Introduction
The National Cancer Institute's (NCI) 5 A
Day for Better Health Program (the Program) is a
national program that approaches Americans
with a simple, positive message: Eat 5 or
more servings of vegetables and fruit daily for
better health. In September 1999, the Director of the
NCI established the 5 A Day Program Evaluation Group (the Evaluation Group) to review and
evaluate the Program. Specifically, the Evaluation
Group was asked to review (1) the science underlying
the Program, (2) the implementation and accomplishments of the Program, and
(3) the degree to which the Program has achieved its goals and objectives.
The Evaluation Group also was charged with making recommendations to the NCI about the future conduct of the Program and to
articulate NCI's role in large, coordinated efforts to
promote healthy eating. Chapter 1 of this report
provides more detailed information about the charge to,
and process of, the Evaluation Group.
Chapter 2 of this report reviews the evidence that vegetables and fruit protect health,
particularly the protection from cancer. Chapter 3
describes the origins and early years of the 5 A
Day Program and includes information about its
scientific and programmatic justifications.
Chapter 4 describes the 5 A Day Program as proposed to NCI's Board of Scientific Advisors
in 1991.
Chapter 5 describes the media and health-
message environment in which the Program
operated. It reviews the recent expansion of
the communications infrastructure, the large
volume of food and nutrition advertising, and the
contradictory nature of nutrition-related news.
Finally, this section explores the effects of this
environment on the delivery of the 5 A Day message.
Chapter 6, the Evaluation of the Program,
is divided into four sections: (1) evaluation of
the implementation of the Program; (2) evaluation
of the Program using process measures (primarily, communication of the 5 A Day message); (3)
evaluation of the Program using outcome
measures—namely, measures of dietary change and factors
that mediate dietary change (such as knowledge of
dietary recommendations); and (4) evaluation of randomized, controlled trials of dietary
interventions.
The conclusions of the Evaluation Group
are found throughout the report and summarized in the next section. The recommendations of
the Evaluation Group immediately follow the conclusions.
Conclusions of the Evaluation Group
The Evidence That Vegetables and Fruit
Protect Health
When the 5 A Day Program was first
developed, the recommendation to consume at least 5
servings of vegetables and fruit per day was
supported by a diverse and convincing body of evidence.
No subsequent finding has contradicted this conclusion. Indeed, since the start of the 5 A Day
Program, further evidence has accumulated to
support the hypothesis that a diet rich in vegetables
and fruit reduces the risk of cancer and other
chronic diseases. Specifically, the evidence for an
inverse association with the risk of several epithelial
cancers has been strengthened, evidence has begun
to accumulate for hormone-dependent cancers, and a variety of mechanisms have emerged for the
protective effect of specific constituents in
vege tables and fruit, not only in animal studies, but
also in humans.
Although evidence also has emerged for a
role of vegetables and fruit in reducing the risk of
cardiovascular disease, obesity, and diabetes,
the most impressive body of evidence exists for
protection against cancer. The recommended
5 servings of vegetables and fruit a day is a minimum rather than a maximum target for
consumption, and any increase above current levels of
consumption is to be encouraged for individuals and populations.
Implementation and Process Measures
Collaborations and Partnerships
NCI's collaboration with private industry had
a positive effect on expanding the impact of the
5 A Day message and bringing additional
resources to the task. In addition, this partnership
marked the first time that the producers and retailers
of vegetables and fruit joined to undertake a common task. Key elements in ensuring the
effectiveness of the partnership were the valuable
in-kind contributions and the strong commitment of
the industry. Beneficial outcomes of the
partnership included an expanded communication base for
the 5 A Day message and the promotion of national nutritional objectives. The public/private
partnership, with its identifiable structure and
modules, represents a model for the implementation
of other public health endeavors.
The industry partnership approach may have been too vulnerable to market
considerations which, if not balanced by public health
considerations, could readily lead to ignoring segments
of the population not viewed as attractive markets.
Further, the social marketing strategies of the
NCI and its media partners tended to exclude the
most underserved populations. These reasons may explain why the Program was less successful
in reaching minority and low-income populations, even though research indicates clearly that
such populations can be reached effectively.
