Garlic, onions, and olive oil daily reflects the Mediterranean diet patterns most consistently linked to cardiovascular health and longevity. The combination is among the most studied and most consistently positive in nutrition research. Simple to implement at any level of cooking skill.
Why these specifically
Olive oil: monounsaturated fats, polyphenols, anti-inflammatory effects (extra virgin has strongest evidence). Garlic: cardiovascular benefits, mild antibacterial, anti-inflammatory. Onions (and other alliums): polyphenols, prebiotic fibre for gut bacteria.
How to use daily
Cook savoury meals with olive oil base. Add chopped onion at start of most savoury dishes. Crushed garlic added later (don't overcook — degrades benefits). Salad dressings with extra virgin olive oil + lemon. Drizzle olive oil on finished dishes.
Cost is modest (good quality olive oil £5-15 per bottle, lasts months; garlic and onions cheap year-round). Benefit is consistent across diverse health markers. Boring foundation that pays back over years.