Understanding How can nutritional factors cause disease?

October 23, 2025 •

5 min read

According to the World Health Organization, millions of deaths annually are linked to diet-related risks, such as high sodium and low fruit intake. These statistics highlight the profound ways dietary choices impact health and underscore the critical question of how can nutritional factors cause disease, both through inadequate and excessive consumption.

Quick Summary

Nutritional factors cause disease through complex pathways involving nutrient deficiencies, overconsumption, poor food quality, gut microbiome dysregulation, and gene-diet interactions. Malnutrition, both under- and overnutrition, can lead to metabolic dysfunction, chronic inflammation, and an increased risk of a wide range of illnesses, from infectious diseases to heart disease and cancer.

Key Points

Dual Threat: Malnutrition encompasses both nutritional deficiencies (undernutrition) and excessive intake (overnutrition), both of which cause significant health problems.
Modern Illnesses: While severe deficiencies cause classic diseases like scurvy and rickets, overconsumption of processed foods is a primary driver of modern chronic diseases, including obesity, type 2 diabetes, and CVD.
Chronic Inflammation: The Western diet, rich in unhealthy fats and sugar, promotes a state of chronic, low-grade inflammation that damages tissues and increases disease risk over time.
Microbiome Matters: Diet directly shapes the gut microbiome, and an imbalance (dysbiosis) can compromise the intestinal barrier and trigger systemic inflammation, impacting immune and metabolic function.
Genetics Play a Role: An individual's genes (nutrigenomics) can determine how they respond to dietary factors, explaining why some people are more susceptible to diet-related diseases than others.
Processed Food Risks: Ultra-processed foods contain additives and inflammatory ingredients that can trigger immune responses and worsen conditions, including autoimmune disorders.

The Dual Threat of Malnutrition: Deficiency and Excess

Nutritional factors can cause disease through two primary routes: undernutrition (deficiencies) and overnutrition (excesses). Both conditions represent forms of malnutrition and place significant strain on the body's physiological systems. Deficiencies of specific vitamins and minerals have historically been linked to well-known diseases, but modern understanding reveals that chronic, marginal deficiencies and overconsumption of certain dietary components are also powerful drivers of contemporary chronic illnesses.

Consequences of Undernutrition

Undernutrition, resulting from insufficient intake of energy or specific nutrients, has profound effects on health. Protein-energy malnutrition (PEM), common in developing countries but also seen in some chronic illness patients, manifests as conditions like marasmus and kwashiorkor, characterized by severe weight loss, muscle wasting, and edema.

Micronutrient Deficiencies: A lack of essential vitamins and minerals can severely disrupt bodily functions:
- Vitamin A Deficiency: A leading cause of preventable blindness in children, it also impairs immune function and increases susceptibility to infection.
- Iron Deficiency Anemia: The most prevalent nutritional deficiency, it causes fatigue, weakness, and impaired cognitive development, and increases pregnancy risks.
- Iodine Deficiency: Can lead to goiter, impaired growth, and mental retardation, especially during fetal development.
- Vitamin D Deficiency: Causes rickets in children and osteomalacia in adults, characterized by weakened, softened bones.

The Impact of Overnutrition

Excessive intake of energy and certain nutrients can be just as detrimental. The global rise in overnutrition is a major public health concern, primarily due to its link to obesity and associated chronic diseases.

Obesity: A state of excessive fat accumulation, obesity is a significant risk factor for a range of metabolic and inflammatory disorders.
Type 2 Diabetes: Diets high in refined carbohydrates and sugar contribute to insulin resistance, increasing the risk of type 2 diabetes.
Cardiovascular Disease (CVD): High consumption of unhealthy fats (saturated and trans fats) and sodium raises cholesterol levels and blood pressure, major risk factors for heart disease and stroke.
Nutrient Toxicity: While rare from food alone, excessive intake of fat-soluble vitamins (A, D, E, K) or certain minerals from supplements can be toxic and cause serious health issues.

Chronic Inflammation and Processed Foods

Chronic, low-grade inflammation is a central mechanism by which poor nutrition drives disease development. The modern Western diet, rich in ultra-processed foods (UPFs), is highly pro-inflammatory. UPFs contain ingredients and additives that can disrupt gut health and trigger an immune response, even independently of obesity.

Refined Carbohydrates and Sugars: Rapidly increase blood sugar and insulin levels, which promotes a pro-inflammatory state.
Unhealthy Fats: Excess omega-6 fatty acids and trans fats in processed foods can increase inflammation, shifting the body's fatty acid balance away from the anti-inflammatory omega-3s.
Food Additives: Emulsifiers and artificial sweeteners found in UPFs can disrupt the gut microbiota and increase intestinal permeability, also known as 'leaky gut', triggering inflammation.

The Gut Microbiome: A Key Mediator

The trillions of microorganisms in the human gut, collectively known as the microbiome, are profoundly influenced by diet and play a central role in both health and disease.

Gut Dysbiosis: An unbalanced diet, particularly one high in processed foods and low in fiber, can lead to an imbalance in the gut microbiota (dysbiosis). This shift often favors pro-inflammatory bacteria over beneficial ones that produce anti-inflammatory short-chain fatty acids (SCFAs).
Compromised Gut Barrier: A diet rich in UPFs can weaken the intestinal lining, allowing bacteria and other inflammatory molecules to leak into the bloodstream. This activates the immune system and contributes to chronic inflammation throughout the body.
Gut-Brain Axis: The gut microbiome communicates with the brain, and dysbiosis has been linked to neurodegenerative diseases, depression, and anxiety.