The 5 A Day Program developed
successful collaborations with a range of Federal, state,
and voluntary agencies. These collaborations
provided mechanisms whereby the 5 A Day message
was incorporated into a range of programs, from
the school lunch program to statewide
public-health interventions.
Message Delivery and Environment
The 5 A Day promotion campaign used a
combination of strategies that leveraged
advertising from its industry partners and developed
relationships with media outlets to generate and
inform news stories related to the Program. The
media placement data suggest that media relations
strategies were less successful after the first 1-2
years of the campaign, and that advertising
strategies dominated.
Commercial advertisers have learned that a
consistent and prominent presence in the
marketplace is key to achieving and holding market share.
Expenditures for the marketing of food, fast
food, and beverages (nearly $10 billion in 1999
alone) dwarf the $1 million spent each year by the
NCI during the first 10 years of the 5 A Day
Program. The difference in magnitude is instructive
and speaks in support of what the 5 A Day Program accomplished with modest means. It also
speaks to the magnitude of the behavior-change
problem in the United States in continued
overconsumption of total calories and less healthful eating
patterns.
Although new channels offer the possibility of more tailored communication to specific
groups, the fragmentation of the communication
system makes it more difficult to reach the majority
of Americans consistently and inexpensively. The volume, inconsistency, and often
contradictory nature of information in the marketplace have
created less than ideal conditions for healthful
behavior change. The effect of these factors is
that the public frequently is overwhelmed by the sheer
volume of information and left confused by
the pastiche of entertainment, news stories,
advertising, and other sources of health information
about food, diet, and nutrition.
Other Implementation and
Process Measures
The 5 A Day Program was implemented in
ways that differed substantially from what was
planned; most importantly, neither the central capacity
for outcome evaluation nor the senior leadership
and administrative support for the Program was
ever established effectively. This may explain, in
part, why efforts to monitor implementation of the
Program, particularly at the state level, were
not entirely successful. Consequently, NCI's ability
to conduct a comprehensive evaluation of the
Program was compromised.
The redirection of resources from community/state capacity building to university-based
research strengthened the opportunities to test
well-designed intervention strategies for specific channels
and targeted populations. This redirection, however,
left little support for capacity building at the
state and community level.
Changes in Nutrition Policy
and Public Health Practice
Changes in the focus of dietary
intervention research and public health nutrition policy
have occurred during the period of implementation
of the 5 A Day Program. Most important, there has been a shift from the
nutrient-based message—for example, eat more fiber—to the food-based
message—eat more vegetables and fruit. This has
been reflected, particularly, in an increased emphasis
on eating vegetables and fruit in the Dietary
Guidelines for Americans and in the U.S. Department of
Agriculture's (USDA) Food Guide Pyramid. Though
not necessarily a consequence solely of the 5 A
Day Program, these shifts reflect the incorporation
of the 5 A Day message into nutrition-related
health promotion programs by Federal, state, and
private agencies.
Dietary Change and Related Outcomes
Knowledge and Awareness
NCI scientists found that the strongest
predictors of dietary change were knowledge of
the recommendation to eat 5 or more servings per
day, taste preferences, and self-efficacy (in this
con-text, confidence in one's ability to eat
vegetables and fruit in a variety of situations). Changes in
these factors can be used as secondary indicators of
intervention program effectiveness.
Before the 5 A Day Program, a small proportion (8%) of the American public understood
at least part of the 5 A Day message.
Subsequently, there have been increases in knowledge of the
5 A Day Program (18%) and its message (20%). The message has reached more women than
men, and more whites than Latinos or African Americans.
Consumption
There has been a slow and steady increase
in vegetable and fruit consumption in the United States during the period of the implementation
of the 5 A Day Program and continuing through at least 1998. Possible inferences from these
changes on the effectiveness of the 5 A Day Program
are limited. Most important, there is no
comparison group that was not exposed to the Program.
The possibility cannot be ruled out that, without the
5 A Day Program, there would have been
substantial decreases in vegetable and fruit
consumption, paralleling the rapid increase in obesity
over the same time period. It is also possible
that other factors may be influencing dietary
behavior change in the United States, and that increases
in vegetable and fruit intake are attributable to
other programs. Nevertheless, the results are
consistent with the inference that the 5 A Day Program
has contributed to the continuous small increases
in vegetable and fruit consumption over the past
decade.
