Breaking Down Nutrition: Part 2
November 08, 2012This is where we will get a little more technical about the building blocks that make up nutrition. Each type of nutrient is important for distinct reasons. All can also be found in plant-based food.
Protein
Proteins are made up of chains of amino acids. Amino acids are compounds containing carbon, hydrogen, oxygen, and nitrogen that combine together to create the unique structures of different proteins. There are essential and nonessential amino acids. Nonessential amino acids can be synthesized in our bodies while essential amino acids can only come from the food we eat.
Proteins are necessary for proper growth, maintenance, and repair of our cells. Protein is highly important to healthy muscle and organ cells, goes into hair and nails, and makes up vital enzymes and hormones our body uses to guide digestion, metabolism, oxygen transport, and other processes.
Most plant foods are considered incomplete proteins, meaning they do not contain high amounts of all the essential amino acids. This is often the biggest argument against eating an all plant-based diet, but it is also a flawed argument. Most vegetables contain some of the essential amino acids and many contain high amounts of protein, but may be deficient in a couple amino acids. Each plant has a different mix of strengths and weaknesses. This means the problem of not getting enough of each essential amino acid is easily overcome by eating a variety of plant foods throughout the day. Different proteins do not need to be paired at each meal. The body doesn’t store amino acids, but they remain long enough to be combined with new amino acids that are introduced at a later meal.
Animal protein is considered a complete protein, containing all essential amino acids, but also comes with elevated levels of fat, cholesterol, and cellular damaging free radicals. Our protein requirements also aren’t nearly as high as most of us think. Even those who exercise regularly don’t need much extra protein to repair muscles. Too much protein can also stress the liver and kidneys, lead to weight gain as fat, cause intestinal irritation, and lead to dehydration. Eating too much animal protein can also raise risks of heart disease as you’re also eating more fat and cholesterol.
Carbohydrates
Carbohydrates are molecules made up of carbon, oxygen, and hydrogen that serve as food stores, fuel, and metabolic intermediaries. They are also used for structure by plants and bacteria, going into cell membranes and walls. Carbohydrates are also referred to as saccharides.
Monosaccharides are the smallest type of carbohydrate, often called simple sugars. Glucose, galactose, and fructose are examples of monosaccharides. Glucose is a major source of energy in human cells. When we talk about blood sugar, we refer to glucose.
Disaccharides are two monosaccharide molecules bonded together. Common forms of disaccharides are lactose, maltose, and sucrose.
Polysaccharides, or complex sugars, are two or more mono-saccharides bonded together in a chain. These chains can be branched like a tree or unbranched. Polysaccharides serve as storage, like starch and glycogen, or as structure, like cellulose and chitin. Some polysaccharides are digested and used by the body and some are not digested; a lot of dietary fiber is made of carbohydrates, but cannot be broken down and used by humans. Fiber is then classified as soluble, dissolvable in water, or insoluble. Neither one supplies any nutrition, but fiber has beneficial effects on the digestive system, controls sugar absorption, and helps remove cholesterol and other fats.
Carbohydrates are the main fuel of most living organisms and the only fuel our brains can use. Neurons cannot burn fat, so they rely on a constant stream of carbohydrates in the form of glucose.
Fats
Lipids are used as energy storage, structure for cellular membranes, and as signaling molecules. Cell membranes in humans are made up of lipids and proteins, with lipids providing between 20% or 80% of the composition of these membranes, depending on type of cell and location. The brain holds high amounts of lipids, as neuron membranes require more of these important signaling compounds.
Fats have gotten a bad name over the years. Some are harmful. Saturated fat is saturated with hydrogen and comes mainly from animal foods. Trans fat also comes from animal food, but is mainly man-made by forcing hydrogen into oils to make them more like saturated fats. Both these fats can raise bad cholesterol and lower good cholesterol, contributing to heart disease.
But some fats are essential to proper health and function. Monounsaturated and polyunsaturated oils are healthy oils found mainly in vegetable sources. These include omega fatty acids that are vital to brain and heart health and maintaining normal cholesterol levels. These good fats are found in olive oil, seeds, nuts, and avocados. Good fats also help us absorb and use some vitamins that are fat soluble, like vitamin K.
Vitamins and Minerals
Vitamins are organic substances made by plants and animals your body needs in small amounts to grow, develop, and function properly. We get vitamins from food, because our bodies either do not make enough of our own or because we make none at all.
Vitamins fall into two categories, fat soluble and water soluble. The fat soluble vitamins, A, D, E, and K, dissolve in lipids and can be stored within these fats in the body. Water soluble vitamins, C and B complex, must be dissolved in water to be absorbed and cannot be stored by the body. Since these water soluble vitamins cannot be stored, any that is not absorbed is lost.
Minerals are inorganic substances absorbed from water and soil by plants that our bodies require for optimal health and are crucial in many metabolic functions. Minerals are used as part of enzymes, as structure in our bones, as oxygen transporters in our blood stream, and to balance the fluid levels of cells and tissues.
Some major minerals are required in relatively large amounts. Major minerals include calcium, magnesium, sodium, chloride, potassium, magnesium, and sulfur. These minerals are also called macro-minerals.
Other minerals are needed only in trace amounts. These trace minerals, or micro-minerals, include chromium, cobalt, copper, manganese, molybdenum, nickel, selenium, silicon, and zinc.
Even a modest deficiency in certain vitamins and minerals can have severe consequences. It’s important to eat foods rich in these vitamins and minerals. Processed foods have often been stripped of these valuable nutrients. Plant-based foods offer abundant vitamins and minerals.
Antioxidants
Antioxidants can be vitamins like C, A, and E; minerals like selenium; enzymes; or other molecules and compounds that provide plants with protection, flavor, and color. Fruits and vegetables are the best source of powerful age fighting antioxidants. Brightly colored ones like carrots, berries, tomatoes, and dark greens are even more likely to have plentiful antioxidants.
Water
Water, as most of us know, is composed of hydrogen and oxygen. Water makes up most of the human body and has unique properties that have made life possible. It dissolves nutrients and helps carry them through our systems. As a solution, it facilitates the electrochemical needs of our brains. It keeps our cells from collapsing and ceasing to function. Water is necessary for us to breakdown and use food stores.
Fresh, clean water is essential to health. The water content of fruits and vegetables makes them more filling while keeping the calories low, whereas processed food is denser, packing high calories and removing water content. Water should be a part of any healthy lifestyle. Sugary drinks and soda do not count. Many sodas actually dehydrate the body and the concentrated sugars are not healthy.
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