Plant-Based and Vegan Diets

Spectrum

• Vegan: no animal-source foods.
• Lacto/ovo vegetarian: includes dairy/eggs.
• Pescatarian: adds fish/seafood.
• “Plant-based”: mostly plants, allowing small amounts of animal foods.

What the evidence shows

• Adventist Health Study and EPIC-Oxford show lower BMI, lower cardiovascular mortality, lower type-2 diabetes incidence in vegetarians vs. meat-eaters in matched cohorts.
• Quality matters: a vegan diet of refined grains, sugar, and processed vegan foods has different effects than one built on whole foods (Satija et al.).
• Predominantly plant-based diets reliably lower LDL, blood pressure, and inflammatory markers.

Nutrient watch-points

• Vitamin B12 — absent from plant foods; supplementation or fortified foods required for vegans, recommended for many vegetarians.
• EPA/DHA — minimal in plant foods; algae-based supplements available.
• Iron — non-haem iron is less bioavailable; pair plant-iron sources with vitamin C.
• Zinc, iodine, choline — can be lower; plan intentionally.
• Calcium, vitamin D, vitamin K2 — especially relevant in older vegan adults.
• Protein — achievable on plant-only diets with attention to total intake and leucine; older adults need to plan more carefully.

Practical guidance

Whatever the label, a diet built on vegetables, legumes, nuts, whole grains, and (if included) fish or fermented dairy will outperform most alternatives for cardiometabolic aging.

More on this topic

• Homocysteine — Biomarker.
• Methylmalonic Acid (MMA) — Biomarker.
• Vitamin B12 (Cobalamin) — Biomarker.
• How Not to Die — Michael Greger (2015) — Book.
• Omega-3 Fatty Acids (EPA / DHA) — Intervention.

Related entries

Mediterranean diet, Protein and mTOR, Cardiovascular disease.