I haven’t read that, but almost anything can be carcinogenic if used for long enough. Most fats are altered to some extent by heating to cooking temperatures but as far as I know trans fats have definitely been shown to be harmful and implicated in heart disease. I think I’ll take my chances with olive oil and butter.
The Dangers of Soya
- Thread starter Treg
- Start date
The problem with any research is that it is very expensive and has to be paid for by someone. The “ivory towers” have long gone. This means that all research is inherently biased. However it can still be valuable so long as trials are well designed, the raw data available for scrutiny and potential conflicts of interest declared. This should always be the case nowadays but in the past was not. Eg the statin trials and the infamous Ancel Keys 7 countries study on which shaky ground all our nutritional advice has been based for over 60 years.
It was specifically olive oil that was the problem for frying, rapeseed oil was fine. As indeed was butter, but then that's different type of fat to begin with. I can see I'm gonna have to do some googling.....
Old McDonald
Member
- Location
- Harray, Orkney
Miserable drizzly weather so olive harvesting is on hold. It has taken me a little while to pull together all the information. I have rather a lot that I have gathered over the last 17 years of olive growing. As many TFF members will know I sell my EVOO as well as oil based products – plug www.montechava.com In addition to this I had the time to undertake a very detailed look at many things on the internet following heart surgery because I was unable to do any work for quite some time. I must admit that early this year I had limited knowledge of human nutrition in relation to heart disease simply because I had no interest in it. Now, I think I need to be better informed, especially since I was advised that if I ever have a repeat heart or arteries problem it is likely to come from contracting diabetes or high cholesterol causing blockages. Apparently my arteries problems were due to calcium deposits, an age related problem and not dietary.
I will not quote all the posts to which I am replying because they are numerous, but my following is the necessarily lengthy response due to the number of posts to which I am responding -: @Treg #43; @Scribus #44 & 51; @Cowgirl #49, 61 & 62; @DaveGrohl #56 & 63; @Farmer Roy #57 and @MiJ #64. I appreciate most members will not read it, yet they probably would if I answered ten single posts separately.
Olives are a fruit, therefore olive oil is a fruit oil and not a vegetable oil. So far as I know most fruit oils are made from the whole fruit (with the exception of those drupes like almond, which I also grow, and coconut oil) and vegetable oils only from the seeds of the vegetables concerned, e.g. soya, sunflower, rape, maize/corn, etc. Wikipedia informs us that Palm Oil is made from the fruit of several species of Palm, yet also states that it is a vegetable oil. Dangerous to accept information like that.
You can easily find articles claiming that canola is different to rapeseed oil on the basis that canola (CANadian Low Acid) is a special type of “what used to be” rape. Also Lear (Low Erucic Acid Rapeseed) oil. The claim being that “ordinary” rape can contain up to 54% Erucic Acid. I am not in favour of one group of farmers knocking another group and so I do not go along with the idea that rape that is not grown in Canada is an inferior product. I am sure that cold pressed UK rapeseed oil is a good oil for human consumption, subject, of course, to the Erucic Acid not being too high due to its known bad effects on the heart.
Most olive producing countries of the world, and many non producers such as the UK, are members of the International Olive Council, USA and Canada being notable exceptions and both countries produce olive oil. Admittedly it is not a major crop in Canada, and I understand there are a small number of olive trees thriving in the UK. What this means in practical terms for the UK consumer is that the different grades of oil referred to are not the same in IOC member countries and the US or Canada. Therefore information from USA cannot be directly compared to information from IOC countries in regard to the use of olive oils.
Apart from the obvious differences in taste, olive oil and rapeseed have different levels of the various fats, and both have their supporters. It is rather like arguing between the various types of spirits such as whisky v vodka v brandy, or red wine v white wine, beef v lamb. They are different products serving similar purposes. I always consider olive oil to be very similar to wine. There are probably more cultivars (botanically and to be pedantic they are cultivars and not varieties) of olives than there are wine grape varieties, consequently there are a vast range of flavours, not only due to the different taste of the cultivars, but also including where they are grown and the stage of ripeness at harvest.
