A philosophical Prince of Leaves and his purple coloured hygiasticon

Last Friday I was fortunate enough to join colleagues in celebrating the 50th anniversary of the University of Salford becoming a university. The black tie dinner was an opportunity to celebrate and reflect on our achievements over the last 50 years. We were able to do so with many people who will continue to work with us over the next 50 years. The food was prepared and served by SALFOOD and they made a great job of it. The main course for us vegetarians was a Lancashire Vegetable Hotpot, and lovely it was too. However, there were no Purple Vikings, or Peruvians or Purple Majesty’s to be seen. These are varieties of purple potatoes which originate from Bolivia and Peru.

There is a reason for mentioning this although I will admit it’s slightly tangential. My co-table host was Dr Fairclough, a colleague from the School of Arts and Media and someone who has a passion for TAFKAP (or Prince to us older folk). Indeed she is organising an interdisciplinary conference on the life and legacy of Prince (due to run in May this year) entitled ‘Purple Reign’. It did occur to me that she might like to get some Purple Majesty’s in for the conference dinner…

The other reason she might like to consider purple potatoes is that apart from their earthy nutty flavour they have 4 times the level of antioxidants as ordinary white potatoes. Anthocyanin is the antioxidant that creates the purple colour. Purple potatoes are really good for your health, helping to reduce high blood pressure, increasing weight loss, helps prevent depression and can keep your skin looking younger. You can buy purple potatoes in the UK, Waitrose and Sainsbury sell them when in season, or if you can’t wait, the Fine Food Specialist online store was selling them last week. However at over £11.00 a Kg it could be an expensive sausage and mash dinner. 

Of course, potatoes are not the only vegetable that might be good for you. Way back in the 17th Century, the philosopher Leonard Lessius (who was also known as the Prince of Philosophers) described in his work ‘Hygiasticon’, the relationship of diet and health. Much later, in 1980, those canny Californian’s adopted the now famous 5-a-day phrase as way of promoting better health for all. A little later still, the World Health Organisation estimated that globally 2.7 million lives were lost each year as a direct result of low intakes of the recommended 400g of fruit and veg a day. They based this on eating 5 x 80g potions but excluded potatoes! Interestingly the 5-a-day advice wasn’t initially based upon a solid evidence base.

The WHO commissioned the European Prospective Investigation into Cancer and Nutrition (EPIC) trial, which during 1992 and 1999 looked at the diet, life style choices, anthropometric measurements, and medical histories of more than 521,000 participants from 23 centres across 10 European countries. This study did provide evidence that fruit protected against bowel cancer in women (but not men) and against lung cancer (although vegetables didn’t). It was only in 2014, that follow up data provided stronger evidence of the benefits of the 5-a-day approach.

For people eating more than 569g of fruit and veg (around 7 portions) they were found to be 15% less likely to die from a circulatory disease; 27% less likely to die from a respiratory disease; and 40% less likely to have died from a digestive system disease compared to those eating less than 249g (about 3 portions). In this later study it was vegetables that were seen to provide the most protective effect. So should we all now try and eat 7-a-day? The answer is probably no. There is evidence to suggest that for every extra portion of fruit eaten each day the overall risk of death reduces by 6% and for vegetables, 5%. However, after 5 portions, the risk of dying from any disease (other than cancer) does not reduce any further. None of the studies can confirm what the protective effect is against cancer. 

So until the next tranche of research is published I guess we should all just try and stick to the 5-a-day programme. And its likely that the next research study will produce results that once again will help us all make decisions over how we choose to live our lives. That research is likely to be carried out by those working in universities, and undertaken by those skilled in study design and in ensuring methodological rigor and outcome reliability. I am so proud to be part of a University community that is serious about research, and is committed to making a difference to people’s lives. Equally, I am also proud to be part of a community that can celebrate purple potatoes being eaten by Princes in the purple rain.