Importance of nutrition on the health of the human body

 

Abstract:

This paper researches the benefits of healthy eating and how it impacts human physical and mental health. Initially, the paper defines healthy eating and the research related to nutrition. The current definition of nutritious food includes whole unprocessed food packed with required macro and micronutrients indicating a highly nutritious quality. Processed food with minimal nutrients can deprive the human body of essential nutrients required for its healthy functioning. Evolutionary research indicates that humans have evolved in a manner that prefers a diet containing essential nutrition. Additionally, current research suggests that nutrition affects gene expression and DNA methylation. Hence, in conclusion, proper nutrition is beneficial for both the mental and physical health of humans. 

Introduction:

Various factors including genetics, environment and nutrition affect human health. Nutrition has a prevalent impact as the human body requires many nutrients for normal operation. Carbohydrates, proteins, and fats are termed macronutrients and are essential for growth and energy synthesis. Additionally, micronutrients like vitamins and minerals are beneficial for metabolism. The research presents that a diet consisting of natural whole foods is supportive of ideal mental and physical health as it includes macro and micronutrients. This review paper defines what a typical healthy diet contains. Moreover, a diet that avoids processed food is effective in preventing cardiovascular diseases, cancer, and possible Alzheimer’s. Therefore this paper explains the research results that explore the influence of diet on health. Diet also influences mental health by providing a proper supply of nutrients to the brain. The kind of nutrients that are required for the brain is later explained in the paper. There is an overwhelming amount of evidence that suggests that diet also affects how genes are expressed. Discussion on how genes are expressed depending upon the diet of an individual is explained in detail. Human evolution suggests that the human body has evolved to absorb nutrients in an essential manner. The track of human evolution depending upon diet is later explored. 

What is nutrition?

Research proves that the human body requires many nutrients through the diet for its healthy functioning. These nutrients include essential amino acids, vitamins, and minerals. It is crucial for the human body to receive these nutrients for metabolism, growth, injury repair, and cognitive processes. A diet that includes the appropriate amounts of essential nutrients is supportive of a strong immune system, healthy cognitive functioning, and reduced risk of acquiring non-communicable diseases including cancer, and cardiovascular disorders. These nutrients are crucial for energy production within the human body. Carbohydrates, proteins, and fats comprise macronutrients whereas vitamins and minerals constitute micronutrients. A diet consisting of these nutrients is termed healthy. According to Cena et. al, “A healthy diet is one in which macronutrients are consumed in appropriate proportions to support energetic and physiologic needs without an excess intake while also providing sufficient micronutrients and hydration to meet the physiologic needs of the body” (2). Also as per CDC, a diet that consists of foods mentioned in the table below can be termed healthy. 

                                                          

 

Effects of Western diet on human health:

A western diet or a diet comprising of highly saturated fats, processed foods, and sugars has been proven to have unhealthy effects on the human body and brain. The rationale behind unhealthy effects can be the inadequacy of the western diet to provide essential nutrients through diet. Moreover, an excessive amount of LDL cholesterol present in processed and high-sugar-containing food contributes to atherosclerosis thus making an individual susceptible to developing cardiovascular disease and “developing dementia later in life” (8). The western diet also comprises trans-fat that has known to have “adverse health effects (8). Trans-fat is known to cause an increase in LDL number, promote inflammation and contribute to cardiovascular disease (11). Moreover, food items that have a high glycemic index contribute to an increased risk of diabetes II, metabolic syndromes, and obesity (11). In general, processing of the food results in a decreased nutrition level. Therefore the body is deprived of the essential nutrient it requires for healthy functioning. According to Mosconi, the author of the book Brain Foods, a western diet leads to the shrinkage of the brain and depletion of the neurons that ultimately leads to dementia in the older age. The figure below demonstrates the condition:

Nutrition and genetics:

Genetics and nutrition are interrelated factors that affect the typical process of the human body. An example of this concept is the lactose intolerance present in a certain population. Due to the genetic inability to synthesize lactase, the population develops lactose intolerance. Similarly, the lack of gluten digesting enzyme, a cohort of the population has difficulty digesting gluten. The variability in the population can be explained by human evolution. A population that required lactose for obtaining essential nutrients through dairy developed the trait to express lactase. This requirement to digest lactose might be a result of an environmental stressor where dairy was the prevalent medium to ingest essential nutrients. As this population was naturally selected, the lactose digesting population is prominent in modern times. Subsequently, nutrients obtained from the diet also have an important effect on genetics. If there is inflammation experienced by the body, genes express anti-inflammatory proteins. However, when omega-3 is introduced through the diet, the anti-inflammatory protein expression is halted (8). Similarly, the methylenetetrahydrofolate reductase gene (MTHFR)  important for the production of folic acid and maintaining normal blood levels of homocysteine. However, when there is a folic acid deficiency, the homocysteine levels increase. An increase in homocysteine levels is linked to an increased risk of developing cardiovascular disease (4). Hence nutrients and genetics are interrelated concepts that influence how the human body responds to the daily diet. 

