Plant-Based Nutrition

What the evidence says about plant-based diets and longevity

The epidemiological data on plant-based diets is substantial and largely positive. A 2025 meta-analysis of prospective studies covering nearly 1 million participants found that higher adherence to plant-based dietary patterns was associated with a 10% lower risk of all-cause mortality and a 23% lower risk of coronary heart disease mortality compared to the lowest adherence ^[1]. A separate 2024 meta-analysis confirmed reduced risks of type 2 diabetes, cardiovascular disease mortality, and cancer mortality in those eating more plant-based foods ^[2].

But the details matter. These studies compare more plant-based eating to less plant-based eating — they don't prove that fully eliminating animal products is necessary or even optimal. Blue Zone populations, the longest-lived communities on Earth, eat predominantly plant-based diets (~95% plants) but most include small amounts of fish, dairy, or occasional meat. The consistent signal from longevity research isn't "eliminate all animal foods" — it's "eat far more plants than most people currently do."

Why plants protect against chronic disease

Plants contain thousands of bioactive compounds that animal foods don't. Polyphenols, flavonoids, carotenoids, and glucosinolates function as antioxidants, anti-inflammatory agents, and epigenetic modulators. Fiber — essentially absent from animal foods — feeds beneficial gut bacteria that produce short-chain fatty acids, which regulate inflammation, insulin sensitivity, and even mood through the gut-brain axis ^[3].

The protective mechanisms go beyond individual nutrients. Whole-food plant-based diets tend to be lower in saturated fat, higher in potassium, and richer in phytonutrients that work synergistically. A 2025 Lancet study found that healthy plant-based diets reduced the burden of multimorbidity (simultaneous cancer and cardiometabolic disease) in middle-aged and older adults ^[4]. The key qualifier: "healthy" plant-based, meaning whole foods — not processed vegan junk food, which provides none of these benefits.

The nutritional gaps you need to address

Plant-based diets have real nutritional vulnerabilities that require attention, particularly as you move further toward full veganism. Ignoring these doesn't make them go away — it creates deficiencies that undermine the very health benefits you're trying to achieve.

Vitamin B12 is the most critical concern. Plants don't produce it, and deficiency rates among vegans reach 44% without supplementation ^[5]. B12 deficiency causes fatigue, cognitive impairment, nerve damage, and elevated homocysteine — a cardiovascular risk factor. Supplementing with 1,000 mcg of methylcobalamin or cyanocobalamin daily is non-negotiable for anyone eating fully plant-based.

Other nutrients that need monitoring include iron (plant-based iron is less bioavailable — pair with vitamin C to improve absorption), zinc, omega-3 fatty acids (consider algae-based DHA/EPA supplements), vitamin D, iodine, and potentially calcium and creatine ^[6]. A well-planned plant-based diet can cover most needs, but "well-planned" requires actual planning and periodic blood work to confirm.

Protein quality and quantity

The protein question is the most common concern about plant-based eating, and it's partially justified. Plant proteins are generally lower in leucine (the amino acid that triggers muscle protein synthesis) and may be less digestible than animal proteins. However, eating adequate total protein (1.6-2.0 g/kg body weight for active adults) from varied sources — legumes, soy, tempeh, seitan, quinoa, hemp — can fully support muscle maintenance and growth.

The practical approach for most people isn't all-or-nothing. Increasing plant food consumption to 70-80% of your diet captures most of the documented health benefits while avoiding the supplementation complexity of strict veganism. If you do go fully plant-based, treat supplementation and blood monitoring as essential components of the diet, not optional extras.