This comprehensive analysis reveals that the modern Western diet—high in processed foods, refined carbohydrates, and sugars—is directly linked to numerous chronic physical and mental health conditions. Multiple studies demonstrate that populations consuming traditional, whole-food diets experience dramatically lower rates of obesity, diabetes, heart disease, depression, and anxiety. Remarkably, research shows these "diseases of civilization" can be reversed within weeks when individuals return to traditional eating patterns, highlighting the profound impact of dietary choices on overall health.

The Western Diet and Its Impact on Modern Health: What Patients Need to Know

Table of Contents

• Introduction: The Problem with Modern Eating
• How Our Diet Has Changed: Health Implications for Today
• Traditional Diets Around the World
• Diet and Mental Health: The Connection to Depression and Anxiety
• Conclusion and Practical Recommendations
• Source Information

Introduction: The Problem with Modern Eating

The Western diet, characterized by high consumption of simple carbohydrates, processed foods, and factory-farmed meats, has been strongly associated with numerous chronic diseases that are rare or non-existent in traditional cultures. These "diseases of civilization" include obesity, diabetes, heart disease, high blood pressure, and certain cancers. What's particularly revealing is that inhabitants of traditional cultures who maintain their ancestral diets tend to be free of these conditions, only developing them after adopting Western eating patterns.

A compelling example comes from Michael Pollan's book "In Defense of Food," which describes a group of overweight and diabetic Australian Aborigines who returned to their traditional homeland and eating patterns for seven weeks. These individuals had developed metabolic syndrome—a cluster of conditions including diabetes, obesity, heart disease, and high blood pressure—after relocating to settlements where they consumed a Western diet. Their traditional diet consisted of foods they hunted and gathered themselves: fish, shellfish, birds, kangaroo, yams, figs, and bush honey.

This contrasted sharply with their previous Western diet, which consisted mainly of "flour, sugar, rice, carbonated drinks, alcoholic beverages, powdered milk, cheap fatty meat, potatoes, onions, and variable contributions of other fresh fruits and vegetables." After just seven weeks of eating traditionally, all participants lost weight and experienced significant health improvements. Their triglycerides and blood pressure decreased, and the metabolic abnormalities associated with their diabetes either improved or completely resolved.

This remarkable transformation demonstrates that the health damage caused by the Western diet may be reversible through dietary changes alone. The following sections examine the scientific evidence behind this connection and what it means for patients today.

How Our Diet Has Changed: Health Implications for Today

A comprehensive 2005 report published in the American Journal of Clinical Nutrition, led by Dr. Loren Cordain, examined seven crucial dietary changes that have occurred since the rise of agriculture and animal husbandry approximately 10,000 years ago. These changes include glycemic load, fatty acid composition, macronutrient consumption, micronutrient density, acid-base balance, sodium-potassium ratio, and fiber content. The researchers argue that these changes happened too recently for the human genome to adapt, making them responsible for many modern diseases.

The research identified five food groups that wouldn't have been available to pre-agricultural humans but now make up 72.1% of total daily calories consumed in the United States:

• Dairy products: 10.6% of daily energy
• Cereal grains: 23.9% of daily energy
• Refined sugars: 18.6% of daily energy
• Refined vegetable oils: 17.6% of daily energy
• Alcohol: 1.4% of daily energy

These foods combine to create the processed foods that dominate the American diet—cookies, cakes, baked goods, crackers, chips, pizza, soft drinks, candy, ice cream, and similar items. The modern diet also contains high levels of salt and fatty domestic meats that weren't part of ancestral eating patterns.

The research team reviewed 172 different articles and studies published between 1967 and 2004 on ancestral diets, the evolution of the Western diet, and Western diseases. They concluded that the prevalence of these modern foods is directly linked to "diseases of civilization" including obesity, type 2 diabetes, hypertension, coronary heart disease, and high cholesterol, as well as other Western health conditions like acne, polycystic ovary syndrome, certain cancers, and skin conditions.

Perhaps most strikingly, the study notes that while these diseases are rare or non-existent in hunter-gatherer cultures and those maintaining traditional diets, they affect 50-65% of the adult population in Western cultures. The report states that "diet-related chronic diseases represent the single largest cause of morbidity and mortality" in modern societies.

The analysis shows convincing evidence that no single dietary element causes chronic disease (such as saturated fat alone), but rather that Western diseases result from a combination of dietary elements introduced through modern food processing and agriculture.

Traditional Diets Around the World

Research by Elizabeth Lipski, PhD, CCN, published in Nutrition in Clinical Practice, examined the health benefits and characteristics of several traditional diets, including those of Tohono O'odham Indians, Eskimos in Labrador, the Maori in New Zealand, Gaelic in Outer Hebrides, and the Hunza in the Himalayas. Lipski notes that "whenever people living traditionally mesh with western culture, noninfectious diseases of modern culture soon follow."

The report reviews the diets and health status of various traditional cultures worldwide, citing work from researchers like Albert Schweitzer and Weston Price who studied indigenous populations in the early twentieth century. Physicians working in eastern and central Africa, Australia, New Zealand, the southern Pacific, and other isolated regions reported few or no instances of dental caries, cancer, heart disease, appendicitis, diverticulitis, diabetes, infectious disease, and other common Western ailments. These sources consistently reported that native health deteriorated when European diets were introduced.

