The last thing you want to wear into Dr. Robert Bibb's dermatology office is a dark tan and a milk mustache.

"A tan is the body's response to damage," said Bibb, who suspected that ultraviolet A rays were more than innocent bystanders to sun damage years before it became popular knowledge. Now, dairy products and their link to hormonally sensitive cancers is on his radar. While dermatologists routinely advise patients to get their vitamin D from dietary sources instead of sunlight, Bibb doesn't want them getting it from yogurt and cheese.

He's working on a book titled "Death by Dairy" to warn consumers about a possible dietary danger.

From 1928 to 1948, milk was exposed to ultraviolet light to form vitamin D, Bibb said. During that time, no active hormones were present in milk. Then the industry started adding vitamin D powder, a cost-saving alternative, but soon after, breast and prostate cancer rates began a steep rise.

"My working hypothesis is that ultraviolet light incidentally inactivated the homones and proteins in dairy - and we proved this at Clemson [University]. There's an association between dairy [consumption] and hormonally sensitive cancers. I looked, but I can't find any other factors that fit epidemiologically [for the rise in cancer]."

Non-dairy consuming countries, such as China and Japan, have lower rates of prostate and breast cancer, Bibb said.

"It's a Western Hemisphere phenomenon. It's not just us. Man is the only mammal that doesn't wean its babies off milk."

That's not Bibb's only concern. When cows are treated with genetically engineered growth hormone to boost milk production, they produce more insulin-like growth factor, which stimulates cell growth. Bibb's theorizes that dairy-rich diets may render children less resistant to cancer.

"A gene can be turned on or turned off," said Bibb, "Suppose your consumption of dairy turned off some of the switches, but you didn't get cancer. You pass your gene on to your daughter or son and they have some of those turned-off switches ... this is all theory, but I believe it explains the phenomenon [of prostate and breast cancer occuring in younger people]."

Although dairy products' link to certain cancers have been suspected for at least 30 years, many health groups vouch for their safety. But other scientists, such as Dr. Ganmaa Davaasambuu, a research fellow at the Harvard School of Public Health, are independently questioning dairy's relationship to cancer.

"A groundswell is building on this thing," said Bibb, who filed for a patent for a dairy process that would neutralize harmful proteins and hormones. The whole exercise could be a waste of time if the dairy industry doesn't respond, or it could become the biggest thing since pasteurization.

"I'm not out to destroy the dairy industry," Bibb said. "I'm going to save them."

He ran his ideas past Dr. Daniel Nixon, a Charleston internist and cancer researcher, known for his work at Hollings Cancer Center at the Medical University of South Carolina.

"We've already proved that lower-fat diets help. That may tie into Bibb's milk theory. It's a testable hypothesis to see if he's right," Nixon said. "This is the way scientists work most of time. That's why I appreciate Dr. Bibb - because he's willing to have his ideas tested in the lab."

Bibb first met Nixon at one of his lectures on the chemopreventive properties of ellagic acid in raspberries.

"That was about 10 years ago. [He] also heard me at a lecture talking about the different chemicals in plants with cancer-fighting properties. There are about 1,000 of them," Nixon said. "One of the things I put into my lectures is that 80 percent of cancers are preventable - skin, prostate, breast, colon, the common ones - through diet and nutrition."

Bibb already takes all his acne patients off dairy because those foods aggravate the condition. As a vegan, he avoids milk products in his own diet. And it makes him nuts when celebrities - especially those who have had cancer - show up in "Got Milk?" ads.

Breast cancer survivor Sheryl Crow was interviewed in a cancer magazine where she also endorsed milk in an ad, so Bibb wrote the singer and the magazine about misleading the public.

"She didn't respond," he said.

Unless he can make his case on "Oprah," Bibb's afraid public opinion will remain in the hands of the Dairy Council because most people don't read scholarly research studies in their spare time.

"People say to me, 'Bob, you can't change an industry,'" Bibb said. "But 'Silent Spring' by Rachel Carson made people realize that the pesticide DDT was concentrating its way up the food chain."

When that prompted Congress to investigate, under mounting public pressure, production stopped, he said.

"If I do this [book] well and explain in layman's terms ... Even if you don't care about you, what about your grandkids?"