An AICR-funded researcher interested in how dietary components can aid cancer treatment, Gilda Hillman, PhD, is exploring how soy may sensitize cancer cells to radiation therapy. Hillman is an Associate Professor of Radiation Oncology at the Karmanos Cancer Institute at Wayne State University School of Medicine in Detroit, Michigan. Her latest research, now in clinical trials, has shown that soy isoflavones not only improve the ability of radiation to kill prostate cancer cells but also protect healthy cells from the lethal effects of radiation.
Q: How did you become interested in soy and cancer prevention and what have you found?
A: As a radiation oncologist, I was interested in finding ways to improve radiotherapy. Radiation is typically very effective but there are always resistant tumor cells. I worked closely with clinicians and asked how we could improve the treatment. One of my close collaborators suggested I take a look at soy.
We started with cell culture and animal studies and found that soy helped radiation work better to kill tumor cells and inhibit tumor growth by targeting cell survival pathways. We also conducted clinical trials with prostate cancer patients in the early disease stage. What we found was amazing – patients given soy tablets during radiotherapy had fewer side effects, causing less diarrhea and incontinence and better sexual function. Not only can soy enhance the impact of radiation on cancer tissue, it also can protect normal tissue.
"Not only can soy enhance the impact of radiation on cancer tissue, it also can protect normal tissue…. The message for the public is to use soy in the natural way and not use the isolate in high amounts. "
Q: Can you talk more about the cellular mechanisms involved in soy and radiation therapy?
A: When a cancer cell receives radiation, it causes damage to its DNA. This, in turn, activates DNA repair molecules, which try to repair the damage. The molecules involved, APE1/Ref-1 and the transcription factors, NF-kB and HIF-1alpha, make cancer cells resistant to radiation.
We found that soy decreases the expression and activity of these molecules in cancer cells, and soy is generally non-toxic and safe to normal tissues. Dietary isoflavones in soy beans seem to regulate cell signaling and sensitize cancer cells to apoptotic cell death.
A: With funding from AICR, we are currently looking at the effect of radiation on the normal lung. We know that radiation can be very detrimental to lung tissue by causing pneumonitis and fibrosis. Scar tissue that develops in the lung can impact the ability to breathe. We are looking at two things: the effect of soy on lung tumors and on the normal lung.
Q: Are there any downsides to consuming soy?
A: The most active component of soy is genistein. Pure genistein enhances radiation therapy, but when we used it alone, it also promoted metastases in prostate tumor animal models. In our current studies, we use a soy extract rather than purified genistein. The natural soy extract does not promote metastases. The message for the public is to use soy in the natural way and not use the isolate in high amounts. People also need to understand that conventional treatment is necessary to destroy the bulk of a tumor. Cancer cannot be treated successfully with dietary supplements alone.
Q: Have you incorporated soy in your diet?
A: I am a soy milk drinker. I started drinking soy milk regularly more than 10 years ago. Soy is a source from nature. I am French, so I also always encourage vegetables and fruits for my kids. People used to eat in a more natural way centuries ago. We must get back to nature and try to eat fresh salads, vegetables, beans and fruits regularly for cancer prevention.
—Excerpted from ScienceNow.
Along with the numerous health benefits, eating plenty of fruits and vegetables may give your face a tan-like healthy glow and be a marker of good health, suggests research published early online in the journal Evolution and Human Behaviour. The study was conducted by a facial perception laboratory in Scotland.
In one of the experiments, researchers collected fruit and vegetable intake of 82 Caucasian participants and used this data to calculate intake of beta-carotene, a common carotenoid. (Carotenoids are a phytochemical identifiable by their yellow-orange color and well studied as an antioxidant and in cancer prevention.) After controlling for outside activity-time, the study found that participants who consumed higher levels of fruits, vegetables, and carotenoids had a more yellow-golden skin color on multiple areas of the body compared to participants who consumed fewer . Another experiment found that Caucasian participants identified faces with higher carotenoid-coloration as healthier than those with lower levels of the pigment.
Source: Ian D. Stephen, Vinet Coetzee, David I. Perrett. “Carotenoid and melanin pigment coloration affect perceived human health.” Evolution and Human Behavior, 2010.
Dieters who check their weight regularly and often lose more weight than their non-monitoring counterparts, according to a new review of the research on self-monitoring in weight loss published in last month’s Journal of the American Dietetic Association.
