Higher levels of carotenoids may reduce breast cancer risk

At a Glance

The results of a new large study indicate that women with higher plasma carotenoid levels have a reduced risk of breast cancer, and particularly the more aggressive tumors.

 Read more about this research below.

Carotenoids are among the nutrients needed for plant photosynthesis.  They are also the pigments in fruits and vegetables that provide  the yellow, orange and red colors. Of over 600 known dietary carotenoids, a-carotene, b-carotene, b-cryptoxanthin, lutein, zeaxanthin, and lycopene are the most prevalent in the US diet, comprising 90% of circulating carotenoids.  Current evidence suggests that carotenoids may reduce breast cancer risk, but at what stage they are most influential and in what tumor subtypes is less clear. 

In a recent large study published online in the American Journal of Clinical Nutrition, researchers examined the issues of timing of carotenoid exposure as well as associations by breast tumor subtypes. 

The study group included 32,826 women that participated in the Nurses’ Health study and donated blood samples in 1989-1990.  In 2000-2002, 18,743 of these women donated a second blood sample.  Women diagnosed with breast cancer between first and second blood collection, and those diagnosed with breast cancer within ten years of the second collection, were matched with control subjects.

After adjusting for several breast cancer risk factors, significant inverse associations were observed between a-carotene, b-carotene, lycopene, and total carotenoids and breast cancer risk with an overall 18–28% lower risk in the women with the highest blood levels compared to women with the lowest levels. The protective benefits of b-carotene and total carotenoids were more pronounced in leaner women (BMI < 30).  In addition, a-carotene, b-carotene, b-cryptoxanthin, and total carotenoids were associated with a 46% reduction in risk of the more aggressive types of cancer than recurred or caused death.

In this large prospective analysis with 20 y of follow up, women with the highest blood levels of carotenoids had a significant reduction in breast cancer risk, and particularly the more aggressive and lethal subtypes.

A Heather Eliassen et al.  Plasma carotenoids and risk of breast cancer over 20 y of follow-up. Am J Clin Nutr doi: 10.3945/ajcn.114.105080

Moderate soy intake is not related to a negative breast cancer prognosis

Should women be concerned about the potential of soy foods to either cause breast cancer or decrease the survival rate for women who have been diagnosed with breast cancer? 
Here is a report that suggests there is not a connection.

At a Glance

Recent epidemiologic studies report no adverse effects of soy foods on breast cancer survival or prognosis.  Read more about this research below. 

Contrary to earlier clinical studies and some popular media suggesting that soy may promote breast tumor growth, three recent studies show that moderate intakes of soy-containing foods are not adversely related to breast cancer prognosis.

In the most recent study researchers used data from the Women’s Healthy Eating and Living (WHEL) study to examine the effect of soy intake on breast cancer prognosis. Soy isoflavone intake was assessed in 3,088 breast cancer survivors diagnosed between 1991 and 2000. After an average follow-up of 7.3 years, it was found that as isoflavone intake increased, risk of death decreased. Women whose intake was >16.3 mg of isoflavones had a 54% reduction in the risk of death.

This is the third recent epidemiologic study to report no adverse effects of soy foods on breast cancer prognosis. Because these studies varied by ethnicity and the level and type of soy consumed, the investigators stated that when taken together, these studies provide evidence to suggest that it may not be necessary for clinicians to advise against moderate soy consumption for women with a diagnosis of breast cancer.

Caan BJ et al. Soy food consumption and breast cancer prognosis. Cancer Epidemiol Biomarkers Prev. 2011 May;20(5):854-8.

The following is a summary of a previous Essentials of Health from Jan 27, 2010. Also included are two more recent study references with similar outcomes.

“In a large prospective study of female breast cancer patients treated surgically, moderate soy intake was associated with a significant decrease in death and cancer recurrence during a 4 year follow-up. Women whose intake of soy protein was among the top 25 percent of participants had a 29 percent lower risk of death during follow-up and a 32 percent lower risk of recurrence compared to those whose intake was in the lowest quarter.  This study suggests that moderate soy food intake is safe and potentially beneficial for women with breast cancer.”

Shu XO et al. Soy food intake and breast cancer survival.  JAMA 2009;302(22):2437-2443

Zhang YF, et al. Positive effects of soy isoflavone food on survival of breast cancer patients in China.  Asian Pac J Cancer Prev. 2012;13(2):479-82.

Nechuta SJ et al. Soy food intake after diagnosis of breast cancer and survival: an in-depth analysis of combined evidence from cohort studies of US and Chinese women.  Am J Clin Nutr. 2012 Jul;96(1):123-32.

 

Anti-Cancer, a New Way of Life: review

Cancer changes life. I found this book while undergoing treatment for breast cancer.  After I had undergone a lumpectomy and radiation treatments, I wanted to learn more about cancer and more important, be a part of my own healing.

Dr. David Servan-Schreiber*, was a physician and scientist, wrote Anti-Cancer: A New Way of Life to share his experiences with cancer, and what he learned as a result of his ordeal. He was at the top of a successful career as a psychiatrist and research scientist when he discovered by chance that he had a malignant brain tumor. After receiving his unwelcome diagnosis and undergoing the treatment for disease, he found that his physicians could not answer many of his questions regarding what he might do to increase his own ability to fight the cancer.

His thesis is simple: All of us have cancer cells in our bodies, but not all of us will develop cancer.
What are the factors that contribute to the formation of this disease, and what if anything can we do to prevent cancer or discourage it if we already have it?

Dr. Servan-Schreiber shared his journey, research, and what he learned about diet, environment, emotions, stress and lifestyle and how these factors can influence the body's immune response.

He concluded that the causes of cancer are similar to the causes of other chronic diseases, including unhealthy diet high in sugar and fat, exposure to toxins and pollution, high stress lifestyle, lack of exercise, and the loneliness of modern life for many people.  His focus is holistic, looking at the connections between the body, mind and spirit.

I realized that I needed to make significant changes in my life. I had been living at a distance from my family that made it difficult to see them often, so I moved to where they live.

I was disappointed that Dr. Servan-Schreiber has no religious beliefs though, as I personally believe that religious faith can be a strong factor in health and well-being. But overall this is a positive, encouraging book.

The anti-cancer diet is based on the Mediterranean diet.  It is primarily plant-based, including 5-9 servings of fruits and vegetables, and whole grains. It is low glycemic, and also high in omega-3 foods.

Dr. Servan-Schreiber strongly recommended foods that are high in anti-oxidants, but he did not discuss nutritional supplements as a factor in getting enough anti-oxidants.

I found that trying to get enough anti-oxidants and omega-3 fatty acids through my diet alone was complicated.  So I also take a comprehensive nutritional supplements which include mega antioxidants, chelated minerals, and omega 3 fatty acids.

Adopting the anti-cancer diet and lifestyle along with taking nutritional supplements daily has markedly improved my health, given me more energy and greater immunity to colds and flu.

*David Servan-Schreiber (April 21, 1961 – July 24, 2011)^[1] was a French physician, neuroscientist and author. He was a clinical Professor of Psychiatry, University of Pittsburgh School of Medicine.^[2] He was also a lecturer in the Faculty of Medicine of Université Claude Bernard Lyon 1. (from Wikipedia)