📋 Quick Answer
Grass-fed has better fatty acid profile (more omega-3, CLA), more antioxidants. Grain-fed has more marbling (taste). Both are nutritious.
Nutritional Differences
| Nutrient | Grass-Fed | Grain-Fed |
|---|---|---|
| Omega-3 | Higher — 2-5x more omega-3. Still far less than salmon. | Lower omega-3, higher omega-6 (pro-inflammatory ratio). |
| CLA (Conjugated Linoleic Acid) | 2-3x more CLA. CLA has anti-cancer and fat-loss properties in animal studies. | Lower CLA content. |
| Vitamin E | 2-3x more vitamin E (antioxidant — protects fats from oxidation). | Lower vitamin E. |
| Overall Fat | Leaner overall. Less marbling = can be tougher if overcooked. | More marbling (taste). Higher total and saturated fat. Cooks more forgivingly. |
Verdict
Grass-fed is nutritionally superior (omega-3, CLA, vitamin E, antioxidants). Grain-fed is cheaper, more marbled, and easier to cook. If budget allows, choose grass-fed. If not, grain-fed beef is still highly nutritious (protein, zinc, iron, B12 are similar). The difference is real but modest — don't avoid beef if you can't afford grass-fed.