Story by Alan D. McNarie
Photos by Joshua McCullough
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.
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.
“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.”
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.
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.”