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Caffeine

Other Unit: mg

Natural stimulant found in coffee, tea, and chocolate. Increases alertness and may enhance physical performance in moderate amounts.

No established daily requirement for this nutrient.

Top Foods Highest in Caffeine

Amount per 100g serving. Values in mg per 100g.

Foods Highest in Caffeine (Table)

#FoodPer 100gGroup
1Beverages, tea, instant, unsweetened, powder5,714 mgBeverages
2Beverages, coffee, instant, regular, powder3,142 mgBeverages
3Beverages, tea, instant, sweetened with sodium saccharin, le2,240 mgBeverages
4Beverages, coffee, instant, with chicory2,063 mgBeverages
5Beverages, tea, instant, lemon, unsweetened1,794 mgBeverages
6Beverages, coffee, instant, regular, half the caffeine1,571 mgBeverages
7Candies, dark chocolate coated coffee beans839 mgSweets
8Candies, milk chocolate coated coffee beans800 mgSweets
9Beverages, coffee, instant, mocha, sweetened360 mgBeverages
10Cocoa, dry powder, unsweetened230 mgSweets
11Beverages, coffee, brewed, espresso, restaurant-prepared212 mgBeverages
12Beverages, tea, instant, decaffeinated, unsweetened169 mgBeverages
13Beverages, Cocoa mix, powder150 mgBeverages
14Beverages, tea, instant, lemon, with added ascorbic acid124 mgBeverages
15Beverages, coffee, instant, decaffeinated, powder122 mgBeverages
16Chocolate, dark, 60-69% cacao solids86.0 mgSweets
17Baking chocolate, unsweetened, squares80.0 mgSweets
18Chocolate, dark, 70-85% cacao solids80.0 mgSweets
19Cocoa, dry powder, unsweetened, processed with alkali78.0 mgSweets
20Cocoa, dry powder, hi-fat or breakfast, processed with alkal72.0 mgSweets

Health Effects of Caffeine

Function

Caffeine is a methylxanthine alkaloid that blocks adenosine receptors, promoting alertness and reducing fatigue. It enhances cognitive function, physical performance, and metabolic rate.

Deficiency Signs

Not applicable; caffeine is not an essential nutrient.

Excess / Toxicity

Excessive caffeine (>400mg/day in adults) can cause anxiety, insomnia, heart palpitations, digestive issues, and elevated blood pressure. Pregnant women are advised to limit intake to <200mg/day.

Absorption & Interactions

How It’s Absorbed

Rapidly and completely absorbed from the stomach and small intestine, reaching peak blood levels within 30-60 minutes. Half-life averages 5 hours but varies widely (3-7 hours) based on genetics (CYP1A2 polymorphisms).

Key Interactions
Iron Inhibitor
Polyphenols in coffee and tea (not caffeine itself) inhibit non-heme iron absorption by 40-60%. Separate coffee/tea from iron-rich meals by 1-2 hours
Calcium Inhibitor
Caffeine modestly increases urinary calcium excretion (~6mg calcium per 100mg caffeine). Effect is negligible if calcium intake is adequate

Other Other

Frequently Asked Questions

How much Caffeine do I need per day?

There is no established daily requirement for Caffeine.

Which food has the most Caffeine?

The food highest in Caffeine is Beverages, tea, instant, unsweetened, powder with 5,714 mg per 100g.

What does Caffeine do in the body?

Natural stimulant found in coffee, tea, and chocolate. Increases alertness and may enhance physical performance in moderate amounts.