Also in this issue:
- In Brief: Cancer Trends and Risks Among Hispanics
- Be More Productive with Fruits, Veggies and Exercise
- Stopping Cancer’s Spread
- Stemming Cravings by Paying Attention
Berries: Sweetening Cancer Prevention
When it comes to cancer prevention, berries are among the more diverse and powerful members of the fruit family. AICR’s expert report and its updates show that eating a diet high in fruit reduces the risk of cancers of the esophagus, lung, stomach, mouth, pharynx and larynx. Research is providing new evidence that berries are not only strong antioxidants, but affect the expression of a vast range of genes and molecular pathways associated with the development of cancer.
According to Gary Stoner, PhD, a Professor of Medicine at the Medical College of Wisconsin who has studied berries' potential link to cancer prevention for more than two decades, berries contain two particularly active classes of compounds that may make them tough anti-cancer contenders: anthocyanins, flavonoids that give berries their dark color, and ellagitannins, the source of the polyphenol ellagic acid.
Anthocyanins are probably the key cancer preventive agents in most berries because they are present in high concentrations. Berries also contain vitamin C and fiber, along with trace amounts of vitamins A and E, calcium and selenium.
What the Studies Show
Berries' anthocyanins and ellagic acid are poorly absorbed in our blood, says Stoner. This has led scientists to focus primarily on cancers that come into direct contact with berry’s phytochemicals, such as cancers of the mouth, esophagus and colon. Recent evidence suggests our gut bacteria metabolizes berries’ anthocyanins into metabolites that are better absorbed than the anthocyanins themselves, suggesting the metabolites may be the ultimate cancer preventive agents.
Animal studies conducted by Stoner found that a diet of freeze-dried black raspberries or strawberries can inhibit esophageal cancer in rats by 30 to 70 percent and colon cancer by up to 80 percent. In these studies, researchers ground freeze-dried berries into a powder to make a concentrated formulation
In early phase clinical studies, Stoner and his colleagues have found that black raspberry and strawberry powder is safe and well tolerated. Current pilot studies are focusing on berries acing as chemoprevention agents for individuals at high risk for cancer.
Berries and Breast Cancer
AICR grantee Harini Aiyer, PhD
In animal studies investigating the effect of blueberries and black raspberries on estrogen-receptor (ER) positive breast tumors, Harini Aiyer, PhD, Postdoctoral Research Fellow at Lombardi Cancer Center, Georgetown University School of Medicine, found that a six-month diet of black raspberries reduced tumor volume in rats by 70 percent.
The same diet length of blueberries had similar results, says Aiyer, who conducted this research in graduate school. In later cell studies, Aiyer also found that adding ellagic acid to ER positive cells treated with tamoxifen made them less likely to become resistant to the effects of the drug. Although promising, the data is preliminary and further studies are needed.
“If we look at estrogen as the fuel for some breast cancers that guides the car forward, we may be able to use ellagic acid, which acts like an anti-estrogen, to cut off the fuel supply or even stop the engine," said Aiyer, an AICR grantee.
Incorporating Berries into the Day
Research with berries and cancer prevention often includes different berries, and there may be a lot of merit to mixing berry types, said Stoner. “In animal models of esophageal cancer, we have found that at least seven berry types are effective in preventing cancer irrespective of their chemical composition.”
According to Stoner, one possible concern with eating berries is that some people may experience mild gastrointestinal disturbances, but these are usually transitory. He suggests people get about four to five helpings of berries per week.
Likewise, Aiyer suggest people try to eat berries every day, also stressing the whole food approach. It’s the combination of berry’s compounds that appears most effective for cancer prevention. Aiyer’s animal studies, for example, found that a black raspberry diet was more effective in reducing mammary tumors than a pure ellagic acid diet. “This was due to the berries’ anthocyanins that synergize with ellagic acid to provide greater benefit,” she said.
Excerpted from ScienceNow.
In Brief: Cancer Trends and Risks Among Hispanics
Obesity in Adults by Ethnicity and Sex,
United States, 2009 Through 2010.1
Cancer now tops heart disease as the leading cause of death among US Hispanics, with lifestyle-related risk factors varying based on a person’s country of origin, according to reports published online yesterday in CA: A Cancer Journal for Clinicians.
The positive trend is that both cancer incidence and deaths have declined slightly among Hispanics over the 10-year period studied (2000 to 2009); it’s just that heart disease dropped even more quickly. The report estimates that in 2012, 112,800 new cases of cancer will be diagnosed and 33,200 cancer deaths will occur among Hispanics.
The cancers seen among Hispanics may reflect the demographics: Just one in ten US Hispanics is 55 years or older compared with almost one in three non-Hispanics. The majority of cancers are diagnosed among people ages 55 and older.
Hispanic refers to persons of Mexican, Cuban, Puerto Rican, South or Central American, or other Spanish descent. Among this diverse population, Hispanics have lower incidence and death rates than non-Hispanic whites for all cancers combined and for the four most common cancers: breast, prostate, lung and bronchus, and colorectum. Hispanics have higher incidence and mortality for several types of cancers, including liver, stomach, and gallbladder. This could reflect differences in lifestyle and diet, screening rates, and genetic factors, the report notes.
