Eating loads of fruit and vegetables – 10 portions a day instead of the recommended “5 a Day” – may give us longer lives, say researchers.
The international “study of studies” also identified specific fruit and veg that reduced the risk of cancer and heart disease.
The following fruit and vegetables were found to help reduce the risk of:
- Coronary heart disease – apples or pears, citrus fruit, fruit juices, green leafy vegetables, beta carotene-rich vegetables such as carrots and sweet potato, and vitamin C-rich fruit and vegetables
- Stroke – apples or pears, citrus fruit, green leafy vegetables and pickled vegetables
- Cardiovascular disease – apples or pears, citrus fruit, carrots, green leafy vegetables and non-cruciferous vegetables such as butternut
- Total cancer – cruciferous vegetables such as cauliflower and broccoli
- All cause of death – apples or pears, berries, citrus fruit, cooked or raw vegetables, cruciferous vegetables, potatoes and green leafy vegetables or salads
Researchers looked at more than 350 studies from around the world that examined the impact of fruit and veg consumption on a range of health outcomes, such as cancer, stroke and premature death.
They found eating more fruit and veg was linked to a lower risk of getting these diseases and dying early when eating up to 800g a day (around 10 portions), or 600g a day for cancer.
So does that mean campaigns in New Zealand and Australia encouraging people to have at least five portions of fruit and veg a day should be updated?
Public health campaigners around the world chose five portions because it was seen as an achievable target for most people.
Dr Alison Tedstone, chief nutritionist at Public Health England, explained to the BBC that, “Whilst consuming more than five portions of fruit and vegetables a day may be desirable … adding pressure to consume more fruit and vegetables creates an unrealistic expectation.”
Critics have already pointed out that it’s simply too expensive for even a mid-sized family, and it’s doubtful whether that amount of fruit and veg could be grown from current resources.
The study was carried out by researchers from academic and medical institutions in Norway, Imperial College London and Leeds University in the UK, and Harvard University and the Icahn School of Medicine in the US.
The study was published in the peer-reviewed International Journal of Epidemiology.
The researchers analysed data from 95 studies that monitored people over time, and looked at fruit and vegetable intake and the risk of various diseases.
The studies were mostly from Europe and the US, but also included research from Asia and Australia. These were large studies, so there was data available from 227,000 to 2,125 million people for each analysis.
Researchers estimated that globally, a total of 5.6 million early deaths in 2013 were down to eating less than 500g a day of fruit and vegetables.
Researchers estimated that when using 800g a day as the optimal intake of fruit and vegetables, 7.8 million early deaths could have been avoided by people eating this amount.
However, Britain’s National Health Service website raises some caveats.
“Before we take this at face value, there are some important considerations:
- There are likely to be many factors that may have affected the results. It might be that people who eat a lot of fruit and veg are also more likely to be physically active, consume less alcohol, not smoke and be a healthy weight, or other factors that might mean better health outcomes. It’s not just fruit and vegetable intake that influences the risk of getting certain diseases and dying early.
- The study didn’t look at all diseases, such as infectious or respiratory conditions, so it might be the case that eating more fruit and veg than the guideline amount is not beneficial for reducing the risk of developing all diseases.
- The studies included might have varied in several ways – for example, the country the research was conducted in might have influenced things like the way fruit and vegetables were prepared, the different types of fruit and vegetables available, and other dietary and lifestyle factors.
- There were few studies looking at the specific types of fruits and vegetables, so it might be there are other fruit and vegetables that are also beneficial but not listed.
- There were considerable differences between the studies. This means that when you pool their results together, you need to view the results with some caution. This was particularly true for cancer, stroke and all causes of death.
“As with most studies assessing diet, they are reliant on accurate self-reporting of food intake, and may not take into account changes in diet over time,” it concludes.