WASHINGTON, DC—By the year 2030 the number of Americans age 65 and older will swell to 78 million as the baby boomers age—almost 20% of the US population. Cancer risk rises steeply with age, but many older Americans are unaware of that link and unaware that there are steps they can take to lower that risk. That is the conclusion of a new survey from the American Institute for Cancer Research (AICR).
To help Americans over age 50 become informed and adopt healthy habits, the AICR launched a new campaign, “It's Never Too Late to Lower Your Risk,” at its annual research conference here.
While 76% of Americans 50 to 59 said their cancer risk increases with age, that number declined with older age, with only 61% of Americans age 60 to 70 recognizing the increased risk, and only 49% of those 71 and older recognizing the increased cancer risk with age. Nearly a third (32%) of respondents age 71 and older agreed with the statement “It's too late for me to do anything about my personal cancer risk.”
The good news from the survey is that 80% of Americans age 50 to 59 and 85% of those 60 to 70 knew that being physically active lowered their cancer risk, but that number declined to 74% in the 71% age group.
Other good news is that among all survey respondents over age 50, awareness that eating a healthy, primarily plant-based diet lowers cancer risk was consistently high—ranging from 90% to 93%.
Need to Be Empowered
In a telephone news briefing held the day before the AICR conference began, speakers emphasized that older Americans need to be empowered to lower their cancer risk.
“Aging is the number one risk factor for cancer,” said JoEllen Welsh, PhD, Professor in the Department of Biomedical Sciences at the University at Albany Cancer Center and Chair of the AICR Research Conference. She pointed out that studies of twins have shown that they do not age at the same rate, demonstrating that “our genes are not the only influence on the aging process.”
Being at highest risk of cancer means that older people stand to gain the most from healthy habits designed to lower risk, added Alice Bender, MS, RD, AICR Nutrition Communications Manager. But, she said, the survey results show that thousands and thousands of older Americans “don't realize what they can do to lower their cancer risk,” and “mistakenly believe it's too late for them anyway.”
Daniel Perry, President of the Alliance for Aging Research, who also participated in the briefing, stated that the longevity of many Americans today is unprecedented in history, noting that beginning in 2011 more than 10,000 baby boomers will turn 65 per day.
Because chronic diseases already account for more than 75% of the US health care bill, it is essential for Americans to adopt healthy habits that will help them to prevent or delay the onset of cancer, he stressed. Mr. Perry noted that according to data compiled by the Alliance, even a 1% reduction in cancer deaths would be worth nearly $500 billion in reduced health-care costs.
New Research on Diet, Physical Activity, and Cancer
At the AICR conference, new findings were reported on diet, physical activity, and cancer. Among the most striking is that reduced sugar in the form of glucose provided to normal human cells in vitro extends their lifespan, but leads to cell death of precancerous cells.
“Sugar restriction kills precancerous cells—this may have strong potential for cancer prevention,” said Trygve Tollefsbol, PhD, DO, Professor of Biology and Senior Scientist in the Center for Aging, Comprehensive Cancer Center, Nutrition Obesity Research Center, at the University of Alabama at Birmingham.
He said his studies also show that sulforaphane, a substance found in cruciferous vegetables such as broccoli, and EGCG (a compound in green tea) inhibit telomerase gene activity in breast cancer cells; telomerase plays major roles in both aging and cancer, maintaining the telomeric ends of chromosomes and leading to cancer cell death.
‘Genes Alone Not Destiny’
Dr. Tollefsbol seconded Dr. Welsh's statement that genes alone are not destiny. He said epigenetics, the science of turning genes on or off without altering the DNA itself, is showing how dietary choices may affect key mechanisms linked to both aging and cancer prevention.
“Most people now believe epigenetics is more important than genetics in reducing cancer risk,” he said. “I really think this is the way to go.”
There are now consistent reports that vitamin D levels are often in the insufficient or deficient range in women who receive a diagnosis of breast cancer, said Pamela J. Goodwin, MD, MSc, FRCPC, Professor of Medicine at the University of Toronto and Head of the Medical Oncology Breast Group at Princess Margaret Hospital. She also said there is evidence from her research that vitamin D deficiency at the time of diagnosis may be linked to poor breast cancer outcomes. But, she cautioned, further studies need to be done, and “To date there is insufficient evidence to draw firm conclusions about a beneficial role of vitamin D adequacy or supplementation in relation to breast cancer.”
Obesity & Prostate Cancer
“Obesity is likely to be associated with more biologically aggressive prostate cancers, and obesity at the time of treatment may be associated with higher risk of post-treatment PSA failure and mortality,” said Edward Giovannucci, MD, ScD, Professor in the Departments of Nutrition and Epidemiology at Harvard School of Public Health and Associate Professor of Medicine at the Harvard Medical School/Brigham and Women's Hospital.
Dr. Giovannucci said a plant-based diet may be preferable in terms of prostate cancer incidence and progression than a Western diet high in dairy products and meat. He cited consuming tomato sauce (which is high in lycopene) after prostate cancer diagnosis as a way to reduce risk of recurrence.
He also noted that long-term androgen-deprivation therapy for prostate cancer causes increased fat mass, decreased lean body mass, and increased fasting glucose and hyperinsulinemia—unwanted side effects which in themselves raise risk.
Brisk Walking after Prostate Cancer Diagnosis
Another study presented at the conference showed that brisk walking after prostate cancer diagnosis may delay or inhibit prostate cancer progression among men diagnosed with localized disease. The researchers recommended launching a randomized trial to formally test this hypothesis.
It is now clear that diet and lifestyle do influence the risk of developing colorectal cancer, said Jeffrey A. Meyerhardt, MD, MPH, a medical oncologist at Dana-Farber Cancer Institute and Assistant Professor in Harvard Medical School's Department of Medicine and an active member of the Cancer and Leukemia Group B Cooperative Group.
“Prospective observational studies have shown that increased exercise after diagnosis and avoidance of a Western pattern diet reduces cancer recurrence and improves overall survival in early-stage colorectal cancer after standard therapy.”
He added that colorectal cancer patients with Class II or III obesity have a modestly increased risk of recurrence, while regular use of aspirin or COX-2 inhibitors decreases recurrence rates, as do increased serum vitamin D levels.
In a separate meta-analysis of cohort studies presented at the AICR conference, researchers from the United Kingdom and the Netherlands found that intake of vegetables is associated with a significant reduction in the risk of colorectal cancer in both linear and non-linear models.
The associations between fruit and vegetables combined or fruit were not statistically significant in the linear models, but there was evidence for a non-linear association for both. The researchers concluded that increasing fruit and vegetable intakes among very low consumers may reduce colorectal cancer risk”