New Evidence Challenges Old Notions About Diet And Survivorship

Main Category: Nutrition / Diet
Also Included In: Cancer / Oncology
Article Date: 09 Nov 2008 - 0:00 PST

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New evidence is shifting traditional approaches to treating and caring for cancer survivors, according to experts at a major conference on nutrition, physical activity and cancer. Researchers, dietitians and policy makers gathered today in Washington to hear about the latest progress in the study of diet's role in survivorship.

The survivorship session was part of the Annual Research Conference on Food, Nutrition, Physical Activity and Cancer hosted by the American Institute for Cancer Research (AICR).

Going Further with Soy and Selenium

Do soy foods help or hinder recurrence of breast cancer? AICR grantee Stephen Barnes, PhD, of the University of Alabama in Birmingham referred to the large body of often-conflicting evidence from animal studies, clinical trials and studies of large populations in Asia and Western countries.

Dr. Barnes noted that eating soyfoods doesn't seem to offer much protection from breast cancer among healthy post-menopausal women. However, scientists are still investigating the possibly protective influence of soy when eaten during puberty.

"It's a good idea to eat minimally processed soy foods such as tofu, soymilk, miso and tempeh, rather than specific, enriched supplements," he said.

Karam El-Bayoumy, PhD, of Pennsylvania State University is investigating how various forms of the mineral selenium seem to alter prostate cancer cells.

"The long development period of prostate cancer presents an ample opportunity to intervene before the disease can progress. Diet appears to play a critical role," he said.

El-Bayoumy reported on his lab's trial with Caucasian and African-American men, where selenium seemed to reduce levels of a substance in the blood that indicates inflammation. This effect was more pronounced among white men. In test tube experiments with prostate cancer cells, selenium seemed to stop cell growth and speed tumor cell death.

Breast Cancer, Fruits and Vegetables

John P. Pierce, PhD, of the University of California-San Diego initiated the Women¹s Healthy Eating and Living (WHEL) trial in 1993. The study randomly assigned 3,088 women aged 18-70 years who had early stage breast cancer to different groups to compare the effects of eating different amounts of high-fiber foods like vegetables and fruits.

The study found that women who were already eating 5-7 or more servings per day of vegetables and fruits and getting 30 minutes of moderate daily exercise before being enrolled in the study had the lowest mortality rate and cancer recurrence rate. However, women who increased fruit and vegetables in their diets after breast cancer diagnosis did not generally reduce their cancer recurrence or mortality risk.

At the AICR conference, Dr. Pierce reported findings from a subgroup of high-risk women who had been treated with tamoxifen. His preliminary findings suggest a potential protective role for fruits and vegetables among this group.

Could Survivors Benefit from Holistic Therapies?

"Whole systems of care are likely to be more effective than reductionist interventions," said Stephen M. Sagar, MD, of McMaster University in Ontario. Nutrition, mind/body therapies and dietary supplements can positive or negative influences a survivor's medication and other standard medical treatments, he said. A comprehensive approach to care is more likely to help their recovery, adaptation and healing following a cancer diagnosis.

Barrie R. Cassileth, PhD, of Memorial Sloan-Kettering Cancer Center, also discussed integrative oncology. "This new field represents the new era of cancer care," she said. The goal is to ease the physical and emotional symptoms that start at diagnosis and may endure for years afterward, using techniques from fitness programs, such as tai chi, and complementary therapies such as acupuncture and massage. Cassileth summarized the research to date in this field.

The Take-Home Message for Cancer Survivors

AICR's expert report recommends that cancer survivors receive nutrition advice from a health professional and follow AICR's guidelines to eat a mostly plant-based diet, get at least 30 minutes of physical activity a day and maintain a healthy body weight.

The American Institute for Cancer Research (AICR) is the cancer charity that fosters research on the relationship of nutrition, physical activity and weight management to cancer risk, interprets the scientific literature and educates the public about the results. It has contributed more than $86 million for innovative research conducted at universities, hospitals and research centers across the country. AICR has published two landmark reports that interpret the accumulated research in the field, and is committed to a process of continuous review. AICR also provides a wide range of educational programs to help millions of Americans learn to make dietary changes for lower cancer risk. Its award-winning New American Plate program is presented in brochures, seminars and on its website, http://www.aicr.org. AICR is a member of the World Cancer Research Fund International.

American Institute for Cancer Research