Vegetarian Diets & Health Risks: Evidence Review

Well-planned vegetarian diets are nutritionally adequate and associated with lower risks of several chronic diseases. The Academy of Nutrition and Dietetics, WHO, and major health bodies affirm this.

Evidence-Based Benefits

• Cardiovascular disease: ↓ LDL, ↓ BP, ↓ BMI → ↓ CHD incidence/mortality (25–30% lower).
• Type 2 Diabetes: ↓ incidence 30–50%; better glycemic control.
• Hypertension: ↓ systolic/diastolic 5–7 mmHg.
• Cancer: ↓ colorectal (red/processed meat avoidance), possibly breast, prostate.
• Obesity: Lower BMI on average.
• Renal function: Slower CKD progression (plant protein vs. animal).

Nutrients Requiring Attention (Not "Risks" If Managed)

• Vitamin B12: Reliable sources: fortified foods, supplements (mandatory for vegans; recommended for vegetarians >50).
• Iron: Non-heme iron absorption enhanced by vitamin C; monitor ferritin.
• Zinc: Phytates reduce absorption; soak/sprout legumes/grains.
• Omega-3 (EPA/DHA): Algal oil supplement if no fish.
• Calcium/Vitamin D: Fortified plant milks, tofu (calcium-set), greens, sunlight/supplement.
• Protein: Adequate from legumes, soy, seitan, dairy/eggs (lacto-ovo); variety ensures all EAAs.

Potential Risks of Poorly Planned Vegetarian Diets

• B12 deficiency → megaloblastic anemia, neuropathy (irreversible if prolonged).
• Iron deficiency anemia (especially menstruating women).
• Low bone density (if calcium/vit D inadequate).
• Inadequate protein (rare in varied diets).

These are planning failures, not inherent to vegetarianism. Registered dietitian guidance ensures adequacy at all life stages.