Friday 28 March 2008

Are some foods 'better for us' cooked?

Frequently on raw food forums I see anxious posts from people new to raw who have been told by friends, or 'experts' that certain foods are 'better for us' cooked. Here's a selection of the sorts of statements made by 'pro-cookers', with reference to counter-arguments put forward by raw fooders.

'Cooked tomatoes give us more lycopene than raw.'

Lycopene is an antioxidant that helps prevent heart disease and cancer. It's found in the cell walls of tomatoes; it's what makes them red. The argument for cooking is that it ruptures the cell walls, thus releasing more lycopene.

Shazzie ('Detox Your World') comments: 'Did nature make a mistake by only offering 'x' mg of lycopene in a raw tomato when its cooked counterpart has twice that? Or could it be that we really only need 'x' mg of lycopene per tomato? And do we need another substance which is destroyed in the cooking process to utilise the lycopene or other tomato nutrients in our bodies?'

Dr Doug Graham ('80/10/10 Diet'): 'cooking damages, destroys, and changes-for-the-worse many nutrients (and yes, a cooked tomato has more lycopene than a raw tomato, but is the amount of lycopene in a raw tomato sufficient? Hint: Yes. And for that one positive aspect of cooking, how many negative aspects are there? Answer: Plenty.') In fact, more recently he has refined this to say that it is the bioavailability of lycopene that rises when tomatoes are cooked but in fact the cooking results in an overall reduction in quantity of available lycopene, so, in his words 'another myth bites the dust' ('Get Fresh!' Spring 09).

My own elementary knowledge of chemistry tells me that many of the substances in our food (some of which scientists may not even have discovered yet) need other substances to work effectively and that surely proportions are important. Is it really a good thing for an unnatural process to give us twice as much of one thing, and, at the same time, damage or destroy other vital chemicals?

What about the Vitamins C, B1 and B6 in tomatoes - all of which can be reduced or destroyed in cooking? I'd rather have my tomatoes not messed around with.

Also, according to Hannah Allen, natural hygienist, the combination of citric, malic and oxalic acids in tomatoes can interfere drastically with starch digestion. Now, raw fooders eat little or no starch anyway, so no problem. But those who do still include in their diets cooked grains and pulses, for example, may be interested to know that these acids are all 'intensified' by cooking. Even more reason not to damage those lovely tomatoes by heating them.

And in fact recent research (reported by Journal of National Cancer Institute) shows that tomatoes' 'protective effects against prostate cancer and cardiovascular disease are due not simply to their lycopene content, but result from the synergy (my italics) of lycopene with other phytonutrients naturally present in whole tomatoes.' How many of these phytonutrients are going to be left after cooking to work synergistically with any increased lycopene? What would be the effect of ingesting increased lycopene without some of the chemicals that work with it in our bodies?

If you'd really like more of that lycopene, there's a way of getting more without cooking. When tomatoes are blended, the cell walls are broken down, thereby releasing more lycopene! A recent study by the Health Research and Studies Center showed that tomatoes processed in a Vitamix blender delivered over three times more lycopene than those prepared in a juicer or eaten whole. And although blending does destroy some other nutrients, it is a far less destructive process than cooking. But, having said that, wouldn't it be better to have the lycopene and other nutrients in the precise proportions delivered by the tomato in it's whole, unadulterated state rather than blended?

Chris Carlton of reminded me that anyone on a raw food diet would get more lycopene than a person on a cooked diet anyway, simply because raw fooders usually eat a lot more tomatoes than people on a standard cooked diet!

And let's remember that lycopene isn't just found in tomatoes - watermelon, apricots, papayas, pink grapefruits and strawberries are also all good sources.

Cooked carrots give us more caretonoids than raw

I'll deal with this one relatively briefly, or rather, Dr Doug will!

'Don't be fooled! We know that carotenoids are highly beneficial, but who says that more than normal amounts are good for you? Giving up vitamins, enzymes, coenzymes, antioxidants and thousands of other phytonutrients in exchange for more carotenoids, while exposing yourself to the dangers associated with the consumption of heated proteins (which are linked to cancer and arthritis), heated fats (which become carcinogenic) and heated carbohydrates (which have been linked to the development of diabetes) is not a healthy tradeoff. Roughly 10,000 nutrients are damaged, deranged or destroyed by cooking for every single nutrient that becomes more bio-available.'

Also, if you have young children, please give them raw carrots - so much better for the development of their teeth and jaws than cooked.

'The body absorbs more iron when vegetables are cooked.'

