July 6, 2022 | 8 minute read

What is more important? Providing people with potentially life-saving advice about lifestyle choices, or driving the foundational research on which reliable advice can be based? AICR has always had a two-sided mission and both are pursued with equal vigor: One is to fund research that will transform the understanding on how our lifestyle choices, including eating habits and physical activity, can reduce cancer risk. And the second is to make sure that the latest and most reliable research reaches people so that they can make informed choices to reduce their cancer risk and support cancer survival.

1983: The First Dietary Guidelines to Lower Cancer Risk

In 1983, AICR was the first to publish dietary guidelines to lower cancer risk. This huge step was based on the findings of a National Academy of Sciences report and began AICR’s four decades of getting the best-available science into people’s hands by translating it into four dietary guidelines to lower cancer risk.

Knowing what we know today, it’s easy to underestimate what a big deal it was to publish these guidelines.

• The guidelines came at a time when reducing cancer risk through anything beyond avoiding tobacco seemed like a “fringe” idea to many people, including many health professionals.

Diet as a factor? The idea that a few changes in eating habits could have a substantial influence on cancer risk was both exciting and shocking for many people. But although these ideas don’t seem earthshaking now, at that time, aiming for multiple daily servings of vegetables and whole grains (what are those?) needed a lot of explaining.

Individual news headlines come and go. But 40 years later, the essence of these earliest recommendations has become a major element of public health and clinical cancer prevention advice. Over the decades, the volume and quality of research has changed dramatically, as has our understanding of cancer. Yet despite these changes, the fundamental advice has been incredibly consistent. This is a testament to AICR’s determined commitment to its mission and the rigorous analysis of research by the scientists and health professionals who shared AICR’s vision.

1997: Recommendations as Part of the First AICR Expert Report

Research was exploding in the 1980s and 1990s. In 1983, the best available evidence relied on laboratory studies and types of population studies that can’t provide evidence as strong as today’s studies can. Most research looked at cancer risk related to external sources of carcinogens, without understanding how other factors influence risk.  Also, nutrition research often focused on individual nutrients. So, our messaging about fruits, vegetables and whole grains tended to zero in on getting more dietary fiber, vitamin C and beta-carotene. All these nutrients are still shown to play a valuable role. But now we see much more clearly that, rather than a trio, our diet is a whole orchestra contributing to the protective song.

The original 1983 guidelines relied on findings from the National Academies report, but, the first AICR  Expert Report was based on a careful review of available research by an independent panel of renowned researchers. It showed more clearly than ever that cancer risk stems from more than simply exposure to carcinogens.

• A wide range of nutrients and food compounds were found that may interact with genes and gene expression. This began the shift to focusing on a whole dietary pattern, which has only grown stronger in the years since.
• Cancer development was considered to occur in a series of phases, each of which could be influenced by lifestyle choices. And population studies that followed people for a long time began to provide a stronger foundation for identifying factors associated with risk of cancer, since this is a disease that usually develops over years.

The First Expert Report was the most comprehensive review of the available evidence and became a hallowed resource for researchers and health professionals. It included 14 recommendations based on research involving this growing range of influences on cancer risk.

• Excess weight and weight gain were included for the first time as important emerging risk factors for cancer.
• Daily physical activity was highlighted for its valuable protective role.
• Dietary supplements were noted as unnecessary and “possibly unhelpful for reducing cancer risk,” following the disappointing results of randomized controlled trials.
• Red meat as a food to limit was now included in defining a healthy diet, going beyond the concern of processed meats (like bacon and sausage) that were part of the 1983 guidelines.
• Alcohol recommendations shifted to avoiding alcohol as best advice, with moderation as the second-choice alternative for reducing cancer risk.

2007: Ten Recommendations Based on Ground-Breaking Analysis of Evidence

In 2007, AICR took another giant leap forward and published the Second AICR/WCRF Expert Report. It provided ten recommendations for cancer prevention based on the most comprehensive collection of scientific evidence available at that time.

