Laura Ungar

USA TODAY

Doctors, genetic counselors and women are challenging comments by singer Melissa Etheridge implying that genes for breast cancer could be turned on or off by diet, calling such assertions inaccurate and hurtful and worrying they may influence millions of people because of her celebrity.

But Etheridge — a breast cancer survivor with a mutation in one of the genes — said in an interview with USA TODAY that she's been misunderstood, and "I was sad there was such a negative response to what I said."

She most recently shared her views in the current issue of AARP Magazine, which describes itself as the world's largest-circulation magazine, with more than 35.2 million readers. In a graphic with an article on how she and singer Sheryl Crow beat cancer, Etheridge is quoted as saying: "I have the BRCA2 gene but don't encourage women to get tested. Genes can be turned on and off. I turned my gene on with my very poor diet."

Twenty doctors, other breast cancer experts and leaders of FORCE, a support group for women with the genetic mutation, signed a letter to the editor of AARP Magazine saying Etheridge "presents information that is dangerously misleading to your readers," and that it's "equally troubling" that she seems to discourage women from genetic testing. The National Society of Genetic Counselors submitted a similar letter, and scores of patients are criticizing her comments on social media.

Doctors say everyone is born with two copies of genes called BRCA1 and BRCA2, but those with a mutation in one of the genes have a much higher lifetime risk of breast and ovarian cancers — up to an 87% lifetime risk for breast cancer. This is "not because the gene is 'turned on' but because they lack a working copy of one of the genes involved in preventing cancer development," the experts wrote.

"At this point, we don't have a way to turn on or off BRCA1 or 2," said oncologist Susan Domchek, director of the Basser Research Center for BRCA at the University of Pennsylvania. "While eating a healthy diet is a good idea for anyone, it does not impact what happens with the gene. There's nothing you can do to make that bad copy into a good copy."

Etheridge, 53, of Los Angeles, acknowledged she shouldn't have used the words "turn genes on."

"I should have said 'gene expression,' " she said. "From what I understand, there are nutritional and environmental factors that contribute to gene expression."

Celebrity doctor Dean Ornish, founder and president of the Preventive Medicine Research Institute, agreed lifestyle changes can affect gene expression. Ornish is submitting a column on the widening controversy to Time and The Huffington Post saying, "Whether or not someone chooses to have a (preventive) mastectomy, changing diet and lifestyle may reduce the risk of developing breast cancer. These lifestyle choices provide an opportunity to empower, not blame."

"The BRCA genes play a role. The lifestyle factors play a role," Ornish said in an interview. "If we're just victims of our genes, then we're powerless."

On the testing issue, Etheridge said it's up to a woman if she wants to get tested, but "if someone asked me personally, I would not encourage them to get tested." She said she got tested on the advice of a doctor.

Domchek countered that "genetic testing can be a lifesaving intervention" because women with the mutation can choose stepped-up screening with breast MRIs as well as mammograms, preventive double mastectomies and surgery to remove their ovaries.

"Not looking doesn't mean the gene mutation is not there," said Judy Garber, director of the Cancer Risk and Prevention Program at Dana-Farber Cancer Institute.

Katie Pass of Louisville underwent preventive surgery to remove both breasts last year after learning in 2009 she had the BRCA2 mutation, placing her among around one in 300-500 people with either of the BRCA mutations. Breast cancer seemed to stalk her family, killing her mother when Pass was 8.

Pass called Etheridge's comments "absolutely ridiculous."

"I don't think that diet and exercise alone can keep you from getting cancer," said Pass, 32, adding that Etheridge should have thought more about what she said. "There are some people who will listen to her. Celebrities have a big impact on society."

Amy Clukey, outreach coordinator for FORCE in Louisville, agreed, saying she conversed with Etheridge on Twitter about the nutrition issue. "So many of us have seen family members die," she said. "They don't cause their own cancers. It doesn't matter how much green tea you drink or how much yoga you do. This is victim-blaming."

Etheridge said, "The last thing I want to do is blame people."

But she said she deeply believes in the power of good nutrition and would encourage other people who are so inclined to look into it as well. She said she began adopting a more balanced, alkaline diet during chemotherapy, which involves eating more vegetables, fruits and whole grains and less processed foods.

Etheridge said she's not surprised by the backlash — or the support she's gotten from some women with the mutation. "I knew all along there would be people who disagreed. I never wanted that to stop me from saying anything," she said. "I can't control the way people understand something."

Robert Love, editor in chief of AARP Magazine, said in a statement that his magazine didn't "take a position or prescribe medical recommendations for breast cancer testing or treatment" and "did not intend for the views expressed in the article to be interpreted as medical advice." Love pointed out that in the same story Crow recommended regular mammograms and testing.

Etheridge said she never meant to stir up controversy about testing and nutrition, but added: "If I can start a conversation, if there's thought and introspection on this subject, that's got to be a good thing. I know I'm walking a very fine line. Believe me, I know this is hard. I mean no ill will."