A significant meta-analysis looked at over 350 research from throughout the world to attempt and identify different impacts of eating both fruits and vegetables. They examined health outcomes, such as early mortality, malignancies, and cardiovascular events. Since all of the research were prospective cohort studies, the findings could only demonstrate association rather than causality between the prior events and the outcomes.
The researchers came to the conclusion that those who regularly consumed 800g or more of fruit and vegetables per day—equivalent to 10 pieces compared to the 5 presently advised—had a lower risk of developing harmful health issues. In fact, the cancer risk began to decline around the 600g threshold.
The purpose of this study was to determine the advantages of various fruits and vegetables for various medical conditions. For the simple reason that the majority of individuals do not even eat the recommended 5 portions nowadays, this study is unlikely to result in a contemporary recommendation.
This is a classic example of how practicality overrides scientific truth when deciding what advice should be conveyed to the general public under the justification of not wanting to put them under undue pressure. The reality is that in one study, the simple but effective intervention of physically giving food to a target group of very young individuals, without any extra reminders or pestering, immediately increased the number of portions in this group by a factor of two.
This contrasted with the lack of benefit observed in a control group who were given vouchers to buy roughly the same amount of fruits and vegetables of their own choosing and to prepare them for consumption however they pleased, along with twice-daily reminders, even though these latter messages were not regarded as obtrusive but rather helpful. The greatest strategy to increase consumption, rather than several teaching programs, may be to make fresh fruit available and free wherever people congregate to eat.
By 200g increments, increased fruit and vegetable consumption was examined with regard to:
Ischemic heart disease: each 200g increase in consumption reduced the risk by 8%, especially with sources of vitamin C, and with apples or pears, fruit juices, green leafy vegetables, carrots and sweet potato
Stroke: risk reduced by 16% per 200g increase in consumption, particularly apples or pears, citrus, green leafy vegetables and vegetable pickles
Cardiovascular disease in general: 8% reduction per 200g increase, especially with apples or pears, citrus, carrots, green leafy vegetables and other vegetables outside the cruciferous (Brassica) family
Cancers: 3% reduction per 200g increase, with cruciferous vegetables in particular, and with increases up to 600g per day
Mortality from all causes together: 10% reduction per 200g increase, especially with apples or pears, citrus fruit, berries, vegetables of all kinds and potatoes