The Interplay of Genetics and Nutrition (Nutrigenomics)

Not everyone responds to dietary factors in the same way, and genetics play a significant role in determining an individual's susceptibility to diet-related diseases. This field, known as nutrigenomics, examines how dietary components influence gene expression and how genetic variations affect an individual's response to nutrients.

Genetic Polymorphisms: Variations in genes can affect how the body metabolizes fats, controls blood sugar, or processes certain vitamins. For example, variations in the APOE gene influence how the body metabolizes fats and cholesterol, affecting cardiovascular disease risk.
Epigenetics: Nutrients can influence epigenetic changes, modifications to gene expression that do not alter the DNA sequence itself. This was observed in the Dutch Famine Cohort, where maternal starvation altered metabolic disease risk in offspring, highlighting that nutrition can leave a long-lasting signature on our genes.

Comparison of Nutritional Causes of Disease


Cause Category	Examples of Nutritional Factors	Associated Diseases	Underlying Mechanisms
Deficiency	Lack of Vitamin C, Iron, or Iodine	Scurvy, Anemia, Goiter	Compromised biological functions (e.g., collagen synthesis, oxygen transport, hormone production) due to lack of essential cofactors.
Overnutrition	Excess calories, unhealthy fats, and sodium	Obesity, Type 2 Diabetes, Hypertension, CVD	Metabolic overload, insulin resistance, chronic inflammation, high cholesterol.
Poor Food Quality	High intake of ultra-processed foods	Inflammatory Bowel Disease, Metabolic Syndrome	Gut microbiome dysbiosis, systemic inflammation, leaky gut, additive toxicity.
Gene-Diet Interaction	Specific genes interacting with dietary intake	Familial hypercholesterolemia, variable responses to dietary fat/salt	Genetic predispositions altering metabolism and response to nutrients.
Food Sensitivity	Unrecognized triggers like gluten or dairy in susceptible individuals	Exacerbated autoimmune diseases (e.g., MS, Celiac disease)	Increased intestinal permeability ('leaky gut') and triggered immune response causing systemic inflammation.
Nutrient Toxicity	Excessive supplement use (e.g., Vitamin A, D, Iron)	Liver damage (Vit A), blood thinning (Vit E)	Overload of certain nutrients beyond the body's ability to process them safely.

Food Sensitivities, Intolerances, and Autoimmunity

Beyond traditional nutritional deficiencies and excesses, individual food sensitivities and intolerances can also be a significant disease factor, particularly in autoimmune conditions. Unlike immediate IgE-mediated allergies, food sensitivities often involve a delayed, more subtle immune response (IgG antibodies).

The Leaky Gut Connection: Increased intestinal permeability allows undigested food particles to enter the bloodstream, triggering an immune attack.
Exacerbating Autoimmune Disease: This chronic, low-level immune activation can drive systemic inflammation, worsening the symptoms and progression of autoimmune diseases like multiple sclerosis and lupus.

For more information on the deep connections between genetics and nutrition, consult resources like the NCBI Bookshelf.

Conclusion

The connection between diet and disease is far more intricate than simply consuming enough or too little of a particular nutrient. Nutritional factors cause disease through a multifaceted web of interactions, from the stark consequences of severe deficiency and the long-term metabolic damage of overconsumption to the subtle, ongoing assault of chronic inflammation fueled by modern processed foods. The gut microbiome emerges as a key player, mediating many of these dietary effects, while our individual genetics predispose us to different responses. A holistic understanding recognizes that food is not just fuel but a powerful determinant of our biological processes. Prioritizing a balanced, minimally processed diet rich in diverse, whole foods is the most robust strategy for disease prevention, offering not only essential nutrients but also a supportive environment for our microbial and genetic health.

Frequently Asked Questions

Food allergies involve an immediate, severe immune response (IgE antibodies) to a substance, potentially causing anaphylaxis. Food sensitivities often involve a delayed, less aggressive immune response (IgG antibodies) and can cause systemic inflammation and symptoms hours or days after consumption.

Yes. People with autoimmune diseases often have a higher prevalence of food sensitivities. When certain foods trigger a chronic inflammatory response, it can exacerbate the symptoms and progression of autoimmune conditions like multiple sclerosis, lupus, and inflammatory bowel disease.

Chronic inflammation, often fueled by poor diet and a disrupted gut microbiome, can damage healthy cells and tissues over time. This ongoing inflammatory process is a key factor in the development of chronic conditions such as diabetes, heart disease, rheumatoid arthritis, and certain cancers.

The gut microbiome plays a vital role in digestion, nutrient absorption, and immune function. An unbalanced diet, particularly high in processed foods, can alter the microbiome's composition (dysbiosis). This can lead to increased gut permeability, systemic inflammation, and a higher risk of diseases like IBD, obesity, and diabetes.

Yes, taking in too much of certain nutrients can be toxic. Overuse of supplements containing fat-soluble vitamins (A, D, E, K) or minerals like iron can lead to nutrient toxicities, causing liver damage, blood thinning, or excessive iron accumulation.

Ultra-processed foods (UPFs) are industrially formulated products with synthetic ingredients that can promote inflammation and disrupt the gut microbiome. They are typically high in unhealthy fats, sugar, and sodium, and low in fiber and beneficial nutrients, contributing significantly to metabolic dysfunction.

Nutrigenomics is the study of how nutrients influence gene expression and how genetic variations affect an individual's response to diet. It helps explain why some people are more susceptible to diet-related diseases and can inform personalized nutrition strategies based on genetic profiles.