There are two types of olive waste – water and the pomace (solid material) after oil extraction. These tend to be collectively referred to as Olive Mill Waste (OMW). Neither is toxic in a general meaning of the word. The waste water can be toxic to bacteria, but OMW can be used as a soil conditioner, biomass fuel, compost, or as starting material to obtain antioxidants, enzymes and biogas. Reuse of process water for irrigation purposes is possible. This depends on the processing of the olives to make oil. There is a tendency in modern mills to reduce the amount of water used not only because it has to be bought by the mill owner, but it is also costly to dispose of.
Pomace is primarily used as a fuel and the ash can be incorporated into blocks for building. Pomace is also used as a means of increasing soil organic matter. It does break down, but there is a lot of slowly decomposing OM in the seed covering portion of the pomace. Many will consider this slow breakdown to be a strong point in its favour. It is also used in smallish quantities in ruminant livestock feeds.
All fats and oils are damaged by excessive heat. Excessive in this case meaning being heated beyond the smoking point. When roasting in an oven, oil will get up to the oven temperature, 180°C being common. For pan frying or deep frying around 180°C is also ideal. Consequently any oil with a smoke point higher than 180ºC can be used for all normal forms of cooking. Even those sites trying to persuade you not to use olive oil will give a smoke point of 190º for EVOO. In reality it is somewhat variable but usually higher than this, over 200º. All refined oils will have higher smoking points – but do you really want to use refined oils in your cooking? It seems most folks are happy to do so, or ignorant of the fact that they are using refined oils. I am aware of oriental cooking sites that go so far as to say the oil (usually refined peanut) should be heated to beyond smoking point.
It is difficult to look up an accurate figure for other unrefined oils because these appear to differ according to the source. Anyone with a vested interest in a particular product tends to inflate that product’s smoking point and reduce others, although in general it seems that all unrefined vegetable oils have a low smoking point – many being not much over 100ºC. No doubt this is why most vegetable oils in general use are refined before being offered for sale. Butter has a higher smoking point (and clarified butter very high) and is the fat of choice for my wife when frying mushrooms or onions. I go along with that. A mix of butter and olive oil is good for other frying. Butter adds its own unique flavour.
If oils or fats are heated beyond their smoke point then, apart from a fire risk, they can form various harmful compounds, which may be carcinogenic. This is particularly true of oils that are high in polyunsaturated fats, including soy and most other vegetable oils. Saturated fat oils or monounsaturated are resistant to forming these possible carcinogenic compounds. Note resistant, not immune. Coconut oil is saturated and olive oil 70+% mono and about 15% saturated. Moral, do not overheat any oil or fat you use.
Transfats are naturally found in meat and dairy products and the general consensus of those who have done research upon the matter, is that they are harmless. On the other hand there are artificial transfats which are considered extremely bad for human health and these artificial, or hydrogenated, fats are made by chemically altering vegetable oils so that they are solid at room temperature. Interesterified fats are yet another “modified” fat, sometimes made from transfats, and have had the triglyceride molecules altered.
It is true that soy has been eaten for a very long time in various dishes in countries in the Far East, but not in the form of oil. Again, in reference to wine, grapes made into wine can be drunk in fairly large quantities, but change that wine by distilling (refining) it into a spirit and the same quantities cannot be drunk without very serious effects.
