The recently released cancer prevention report – Diet, Nutrition, Physical Activity and Cancer: A Global Perspective, The Third Expert Report – along with 10 new cancer prevention recommendations is the most comprehensive analysis of research on diet, nutrition, physical activity and cancer prevention.
Last week, key members of the report’s expert panel talked about what the findings really mean, for individuals and the research community. The three experts presented to a packed room at the American Society for Nutrition annual meeting in Boston.
Here are just a few highlights of their talk:
Dr. Steven Clinton, MD, Ph.D., at the Division of Medical Oncology, Ohio State University started the discussion with some stark statistics: 1 in 6 deaths worldwide are from cancer. Yet 30-50 percent of all cancers are preventable. “Prevention is clearly an important step,” he stated. Back in 1982 when AICR was founded, research involving diet, physical activity, weight, and cancer risk was a nascent field. That changed with the help of a National Academy of Sciences’ report and AICR’s growing involvement.
Then in 1997 AICR/WCRF published the first report interpreting the global evidence on diet and cancer. Ten years later came another major report, with a clear and rigorous systematic review process. This third report brings more and stronger studies than ever before. The report looks at 17 cancers and includes data on 51 million people. It is a part of the Continuous Update Project, where the goal is to continually evaluate the data on cancer prevention. The AICR/WCRF reports and cancer prevention recommendations are the foundation for policy changes. And the implications for individuals are enormous, Clinton emphasized. The reports have been used to inform the government’s Dietary Guidelines, for example, and AICR’s tools help both health professionals and the general public. Clinton refers his patients routinely to AICR’s New American Plate Challenge, he said.
You can sign up to take the 12-week NAP Challenge here:
Edward Giovannucci, MD, ScD, Professor of Nutrition and Epidemiology at Harvard University, was up next, focusing on AICR/WCRF’s 10 recommendations for cancer prevention, all based on the latest research.
A key point: The overall impact of the recommendations is more important than looking at each individually. “The AICR Recommendations are intended to be used as an overall lifestyle package and are culturally relevant throughout the world,” he said.
One shift from the early research is that there are no recommendations directly centered on fruits and vegetables. The closest relates to recommending we base our diets around plant foods. Yet when it comes to fruits and vegetables, one thing we notice consistently across many cancers, said Giovannucci, is that low intake puts people at higher risk. There seems to be a threshold.
The available literature has more than doubled since the last AICR/WCRF report. This new evidence has strengthened the previous findings, Giovannucci said, including the top recommendation: be a healthy weight. Next to not smoking, maintaining a healthy weight is the most important thing individuals can do to reduce the risk of cancer.
One new recommendation to the list: limit your consumption of sugary drinks. This stems from strong evidence that consuming sugar-sweetened beverages cause weight gain, and having overweight, and obesity.
Giovannucci then pointed to several important directions for research that will inform future recommendation, including how diet, nutrition and physical activity in early life influence, cancer risk in later life. How these factors affect cancer survivors’ is another major area. (Currently, AICR/WCRF recommends that after a cancer diagnosis, individuals follow the other recommendations if they are able.)
A systematic approach to mechanism research
So how exactly does food with fiber lower risk of cancer? Why can too much body fat spur tumor development? And what is happening during your brisk walk that lowers risk of certain cancers?
There are thousands of animal and cell studies working to explain the links seen between a risk factor (such as whole grains or exercise) and cancer risk. This report is driving the mechanism research, said Stephen Hursting, Ph.D., MPH, at the University of North Carolina.
There are links that emerge in human studies that we need to understand, says Hursting. Coffee, for example, is a beverage that has emerged in human studies as lowering the risk for both endometrial and liver cancers. “We can see links with coffee and lower cancer risk but we’re still trying to find out what’s going on. I have a whole bunch of mice drinking coffee at this point.”
Genetics, the microbiome, obesity, inflammation — there are so many possible mechanisms that connect diet, nutrition, physical activity and body fat to cancer risk, he said. This is going to get more and more complex in the next few years, and that’s why we need a systematic approach to better understand the evidence.
Hursting highlighted a recent paper led by scientists at The University of Bristol in the UK. The paper laid out a clear protocol for identifying and carrying out systematic reviews of mechanisms related to exposer-cancer associations.
Here’s our news release about the mechanism paper.
To read the report and use our interactive tool showing how lifestyle factors link to different cancers, visit Diet and Cancer Report.