This article presents a systematic review of the literature on three components of self-monitoring in behavioral weight loss studies: diet, exercise, and self-weighing. The review included all relevant articles published between 1993 and 2009, ending up with 22 articles.
More frequent self-monitoring was consistently linked to weight loss compared to less frequent self-monitoring. However, the review found, the evidence had several limitations. All but two of the studies, participants were predominantly white and women
The most common method of self-monitoring was the traditional paper diary.
Adherence to self-monitoring was reported most frequently as the number of diaries completed or the frequency of log-ins or reported weights. The use of technology, which included the Internet, personal digital assistants, and electronic digital scales were reported in five studies. Descriptive designs were used in the earlier studies whereas more recent reports involved prospective studies and randomized trials that examined the effect of self-monitoring on weight loss. A significant association between self-monitoring and weight loss was consistently found; however, the level of evidence was weak because of methodologic limitations. The most significant limitations of the reviewed studies were the homogenous samples and reliance on self-report. In all but two studies, the samples were predominantly white and women. This review highlights the need for studies in more diverse populations, for objective measures of adherence to self-monitoring, and for studies that establish the required dose of self-monitoring for successful outcomes.
Source: Burke LE, Wang J, Sevick MA. “Self-monitoring in weight loss: a systematic review of the literature.” J Am Diet Assoc. 2011 Jan;111(1):92-102.
The average person can meet all fruit and vegetable recommendations – amounts and variety – in the 2010 dietary guidelines for $2.00 to $2.50 per day on average, according to a new USDA report.
The study used 2008 Nielsen Homescan data to determine the price of 153 commonly consumed fruits and vegetables: fresh, frozen, canned, dried, and 100 percent juice. Study authors found the average prices ranged from less than 20 cents to $2 per cup, or approximately 50 cents per edible cup. The report calculated prices based on only the edible portion of the food once cooked or otherwise prepared for consumption. Broccoli cost per cup, for example, was estimated from the retail price per pound after boiling and removing its stalks.
When looking at all produce in the study, processed fruits and vegetables were not consistently more or less expensive than fresh. For example, canned carrots (34 cents per cup) were more expensive than whole fresh carrots eaten raw (25 cents per cup). Yet canned peaches (58 cents per edible cup equivalent) were less expensive than fresh (66 cents per cup).
For fruits, the lowest average price was for fresh watermelon (17 cents per cup) and the highest was for fresh raspberries (at $2.06 per cup). For vegetables, the lowest average price was for dry pinto beans (13 cents per cup) and the highest was for frozen asparagus cuts and tips, at ($2.07 per cup).
Source: For costs and the full report: Stewart H., Hyman, J., Buzby JC, Frazão E., Carlson, A. “How Much Do Fruits and Vegetables Cost?” Economic Information Bulletin No. (EIB-71) 37 pp, February 2011
Studies have consistently linked high fiber and whole grains consumption to health benefits, and now a study suggests that certain substances produced after the foods are metabolized may play a key role in their health effects. AICR’s expert report and its updates linked foods containing fiber to lower risk of colorectal cancer.
The study, published in the January issue of the Journal of Nutrition, analyzed how consuming high-fiber rye bread and white-wheat bread altered the plasma metabolites of 39 postmenopausal women. In the study, the women consumed one type of bread for 8 weeks, returned to normal eating for 8 weeks, then consumed the other type of bread for 8 weeks. The rye bread was approximately 17 percent dietary fiber and the white-wheat bread almost 3 percent. The bread covered at least 20 percent of daily energy intake – a minimum of four to five portions daily – and participants restricted eating other cereal products while keeping their total calories constant.
After analyzing 540 dietary metabolites, the researchers identified a handful that differed between the two bread groups. At least one of the metabolites is linked with increasing satiety. Now, more studies are needed to confirm and understand the metabolite changes, conclude the authors.
Source: Lankinen M, Schwab U, Seppänen-Laakso T, Mattila I, Juntunen K, Mykkänen H, Poutanen K, Gylling H, Oresic M. "Metabolomic analysis of plasma metabolites that may mediate effects of rye bread on satiety and weight maintenance in postmenopausal women." J Nutr. 2011 Jan;141(1):31-6.