We live in a world where our image plays an important role in social relationships. Many people change dietary habits just because their only goal is to be slim and lose weight. In trying achieving this, they eat less food, assuming less calories, or they do not eat at all for a certain time. Plus, they also try to find help from some magic pills promising to burn fats, thinking they are healthy doing so. But all of this is totally wrong! Being healthy is not a matter of how much food we eat, but is a matter of which food we eat. Do not starve, our body needs food, because it needs proper nutrients to perform all its tasks. And do you know what is the real magic? That we do not need any pills for this! 

Obesity is a problem: it is linked with an increased risk of developing insulin resistance and type 2 diabetes [1], increased risk of hypertension [2] and cardiovascular disease (e.g. heart failure, coronary heart disease, sudden cardiac death) [3], cancer [4], mental disorders [5] and higher mortality [6,7].

If you think that all of this is related to bad genes, then it is better that you requestion yourself: remission of type 2 diabetes comes from changing dietary and physical activity habits [8]; healthy food can reduce hypertension by 21 mmHg (drugs usually reduce it by 10-15 mmHg) [9,10]; fruit and vegetables have a strong protective effect against cardiovascular diseases [11,12], cancer [13,14] cognitive decline [15,16] and all-cause mortality [17,18]; increased consumption of whole grains has been associated with reduced risk of major chronic diseases including cardiovascular disease, type II diabetes, and some cancers [19].

So, what is the power of fruit, vegetables and whole grains? It is pretty simple, they are loaded with all the vital nutrients our body requires to grow and maintain health: vitamins, minerals, fibers, phytonutrients, enzymes and proteins. But pay attention: many of these nutrients are being destroyed by food processing. So, if you want to eat healthy food, choose raw food!

First of all, our body needs energy! This energy is produced by our cells in a process called cellular respiration (Figure 1): fruit, vegetables and whole grain are full of enzymes, carbohydrates, glucose and other forms of sugar that are the main molecules our body uses for energy production. When the glucose enters the cell, a series of enzymes convert it into different forms then uses it to produce energy. When on a diet, many people totally cut the consumption of carbohydrates and of fruits (just because of its sugar contents). Wrong, we need them for our energy!

cellular respiration equation
Figure 1 – Cellular respiration is the process of breaking sugar (glucose) into a form that the cell can use as energy (ATP, adenosine triphosphate). This process also uses special enzymes to convert the glucose in other different forms. (From [46])

Protein is another important component of every cell in the body. Hair and nails are mostly made of protein, that is also an important building block of bones, muscles, cartilage, skin, and blood. Our body uses proteins to build and repair tissues, make enzymes, hormones, and other body chemicals. With food processing, proteins brings substantial physical changes in structure (Figure 2), with resulting loss of function and destruction of some amino acids [20]. Also, antibodies recognize and interact with allergenic proteins through distinctive molecular shapes (epitopes) on the molecule. So, changes in protein conformation lead to the formation of new epitopes (neoallergens), explaining why some people can tolerate certain unprocessed food but not the corresponding processed counterpart [21,22].

Figure 2 – Physical changes in proteins structure due to thermal processing. (From [47])
Enzymes (a subset of proteins) are catalysts that increase the rate of chemical reactions within cells. Without enzymes, these reactions would not occur fast enough to sustain human life [23]. They are very critical as they control some of the essential body physiological functions: food digestion (Figure 3), energy production, oxygen absorption, immune response, waste removal, blood clotting, hormonal function, metabolism, aging process. For example, amylase is essential in digesting carbohydrates, breaking them down into glucose [24]. Proteins are complex molecules broken down by trypsin into amino acids that are easily absorbed into the blood [25]. Although many enzymes are naturally produced by our body’s organs (e.g. salivary glands, stomach, pancreas, and the small intestine), we need to integrate them from food in order to do not stress too much the body. Enzymes are really sensitive and are easily destroyed during food heating and processing. Despite their importance, thermal processing is what food industry uses to make food last longer [26]. But this destroys many useful nutrients and digestibility is affected. Never wondered where the different forms of food intolerance of our days come from?

Figure 3 – Enzymes are chemical elements that speed up the breakdown of complex food into simple nutrients, making simpler nutrients absorption. (From [48])
Vitamins are essential compounds that help the body grow and function optimally. Among multiple other functions, vitamins help to boost immunity, strengthen bones, heal wounds, bolster eyesight and assist in obtaining energy from food. Inadequate vitamin intake risks body’s health. For example, deficiency in B vitamins can lead to permanent nerve damage [27].  Vitamin D deficiency causes rickets in children and other bones problems [28]. Minerals, like vitamins, support normal growth and development. Our body needs them to perform vital functions: calcium helps build strong bones and teeth and plays a vital role in muscle contraction and nerve impulse transmission; iron forms integral part of hemoglobin, essential for providing oxygen to body tissues [29].