• Scientists now saw a bigger picture of influences within the body, such as inflammation, insulin resistance, hormones, and cell signaling.
• Research provided a stronger foundation on which to base recommendations. Meta-analyses and pooling projects quantitatively pulled together results of prospective cohort studies, supplying stronger evidence of the overall picture.

Many of the recommendations from the first expert report were included.

• Emphasize plant foods, limit red and processed meats and alcohol. These recommendations continued, now supported by even stronger evidence.
• Action steps to address risks from excess body fat were added. Obesity’s powerful influence on cancer risk was becoming increasingly recognized. And at the same time, obesity rates were rising. The Expert Panel included recommendations to limit sugar-sweetened beverages and foods very concentrated in calories to highlight steps that could avoid or slow weight gain within the context of a healthy diet.
• Recognizing questions about cancer survivors, a recommendation addressing the question of what to do after cancer treatment was included for the first time. Research specifically focused on cancer survivors was extremely limited. But amid improvements in cancer treatment and early diagnosis, health professionals wanted to know how to answer people’s concerns after cancer.

2018: Ten Cancer Prevention Recommendations—The Power of Strong Evidence

In 2018, AICR published new recommendations based on a comprehensive review of the vastly expanding body of research. Considering the amazing growth in research, these recommendations are remarkably consistent with those of the previous reports.

• The recommendations are based on evidence graded strong and unlikely to change. One of the reasons health professionals rely on AICR’s recommendations is that the Expert Reports separate evidence rated “limited”—which identifies potential links, but not strong enough on which to build a recommendation—from evidence judged to be “strong” by the CUP Expert Panel. The Continuous Update Project (CUP) is an ongoing program that analyzes global research on how diet, nutrition and physical activity affect cancer risk and survival.
• Health professionals advise people: follow AICR’s recommendations, not click-bait headlines that flip-flop back and forth about what makes healthy eating habits.
• Consistent with research for promoting overall health, including lower risk of heart disease and type 2 diabetes, these recommendations are intended as a package of habits to create a healthy lifestyle. Like a blueprint for health, the recommendations address eating habits, body fatness and physical activity and all fit together. The more recommendations that can be followed the better, but any improvements will contribute to reducing cancer risk.

The refinements of the recommendations acknowledge the greater strength and quality of the research evidence and help communicate clearly about the best lifestyle choices in an environment where the healthy choices are not necessarily easy or obvious.

• Limiting high-calorie foods and sugar-sweetened drinks are now independent recommendations. As fast foods and processed foods high in added sugars and fat (often unhealthy types) have become so readily available, it’s helpful to be reminded that both contribute to the obesity and weight gain driving so much of today’s cancer. As ultra-processed foods are gaining increased attention, it’s important to remember that not all processed foods are of equal concerns when it comes to cancer risk.
• The recommendation about alcohol reflects evidence that risk for at least some cancers begins at amounts less than “moderation.” And it’s very compatible with the emerging understanding that alcohol may not be the friend to heart health that it was once thought to be.

The message is stronger than ever: rather than focus on individual factors, aim to get closer day by day to a long-term healthy lifestyle. Each step forward makes a difference, so don’t stay “stuck” waiting for a better time to make just one or two changes.

Recommendations Reduce Mortality Risk from all Causes, Cancer and Heart Disease.

Research shows following the Recommendations improve survival among older adults.

Maintaining healthy body weight, being physically active and following a healthy diet can do more than just lower your cancer risk…it can help you live a longer life, too! 

During the 40 years since AICR’s debut, food choices in the grocery store and restaurants have changed, new tools to track eating and activity have appeared and confusing media stories about extreme diets and “superfoods” have added to information overload. Yet, while the ways in which we reach people, the kinds of recipes they want and how their questions have changed, the consistent thread is that AICR continues to provide recommendations people can trust and practical strategies they can confidently use to reduce cancer risk and support a cancer survivor’s journey.

And amid all the information overload, programs like AICR’s Healthy10 Challenge, which help people make progress one step at a time, have become even more valuable.