Mixing kale, cucumber and spinach at her home in Venice Beach, yoga teacher Kia Miller explains her passion for juice, which fans say can trigger a health "reboot." "I like to do it twice a year, it's like a reset button. You have an opportunity to think about your relationship with food," the 44-year-old told AFP in the trendy ocean-front district. "It's a wonderful way to get powerful nutrients in your body," added Miller, whose house has been transformed into an ashram, a place of peace away from the bustle of Los Angeles, half an hour away.Juice bars are everywhere in southern California, which has long embraced New Age culture. In upmarket areas like Santa Monica or Beverly Hills, they are on every street corner. And it's not uncommon to see Angelenos saunter down the street with a polystyrene cup full of vegetable juice, instead of coffee. "It's the new wine," said Miller, serving up a greenish brew to two visiting journalists. Veggie juices can contain anything from kale to ginger, mixed with beetroot, carrots, coconut milk or almonds. For fruit lovers there are dates, nuts, bananas and apples, while cucumber or celery produce lighter juices. Lose 10 kilos in 5 days And while some limit themselves to occasional juice at a neighborhood bar, others have turned it into a lifestyle option, with "cleansing" or "juice detox" regimes lasting three, seven, or even 30 days. Fans say such "cures" are a kind of spiritual experience. On a more practical level, others note that a five-day "cleansing," consuming nothing but juices, can help one shed 10 kilos (22 pounds). Heather, a 42-year-old physiotherapist, has just finished a 72-hour juice detox -- and raves about the experience. "It makes me feel so good it's almost addictive. I feel closer to myself, I feel clear-headed, I feel more energized and my body gets the chance to reboot," she told AFP. Indian juice bar manager Baba Ji has opened two outlets in the last two years in the hipster areas of Silver Lake and Los Feliz, just east of Hollywood. "In the last few years juicing has exploded -- everybody wants to open a juice bar. Everybody want to do a detox," he said. Depending on where you go, a three-day juice "cure" can cost between $120-250, he said. The price can go up to $400 for five days. His customers say they are convinced it has changed their lives. "I have been drinking green smoothies every day for the past two years and the results just has been phenomenal. Higher on energy, decrease need of sleep and I just feel healthy," said yoga instructor Dharan Avtar, 40. 'It changes your life' David Goodman, 37, an inventor and musician, added: "You feel more energy, you sleep better and sleep less. I felt younger when I was 30 than when I was 16 just because of all the juicing. "I've done one for a month, but over the last seven years I did a lot. It's great, it changes your life." In July, financial news weekly Barron's estimated the value of America's juice industry at $5 billion, with annual growth of 4-8 percent. The country has some 6,200 juice bars, concentrated in Los Angeles and New York. And in a sign that the trend is really taking root, a branch of the national Walgreens drug store chain in Hollywood has a juice bar. And cafe giant Starbucks opened its first juice bars this year in Seattle and San Francisco. But nutritionists, while welcoming the growth of vegetable juices, warn against taking it too far with juice-only diets. "It is kind of extreme, and for the general population it's not necessary to exclude all food," Julieanna Hever, a dietician specialized in plants, told AFP. "Why not just eat a more balanced overall diet? Unfortunately people eat what they want to eat, and then they feel they have to detoxify from it ... we all would be better off if we ate healthily all the time." She added: "Our body is made to detoxify. It's got kidneys and a liver and our skin. "Our organs are made to constantly detoxify. So if we stop putting in all the toxins we are going to get healthy anyway. We don't need to go to a special juice cleanse to detoxify."