e-Library of Evidence for Nutrition Actions (eLENA)

Increasing fruit and vegetable consumption to reduce the risk of noncommunicable diseases

Biological, behavioural and contextual rationale

WHO technical staff
September 2014

Fruits and vegetables are important components of a healthy diet. Reduced fruit and vegetable consumption is linked to poor health and increased risk of noncommunicable diseases (NCDs). An estimated 6.7 million deaths worldwide were attributed to inadequate fruit and vegetable consumption in 2010 (1).

Current evidence indicates that fruits and vegetables consumed as part of the daily diet can help reduce the risk of coronary heart disease (2-4), stroke (4-6) and certain types of cancer (7,8). More limited evidence suggests that when consumed as part of a healthy diet low in fat, sugars and salt/sodium, fruits and vegetables may also help to prevent unhealthy weight gain (8-10). Very limited evidence suggests possible links between fruit and vegetable consumption and osteoporosis (8,11) and type 2 diabetes (12-14), though the latter may be a result of potential effects on body weight.

Fruit and vegetable consumption may reduce the risk of NCDs through the increased availability of various nutrients and their ability to modulate associated risk factors, though exact mechanisms remain unclear. Elevated blood pressure and cholesterol are risk factors for coronary heart disease and stroke, and the potassium provided by fruits and vegetables has been demonstrated to lower blood pressure (15,16). Dietary fibre may also help to lower blood pressure (17,18), and together with phytochemicals such as plant sterols, flavonoids and other antioxidants may be important in modulating cholesterol and other biological processes (19-21) that could reduce the risk of atherosclerosis (thickening of the arteries). Additionally, dietary folate is a determinant of homocysteine* levels in the blood and homocysteine has been linked to coronary heart disease (22,23). Dietary fibre may also help to regulate insulin (24,25), which may impact the risk of type 2 diabetes, and together with the high water content of fruits of vegetables, may help to reduce the risk of overweight and obesity by promoting satiety and reducing hunger (26,27), thus limiting overall energy intake. Antioxidants may also play a role in reducing the risk of cancer by preventing oxidative damage to cells of the body (28).

Fruit and vegetable consumption varies considerably among and within countries, in large part reflecting the prevailing economic, cultural and agricultural environments, but consumption in many parts of the world remains low (29). Low intake of fruits and vegetables is frequently observed with low socioeconomic status and is often due to the high cost of fruits and vegetables relative to other foods and/or limited access as well as wide availability of unhealthy options, such as energy-dense foods (30-33). Additional determinants of fruit and vegetable consumption among children are parental food consumption patterns and availability of fruits and vegetables at home (30,33,34).

Actions to address low fruit and vegetable consumption include:

  • behavioural interventions to increase fruit and vegetable consumption;
  • pricing incentives such as subsidies that lower the cost of fruits and vegetables;
  • promotion and support of gardening in home, community and school settings; and
  • improvements in agricultural and food systems.

Numerous studies have been conducted in high-income countries to assess the effectiveness of behavioural interventions designed to increase fruit and vegetable consumption (35-40), primarily in children as evidence suggests that dietary patterns established during childhood are predictive of patterns later in life (41,42). While most studies have observed small to moderate improvements in fruit and vegetable consumption, some modelling studies suggest that such small-scale interventions may not be cost–effective and that larger scale policies and programmes that influence price and/or availability of fruits and vegetables should also be considered (43). Data suggests that lower prices would improve availability and encourage those in low-socioeconomic group to eat more fruits and vegetables (44) as would other improvements in accessibility, such as home, community and school gardens (31). Though improvements to agricultural and food systems could impact fruit and vegetable consumption on a larger scale, there are few studies assessing the effectiveness of such interventions. Data from policy reviews indicates that some low- and middle-income countries have policies designed to increase availability and accessibility of fruits and vegetables, many of which target promotion of home, community and school gardening as well as urban agriculture initiatives (45,46), however data on effectiveness of specific interventions to increase fruit and vegetable consumption in low- and middle-income settings is very limited.

A substantial body of evidence suggests that consumption of fruits and vegetables is important in reducing the risk of NCDs. However, further research is needed to identify effective interventions and policy approaches to improve the availability and accessibility of fruits and vegetables and increase their consumption, particularly in low- and middle-income country settings.

* an amino acid produced by the body, often as a by-product of consuming meat


References

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