Issue 15.5: October/November 2012

Root Medicine

Story by Alan D. McNarie

Photos by Joshua McCullough

 

Ed Johnston’s verdant farm on the North Hilo coast looks more like a landscaped garden than a commercial nursery. Here at his Alia Point ‘Awa Nursery, samples of the thirteen surviving Hawaiian cultivars of ‘awa all grow scattered along a mountain stream. They are bush-size plants with jointed stems reminiscent of bamboo — except that these stems, unlike straight up-and-down bamboo, tend to twist and branch, and they support heart-shaped leaves. The leaves look pretty much the same in all varieties of ‘awa (also known as kava); it’s the plants’ stems and each cultivar’s unique combinations of chemicals called kavalactones that distinguish them.

 

The ancient Hawaiians were well aware of those differences and put the thirteen cultivars to varying medicinal uses. The Mo‘i cultivar, for instance, has relatively straight stems, so dark that they’re often almost black; often offered ceremonially to the gods, Mo‘i also treated headaches and urinary problems. ‘Awa Nene has green internodes—the sections of stem between the joints—that are heavily mottled with purple spots; in old times, Johnston notes, “It was used for calming upset babies.” Hawaiians traditionally used Papa ‘Ele‘ele, which has short, stout, dark purple-colored internodes, to treat urinary conditions.

 

When Mark Twain visited Hawai‘i in 1866, he saw ‘awa for sale in the local markets. “It is said that but for the use of this root, the destruction of the people in former times by certain diseases would have been far greater than it was,” he wrote. Being Twain, he also noted he’d heard skepticism about those claims. Indeed, though its patterns of consumption have varied widely in the last two centuries, the question of ‘awa’s relationship to human health is still alive and well today—and in labs as far away as Minnesota and Aachen, Germany, promising new discoveries are now being made.

 


 

Before Westerners arrived, drinking ‘awa was a central part of the Hawaiian lifestyle—not just for medicinal and ceremonial purposes, but also simply to relax at the end of a day’s work. The beverage was traditionally made by crushing the ‘awa plant’s roots and mixing them with water (or coconut water or cane juice). The kavalactones they contain functioned as muscle relaxants, giving many drinkers a sensation of calm.

 

Early missionaries likened ‘awa to alcohol and worked to ban it. By the twentieth century, ‘awa had largely disappeared from the landscape. In the 1990s, however, it made a major comeback. ‘Awa bars opened in Mainland and European cities, and commercial extracts of the plant caught on as natural remedies for a stressed-out world. But then a series of studies linked ‘awa to possible liver damage, and several countries, including most of those in Europe, banned ‘awa outright; in the United States, the Food and Drug Administration issued an advisory about the dangers of liver damage in 2002. Sales plummeted.

 

Today interest is again rising in the plant. Recent scientific studies have suggested that the actual rate of liver problems caused by ‘awa ingestion may be as low as one in four million—and that even those cases may have been due to the way some commercial companies prepared their extracts: using stems and leaves along with the roots and extracting the kavalactones with commercial solvents.

 

Other studies are suggesting that ‘awa may be good for far more than relaxation. Researchers at the University of Minnesota, the University of California, Irvine and other schools are finding that the plant may be useful in fighting or preventing lung cancer, colon cancer, bladder cancer, leukemia and hormonal refractory prostate cancer (HRPC).

 

“[N]ew agents that are particularly designed for the prevention and treatment of HRPC are highly desired,” noted the UC-Irvine team of researchers in a paper announcing the discovery of one such agent, a chemical called flavocawain B found in ‘awa. In fact, said team member Dr. Xiaolin Zi, the researchers found that several bioactive compounds in ‘awa send signals to HRPC cells to destroy themselves— to commit, as Zi puts it, “cancer cell suicide.”

 

Zi, an associate professor of urology, pharmacology and pharmaceutical sciences at UC-Irvine, has been studying the possible effects of kavalactones on cancer since 2000. His studies have used rats that are injected with tobacco carcinogens and then exposed to various compounds isolated from ‘awa. He is convinced that several of those compounds can help prevent bladder and prostate cancer.

 


 

Chengguo Xing, a member of the research team at the University of Minnesota, is more cautious, but he too is optimistic about ‘awa’s impact on human health. “What we can say at this moment is that kava can slow down cancer development in animal models,” he says. “We don’t know if kava can be used to treat cancer [in humans].” The Minnesota studies were originally designed “to explore if ex-smokers … should take kava as a preventative approach to reduce their risk of lung cancer,” Xing says. To test the question, mice in the very early stages of cancer were given ‘awa in their food.

 

“Our data clearly demonstrated that the mice that take kava on a daily basis have a smaller lung cancer load [number of tumors], and the tumors are smaller, too,” says Xing, who notes similar results with colon cancer.

