MALAYSIA - (THE STAR/ASIA NEWS NETWORK) The new trendy diet that is the fixation of certain Hollywood stars is not actually new at all. In fact, it's old - very old - as Annie Mok from Kampar, Perak can attest.

"My mother learned it from her mother, who in turn learned it from her mother," says Mok. "We don't actually know where the recipe came from or how it evolved."

We're talking about bone broths.

This humble dish was once a culinary staple in many homes including Mok's. "I had soup with almost every meal," says the business operations manager and food blogger of Annielicious Food. "The ingredients varied from time to time but it would always be boiled from bones."

Grandma saw it as a source of nutrition, says Mok, not unlike many Chinese at the time. "She always tells me that drinking it will make a woman younger and prettier."

Mok's grandmother was onto something, all right. It's called collagen, the high-protein connective tissues found in animal bones. A powerhouse of vitamins and minerals, collagen has been credited for everything from shinier hair to dewier complexions.

Fast forward several decades and this old curative is experiencing a renaissance. Dubbed the new miracle water by health-conscious proponents, these steaming stews have become a favourite of well-known individuals like Kobe Bryant and Gwyneth Paltrow.

It has also elbowed its way into restaurant menus across the world.

In New York, the fashionable and hipster-ish masses are flocking to the city's first dedicated bone broth specialist, Brodo, where stocks are served Starbucks-style, in takeaway cups.

In Japan, Taiwan and Singapore, the same soups are being marketed as beauty elixirs in ramen bars and hotpot restaurants.

It's no different back home.

At Shabuton Tei, a casual Japanese eatery that opened in Kota Damansara last year, young female patrons can usually be seen tucking into collagen shabu-shabu at all hours of the day.

This meat- and seafood-laden steamboat, with its velvety stew boasting "pure collagen" extracted from chicken carcasses as well as pork femurs and knuckles - all parts with an abundance of cartilage, gelatin and marrow - is served with or without limited-edition slivers of 24-karat gold to amp up its alleged beauty-boosting benefits.

To make what the restaurant calls its "leng lui buo" (pretty girl brew), bones are first thrown into a large boiling vat of purified water together with salt as well as little sachets containing the restaurant's six secret ingredients and cooked for at least 12 hours at a precise temperature, then rested and kept overnight in a chiller.

It arrives at the table resembling Jell-O; but will soon revert back to broth once it's heated up.

Diners, who are encouraged to take the first sip from a teacup, will find it rich and warming, salty but addictive, like something you'd crave when you're not feeling well.

The soup is a concoction of Chef Kanji Fujine, who mastered the art of broth brewing during his eight years as a ramen chef at the legendary Taishoken in downtown Tokyo.

Fujine, who can often be seen sipping the stuff from time to time while he works ("quality control," he says), claims the collagen craze took off in Japan about five years ago.

"It started with the pharmacies. Ladies were buying collagen supplements and topical ointments off the shelves. However, they're realising you can get collagen the natural way, through soups and stocks."

Fujine San, who claims the original Japanese soup is saltier and oilier, spent months experimenting in the kitchen to come up with a lighter version that would appeal more to Malaysians.

And these days, even the men want some. Says Shabuton's spokesperson Janice Chiu: "Just the other day, a group of male diners said they found our place after googling for collagen broth."

To cash in on this fad, Hong Kong-inspired steamboat restaurant Bone & Pot, which has multiple branches across the Klang Valley, has recently introduced collagen soup to its usual repertoire of broths.

With its tagline 'the perfect hotpot recipe for beauty and confidence', this special stew - which is also served in a gelatinous form but with an aside of Chinese herbs such as red dates and wolfberries - combines the restaurant's signature chicken-bone-derived stock and cubes of milky white collagen shipped over from Osaka, Japan.

Processed from fish scales - restaurant owner Mike Cheam prefers to keep any knowledge of the preparation method to himself - the collagen jelly imparts a subtle taste when added to the broth.

Cheam, who spent many years as a restaurateur in Hong Kong, says he got the idea for the collagen soup on a working trip to Japan and Taiwan.

"My brother and I were on the lookout for something new, and we saw how popular collagen was," he says, adding that he now sells four to five bowls of the stuff per day.

Demand for collagen soup is still low in Malaysia, reveals Cheam, because its jelly-like appearance puts people off.

"They are under the impression that it has a higher fat content, but the truth is that any fat or sediment are ladled out as soon as they float to the surface in the boiling process." As such, collagen soup isn't fattier than other bone broths.

The payoff? A range of anti-ageing benefits, from the reduction of wrinkles to the shrinking of pores, at least according to the product brochures available in the restaurant.

This view is echoed by Jasmine and Melissa Hemsley, London-based health-food writers who, in their highly acclaimed book The Art Of Eating Well, lists out a number of recipes for bone broths.

"It is delicious. Natural fats and animal bones are a significant form of protein, collagen, vitamins and minerals - broth is a nourishing all-rounder that is amazing for skin, hair and even dreaded cellulite. It is instrumental in maintaining a healthy gut and an easy-to-digest source of energy that doesn't make you crash or give you jitters like caffeine," says the sisters in a recent interview with UK paper The Guardian.

Aesthetic practitioner Dr Liow Tiong Sin says that, while collagen soups are certainly nutrient-rich, claims that it could work wonders have not been verified scientifically.

"Animal protein contains sufficient amounts of all kinds of essential amino acids for our bodies, and collagen is no different. You can get the same benefits from eating protein-rich foods like meat and cheeses."

Still, people keep coming back for more. Nutritionist Kong Si Mun drops by a hotpot restaurant at least once or twice a month to get her collagen fix and swears by the stuff.

"Frankly, it looked quite unappetising when I first saw it," says Kong who, only last year, made the switch from popping collagen-rich pills to slurping bone broths while pregnant with her first child. "It turned out to be quite delicious."

Meanwhile, Mok prefers making collagen soup at home, the way the women in her family used to do when she was growing up; she now pre-makes six litres of the broth at any one time and sets it aside for days when she needs a jolt.

The soup differs from meat stock, she says: "Meat stock does have collagen content, but it is very low."

"Some women are squeamish when it comes to chicken feet and pig skin, but let me tell you, when it comes to collagen, those parts are a gold mine," she says.