This statement came from researchers at the American Chemical Society after they found that the body more easily absorbs iron from 37 of 48 vegetables tested when boiled, stir-fried, steamed or grilled, eg absorbable iron in cabbage jumped from 6.7% to 27% with cooking.

But Arthur M Baker (author of 'Self Healing Body') says, 'what the researchers were apparently unaware of is the potential harm of high inorganic iron absorption. The reason for iron becoming more absorbable with cooking is that heat breaks down cell structure more completely than chewing alone. The ferrous iron (plant form) is changed to a more elemental inorganic form that is more easily absorbable in the intestine. But the more elemental iron begins to overload the system since it is relatively difficult for the body to eliminate. The iron in cooked food is altered by heat. Iron absorbed from cooked food is detrimental compared with raw. There are several forms of iron, and the body alters them to suit its needs. Elemental iron is inorganic. After cooking, the structures and bonds have been radically altered. Excess inorganic iron can be a problem; it is associated with increased infection, heart disease and predisposition to formation of free radicals.'

'Pulses are more digestible when cooked.'

In fact, provided we have a reasonably healthy digestive system there should be no problem digesting raw pulses (provided they have been soaked, ie rehydrated - please no one try to eat them dried!).

We're all familiar with the jokes about beans and flatulence, and my husband has cracked most of them when served with cooked pulses. However, since he's had them raw and sprouted - no problems! My experience, and that of many other raw fooders, is that sprouted pulses produce less gas in the digestive system than cooked pulses. How can this be?

One reason is enzymes. OK, the enzymes thing is controversial in the raw food world, but there's the argument anyway: we soak, then sprout, raw pulses become living foods - enzyme inhibitors are unlocked and enzymes activated. This places less burden on our own digestive enzymes, so we need less energy to digest sprouted (live) pulses than cooked (dead) pulses. The enzymes break down the protein in the pulses into its amino acids. So perhaps sprouted pulses are less gas-forming than cooked, as they are already partly digested by the enzymes in the sprouts.

Another reason for increased digestibility is that sprouting changes the starches into sugar. Alissa Cohen, 'Living on Live Foods': 'Sprouting...makes them far more digestible because their protein is broken down into amino acids, their starches are changed into simple sugars...'

The strangest advice I've heard in 'the raw food world' is people advising others to go to all the trouble of sprouting pulses (and grains) then telling them to cook them (oh by steaming of course...). In other words, release the life energy by soaking and sprouting, increasing digestibility by doing so, and increasing vitamins manifold, then...reverse all that by cooking at 212 F, destroying at least 10% of the vitamins in the processes. (Nutritionists say that when we cook grains B vitamins are lost, and the body, to metabolise the grains, has to raid its own stores of these.

'Some foods, like squash, are too tough to eat raw.'

It's true that most people on cooked diets would see raw pumpkin,or butternut squash, or perhaps sweet potato, as somewhat unpalatable.

So why might we have problems here? One reason is that for generations we have lived on diets consisting predominantly of mushy cooked food. John Coleman: 'the widespread consumption of cooked food has contributed to the growing incidence of dental problems...deprives our jaws of the natural requirement to chew, and is perhaps partly responsible for the widespread facial deformities (eg poorly-formed dental arches) seen in populations who no longer eat significant amounts of raw foods.'

Luckily, the raw fooder can use gadgets to do for us what our jaws and teeth are no longer able to do easily. A 'spiraliser' can make squash into 'spaghetti', a blender will blend squash into a soup, and one of my favourite juices is butternut squash and apple. Sweet potato is very good grated.

There are some who say that, even in this form, they 'cannot digest' these sorts of foods because they're 'too starchy', they have digestive issues and will have stomach aches if they eat them. Those digestive problems are very likely to do with the cooked food they've eaten throughout their lives. So why compound the problem by cooking those wonderful vegetables, thereby putting into their bodies yet more heat-damaged food? Again, juicing can come to the rescue here, and the fibre (pulp) can be stirred back in if desired.

Although here's an opposing view on the starch thing...admittedly the nutritionist Milo Hastings was writing 50 years ago, but I offer it to you for your interest (and amusement):

'Closely akin to the idea of predigesting cereals by roasting and toasting them are the old notions that raw starch is indigestible and that all home cooked starchy foods need very long, tedious periods of cooking....I got suspicious of the idea that humans couldn't digest raw starch when I was in college and read about experiments in cooking grain for farm animals, in which the scientists proved that the cooked foods were less digestible than uncooked foods - for animals. The human food teachers came back by saying that man's digestive system has been changed by long ages of cooking and had lost the power to digest raw starch. So I tried it, and did my college thesis with a series of experiments on the digestion of raw versus long cooked cereal starches. I found out that my own particular digestive organs worked just like the pigs' and the cows'. Worse yet for the popular theory, my mother insists that I wasn't descended from raw turnip eaters, but that our folks came over in the next ship after the Mayflower and had been cooking as long as the rest of them.'

