Immunity-building foods include plant-based fresh food and nuts. It is estimated that about 2 billion people live primarily on a meat-based diet, while 4 billion focus on a plant-based diet. The US food production system, a dominant meat-based market with a population of just 300 million, uses about 50% of the total US land area, 80% of its freshwater, and 17% of the fossil energy. Therefore, a vegetarian diet is more ecologically sustainable when compared to a meat-based diet (Pimentel et al., 2003).
Fruits and vegetables are rich in phytochemicals-these help in building body immunity. Three types of phytochemicals have been identified—carotenoids, polyphenols, and allium compounds.
Carotenoids are abundant in red, yellow, orange, and dark-green colored fruits and vegetables. Polyphenol-rich foods include herbs, spices, vegetables, green tea, apples, and berries. Allium-rich compounds are garlic, onions, leeks, and related vegetables. Many of these vegetables contain antioxidants such as β carotene, selenium, and vitamins C and E. These chemicals reduce the risk of cell damage. All these are examples of immunity-building foods
Oxidants are the most common of the cell damage-causing molecules. Oxidants are produced during healthy cellular metabolism. This modulates inflammation, kills bacteria, detoxifies toxins, and maintains a good vascular (blood vessel) tone. Excess, unutilized oxidants damage cell membranes, lipids, and DNA. This damage gets repaired by antioxidants obtained from food.
We get exposed to oxidants from external sources too. Smoking, alcohol, certain drugs, and deep-fried and fatty foods are other sources. We get exposed to oxidants through radiation, UV light, heat shock, and strong sunlight. Other oxidant sources are air fresheners as well as vehicular and industrial pollutants. Oxidants interact with antioxidants, destroying these. Diet must have enough surplus antioxidants to counterbalance the loss from oxidants.
Free oxidants not neutralized by antioxidants can cause degenerative diseases such as atherosclerotic heart disease, diabetes, skin ailments, arthritis, neurodegenerative disorders, cancers, etc.
Vitamins B and D and calcium in plants and other foods have cancer-preventive properties. Dietary fiber found in whole grains, seeds, legumes, pulses, vegetables, fruit, and products made from these helps easily evacuate stool. Plant-based phytochemical-rich foods help regulate hormones such as estrogen, slow cancer cell growth, and block inflammation.
Cruciferous vegetables such as broccoli, cauliflower, cabbage, related vegetables, lycopene found in tomato products, pink grapefruit, watermelon, and apricots protect against several types of cancers. A plant-based diet is composed largely of immunity-building foods
No single antioxidant molecule has been found that can replace the health benefits generated by a combination of natural phytochemicals found in fruits and vegetables. Consumers need to eat 5–10 servings of a wide variety of fruits and vegetables daily to mitigate the risk of chronic diseases and to meet nutrient requirements essential for optimum health (Liu, 2004).
This is a vast and extensively studied subject area and what I presented above is just a preview.
Additional reading:
- Natural Solutions for Cancer
- Nutrition Facts- A guide to good health
- Natural Solutions for Diabetes
- Natural Solutions for Obesity