Topic: Bitter truth: How we’re making fruit and veg less healthy (New Scientist)

[Vinlander]

A subject close to my heart (literally) since apparently my arteries are "normal"  though medical professionals look at me (a self-confessed fat bastard) and say the word normal in the way ordinary people might say "oh my god you're a potential baby-eating extraterrestrial"...

https://www.newscientist.com/article/mg22730322-100-bitter-truth-how-were-making-fruit-and-veg-less-healthy/?utm_source=third-party-widget&utm_medium=third-party-widget&utm_term=philips&utm_campaign=philips

Here's to my favourite red mustard "broccoli" and my favourite bittercress.

Cheers.

PS. Continuing with the counter-intuitive - add this to the idea that damaged food plants produce salicylate - with all of it's health benefits - but protecting your plants stops them producing it (even - annoyingly - the 'cide-free methods I use  ).

[galina]

Interesting article Vinlander. 

There is a second, wide ranging problem with the shop bought vegetables we are eating.  Not only are they less nutritious due to the bitterness taken out, but they are also demineralised. 

Monoculture foods grown on the same land time after time (or more generally on depleted soils) are fertilised by farmers with NPK.  This means no other plant foods are available for the growing plants and as a result we are getting vegetables that are mineral and trace nutrient depleted.  Agricultural plants are grown to be large, uniform and blemish free.  However the insecticides and herbicides that achieve this aim do not call up the plant's natural defence systems.  A plant that has grown through some insect damage, or a plant that had to struggle against competition in some way, has a different chemical make-up to an over-fed industrial vegetable.  We all know that often our garden vegetables are smaller than their shop-bought counter parts and have blemishes, but they taste much stronger (better), more concentrated flavour.  As they contain many more micro-nutrients, especially when grown on mineral rich soil, they are more nutrient dense and healthier for us. 

(Semi)-wild plants and herbs like your bittercress Vinlander, are a very valuable addition to healthy eating.  It takes a bit of effort for cooks on a busy day, but we should always cook with herbs and spices for extra nutrition - and eat the herb garnish too.  It really isn't just a 'cheffie' pretty thing   

[markfield rover]

Thank you both for the above,  I am glad I read this I live closer to the supermarket than the allotment but the above info on a wet day if I am feeling lazy makes the allotment without doubt where I should go. New Years resolution number one!

[okra]

Very interesting article thanks

[PondDragon]

Interesting article - thanks for linking to it. I was researching polytunnels recently with a view to possibly getting one for the garden, and one issue with these is that some of the covering films used can block a lot of UV light. This can cause plants to grow a bit faster, since they're not being exposed to as much damaging UV, but produce less of the phytochemicals that they normally use to protect themselves. So, less tasty and less healthy to eat. There are alternative films that transmit more UV, but I don't know how widely these are used.

[galina]

Interesting article - thanks for linking to it. I was researching polytunnels recently with a view to possibly getting one for the garden, and one issue with these is that some of the covering films used can block a lot of UV light. This can cause plants to grow a bit faster, since they're not being exposed to as much damaging UV, but produce less of the phytochemicals that they normally use to protect themselves. So, less tasty and less healthy to eat. There are alternative films that transmit more UV, but I don't know how widely these are used.

Swings and roundabouts.  At least you are getting  m o r e  of peppers and tomatoes with the tunnel most years (this year was an exception), and that must mean more good nutrition overall.  I would still go for the most durable cover (and use hotspot tape).  You can certainly grow quite a few more crops in a poly if you consider winter veg gardening in addition to the summer crops.  Crops you would not grow outdoors at all - and this means more nutritious food overall. 

[Vinlander]

I use a (spanish-made) cover which is supposed to have twice as much UV inhibitor as the UK version. What I don't know is whether it blocks the UV or somehow protects the plastic in some other way. On the other hand they do sell a special version that blocks all UV and is supposed to put off pests.

Certainly Polycarbonate blocks nearly all UV (even more when it goes yellowish - apparently the damaged polymer changes into an even more absorbent yellow version).

One clear result of this is that terrestrial cacti sulk under PC but the jungle types do fine because they are used to being shaded by leaves. There is a suspicion that climbing types (Hylo- and Selenicereus) won't flower or fruit properly until they grow through the canopy and get some UV.

Do plants that evolved in high-UV environments (especially anything from the high Andes -  toms, peppers etc) need UV to produce the more exotic flavours and phytochemicals? Any actual research?

Cheers.

[galina]

Well without being a scientist in any way just trying to grow and eat healthier, I have learned than anthocyanin is nature's 'sunscreen'.  Healthy black tomatoes, like Indigo Rose, Helsing Junction Blues etc are darker where the sunlight gets to them and red (when ripe) where it does not.  Anthocyanin is a great antioxidant for us.  Not just in 'superfood' blueberries, but in any purple/black fruit and veg.  I am not convinced that reduced UV (such as the light through my less than sparkling clean greenhouse glass) inhibits the development in a crucial way as I had very good black tomatoes both in the greenhouse and out, but 'black' tomatoes, picked green and artificially ripened with ethylene gas in storage, would probably not show much of the healthy black colour and not contain much anthocyanin. 

Presumably the same is true for the nutrient content of all artificially ripened fruit and veg that has been  'ripened' away from sunlight.  Yet another reason why fresh-picked and ripe, seasonal, allotment produce is better for our health.   

[PondDragon]

Swings and roundabouts.  At least you are getting  m o r e  of peppers and tomatoes with the tunnel most years (this year was an exception), and that must mean more good nutrition overall.  I would still go for the most durable cover (and use hotspot tape).  You can certainly grow quite a few more crops in a poly if you consider winter veg gardening in addition to the summer crops.  Crops you would not grow outdoors at all - and this means more nutritious food overall.

This is potentially a major issue, given the large amounts of commercial fruit & veg now grown under plastic (e.g. in Spain - photo). Reading about it further, it seems some crops are affected more than others. Research at Reading University found a big effect of UV on red lettuce (substantial increase in phytonutrients, decrease in yield), but no effect on strawberries, raspberries or blueberries. I haven't found much yet on the effect on tomatoes or peppers.