Nutrition is about getting essential elements and compounds from our environment and transforming them into the metabolic building blocks of optimal health.
Nutritional status exists on a continuum from simply staying alive to optimal health. Humans can stay alive with a few dozen essential nutrients. Optimal health involves thousands of compounds, many lumped into the category of “phytonutrients”, where “phyto” refers to plants. Phytonutrients are often referred to in terms of their antioxidant properties, which play a key role in a whole host of metabolic processes. This is the central reason for the importance of a plant based diet in optimal health.
In the short term, oxygen is the most essential element. Without oxygen, we would die within minutes. Breathe! The most fundamental metabolic process is oxidation, coupled with reduction. Oxidation is the chemical process where atoms and molecules gain electrons, whereas reduction is the loss of electrons. This oxidation-reduction process is how energy is transferred to power the thousands of different chemical reactions in your body. Maintaining the balance of oxidation and reduction is the most fundamental metabolic balance in your body. This is why antioxidants (reductants) are so important and play a central role in overall nutrition and health.
Without water, we would die within days. Water is a miraculous molecule with unique physical and chemical characteristics which make human life possible. Water comprises the majority of our body weight (in a healthy body). Not surprisingly, hydration is important for our health. Drink up!
Provided we have oxygen and water, it is possible to live for months on foods of very poor nutritional quality, that provide mostly energy/calories. The caloric nutrients are carbohydrates (starches and sugars), fat, protein, and alcohol. Carbohydrates are the most easily converted to energy in the body, and produce water right along with their metabolism (that’s why they are called carbo-hydrates). Fats are the most energy dense of the caloric nutrients and the primary way we store energy over the long haul. Protein functions primarily as a building block for muscle and enzymes in the body, but excess protein is converted to energy or stored as fat. During caloric restriction, protein may be broken down for energy. Alcohol is calorie dense, may impair the metabolism of other nutrients, and can dehydrate the body. Fats have 9 calories per gram; carbohydrates and protein have 4 calories per gram; and alcohol has 7 calories per gram.
To survive over the years, your body requires vitamins and minerals. Most vitamins are essential enzymes that cannot be manufactured by the body, so you must get them from your diet. Most minerals are involved as cofactors of enzymes, hundreds of enzymes! Enzymes make complex chemical reactions work in your body. Think of enzymes as workers on an assembly line. You need many workers to work together to produce a complex product. With so many enzymes in action, this is why supplementing or fortifying with a small number of vitamins and minerals often doesn’t promote balanced nutrition. It’s like having one, or a few, kick-ass assembly line workers, but instead of assisting the assembly process, they just end up diverting energy elsewhere. An assembly line is only as fast as it’s slowest worker! So, vitamin and mineral supplementation/fortification is good for preventing a limited number of deficiency states, but it cannot address the whole range of metabolic processes that need to be coordinated and boosted across the board for optimal health. This is why a good diet must be based on whole foods. We need foods that will infuse our bodies with a robust range of nutrients — that, like a tide, will rise the boats of all of the assembly workers (to mix in another generous portion of metaphor).
To live a long, healthy life, we need thousands of nutrients — not merely the few dozen “essential” nutrients identified in the last century. There are estimated to be tens of thousands of different phytochemicals. Only a few percent of these have been isolated; and only a small fraction of these have been analyzed and tested. Nonetheless, while the nutritional science of phytochemicals is young, phytonutrients are not some mystical concept. Research thus far shows that:
• Most phytochemicals have antioxidant activity that protect our cells against oxidative damage; this antioxidant activity reduces inflammation, the root cause of much degenerative/chronic diseases
• Some phytochemicals stimulate enzymes, promoting healthy metabolism and detoxification
• Some phytochemicals help regulate healthy hormonal action
• Some phytochemicals regulate and protect DNA, affecting cancer prevention and healthy aging
• Some phytochemicals have anti-microbial properties, fighting against pathogenic infections and stimulating a health gut flora
One common nutrient is found only in plants: fiber. Fiber is often considered “non-nutritive”, but this is a big mistake. There are two basic types of fiber: insoluble and soluble. Most fiber is insoluble and provides the bulk or roughage in our diets. Soluble fiber is particularly adept at binding with cholesterol and toxins to carry them out of your system. Fiber slows the digestion of nutrients, spreading out the intake of caloric nutrients, allowing for a more balanced and healthy metabolism. Fiber is the single most important factor in satiety, feeling full. Fiber may not be digested by human enzymes but it is partially digested by the gut bacteria living in the most concentrated, biodiverse place on the planet. This promotes healthy gut bacteria, which are essential to optimal human nutrition. Fiber is the most basic pro-biotic.
In short, a diet rich in whole plant foods is the foundation for optimal nutrition and health.