As I know the readers of this article will include not only 100% raw fooders, but those with no more than a toe in the water, could I suggest that if you really can't take certain foods raw, (whether it's squash, grains, pulses, (even if sprouted), don't cook them. Why eat damaged food just because you feel you must have a particular food? Just find something else to eat - there are thousands of delicious raw foods out there from which to obtain your nutritional requirements.

'Rice HAS to be cooked.'

Well, does it? Experimentation in the raw food world has suggested that some rice can be eaten raw and sprouted. However, most of the rice available in the UK won't sprout (it's often heat-treated)
And whether rice can be sprouted or not...

Viktoras Kulvinskas ('Survival in the Twenty-First Century'): 'Dr Koratsune, Japanese researcher, observed in 1951, that as long as he ate uncooked whole rice and raw radishes, spinach, kale and grated raw potatoes, he found he had excellent quality blood, even though his diet was poor in protein and calories. However, as soon as he ate the same quantity of vegetarian food in a cooked form, he began to notice symptoms of edema and anemia.' (Kyushu, Memoirs of Medical Science, v2, 1-2)
(I think Dr K might have been even healthier if he'd given the potatoes a miss...)


Someone on a raw food forum said to me that asparagus had to be cooked to be digestible for her.

My first comment was that, if the asparagus was slender and tender - no, it didn't have to be cooked. She replied by saying that the asparagus she enjoyed on French holidays was of the more thicker-stemmed, woodier kind, and was I suggesting she deprive herself of this pleasure?

Well...yes! I used to derive pleasure from all sorts of cooked foods, but now derive pleasure from raw foods (to think I hadn't truly discovered the pleasure of young coconut, durian and persimmons before raw!). If asparagus is thick-stemmed and woody and not palatable raw, then this is telling us it's not fit for human consumption. Cooking it to tenderise it, changing the natural food in the process, is not a solution. The solution something else.

'Potatoes don't taste good raw!'

They sure don't.

But I subscribe to the Natural Hygiene philosopy here, that if foods don't taste good in their raw state, perhaps they weren't intended to be food for human beings at all.

We haven't been eating potatoes for very long. The Spanish conquistadors discovered them in 1537 in the Andes and brought them back to Europe. Initially, people wouldn't touch them; they were considered poisonous, or evil. But eventually Sir Walter Raleigh and others persuaded the masses that potatoes were a great thing to eat. America didn't receive its first batch of potatoes until 1621 and it reputedly took seven transatlantic crossings before the potato gained acceptance there.

No, most people don't find potatoes palatable raw. But do they even taste good cooked? Really? If you are still eating cooked potatoes, when was the last time you ate one without any fat (eg cooking fat, butter, spread), salt, pepper or herbs? Do you really enjoy the taste of the potato itself? Or is it just a 'carrier' for fat and salt?

So I go with the radical view that potatoes are not food (for human beings, at least)

'Some foods are poisonous raw.'

Yes, they are. Yams and red kidney beans for instance. And, if poisonous in their raw state, they are not suitable for human consumption - full stop. (Note to US readers - some of you call what we in the UK call 'sweet potatoes' 'yams'. Sweet potatoes (red on the outside, pink/orange inside) aren't poisonous - they're delicious raw (eg grated). When I say 'yams' I mean the 'yams' that are the large grey root veg of West Indian/African origin.

So, do some foods 'need' to be cooked?

I haven't yet found one argument that persuades me that any raw food is better for us cooked.

Human beings have only started to cook food relatively recently. I wonder how we managed before. And how does every one of the billions of other creatures we share the world with manage without cooking their food?


mica said...

synergy, really? within tomatoes? weird and wonderful I say, and, well, if mixing them like that increases the lycopene content 3x, does it do any of the negative things that cooking does to them as well?

tomatoes are so lovely in the raw, but its hard to argue with them in a more prepared and cooked state either... can I just eat tons of them everywhichway and everything will make its proper balances? I haven't really seen anything that tells me off the best amount of lycopene-- at least 6.5 mg per day says this, but no ideals that I can find... anybody seen anything more concrete??

Debbie Took said...

Hi Mica

Blending breaks down the cell walls, thus releasing more lycopene. It should not result in the same effect as cooking because the food is not damaged by heat. Although the speed of the blades can create heat, my observation is that at worst the mixtures are warm rather than hot.