Lipski's research utilized 60 different articles and studies examining early observations about indigenous health, contemporary research on traditional diets, cooking methods, functional foods in traditional diets, and health improvements when traditional diets are restored. Although traditional diets varied widely, nearly all traditional cultures used cooking methods that "enhance digestion and nutrient availability," such as soaking, fermentation, pounding, and sprouting. The use of these traditional methods decreased as families became wealthier and adopted more Western practices.

Traditional cultures also employed "folk functional foods" for medicinal and healing properties. Several studies observed health improvements after returning to traditional diets, including O'Dea's study of Australian Aborigines mentioned earlier. A similar study of overweight Hawaiians who returned to a traditional Hawaiian diet for 21 days showed significant improvements in weight, glucose levels, serum triglycerides, total cholesterol levels, and systolic blood pressure.

This research supports Pollan's position that traditional diets vary widely in nutritional composition yet effectively safeguard against modern diseases. However, returning to traditional diets presents challenges. Traditional foods, skills, and practices are disappearing as elders pass away. Many populations have lost access to traditional foods or the knowledge to identify and prepare them. Additionally, traditional foods have become contaminated with mercury, pesticides, and other pollutants—a problem exemplified by the "Arctic Dilemma," where traditional high-fat foods are less beneficial due to environmental contaminants.

Diet and Mental Health: The Connection to Depression and Anxiety

While the Western diet is commonly recognized as a factor in physical health conditions, less evidence exists regarding its relationship to psychological health. A study published in the American Journal of Psychiatry examined this connection, noting that diet affects biological processes influencing psychological health, including inflammation, brain plasticity and function, the stress response system, and oxidative processes.

Previous studies focused on individual nutrients or food groups, providing an incomplete picture. This study instead examined the effects of overall diet quality on mental health in more than 1,000 Australian women aged 20-92. Participants completed a comprehensive food frequency questionnaire and the 12-item General Health Questionnaire (GHQ-12), where higher scores indicate more health problems.

Researchers defined "traditional" dietary patterns as those high in fruits, vegetables, meat, fish, and whole grains, while "western" diets consisted mainly of processed or fried foods, refined grains, and sugar. Participants also underwent clinical interviews to assess for major depressive disorder, mild chronic depression, and anxiety disorder.

After adjusting for age, socioeconomic status, education, and health behaviors, the results showed that traditional diets were associated with lower rates of depression and anxiety disorders. Better diet quality further decreased the risk of psychological symptoms. Participants eating a Western diet exhibited higher GHQ-12 scores and had an increased risk of major depression or mild chronic depression.

The authors noted that due to adjustments for overall caloric intake, the amount of unhealthy food may be more relevant to psychological health than its percentage of the overall diet. While the association doesn't prove causation, the results align with other research showing connections between diet quality and medical outcomes, including cardiovascular disease and cancer risk. The authors recommend further studies to rule out reverse causality and confounding factors.

Despite the need for additional research, individuals experiencing psychological issues or diagnosed with depression or anxiety disorders would be prudent to increase fruit and vegetable intake while decreasing consumption of processed, refined, and sugary foods.

Conclusion and Practical Recommendations

The health risks associated with the typical Western diet are extensive and severe, but transitioning to a more traditional, plant-based diet presents challenges for many people. Higher costs, limited access to unprocessed foods, and food insecurity create barriers to healthier eating. Environmental contamination issues, like the Arctic Dilemma where traditional foods contain pollutants, further complicate sourcing healthy whole foods.

Adopting practical "food rules" can assist with the transition to a healthier diet. Buying whole grains in bulk and purchasing produce in season can help manage costs. While organic produce is preferable to conventionally grown foods, conventional produce remains a better choice than refined, processed foods. Patients can reduce exposure to chemicals and pesticides by choosing produce with the lowest pesticide residues, such as asparagus, sweet peas, mangoes, and cantaloupe.

Nutritional education improvements are critical for healthier dietary habits. A Consumer Reports Health poll from early 2011 found that 9 in 10 Americans believe their diet is healthy, but only a quarter limit fat and sugar intake, and just one-third eat five or more daily servings of fruits and vegetables. This discrepancy reveals a significant understanding gap about what constitutes a healthy diet, putting people at risk for major chronic diseases and psychological problems.

Patients should be wary of dietary fads and trends and maintain healthy skepticism about "new" scientific research on specific nutrients or food groups, which often creates confusion about healthy food choices. The most important guidelines are to avoid processed foods when possible, choose foods with few ingredients, prioritize quality over quantity, and focus on whole fruits and vegetables. As Michael Pollan succinctly advises: "Eat food. Not too much. Mostly plants."

Source Information

Original Article Title: The Western Diet and Diseases of Civilization

Author: Karen Eisenbraun

Publication Details: Nat 309: Topics in Holistic Nutrition, November 13, 2011

Note: This patient-friendly article is based on peer-reviewed research and includes data from multiple scientific studies referenced in the original work.