What Are Antioxidants and Do They Actually Work?

Antioxidants show up on packaging for everything from berries to skincare, but the term gets used loosely. Here's what they actually do in the body, and how much of the marketing holds up.

What antioxidants actually do

Antioxidants are compounds that neutralize free radicals — unstable molecules produced naturally through metabolism and increased by things like pollution, UV exposure, and smoking. Left unchecked, free radicals can damage cells in a process called oxidative stress, which is linked to aging and chronic disease risk over time.

Free radicals aren't purely bad

Your body actually needs some free radical activity — it plays a role in immune defense and cell signaling. The goal isn't to eliminate free radicals entirely, but to keep oxidative stress in a healthy balance, which is where dietary antioxidants help.

Best food sources

Berries, dark leafy greens, dark chocolate, nuts, and colorful vegetables like beets and red cabbage are particularly rich in antioxidant compounds like vitamin C, vitamin E, and various polyphenols. Coffee and tea are also major antioxidant sources for many people simply due to how often they're consumed.

Do antioxidant supplements help?

Large clinical trials on high-dose antioxidant supplements (like vitamin E or beta-carotene pills) have generally failed to show the same benefits seen with antioxidant-rich food, and some trials found potential harm at high doses. Whole foods appear to work better than isolated supplements, likely because they deliver antioxidants alongside fiber and other beneficial compounds.

The bottom line on marketing claims

A high 'antioxidant score' on a product label isn't a reliable health signal on its own — a varied diet with regular servings of fruits, vegetables, and plant-based foods provides antioxidants without needing to track any specific number.