The Global Burden Of Disease Attributable To Low Consumption Of Fruit And Vegetables: Implications For The Global Strategy On Diet

Abstract

Objective We estimated the global burden of disease attributable to low consumption of fruit and vegetables, an increasingly recognized risk factor for cardiovascular disease and cancer, and compared its impact with that of other major risk factors for disease. Methods The burden of disease attributable to suboptimal intake of fruit and vegetables was estimated using information on fruit and vegetable consumption in the population, and on its association with six health outcomes (ischaemic heart disease, stroke, stomach, oesophageal, colorectal and lung cancer). Data from both sources were stratified by sex, age and by 14 geographical regions. Findings The total worldwide mortality currently attributable to inadequate consumption of fruit and vegetables is estimated to be up to 2.635 million deaths per year. Increasing individual fruit and vegetable consumption to up to 600 g per day (the baseline of choice) could reduce the total worldwide burden of disease by 1.8%, and reduce the burden of ischaemic heart disease and ischaemic stroke by 31% and 19% respectively. For stomach, oesophageal, lung and colorectal cancer, the potential reductions were 19%, 20%, 12% and 2%, respectively. Conclusion This study shows the potentially large impact that increasing fruit and vegetable intake could have in reducing many noncommunicable diseases. It highlights the need for much greater emphasis on dietary risk factors in public health policy in order to tackle the rise in noncommunicable diseases worldwide, and suggests that the proposed intersectoral WHO/FAO fruit and vegetable promotion initiative is a crucial component in any global diet strategy.

Generated Summary

This study, published in the Bulletin of the World Health Organization, estimates the global burden of disease attributable to low consumption of fruits and vegetables. The research employs a comparative risk assessment framework, analyzing data on fruit and vegetable consumption in populations and its relationship to various health outcomes. The study’s scope includes assessing the impact of low fruit and vegetable intake on diseases such as ischaemic heart disease, stroke, and several cancers, stratified by sex, age, and geographical region. The primary method involves combining data on fruit and vegetable consumption levels with estimates of relative risks (RRs) between intake and specific health outcomes. Consumption data was obtained through national representative surveys and extrapolated using FAO data where surveys were unavailable. Risk factor epidemiology involved systematic reviews of literature and meta-analyses to determine the associations between fruit and vegetable intake and selected health outcomes. The goal is to understand the implications for global health strategies, particularly concerning dietary risk factors and the rise of noncommunicable diseases worldwide. This is a crucial component in any global diet strategy.

Key Findings & Statistics

• The total worldwide mortality currently attributable to inadequate consumption of fruit and vegetables is estimated to be up to 2.635 million deaths per year.
• Increasing individual fruit and vegetable consumption to up to 600 g per day (the baseline of choice) could reduce the total worldwide burden of disease by 1.8%.
• Reduce the burden of ischaemic heart disease and ischaemic stroke by 31% and 19% respectively.
• Potential reductions for stomach, oesophageal, lung and colorectal cancer were 19%, 20%, 12% and 2%, respectively.
• Cardiovascular disease accounted for 16.7 million deaths globally (29.2% of the total), while cancer contributed to 7.1 million deaths (12.5% of the total).
• The choice of outcomes was guided by previous reviews of the literature, which reported a consistent protective effect of fruit and vegetable intake on these health problems.
• For coronary heart disease, ischaemic stroke, and lung cancer, significant RR (P<0.05) were estimated.
• Intakes varied by age, with children and the elderly generally having lower intakes than middle-aged adults.
• The studies used to derive RR estimates came mainly from Japan, the USA and Western Europe.
• The study estimated the regional mean intake of fruits and vegetables (grams per person per day), with varying results between regions. For example, for the age group 15-29:
• Africa D (Male: 288, Female: 302),
• America A (Male: 257, Female: 234),
• America B (Male: 148, Female: 167),
• Europe A (Male: 423, Female: 423).
• The total worldwide mortality attributable to inadequate consumption of fruit and vegetables was estimated to be approximately 2.6 million deaths in 2000.
• About 1.8% of the total burden of disease worldwide was estimated to be attributable to inadequate consumption of fruit and vegetables.
• For the diseases considered, diet is only one of many contributory factors (such as smoking or lack of physical activity).

Other Important Findings

• The study emphasizes the need for greater emphasis on dietary risk factors in public health policy to address the rise in noncommunicable diseases worldwide.
• The research highlights the potential large impact that increasing fruit and vegetable intake could have in reducing noncommunicable diseases.
• The study notes that policies aimed at reducing chronic noncommunicable diseases have typically emphasized selected risk factors like smoking and fat consumption, with less attention given to fruit and vegetable intake.
• The nutrition transition, occurring in all but the poorest countries, is resulting in the replacement of traditional plant-based diets rich in fruit and vegetables with diets high in animal fats and sugar and low in complex carbohydrates.
• Fruit and vegetables protect against cardiovascular diseases and some cancers, but their precise contribution has been unclear.
• The baseline of choice (600 g per day) could reduce the total worldwide burden of disease by 1.8%, and reduce the burden of ischaemic heart disease and ischaemic stroke by 31% and 19% respectively.
• The study uses the framework called comparative risk assessment (CRA). For the first time this included “fruit and vegetable consumption” as a risk factor.
• The regional analyses show that fruit and vegetable intake is a significant determinant of disease burden in both developed and developing regions.
• The choice of optimal consumption was thus set at 600 g per day in adults, and this is consistent with other health promotion initiatives.
• The study suggests that nutrition should be much higher on the policy agenda as we seek to address the increase in major noncommunicable diseases worldwide.

Limitations Noted in the Document

• The study acknowledges limitations imposed by the methods used, designed to assess a wide range of exposures across various disciplines.
• There is uncertainty surrounding the estimation of exposure levels and exposure-outcome relationships.
• The selection of the baseline of choice, and the statistical methods used to obtain disease burden estimates are subject to uncertainties.
• Sources of uncertainty include parameter uncertainty and model uncertainty, due to gaps in theory, measurement technology or lack of data.
• The nature of the exposure-response relationship, levels of bias in measurement, plus the extrapolation of exposure from one population to another, add to the limitations.
• It was not possible to estimate the uncertainty involved in extrapolating from a limited number of studies to a wide range of very different populations exposed to diverse dietary and other factors, any of which might interact.
• The study recognizes that estimating the joint population attributable fraction for some major worldwide diseases is a complex task.

Conclusion

The study underscores the critical role of nutrition in global health, particularly concerning the increasing prevalence of noncommunicable diseases. The findings highlight the significant impact of low fruit and vegetable consumption on global mortality, estimating that a substantial number of deaths annually could be attributed to this factor. The potential for substantial reductions in disease burden, particularly for cardiovascular diseases and certain cancers, through increased fruit and vegetable intake, is a key takeaway. The research strongly advocates for a shift in public health policy to prioritize dietary risk factors, aligning with the World Health Organization (WHO) and Food and Agriculture Organization (FAO) initiatives promoting fruit and vegetable consumption. The study emphasizes the complex interplay of factors in dietary impact, including the need to address the determinants of fruit and vegetable consumption rather than solely focusing on individual behavioral change. The study suggests the need for a comprehensive, multi-sectoral approach involving agriculture, food labeling, and nutrition programs. The study reinforces the need for increased emphasis on nutrition in public health policy and suggests that the WHO/FAO fruit and vegetable promotion initiative is a crucial component of any global diet strategy. Furthermore, the authors emphasize that intersectoral policy approaches to food, nutrition and health appear to be an important new way forward for tackling the rise in obesity, cardiovascular disease and cancer worldwide.