There was a long pause.

‘‘Eat right and exercise,’’ the doctor said, adding, ‘‘Aren’t you a dietitian?’’

It was Dyer’s turn to pause. Her knowledge was basic at best.

‘‘I knew cancer patients should eat all foods in moderation, get five servings of fruits and vegetables each day, reduce fat in the diet to less than 30 percent (of total daily calories) and reduce alcohol or limit it to one drink a day,’’ said Dyer, who was a featured speaker at the Nutrition After Cancer conference in Chicago earlier this month. The American Institute for Cancer Research, a charitable organization, sponsored the daylong event.

After this exchange with her oncologist, Dyer figured it was time to find out more about how diet can positively affect cancer survivorship. She redirected her career path, since self-publishing a book and developing an Internet site,

http://www.CancerRD.com/

She figured meals lovingly prepared would boost her energy and spirit, even if no researcher could quantify the effect.

‘‘The first thing I did was go back to cooking,’’ she said. ‘‘I wanted to get my family out of the fast-food habit.’’

Dyer focused on which foods are most potent in the phytochemicals (plant substances) that fight off cancer. The result is a full two-week ‘‘family tested’’ menu on her Internet site.

‘‘A slice of whole wheat bread has 800 phytochemicals,’’ she said. ‘‘A slice of white bread has eight. I want every one of those molecules in my body.’’

Dyer is faring quite well since 1995, which was her second breast cancer diagnosis. Doctors first spotted breast cancer in 1984. The last diagnosis prompted her to be more aggressive with her nutrition plan.

More than 200 people attended the downtown Chicago conference. One-third were nutritionists, while the remainder of the group were cancer survivors and loved ones. It was the third conference about nutrition therapy and cancer sponsored by the American Institute for Cancer Research, to be commended for helping break new ground in the nutrition field. Ten years ago, any doctor promoting nutrition as therapy was considered suspect.

‘‘MDs used to talk about physicians who had ‘gone off to alternative medicine’ as if they had decided to live at the bottom of the Grand Canyon,’’ said Dr. Richard Rivlin, the conference’s leadoff speaker.

Rivlin built an inter-institutional nutrition program at Memorial Sloan-Kettering Cancer Center and Cornell University. There still is significant room for improvement, he said.

‘‘You want to guess how many U.S. medical schools require nutrition classes? he asked the audience. ‘‘Only one-quarter.’’

For the cancer survivors in the room, Rivlin and other speakers offered practical tips. Rivlin’s lab is showing that garlic supplements might provide more anti-cancer agents than fresh garlic. He said carrots seem to be better cancer fighters when steamed slightly because of ‘‘bioavailability.’’

Mark Messina, a soy researcher at Loma Linda University in California and former National Cancer Institute leader, presented evidence that childhood and teenage consumption of soy might protect against cancer, even if soy intake decreases in adult years.

Another attention-getter was a study of 40 men with prostate cancer who didn’t react well to medical treatments but experienced improvement by adding two daily servings of soy.

Duke University researcher Wendy Demark-Wahnfried offered some educated guesses about flaxseed.

‘‘We don’t know the exact dose of flaxseed for preventing cancer recurrence,’’ said Demark-Wahnfried. ‘‘Three tablespoons per day is what we are using 1/8in a new government-funded prostate-cancer study that produced beneficial preliminary results 3/8. We arrived at this amount because the average man gets about 14 to 15 grams of fiber in his daily diet. Adding this much flaxseed pushes it to about 30 grams. We didn’t want to push the upper limits of 35.’’ (That would be overdoing it.)

Flaxseed is high in omega-3 ‘‘good’’ fats associated with protecting against cancer and heart disease. You can grind flaxseeds with a coffee bean grinder and add them (providing a nutty flavor) to cereals, yogurt, smoothies, puddings, juices, muffins and breads.

Flax oil is available at natural groceries and health-food stores. You pay for convenience - seeds are inexpensive - but Demark-Wahnfriend warned not to sacrifice nutritional value.