{"id":2942,"date":"2014-04-01T22:59:40","date_gmt":"2014-04-01T21:59:40","guid":{"rendered":"https:\/\/www.zoeharcombe.com\/?p=2942"},"modified":"2018-10-18T11:00:05","modified_gmt":"2018-10-18T10:00:05","slug":"seven-a-day-fruit-and-veg","status":"publish","type":"post","link":"https:\/\/www.zoeharcombe.com\/2014\/04\/seven-a-day-fruit-and-veg\/","title":{"rendered":"Seven a day fruit and veg?!"},"content":{"rendered":"
On Tuesday 1st April I thought I’d spotted the April Fool joke for the day when I woke up to headlines such as “Seven-a-day fruit and veg ‘saves lives’<\/a>” and “Diet that adds years to life<\/a>.” Sorry BBC – no lives will be saved – we’re all going to die. We’re also not going to live for years longer by having 7 fruit & veg a day.<\/p>\n The stories were based on this press release <\/a>and this journal article<\/a>.<\/p>\n The Abstract<\/strong><\/p>\n The first thing that I noticed was that the abstract (in italics below) declared that everything except smoking had been adjusted for. Table 1 then showed that 39% of the 0-1 portion a day people smoked vs. 10% of the 7+ portions a day people.<\/p>\n “Methods<\/strong> Cox regression was used to estimate HRs and 95% CI for an association between fruit and vegetable consumption and all-cause, cancer and cardiovascular mortality, adjusting for age, sex, social class, education, BMI, alcohol consumption and physical activity, in 65\u2005226 participants…”<\/em><\/p>\n I emailed the named person on the report who described leaving this out as a “terrible oversight.” Jolly good of her to get back to me so quickly, as Dr Longo still hasn’t<\/a>. I’d already done a couple of interviews before the reply, during which I said that the abstract didn’t record having adjusted for smoking. There is a huge lifestyle thing going on here, however and I don’t know how you can adjust for an entire lifestyle.<\/p>\n The study The study did a similar thing to the Longo animal protein study – they didn’t divide the subjects studied into equal sized groups – quintiles. They divided them into uneven groups of those whom (when asked what they ate yesterday<\/em> – yes, I know – usual huge caveats) replied:<\/p>\n 0-<1 portion of fruit & veg (15.2%);<\/p>\n 1-<3 portions of fruit & veg (30.9%);<\/p>\n 3-<5 portions of fruit & veg (29%);<\/p>\n 5-<7 portions of fruit & veg (15.7%); and<\/p>\n 7+ portions of fruit & veg (9.3%).<\/p>\n By allocating people unevenly to researcher defined groups (0-<1; 1-<3; 3-<5 etc) rather than to quintiles, an artificial baseline and opposite extreme can be created. I use the analogy – it’s like doing a study about height and using basketball players as the benchmark.<\/p>\n All the headlines then came from comparing the people who didn’t even have 1 portion of fruit or veg the day before, with the people who had 7+ portions. Let’s see Table 1 for some further comparisons of these two extreme groups, which don’t even account for 25% of all people in the study. Let’s call them baddies (0-<1) and goodies (7+) and then let’s play the relative comparison game:<\/p>\n – Smoking is four times higher in baddies;<\/p>\n – Inactivity is four times higher in baddies;<\/p>\n – Baddies are almost twice as likely to be in manual jobs;<\/p>\n – Baddies are more than twice as likely to have no<\/em> qualifications. The goodies are four times more likely to be university educated.<\/p>\n This isn’t just about fruit and veg – it’s about a whole lifestyle of advantaged people and disadvantaged people.\u00a0 Do researchers really think that we could take a Glaswegian man or woman – with a life expectancy <\/a>of 71.6\u00a0 and 78 respectively – and give them the life expectancy of the men and women in Kensington and Chelsea – 85.1 and 89.8 respectively – with extra portions of fruit and vegetables? May I suggest that the fruit and veg intake is a marker<\/em> of a healthy lifestyle and not the maker<\/em> of one?<\/p>\n
\n<\/strong><\/p>\n