Because insufficient capacity existed for
monitoring program implementation at the state
level and for relating program implementation to
changes in vegetable and fruit consumption, no
conclusions can be drawn from the extensive data collected
on state-level implementation intensity.
Even though safety is not an issue if
vegetables and fruit are handled properly, the potentially
undesirable sensory qualities of some
vegetables and fruit (e.g., bitterness, sourness, pungency,
astringency) may act as significant barriers to
the adoption of a diet that is high in vegetables
and fruit, especially among children. The dilemma
here is that the strong-tasting compounds as a
group overlap extensively with the compounds that
are potentially protective against cancer; therefore,
removing strong-tasting compounds may reduce
the protective effect.
Randomized Trials and Other Experimental Studies
The NCI-funded randomized trials represent
a significant body of research and offer a
persuasive argument that behavioral interventions can have
a positive impact on vegetable and fruit consumption. Elementary school behavioral and food
service interventions had a positive impact on student vegetable and fruit consumption. The
studies proved it is possible to change the
elementary school environment and to reinforce the
healthy dietary practices taught through the classroom
curricula. The average effect increase was 0.62
servings per day, and the largest was 1.68 servings
per day.
Among adults, changes in the worksite,
church, or family social environment were found to be
possible, and these changes led to increases in
the availability and consumption of vegetables and fruit. The average effect size was 0.48 servings
per day, and the largest effect was 0.85 servings
per day. For both school-based and adult studies,
larger effects were observed in fruit
consumption than in vegetable consumption.
Surveillance
There are inadequacies in the surveillance
and monitoring of vegetable and fruit intakes in
the U.S. population. In particular, these include
inconsistencies in measurement techniques and
assessment methodologies, a lack of coordination
across surveys such as the Continuing Survey of
Food Intake by Individuals (CSFII) and the
Behavioral Risk Factor Surveillance System (BRFSS),
and weaknesses in the analyses of the resulting data.
Recommendations of the Evaluation Group
Overall Recommendations
- That the NCI continue the 5 A Day Program
as a multifaceted program to support research and applied public health programs to promote
increased vegetable and fruit consumption.
- That the NCI continue to lead the 5 A Day
Program and, to accomplish this task,
ensure that it has a strong senior leader and
specific scientific expertise in evaluation,
intervention methods development, media, and
community-based interventions, as well as nutrition and
epidemiology.
- That the NCI partner more closely with
the USDA to focus dietary guidelines better and to promote research in agricultural and
economic policies that encourage vegetable and fruit
consumption.
- That the NCI partner with other National
Institutes of Health (NIH) institutes to
(1) promote research into the role of specific
vegetables and fruit and their components in
lowering disease risk more generally, (2)
promote methodologic and applied behavioral
research, (3) expand awareness of the scope
of chronic and deficiency diseases that may
benefit from the increased consumption of
vegetables and fruit, and (4) develop a
comprehensive and rigorous surveillance plan to
monitor vegetable and fruit consumption and the related psychosocial and economic
factors. This last effort should include the Centers
for Disease Control and Prevention (CDC) and
possibly the U.S. Food and Drug Administration (FDA).
- That the NCI partner with the CDC to
develop and manage state-level 5 A Day programs.
Implementation
The Media and Message Delivery
- That the 5 A Day Program, as part of its
continuing public relations efforts, seek to
prevent the further growth of "dietary helplessness,"
to help the public differentiate between good and poor information, to provide a larger
context for personal dietary decisions, and to help
clarify the confusion engendered in the message
environment. In the dense, fragmented, and competitive message environment surrounding
diet and behavior, there is a need for reliable
and credible sources of information.
Resources
- That direct expenditures and leveraged
resources furthering delivery of the 5 A Day message
be increased.
Message Design
- That the NCI reconsider the design and
emphasis of the 5 A Day message. Specifically, media process-evaluation data suggest the
need to "reinvent" the 5 A Day message on a
regular basis to prevent "wear-out" and to enhance
its continuing attractiveness to the mass media.
