Smoothies

Posy

Quick question- is blending up several pieces of fresh fruit and drinking them as a smoothie as good as the real thing or do you lose some nutritional value by blending them? I usually drink a couple of smoothies a day as I don't eat much fruit generally but saw an article in the paper saying they are not as healthy eating a fruit salad etc. Can this be right, because I always figured they are as good as the genuine article.

Shrimp

I would imagine there would be absolutely no difference between eating a grape than there would be blending then drinking a grape. The blender is just like the mechanical breakdown of food in your mouth, except it's a lot more thorough.

I'd like to have read that article, what publication did you read it in?

hunnymonster

Karyn, There are two issues.

Firstly, a good proportion of the nutritional value is associated ewith the skins of several fruit so if you peel your apple before blending it it will contain less value than just washing and eating it.

The second issue is degradation of the nutirients when making smoothies, for example if the fruit is exposed to too much mechanical pressure, heated etc reactive oxygen species (free radicals) can be introduced.


So, if you use the whole fruit, make it in a high quality juicer/smoothie maker and drink it straight away you should be ok. Otherwise, it's probably better to stick to the fruit as nature intended.

rubadub

Did the article give reasons? Perhaps it was talking of commercially available smoothies, these are a rip-off and probably heat or chemically treated to prolong shelf-life

damianmckeever

Now I'm no expert on the subject, but there was about a 15 minute spell in Home Economics Class when someone woke me up and I seem to remember been told that with fruit once the fruit is cut and it's exposed to oxygen you are losing some of the nutritional value. If I remember correctly it's similar to boiling Turnip, you actually lose the B vitamins out of turnip if you don't eat it raw.

like when you cut an apple and leave it exposed you can see the apple turn "bad". If you're literally just getting your fruit throwing it "whole" into the blender and then drinking straight away I can't imagine you're losing very much. I'm sure someone has a more scientific answer.

g'em

let's be realistic about this: fruit, whether it's whole or blended is good for you.

Raw, fresh fruit: contains all the nutrtional benefits, fibre, high levels of vitamins and antioxidants. But most will have been subjected to some sort of pesticides/ treatments unless you buy organic.

Juices: (freshly made, not from cartons or concentrate): will still contain the vitamins, antioxidants, flavenoids as a whole fruit (although probably in lesser amounts as some will get lost along the way from processing), but without the fibre. This may actually allow for quicker abosrption of the "good stuff" though.

Smoothies: (again freshly made) these will have the skins as well as the inners and so will still have fibre in them, as well as the nutrients, vitamins etc.

It comes down to what you need at any given time. I, personally, love smoothies. In one smoothie I can get manganese, Vit B6 & B1 from pineapple, folate, B2 & B3 from raspeberries, Vit C from kiwis and oranges and a heapload of dietary fibre all in one easy to carry, tasty, good-on-the-go container. That is I can get a more diverse range of vitamins than I would from eating individudal fruits.

It won't provide me the same sateity, and they're relatively calorie heavy (compared to fruit alone) but they're a great, healthy addition to my diet. I always make mine up fresh myself or get them from a juice bar, never from a carton.

A (freshly made) smoothie/ juice/ whole fruit will always be infinitely better for you than a milkshake/ fizzy drink any day.

rubadub

They had a program on BBC2 last night going on about antioxidants in fruits & veg. If you are eating tinned fruit like pineapples or tomatoes are all of these antioxidants destroyed by the heating process?

They had people eating tomato puree for their skin, that is probably heat treated too. They gave the people controlled sunburn, and 6 months after eating tomatoes everyday, gave them sunburn again and it was 30% less damage.

g'em

It depends on the antioxidant and the treatment process. The term antioxidant itself is an umbrella term that describes any substance which reduces the rate of oxidation reactions, where electrons are transfered from one chemical to another. Ascorbic acid (vit C), glutathione, Vit E and Vit A and flavenoids are all antioxidants.

During heating with water flavenoids get hydrolysed - water is added to them breaking htem apart, and so their nutritional value is partially lost. Evaporation causes the least amount of damage to antioxidants as heat exposure is minimised, but it's an expensive process and not favoured during food manufacture. During "dry" heating the temperature isn't as evenly spread across the food and so antioxidant los will be greatest at the outside. Antioxidants may also be lost during prolonged periods of storage at ambient or room temperature.

So the answer is that generally some, but not all, of the antioxidants get lost. Tinned fruit (in its own juice, NOT syrup) is better than no fruit at all, but not as good as fresh fruit. Tomato puree isn't as good as whole tomatoes but there is evidence that the lycopene of tomatoes is more reaily absorbed after prior processing.

There's nothing wrong with having tinned fruit or the like in your diet as an addition and not a replacement of whole fresh fruits and vegetables.

rubadub

Thanks for the info

g'em wrote:

Tinned fruit (in its own juice, NOT syrup) is better than no fruit at all,

I always go for it in its own juice since it is nicer anyway. But I have recently noticed a lot of fruits are in "juice" rather than their own juice. So instead of using a strawberry milkshake powder in a protein drink I would put in a tin of strawberries, but they are in grape juice.

Is there something wrong with the syrup, other than it is just plain sugar and is missing the nutrients that the juice would have (be it grape or its own juice).

I also use frozen berries which I suspect are very good and contain all the nutrients, also the added benefit of cooling the protein shake. But frozen berries are far more expensive than tinned, over twice the price, so probably eating twice as much tinned would give the same benefits of fresh/frozen and be cheaper and add more flavour to my shake. Of course that will have more calories but these are PWO shakes.

there is evidence that the lycopene of tomatoes is more reaily absorbed after prior processing

In the program it was lycopene that helped the skin.

g'em

rubadub wrote:

Is there something wrong with the syrup, other than it is just plain sugar and is missing the nutrients that the juice would have (be it grape or its own juice).

that's essentially all it is.

rubadub wrote:

I also use frozen berries which I suspect are very good and contain all the nutrients, also the added benefit of cooling the protein shake. But frozen berries are far more expensive than tinned, over twice the price, so probably eating twice as much tinned would give the same benefits of fresh/frozen and be cheaper and add more flavour to my shake. Of course that will have more calories but these are PWO shakes.

frozen berries are fantastic!! generally speaking it's now nearly better for you to buy frozen over fresh for most vegetables (unless bought organically at farmers markets). Some of the bigger brands have begun to "snap freeze" their veg so that all the nutrients are kept. When the veg are transported or stored for long periods of time teh nutrients will leech out. Plus they will more often than not have been chemically treated to prolong shelf-life.

And then there's economics to be considered - I tend to buy mroe frozen veg than fresh because if I buy lots of fresh produce once a week at the market (and it's only open on a Sunday), by mid-week its begun to spoil and it's a waste of money.

Posy

Well, the article was in the paper (the mirror) in the health section. I think they mentioned that shop bought smoothies often contain honey and yogurt, therefore are more fattening. It also said that no matter how many you drink, they never total more than one of your 'five a day' which I find pretty far-fetched. :rolleyes:
I think I'll stick with the smoothie drinking, but try to make my own, that way at least I know exactly what's in them!

Superdub2

damianmckeever wrote:

Now I'm no expert on the subject, but there was about a 15 minute spell in Home Economics Class when someone woke me up and I seem to remember been told that with fruit once the fruit is cut and it's exposed to oxygen you are losing some of the nutritional value. If I remember correctly it's similar to boiling Turnip, you actually lose the B vitamins out of turnip if you don't eat it raw.

B vitamins are water based so when you boil a turnip they end up in the water and that is why you lose them