“Eat your vegetables” is probably one of the most repeated phrases in the history of parenting. Since time immemorial, nutrition experts have been trying to get people to eat more greens. From children to adults, many of us work hard to meet the goal of consuming five cups of fruits or vegetables each day. Aside from ensuring peace at the dining table, why exactly is eating your vegetables so important?
The First Line of Defense
The immune system is a network of complex biological processes made up of various organs, cells, and proteins. Immune responses detect and protect us from a range of harmful foreign invaders including bacteria, viruses, parasitic worms, and even wood splinters. Humans have two types of immune systems. The innate immune system is the one that we are born with. Referred to as the non-specific immune system, it provides a preconfigured, general defense against a wide spectrum of germs and substances. The adaptive immune system, as its name suggests, is one that constantly acquires new ‘battle strategies’. Referred to as the specific immune system, it learns to recognize antigens that it has previously encountered and makes precise antibodies to address them. This allows our bodies to fight bacteria or viruses that mutate over time.
As with our physical fitness, our immune function may become depressed due to a variety of factors. Age and chronic disease are clear causes of diminished immune function, but there are other less direct contributors. Environmental factors—for instance, polluted air and drinking water—can impair the normal behavior of our immune cells. This includes excessive consumption of voluntary vices such as alcohol or cigarettes as well. Chronic stress has been also shown to affect our immune response as stress hormones like cortisol suppress the inflammation action required to activate immunity. Similarly, lack of sleep lowers the amount of cell signaling proteins known as cytokines, which have important immunomodulating functions. Finally, malnutrition from inadequate nutrient intake can lead to immune dysfunction and overlapping comorbidities.
It is important to note that malnutrition does not refer to insufficient caloric intake. A person can consume a large amount of food in terms of calories or macronutrients (carbohydrates, fats, and proteins) but may still be gravely deficient in certain micronutrients. For example, fried chicken has lots of fat and protein but does not contain vitamin C. Micronutrients like vitamin C, vitamin D, zinc, and selenium have been shown to be essential for the growth and function of immune cells. Therefore, eating a balanced and varied diet is vital in maintaining a healthy immune system. The modern Western diet of ultra-processed food, meat-heavy meals, and tons of refined sugar can lead to clinical malnutrition, negatively affecting the immune system, and causing chronic systemic inflammation.
It’s Easy Being Green
A diet abundant in plants has been known to bring with it a myriad of positive health effects. Fruits and vegetables have been shown to help to lower blood pressure, regulate blood sugar levels, increase digestive health, reduce the risk of heart disease and stroke, and even keep some types of cancer at bay. Considering that vegetables are generally low in calories, they are extremely nutrient-dense. Some legumes like soy and chickpeas are high in protein yet consist of virtually no fat or cholesterol. And because vegetables are rich in dietary fiber, they promote digestive health and fill you up faster, assisting in weight management. Fruits and vegetables come in all the colors of the rainbow, making up approximately nine different families with unique blends of beneficial nutrients.
Cruciferous vegetables from the Brassica genus—such as Brussels sprouts, broccoli, cauliflower, cabbage, and kale—are the powerhouses of the vegetable world. Besides their high fiber content, they are excellent sources of nutrients. Cruciferous vegetables contain beta-carotene, lutein, and zeaxanthin, which are important carotenoids and antioxidants. They also contain many of the B vitamins; vitamins C, E, and K; as well as minerals like magnesium, phosphorus, potassium, and manganese. In addition, researchers at the University of California at Berkeley discovered that diindolylmethane (DIM), a compound found in cruciferous vegetables is a powerful enhancer of the immune system.
While we may all love to incorporate more plants into our diet, it can be difficult. Not everybody has access to a wide selection of fresh fruit and vegetables, and they can be quite costly in some areas. Some of us may find ourselves too busy to eat wholesome meals or too tired to think about cooking after work. Or, perhaps, you just cannot bear the taste of vegetables. For people who find it hard to meet their daily fruit and vegetable requirements, there are now vegetable supplement pills that can help you to reap the benefits of vegetables without you actually having to eat them. Furthermore, there are proprietary supplements that combine DIM with essential micronutrients, allowing you to boost and revive your immune system easily. With advances in nutrition technology, eating your vegetables is no longer a struggle.