In addition, the current strategy seems less
successful in reaching minorities and low-income groups, which suggests that any change in
message emphasis should take these groups
into consideration.
Media Strategies
- That the 5 A Day Program devote
additional resources to a variety of media strategies,
including a systematic media relations effort to educate reporters, editors, and producers
about diet and nutrition issues. As part of this
approach, program planners should consider pursuing partnerships with the media to develop
a long-term community emphasis on the 5 A Day message. The goal is to influence both the
quantity and quality of news coverage of the
5 A Day Program in particular and of diet
and nutrition issues in general.
- That the 5 A Day Program rethink its
channel-use strategy, with a particular focus on
new media, tailored communications, and how
media channels may be used as part of a collective approach to reaching lower
socioeconomic groups and the disadvantaged.
Evaluation of Communication Efforts
- That the NCI and the 5 A Day Program
partners pay close attention to developing a
package of media evaluation approaches that are
consistent, simple, complete, and
affordable.
Industry
- That NCI's collaboration with the Produce
for Better Health (PBH) Foundation be continued and expanded.
- That the NCI use its relationships with
industry specifically to ensure that vegetables
and fruit become more available to high-risk and underserved communities.
States
- That the NCI increase the resources,
staffing, and expertise made available to the states
for the dissemination, monitoring, and evaluation of the 5 A Day Program.
Minorities and the Underserved
- That the NCI, in partnership with relevant
organizations, develop operational
strategies aimed at understanding and reducing
disparities among ethnic groups and across educational
and socioeconomic differences.
Evaluation
- That the NCI continue to take the lead in
evaluating the effectiveness of the 5 A Day
Program. This evaluation must include the extensive
involvement of the states.
- That the NCI undertake a comprehensive
evaluation of each of the 5 A Day Program components: media; research; and industry,
private nonprofit, state, and Federal partnerships.
Research
- That the NCI maintain and support
intramural and extramural research in the following
areas, noting particularly the need to modify,
where appropriate, available funding and specific
peer-review expertise:
- Research into dissemination
methods—how to translate small-scale research
findings into large-scale, long-term, sustainable community
programs—with particular emphasis on programs of demonstrated
efficacy and for underserved populations;
- Research into behavior change—how to translate established data on changes
that will plausibly reduce risk into choices individuals and communities can make. In
particular,
(a) Research into the development of
more effective dietary intervention programs, determining which components of
such programs contribute most to program effectiveness;
(b) Studies of children and adolescents
as the development of food preferences begins;
(c) Studies on ways to develop
supportive environments and increase the avail-ability of vegetables and fruit; and
(d) Randomized controlled trials of
school-based interventions targeting middle and high school students.
- Policy research—particularly on ways
to establish an optimal environment for making healthy food choices in a
free-market economy;
- Research into environmental influences
on dietary behavior and behavior change,
including agricultural production, food
distribution and availability, food labeling, pricing structures, taxation and price
supports, purchase habits, advertising, cultural and social norms, and so on;
- Research into the mechanisms by
which vegetables and fruit reduce cancer risk, particularly in humans;
- Research into influences on food choice, particularly genetic and environmental
influences on taste preferences; early
life experiences involving exposure to food; and education about food, food choice,
and food preparation;
- Research into methods of measuring
dietary behavior, particularly the further
development of short- and long-term biological markers. In these research endeavors,
access to relevant data collected by industry partners seeking to understand human
preferences, behavior, and biology could prove a significant resource.
- That research focused on vegetable and
fruit consumption measure and report vegetables
and fruit separately, rather than combining the
two into a single measure.
Surveillance
- That the NCI, in partnership with other
relevant Federal agencies—including the U.S.
Public Health Service, the CDC, and the USDA—
coordinate, facilitate, and strengthen surveillance and monitoring of (1) national
vegetable and fruit consumption; (2) psychosocial
mediators of dietary behavior change such as self-
efficacy, knowledge, and taste preferences; and (3) if future research establishes their
importance, possible environmental mediators of
dietary behavior and behavior change,
including food availability, price structures,
taxation policy, and so on.
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