamin C won't keep you from getting sick forever, healthy vitamin C will keep your skin soft, help you avoid illnesses like scurvy, and potentially shorten the duration of colds.
White potatoes on the table contain large amounts of vitamin B6, which is a component of enzymes necessary for the metabolism of carbohydrates, fats and proteins. It also helps make healthy blood cells and is important in the production of neurotransmitters like serotonin and dopamine, both of which regulate happiness and well-being.
One of the most important vitamins you get from green vegetables, especially leafy vegetables like kale, spinach, kale and Brussels sprouts, is vitamin K. Vitamin K is an important component of enzymes that make bone proteins and proteins that help blood clot after an injury.
Vitamin A is another important fat-soluble vitamin found in spinach and orange vegetables. The source of vitamin A in vegetables is actually beta carotene, which breaks down into two molecules of active vitamin A after consumption. Vitamin A is essential for vision, cell differentiation, reproduction, bone health and immune system function.
Eating vegetables that contain micronutrients is important, but equally important is the body's ability to absorb nutrients and deliver them to the cells where they are needed. Macronutrients such as carbohydrates, fats, and proteins are the main components of the food we eat, and they are efficiently absorbed into the bloodstream. However, only 3%-10% of micronutrients can actually enter the human body. Other ingredients and factors in food can affect the body's absorption of vitamins and minerals.
Side dishes made with colorful vegetables are a holiday staple for many. Therefore, when cooking vegetables, it is important to pay attention to improving the body's ability to absorb the vitamins and minerals it needs.
A good example of this is iron - specifically the iron found in the foods you eat. Heme iron is the form necessary for integration into the body, comes only from animal products, and is most easily absorbed by the body. The plant-based iron contained in green and orange vegetables is not bound to heme, so it is not easily absorbed by the body. Taking vitamin C along with vegetables can increase the absorption of non-heme iron. So, a squeeze of lemon or orange juice not only enhances the flavor of your vegetables, but also increases the micronutrients you get from them.
Fat-soluble vitamins, such as vitamin K and vitamin A, are best absorbed when the meal contains some dietary fat (which can be obtained from oils). This is especially important for vitamin K, since green vegetables are the main dietary source. In contrast, the other minerals and vitamins we discussed can also be obtained from animals or legumes because they already contain some amount of dietary fat.
After consumption, vitamin K must be packaged with other fats into micelles or lipoprotein structures in order to flow in the blood. This means that when cooking your vegetables, it's a good idea to add some fat - olive oil, avocado oil, butter, or even a little bacon grease.
So if you're staring at those Southern-style lettuce on your plate and wondering whether they're as healthy as eating the leafy greens raw, think about it biochemically. While raw green vegetables can provide you with plenty of fiber and minerals, they won't help boost your vitamin K levels like green vegetables cooked in oil.
Enjoy your time at the holiday table. Load your plate with whatever you like and make sure it's not completely fat-free to help your body process and utilize all the micronutrients.