By Carrie Peyton Dahlberg - cpeytondahlberg@sacbee.com Published 12:00 am PST Tuesday, February 12, 2008

Our bodies are not created equal. A particular lung cancer treatment can be riskier for people of Japanese ancestry. And there's a new heart failure drug that helps African Americans more than other racial groups.

Yet as geneticists and physicians delve deeper into differences that could save lives, many doctors worry about a dangerous gap in one of the biggest arenas of medical research.

"Pharmaceutical companies do not require minorities. They're just notoriously low" in diverse participation in clinical trials, said Dr. Charles DeCarli, a neurologist who is director of UC Davis' Alzheimer's Disease Center.

While doctors can do preliminary research in labs or on animals, ultimately, they need people to compare results of new diets, drugs or surgical techniques. Many of those treatments will affect all groups the same way, but some won't.

"New knowledge comes from diversity," DeCarli said. "The more diversity you have, the more likely you are to find scientific discoveries."

Since the early 1990s, when the National Institutes of Health began pushing aggressively for racial and ethnic diversity, a divide has emerged in the research that guides health care.

Government-funded research has gradually become more diverse. Industry-sponsored investigations have not, said Ken Getz, a senior research fellow at the Tufts Center for the Study of Drug Development.

The difference is especially troubling, he said, because only about 15 percent of trials for new drugs and treatments are funded by the government. Industry funds 85 percent.

The Endocrine Society, whose doctors treat diabetes, thyroid disease and other hormone-related ills, is so concerned that in December it called for a national task force to address the issue. Already it is suggesting the Food and Drug Administraton require greater ethnic participation in drug trials before new drugs are approved.

A web of factors influences who volunteers for medical studies, ranging from potential risks to personal preferences to how hard recruiters work to be inclusive. Participation is not a choice for everyone.

"You're a guinea pig. I've referred to myself as a human lab rat," said the Rev. Tammie Denyse of Sacramento. "But if we don't have lab rats, we don't ever grow."

Denyse spent hours asking questions and more hours praying before she agreed in 2005 to take part in a breast cancer drug trial.

She ultimately concluded she had to, "for the next generation."

One of her struggles was coming to terms with randomization, knowing she might be assigned to a group that would get a drug combination whose efficacy and side effects weren't fully understood.

In the end, Denyse opted to join partly because doctors told her they didn't know whether certain medications could affect African American women differently.

That's "absolutely unacceptable," she said.

Denyse, whose cancer is three years in remission, hears concerns from fellow cancer survivors about trust, about doctors who already "play with us enough," and about the scandalous Tuskegee study, which still resonates 36 years after it was shut down amid national outcry.

Begun in the 1930s with the aim of monitoring African American men with syphilis, the study never properly explained its goals or got full consent from participants. In the 1940s, it also withheld treatment from participants, even after penicillin became the accepted remedy.

In January, a study published online in the journal Medicine suggested the legacy of Tuskegee partly explained a deep distrust of doctors. Among medical patients surveyed in Maryland, the study found 58 percent of African Americans believed doctors prescribe medicine to experiment on people without consent, compared with 25 percent of whites. And 25 percent of the African Americans – but only 15 percent of whites – thought their doctor would ask them to take part in a study that would hurt them.

Other studies and accounts from research physicians suggest it is incorrect to blame unbalanced research simply on mistrust, language barriers or cultural differences.

"The best way you do this is you just demand you enroll minorities," said UC Davis' DeCarli, who is part of a nationwide team recruiting participants – one-third of them African American, one-third Latino and one-third white – for an Alzheimer's study.

With prodding from the National Institutes of Health, researchers have learned how to better explain their work, explain it in more languages and employ more diverse researchers, DeCarli and other doctors said. Many report success.

For one pilot study looking into prostate cancer markers in African Americans, UC Davis initially recruited 50 people who were willing to hear the study described in detail.

"Not a single African American patient turned us down for this study once they talked to us," said Dr. Ralph deVere White, director of the UC Davis Cancer Center.

Of more than 300,000 people recruited by Kaiser Permanente of Northern California for a vaccine study, about 19 percent are Latino, 19 percent multiethnic, 13 percent Asian American and 8 percent African American.

Nationwide, the NIH found significant diversity in 2006 in "Phase III" clinical trials, the large trials that are the final step of testing before new treatments can be adopted.

When researchers tracked Latino heritage separately from race, and included both at-home and overseas trials funded by the NIH, they were studying a population in 2006 that was about 47 percent white, 18.8 percent black, 12 percent Asian and 11.5 percent Latino.

By comparison, FDA records for one subcategory of new drugs approved between 1995 and 1999 found that only a little more than half of the researchers provided information about race at all.

Of those who did, 88 percent of their research subjects were white, 8 percent black, 3 percent Latino and about 1 percent Asian or Pacific Islander. Black participation dropped nearly in half in the five years studied, and Latino representation was always below population levels.

Pharmaceutical companies understand medicines affect people differently.

They encourage diverse enrollment, but they also work under tough time pressures, said Ken Johnson of the Pharmaceutical Research and Manufacturers of America.

"You can't bring a clinical trial to a screeching halt because you don't fulfill some quota," Johnson said. "You're talking about medicines that save people's lives."

You're also talking about a lot of money – and it can be cheaper to recruit as quickly as possible, even if you don't get an ideal ethnic mix of volunteers, said Dr. Maria Alexander-Bridges, who headed the Endocrine Society's task force on minority participation.

In the face of such cost pressure, the pharmaceutical industry probably will "have to be nudged" by the FDA to widen its net, she said.

"We're trying to understand the disease genes that lead to risk and the genes that lead to differences in how a drug is metabolized in a particular person's body," said Alexander-Bridges.