Evidence for fruit and vegetable consumption in cardiovascular health and lipid management
In line with Public Health recommendations [1], studies have found that consuming at least 5 portions of fruit and vegetables a day are associated with a reduced risk of cardiovascular disease (CVD) [2],[3].
A meta-analysis of 95 studies found that for every additional 200g of fruit and vegetables consumed a day there was an 8% reduction in the relative risk (RR) of coronary heart disease and CVD – up to a threshold of 800g (10 portions)/ day. At this level of intake there was a 28% reduction in relative risk [2].
Currently, as a nation, only one third of adults meet the 5-a-day recommendations – the average intake is between 3 to 4 portions a day.[4]
[1] Eatwell Guide. Public Health England in association with the Welsh government, Food Standards Scotland and the Food Standards Agency in Northern Ireland; https://www.nhs.uk/live-well/eat-well/the-eatwell-guide/
[2] Aune D, Giovannucci E, Boffetta P, et al (2017) Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-a systematic review and dose-response meta-analysis of prospective studies. Int J Epidemiol. 2017 Jun 1;46(3):1029-1056 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5837313/pdf/dyw319.pdf
[3] Wang X, Ouyang Y, Liu J,et al (2014) Fruit and vegetable consumption and mortality from all causes, cardiovascular disease, and cancer: systematic review and dose-response meta-analysis of prospective cohort studies. BMJ. Jul 29;349:g4490. doi: 10.1136/bmj.g4490.
[4] Public Health England. NDNS: results from years 7 and 8 (combined) Results of the National Diet and Nutrition Survey (NDNS) rolling programme for 2014 to 2015 and 2015 to 2016.
Mechanism of action
Fruit and vegetables contain of a number of nutrients and phytochemicals, including fibre, vitamin C, carotenoids, antioxidants, potassium, flavonoids and other unidentified compounds which are likely to act synergistically through several biological mechanisms to reduce the risk of CVD.
Proposed actions include reducing cholesterol levels, blood pressure, inflammation and platelet aggregation, and improving vascular and immune function. The antioxidants in fruit and vegetables may prevent the oxidation of cholesterol and other lipids in the arteries. Fruits, vegetables and fibre intakes may also modulate steroid hormone concentrations and hormone metabolism and may have a beneficial effect on gut microbiota.
A high fruit and vegetable intake could also reduce CVD risk indirectly by displacing unhealthy foods in the diet which are high in saturated fat, trans fats, glycaemic load and salt.