Nutrition and Mental Health:

The brain is an energetically costly organ that requires a constant supply of energy in the form of glucose for its intended functioning. The brain has an extensive nutritional requirement for the production of certain neurotransmitters. A research study demonstrates that the consumption of tryptophan allows the brain to produce a neurotransmitter known as serotonin. This neurotransmitter is essential for “improved mood and sleep” (5). Perhaps an increase in tryptophan consumption in alignment with the dietary recommendations has a possibility of improving mood. Evidence that proves nutrition as an effective treatment for mental health issues can be found in the SMILES trials conducted in Australia. SMILES trial was a randomized study where the qualified dieticians administered dietary interventions to adults with major depression disorders (MDDs). In this research study, the adults in the treatments were administered a modified Mediterranean diet¹ (6) and their progress was tracked. Many participants reported feeling better after their diets were changed to include whole foods. The participants also reported having increased energy and mental clarity. 

 

Micronutrients as a remedy to common human ailments:

Many research articles indicate the importance of micronutrients to treat common ailments including PMS, gastrointestinal discomforts, stress, and inflammation. Vitamin B is known for its role in important processes like DNA methylation, reduction of inflammation, synthesizing neurotransmitters, and also plays a role in the process of glucose metabolism. Hence, an intake of foods or supplements rich in vitamin B can help with inflammation, mood improvement, and healthy glucose metabolism. According to Mikkelson et. al, vitamins B1, B3, B6, B9, and B12 are important for neuronal functions and their deficiencies are linked with depression (7). Like vitamin B, other micronutrients like zinc and magnesium are involved in many aspects of human health. For instance, magnesium is involved in critical biochemical reactions in the body which maintains normal muscle and nerve activity, regulates heartbeat rhythm, enhances bone strength, and assists in oxidative phosphorylation in the mitochondria. Additionally, zinc has important functions in the body which are linked to an improved mood through an increase in brain-derived neurotrophic factor, GABA levels, and healthy GI tract functions (7).

Conclusion:

As seen throughout the paper, nutrition is a crucial aspect of human health. Consumption of essential micro and macronutrients on a daily basis leads to improved physical and mental health. There is still ongoing research investigating how nutrition and genetics interact. However current research suggests that nutrition has an influence on how the genes are expressed. This fact is evident when the consumption of omega-3 fats reduces the expression of anti-inflammatory proteins. Additionally, proper nutrition can lead to improved mood and cognitive functions. Hence this paper signifies the importance of healthy eating. 

 

Citations:

1. CDC. (2021, April 19). Healthy Eating for a Healthy Weight. Centers for Disease Control and Prevention. https://www.cdc.gov/healthyweight/healthy_eating/index.html
2. Cena, H., & Calder, P. C. (2020). Defining a Healthy Diet: Evidence for the Role of Contemporary Dietary Patterns in Health and Disease. Nutrients, 12(2), 334. https://doi.org/10.3390/nu12020334
3. Chen, Y., Michalak, M., & Agellon, L. B. (2018). Importance of Nutrients and Nutrient Metabolism on Human Health. The Yale Journal of Biology and Medicine, 91(2), 95–103. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6020734/
4. Elsamanoudy, A., Mohamed Neamat-Allah, M., Hisham Mohammad, F., Hassanien, M., & Nada, H. (2016). The role of nutrition related genes and nutrigenetics in understanding the pathogenesis of cancer. Journal of Microscopy and Ultrastructure, 4(3), 115. https://doi.org/10.1016/j.jmau.2016.02.002
5. John D Fernstrom, A Perspective on the Safety of Supplemental Tryptophan Based on Its Metabolic Fates, The Journal of Nutrition, Volume 146, Issue 12, December 2016, Pages 2601S–2608S, https://doi.org/10.3945/jn.115.228643
6. ModiMed diet trial→ Opie, R. S., O’Neil, A., Jacka, F. N., Pizzinga, J., & Itsiopoulos, C. (2017). A modified Mediterranean dietary intervention for adults with major depression: Dietary protocol and feasibility data from the SMILES trial. Nutritional Neuroscience, 21(7), 487–501. https://doi.org/10.1080/1028415x.2017.1312841
7. Mikkelsen, K., Stojanovska, L., & Apostolopoulos, V. (2016). The Effects of Vitamin B in Depression. Current Medicinal Chemistry, 23(38), 4317–4337. https://doi.org/10.2174/0929867323666160920110810
8. Mosconi, Lisa. (2018). Brain Food: The Surprising Science of Eating for Cognitive Power. Penguin Random House. New York. 
9. National Research Council (US) Committee on Diet and Health. Diet and Health: Implications for Reducing Chronic Disease Risk. Washington (DC): National Academies Press (US); 1989. 4, Genetics and Nutrition. Available from: https://www.ncbi.nlm.nih.gov/books/NBK218767/
10. Nyaradi, A., Li, J., Hickling, S., Foster, J., & Oddy, W. H. (2013). The role of nutrition in children’s neurocognitive development, from pregnancy through childhood. Frontiers in Human Neuroscience, 7. https://doi.org/10.3389/fnhum.2013.00097‌
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