Your next point: it's not hard to argue with tomatoes cooked if you're a raw fooder :-) For reasons as to why we should not cook the precious raw materials designed for optimum body functioning, see the RawforLife website at

As to how many mg of lycopene we need each day, I believe that there is not one person on this earth who truly knows exactly how many mg of this and that each individual needs each day. But if we eat a tomato in its pure and undamaged state I do know we are eating exactly the correct amount of lycopene that tomato was designed to give us, and that all the chemicals present in that tomato are there in the correct proportions.

Can you just eat 'tons of them everywhichway and everything will make its proper balances'? No. Unfortunately, when we put into our body all sorts of things and hope for the best, we get ill...if not now, later...

Love, Debbie Took

mica said...

ah, thank you darling for the quick reply. I shall definitely check your out the raw food site, and thank you again,


Rita said...

Sprouted kidney beans are not good raw, in fact, they are poisonous. A small amount won't kill you but will make you sick.

Debbie Took said...

That's right, Rita.

My feeling is that, if something is poisonous raw, then it's not food for us.

rost0037 said...

"We haven't been eating potatoes for very long. The Spanish conquistadors discovered them in 1537 in the Andes and brought them back to Europe. Initially, people wouldn't touch them; they were considered poisonous, or evil. But eventually Sir Walter Raleigh and others persuaded the masses that potatoes were a great thing to eat. America didn't receive its first batch of potatoes until 1621 and it reputedly took seven transatlantic crossings before the potato gained acceptance there."

Hey--are the indigenous groups of Latin America not people? They were eating potatoes long before the Europeans came, and Europeans distrusted the potato because it was new and different (they also thought Latin Americans were savages). There may be other good reasons to avoid the potato, but this paragraph...

Debbie Took said...

rost0037, My reference to 'people' means 'UK people' as this is written from a UK perspective. So I can't see anything wrong with the paragraph.

Debbie Took said...
This comment has been removed by the author.
Debbie Took said...

Thinking further on this, by America, I did mean North America ('translantic crossings').

The references came from Wikipedia and I'd suggest that if you still feel the paragraph is incorrect in any way do a Wikipedia 'edit'.

Best wishes

Anonymous said...

Hi Debbie,

I'm new to this whole concept of a raw food diet and am glad that I stumbled upon your website. Regarding potatoes, I actually do like the taste of a plain baked potato. I don't usually add anything to it. It surprised me when you said that potatoes are not fit for human consumption because I thought that they are high in vitamin C and B and potassium, magnesium, phosphorus, zinc, calcium, and fiber.

There's a more comprehensive listing of all of its benefits here:

I also found this:

Please let me know your thoughts on the information presented.

Thank you!

Debbie Took said...

Hi, I hope you don't think I'm being dismissive, as I'm honestly not, could find all sorts of foods that are rich in vitamins and minerals X and Y but aren't food for humans. As a friend of mine once pointed out, a nutritional analysis of a cow-pat would find it full of vitamins and minerals, but it (probably!) wouldn't be a good thing to eat. The fact that you enjoy a cooked baked potato with no salt, fat etc is interesting, but nevertheless it's still cooked. If you honestly feel drawn, feel attracted to eating raw potatoes, and enjoy the taste, then - sure - then I'd say they're a food that your body is asking for. Hovannessian, author of Raw-eating, who I much admire, ate raw potatoes.

Anonymous said...

Hi Debbie,

Thank you for your response. As one who has been health-conscious since age 10, I always want the best for my body and health. Now that I'm 19-weeks pregnant, I want the best for my baby and give him/her a good head-start.'s a further question to your point about how certain foods may be full of vitamins and minerals, yet are not food for humans (as you pointed out about cow-pat): How can we distinguish which foods are/are not fit for human consumption? Is there a hard and fast rule that applies to everybody or is it based on each individual's taste/preference? I need to know if potatoes are food for humans regardless of whether someone likes or dislikes it. So, setting my preferences aside, are potatoes edible? Hovannessian thinks so. But there are others who don't. It's confusing because each person has their own info. to back up their view.

Debbie Took said...

If we pull a potato out of the ground, feel attracted to eating it (in its raw, ie natural state), take a bite and think 'mmm, that tastes good!' and then want to have more, then it's food for us.
It's certainly true in the raw world that everyone has their own views, but that's pretty much mine. It's certainly true that, occasionally, one person may enjoy something that someone else regards as 'inedible', but, as long as we are raw, I think we can trust our own desires/preferences. But...potatoes - I personally find it hard to believe that anyone could find raw potatoes tasty, but perhaps Hovannessian did! Perhaps his body had been very short of something a raw potato supplies, and so it set up a desire for it.