 

Both Zi and Xing say their interest in ‘awa as a cancer-fighting agent sprang from a study that found significantly lower cancer rates in South Pacific societies where ‘awa was still commonly used— especially among men, the primary users of ‘awa, even though the men often smoked.

 

The University of Minnesota team also looked into the link between ‘awa and liver damage and found something salient: “We noticed that the commercial preparation of ‘awa has quite a different composition compared to the traditionally prepared water mix or coconut water mix,” says Xing. 88The group obtained both traditional ‘awa infusions and several brands of commercially prepared ‘awa, broke them into “fractions,” analyzed the components of each fraction and fed the different fractions to different groups of mice. “The mice that got the traditional kava survived okay,” says Xing. “But the mice that got the extra components from commercial kava not detectable in traditional kava were immobilized really quickly and died.” In fact, he adds, they died too quickly to determine whether liver damage had occurred: “The extra components in commercial kava are definitely more toxic. Whether they are more liver-toxic, we don’t know at this point.”

 


 

To get their supplies of pure, traditionally prepared ‘awa, the Minnesota researchers turned to Johnston. They sent a graduate student, Amanda “Cece” Martin, to Johnston’s nursery to learn his methods, from the first plantings to the final preparation of the drink. Johnston, who has been growing and drinking ‘awa for almost three decades now, is a master at preparing the drink. Martin returned to Minnesota with live and frozen plant samples and new insights about why the traditional waterbased solution may be safer than commercial powders and tinctures. When the ‘awa drink is being made, she says, “You can actually see the kavalactones coming out, because they’re yellow and kind of oily, so you have this yellow oily sheen on the water.” Water, she notes, is not a great solvent for extracting oily substances, so some commercial producers use solvents such as ethanol to get more kavalactones out of each pound of ‘awa. But in medicine, she notes, “It’s not necessarily that more is better. [What you’re looking for] is the right amount. And with kava an aqueous solution produces the right amount.” Industrial solvents may even extract some compounds from the plants that water will not, which could explain the different chemical signatures of traditional ‘awa drinks and commercial powders.

 

Johnston also showed Martin how to properly ship cut ‘awa nodes in slightly moist sphagnum moss. After much experimentation with moisture and light levels, she’s now successfully growing the descendants of those cuttings—eight traditional Hawaiian ‘awa cultivars—in greenhouses in Minnesota.

 

Meanwhile, over in Germany, a team of scientists at the University Hospital Aachen has been examining the possible effects of ‘awa on another vicious disease: Alzheimer’s. Lethal though some kavalactones may be for cancer cells, they may have just the opposite effect on neural cells: a 2008 study by the German team found that kavalactones may help prevent Alzheimer’s-affected neurons from dying.

 

It works like this, they believe: If too much oxygen gets into a cell, it can damage vital cellular components such as lipids, DNA and RNA; some studies indicate that brain cells in Alzheimer’s patients may be destroyed in part because the patient’s altered brain chemistry allows such oxidative stress. The German study found that kavalactones can help activate neurons’ natural defenses against oxidative stress. “These findings indicate that the use of purified kavalactones might be considered as an adjunct therapeutic strategy … in Alzheimer’s disease and other oxidative stress-related diseases,” the study concluded.

 


 

Most of this new research is still very preliminary, full of qualifying words such as “may” and “might” and often ending in recommendations for further study. But it’s still good news for ‘awa growers like Johnston, who has been cultivating his own relationship with ‘awa since 1985, when a friend first guided him to two ‘awa patches during a hike in Waipi‘o Valley. Intrigued, he began collecting different varieties, and today he is a leading authority on the plants. In 1998 he and famed Hawaiian agronomist Jerry Konanui founded the Association for Hawaiian ‘Awa, and in 2006 the association published probably the best reference work available on local ‘awa: Hawaiian ‘Awa: Views of an Ethnobotanical Treasure, which Johnston co-wrote and co-edited. He and Konanui discovered that ‘awa begins to spoil almost immediately after it comes out of the ground; they’ve taught other local growers to purée and freeze the roots on the day of harvest, and some local kava bars have begun selling drinks made from this healthier—and much better-tasting—alternative to powdered ‘awa.

 

Though the FDA advisory on ‘awa still stands, Johnston is hopeful that more research will clearly illustrate the differences between fresh, properly prepared ‘awa and commercial concoctions. He is hugely optimistic about the plant’s future and its potential. “My thoughts always go back to the Hawaiian people, who today have such high rates of cancer,” he says. “Their ancestors selected these thirteen ‘awa cultivars, all of which are unique to Hawai‘i. If people today could just reconnect and embrace ‘awa as a part of their culture, it would be an amazing thing if that would also cause cancer rates to go down. The link hasn’t been totally proven yet—but it’s sure beginning to look like it exists.”