By Laurie Noreau – Agence Science-Pesse
The message has been hammered into our heads for years – you have to eat at least 5 portions of fruits or vegetables per day. Where does this recommendation come from? And why the number 5? The Rumor Detectors are on the case…
The Origin of the Recommendation
At the beginning of the 2000s, faced with a steep rise in the number of cancers and cardiovascular illnesses, public health agencies started promoting healthy eating. There was already ample proof that fruits and vegetables lower your risk of developing certain illnesses.
Since 2003, the World Health Organization (WHO) has recommended consuming 400 g of fruits and vegetables daily. If we divide that up, that would mean 5 portions of 80 grams: a way of simplifying the message and making it easy to remember.
But the WHO didn’t invent this. From 1988 to 1991, California organized the “5 a Day – For Better Health!” campaign. The aim was to get Californians to increase their consumption of fruits and vegetables – and get healthy in the process. In the years that followed, almost every state in the union adopted the same program.
Nonetheless, given that the recommendation is often between 5 and 10 portions per day, leaving things open to interpretation, is there an optimum quantity?
In 2014, Chinese and American researchers analyzed 16 studies involving over 800,000 participants. On the whole, each supplementary portion of fruits or vegetables reduced mortality by 5% no matter what other factors were involved. The same was true for cardiovascular ailments. For example, at 2 portions a day, the reduction was 10%, and at 5 portions, it was 25%. Researchers noticed that the health benefits tended to plateau at 5 portions.
But in 2017, an international study upset the applecart. An analysis of 95 studies over several decades revealed that 800 grams of fruits and vegetables is preferable, or 10 portions a day. The meta-analysis estimated that 7.8 million deaths could be avoided each year if this recommendation is followed. In doubling your consumption from 5 to 10 portions, you reduce your risk of developing certain illnesses by 31% on average, a gain of 6% over 5 portions.
Last year, an article in the American Heart Foundation’s magazine Circulation scaled back the recommendation to 5 portions. The benefits of more than 5 are negligible, they wrote. To be more precise, the biggest benefits are to be had by 2 portions of fruits and 3 portions of vegetables.
Note that just 30% of Canadians and 10% of Americans succeed in following the recommendation: increasing to 10 portions a day risks discouraging many, since the added health benefits aren’t enormous.
Some fruits and vegetables are better than others. Canned fruits are to be avoided, since eating them is associated with higher mortality rates, possibly because of all the sugar they contain. Go for fresh fruits and vegetables, whether they’re raw or cooked. Juices are ruled out of these daily recommendations, because of their added sugar.
There’s one more nuance to add to these mega-studies: quite often, people who eat more fruits and vegetables lead healthier lives. They are more active, they don’t smoke, and their eating habits are usually better. So it’s difficult to credit the drop in illnesses exclusively to the consumption of broccoli, carrots and citrus.
What exactly constitutes an 80 gram portion?
– Two big strawberries
– Six radishes
– One pear
– A medium-sized banana
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