A second report focusing on prevention pulled data on diet, activity and other risk factors from several government surveys among adults and adolescents. The authors found that as a group, Hispanic adults are more likely to be obese compared to non-Hispanics. For sub-groups, self-reported data suggests that Mexicans and Puerto Ricans are more likely to be obese than Cubans, Central/South Americans, or Dominicans (see chart). Obesity is linked to increased risk of seven cancers.
Hispanic adults are less likely to be current smokers or frequent alcohol drinkers compared with non-Hispanics, with Cuban men and Puerto Rican men having higher rates. These risk factors are also prevalent among teenagers. Among Hispanic adolescents, one of every five teens reported using a tobacco product and close to half report drinking alcohol.
Hispanics are the fastest growing demographic group in the United States, making up approximately 16 percent of the US population in 2010.
Sources:
- Vilma E. Cokkinides, Priti Bandi, Rebecca L. Siegel, Ahmedin Jemal. “Cancer-related risk factors and preventive measures in US Hispanics/Latinos.” CA: A Cancer Journal for Clinicians. Article first published online: September 17 2012.
- Rebecca Siegel, Deepa Naishadham, Ahmedin Jemal. “Cancer statistics for Hispanics/Latinos, 2012.” CA: A Cancer Journal for Clinicians. Article first published online: September 17 2012.
Research Roundup
Be More Productive with Fruits, Veggies and Exercise
Eating healthy, exercising, and staying a healthy weight – all the hallmarks of reducing cancer risk – may also improve workers’ productivity and performance, suggests a new study published last week.
For the study, approximately 20,000 employees from three companies completed a survey asking about their health, including dietary habits, as well as emotional and physical well being. The employees also answered questions about their work performance and productivity, such as how often they had trouble concentrating at work and why.
When looking at health behaviors, employees who ate healthy the previous day, ate five or more servings of vegetables a week, and exercised at least three days a week had improved performance compared to their colleagues who did not follow these health behaviors.
Smokers and overweight employees were more likely to score in the highest category o poor work performance compared to their non-smoker and healthy weight colleagues. Overall, work related issues, such as no technology support and having too much to do with not enough time, were the largest factors that influenced work performance. But having worksite wellness programs that make it feasible for employees to eat healthier at work and exercise during the day may also help improve productivity, conclude the authors.
Source: William Whitmer, and the HERO Research Study Subcommittee. “Presenteeism According to Healthy Behaviors, Physical Health, and Work Environment.” Population Health Management. Volume: 15 Issue 5: September 11, 2012.
Stopping Cancer’s Spread
More than three dozen compounds found in vegetables, fruits and other plant foods can turn on genes that slow the spread of cancer, according to recent review of the research published in Cancer and Metastasis Reviews.
The review by Washington State University researcher Gary Meadows, PhD, a former AICR grantee, focused on recognized genes that suppress metastasis. Meadows investigated the role of diet and phytochemicals in altering the expression of genes, as opposed to the genes themselves. This relatively new field of study is called epigenetics.
After looking at relevant studies, Meadows documented approximately 40 foods, phytochemicals and nutrients that affect metastasis suppressor genes in some way. The studies were primarily conducted on cells and animals.
Compounds and foods that affected these genes included vitamin D, lycopene and other carotenoids, curcumin and pomegranate juice. The compounds affected gene expression in breast, colorectal, prostate, lung and other cancers. A nutrient that regulates a suppressor gene in one type of cancer may have no affect on another type, noted Meadows. Also, in some cases a compound in a food may turn one gene on and another compound in that same food may turn it off.
The review helps to clarify the need for future research, the author concluded, with the goal to keep cancer from spreading and help increase cancer survival.
Source: Meadows GG. “Diet, nutrients, phytochemicals, and cancer metastasis suppressor genes.” Cancer Metastasis Rev. 2012 Jun 13.
Stemming Cravings by Paying Attention
Dieters who have trouble controlling those dessert cravings may find that paying careful attention to every decadent forkful (or spoonful) may help, suggests a new study published online in the Journal of Consumer Research.
The study included a series of tests that focused on how our self-control influences what we eat. In one test, the researchers found that people who have more self-control eat less sugary foods because they get satisfied on the sweet foods faster. Based on a questionnaire, participants were categorized into having high or low self-control. Approximately 200 participants then chose from either peanuts or raisins – the healthy snacks – or M&Ms™ or Skittles™. They rated how much they liked their first bite both before and after eating the food while watching a video.
The candy eaters with a lot of self-control reported they were less likely to want to eat more of the sweets the next day. And while they liked the candy after that first bite, their enjoyment faded relatively fast after eating them for a while, whereas the healthy snackers liked their raisins and peanuts about the same. For the participants with low self-control, how much they enjoyed the snack was about the same whether they were eating the healthy or unhealthy foods.
In another test, the authors tested their hypothesis that paying more attention to eating foods will increase a person’s satisfaction with the food. They found that candy eaters who counted the number of times they swallowed reported they were satisfied more quickly than those who did not count, whether they had low or high self-control.
Source: Joseph P. Redden and Kelly L. Haws.”Healthy Satiation: The Role of Decreasing Desire in Effective Self-Control.” Journal of Consumer Research, Ahead of Print, p. 000/ The University of Chicago Press.
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