By already peeling fruit and vegetables we can loose vitamins and mineral contents by oxidation [30]. As an example, vitamin C, also known as ascorbic acid (AA, C6H8O6), is susceptible to oxidation, becoming dehydroascorbic acid (DHA, C6H6O6) when in contact with air (Figure 4). In tomatoes, 28% of AA is lost when peeling, while it is almost totally lost if the tomato is cooked peeled. However, also DHA is important and it can be reduced back to AA by our body: AA does not pass from the bloodstream into the brain, while DHA can be transported through the blood–brain barrier, where it is then converted back to AA. Nevertheless, this put our cells under bigger stress, killing also susceptible cell types, e.g. neurons [31]. AA instead is an antioxidant and it is able to increase cells survival, by preventing or reversing oxidation in other cells: e.g., in the stomach, AA reduces the nitrite ion (NO2−) to nitric oxide (NO). If this reaction did not occur, nitrite ions from foods would oxidize the iron in hemoglobin, destroying its ability to carry oxygen. Do you still want to take your magic pills and dietary supplements? Be aware that fruit and vegetables are rich in numerous other micronutrients (other vitamins and minerals), dietary fiber, and phytochemicals (e.g., bioflavonoids), and the presence of some of these may affect the bioavailability of vitamin C [32]. So, if you want vitamin C, eat an orange! Avoid any synthetic or other forms of processing, such as vitamin C supplements and orange juices, and you will have more vitamin C with added beneficial effects from other nutrients.

Figure 4 – Oxidation of ascorbic acid (AA, vitamin C) into dehydroascorbic acid (DHA). By already peeling fruit and vegetables this reaction happens, loosing part of the vitamins contents. (From [49])
Further loss of vitamins and minerals happens during other processing, including cooking and thermal processing in general, washing, soaking, freezing and thawing, extrusion cooking (high-temperature short-time) [33,34,35,36,37,38,39]. These losses begin with harvesting and continue through handling, industrial or home preparation, cooking, and storage of plant foods. As an example, freezing is one of the most used method to preserve food. However during the freezing process, the water contained in the food matrix solidifies and forms crystals [40]. These crystals melt once the food is thawed and bring with them precious nutrients. So the fresher and rawer the food, the better!

Our cells are constantly exposed to a variety of oxidizing agents, some of which are necessary for life. Overproduction of oxidants can cause an imbalance, leading to oxidative stress, with increased risk for cancer and cardiovascular disease [41,42]. Vitamins can help in maintaining the balance between oxidants and antioxidants, sustaining optimal physiologic conditions in the body.  Fruit and vegetables (Figure 5) also contain a wide variety of other antioxidant compounds (phytochemicals) such as phenols and carotenoids that help protect cellular systems from oxidative damage and lower the risk of chronic diseases.

Figure 5 – Example of fruit rich in antioxidants. (From [50])
Many studies have demonstrated the high benefits of phytochemicals for our health, lowering the risk of chronic diseases, cardiovascular diseases, cancer [43,44]. Also in this case, do you want to take your magic pills or supplements? Be aware that there are roughly 8000 phytochemicals in whole foods: no single antioxidant can replace their natural combination in fruit and vegetables and it simply cannot be mimic by pills or tablets. For example, numerous investigations have shown that the risk of cancer is inversely related to the consumption of green and yellow vegetables and fruit, which are full of β-carotene. However, the role of carotenoids as anticancer supplements has recently been questioned as a result of several clinical studies: in one study, the incidence of nonmelanoma skin cancer was unchanged in patients receiving a β-carotene supplement [45].

Fruit and vegetables offer a good variety of nutrients that, combined together, allow many health benefits. Food processing destroys many of these nutrients, making wondering if some of the modern diseases, allergies, intolerance and disorders depend on it. Healthy nutrition is not a matter of quantity and calories, it is matter of quality! Raw food is what nature gave us and it is what our body needs! Have a look to Figure 2: same calories, different food. Do you still think only calories are what matters? Choose healthy food for healthy life and you will have no doubts!

Figure 6 – Junk food vs healthy food. Same amount of calories, however the nutritional values are completely different. (From [50])



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Other websites

[46] What Is the Cellular Respiration Equation?, by Answer GK Planet

[47] Why Does The Yolk Of An Overcooked Hard-Boiled Egg Become Green?, by Science ABC

[48] Digestive System, Enzymes, Absorption in the Small Intestine, by ScienceAid

[49] Chemical Reactions, by Western Oregon University

[50] Antioxidants & Glutathione, by Seed of Life

[51] Breaking down this healthy life thing one baby step at a time, by Misguided Mommy