Carrot juice more than doubles beta-carotene absorption, study finds

Drinking carrot juice more than doubles the body's absorption of beta-carotene compared with eating raw carrots, according to a new South Korean study.

A research team led by Park Eun-ju, a professor in the department of food and nutrition at Kyungnam University, compared beta-carotene bioavailability in 16 healthy adults in their 20s and 30s after they consumed either raw carrots or fresh carrot juice. The findings were published in the international nutrition journal Nutrition Research and Practice, the Korea Food Communication Forum reported Wednesday.

Beta-carotene is the pigment responsible for the orange color of carrots. Once inside the body, it is converted into vitamin A as needed and helps maintain normal vision and immune function.

Participants consumed raw carrots and carrot juice on separate occasions, with both portions calibrated to deliver an identical 25 milligrams of beta-carotene — 320 grams of raw carrot and 530 grams of carrot juice. Because beta-carotene is a fat-soluble nutrient that is better absorbed alongside fat, both groups also consumed 50 milliliters of canola oil.

Ninety minutes after consumption, blood beta-carotene concentration in the raw-carrot group stood at 3.74 micrograms per deciliter, while the juice group measured 8.72 micrograms per deciliter — 2.3 times higher. A marked difference between the two groups persisted from 30 minutes to six hours after consumption.

"It appears that the juicing process breaks down the fibrous structure of the carrot, allowing beta-carotene to be released and absorbed more easily," Park said.

However, juicing strips away most of the dietary fiber found in the original vegetable. Because fiber is concentrated in the skin and pulp, and juicers filter out both, little of it makes it into the final drink.