Refined oils are a different matter. The following is from something I published in 2011:- “My unscientific mind has great problems with the suggestion that seeds of plants that we may well eat frequently in small amounts will undergo an industrial process and be turned into an oil we are encouraged to consume in large doses. I am very wary about consuming an excess of anything by altering its normal form so that much larger quantities can be ingested than would be usual, or is even possible to eat when it is in its normal state. This is the sort of thing they do to lab animals to make them contract diseases – concentrate something and push it into them. How much raw soybeans or maize kernels does it take to produce the amount of oil you are being encouraged to include in your meals twice or thrice a day? Could you eat that much in its unprocessed state, and would you want to? A more scientific mind has suggested to me that concentrating the oils of such plants may also concentrate certain chemicals that are contained in only traces in the raw product, some of which may be carcinogenic or otherwise toxic, although not yet identified as such. I do not take chances so shun soybean products and only use butter, never margarine.”
I am not inclined to denounce Ancel Keys because his work was sound. It may not be generally known to TFF members that the modern notion of the Mediterranean diet originated as the diet of the people of Crete and was promulgated by Keys (who developed the US military K-rations) and others because the Cretans had the lowest rate of deaths from heart disease that he found in his extensive travels. This diet includes very large quantities of olive oil, also animal protein. Crete has for millennia been recognised as a source of quality sheep and goats in particular, but also other livestock, including poultry (meat and eggs).
The much publicised “Diet” and its offshoots (Pyramid, Healthy Plate, etc) put forward by Harvard University about 30 years ago was supposedly based upon Keys’ work, but I have a sceptics view of these diets and here is a small extract from a blog I made in 2014 (before the time I used a mill where I had my own fruit returned to me as oil). Full article https://www.blogger.com/blogger.g?b...onClosedMenu=allposts;postNum=16;src=postname
“To go back to the original source of the MD, Crete, it is estimated that there were over one million goats and sheep on the island in 1990 just before the MD was widely publicised. And people were supposed to eat very little red meat? There were also “large” numbers of pigs whatever “large” means, and “some” cattle.”
The local populace kill these animals at home and they never appear in official statistics. It still happens – nobody has ever asked me how many home-killed animals I have eaten, but it is a lot over the last 70 odd years.
I do not have a note of whether it was Keys or someone else writing at the same time who remarked upon the high intake of animal protein (meat, fish, cheese, eggs) of the farmers. They also drank wine. Given the extreme interest of Keys and his wife in the Med diet and the fact they lived (subject to extensive travel) in Italy until shortly before Keys’ death, I would expect that they followed the real diet in full. Keys was a couple of months short of his 101st birthday when he died, his wife living for another couple of years and dying at the age of 97. A good reason to follow what seems to be the normal diet of country folk around here.
I will not quote all the posts to which I am replying because they are numerous, but my following is the necessarily lengthy response due to the number of posts to which I am responding -: @Treg #43; @Scribus #44 & 51; @Cowgirl #49, 61 & 62; @DaveGrohl #56 & 63; @Farmer Roy #57 and @MiJ #64. I appreciate most members will not read it, yet they probably would if I answered ten single posts separately.
Olives are a fruit, therefore olive oil is a fruit oil and not a vegetable oil. So far as I know most fruit oils are made from the whole fruit (with the exception of those drupes like almond, which I also grow, and coconut oil) and vegetable oils only from the seeds of the vegetables concerned, e.g. soya, sunflower, rape, maize/corn, etc. Wikipedia informs us that Palm Oil is made from the fruit of several species of Palm, yet also states that it is a vegetable oil. Dangerous to accept information like that.
You can easily find articles claiming that canola is different to rapeseed oil on the basis that canola (CANadian Low Acid) is a special type of “what used to be” rape. Also Lear (Low Erucic Acid Rapeseed) oil. The claim being that “ordinary” rape can contain up to 54% Erucic Acid. I am not in favour of one group of farmers knocking another group and so I do not go along with the idea that rape that is not grown in Canada is an inferior product. I am sure that cold pressed UK rapeseed oil is a good oil for human consumption, subject, of course, to the Erucic Acid not being too high due to its known bad effects on the heart.
Most olive producing countries of the world, and many non producers such as the UK, are members of the International Olive Council, USA and Canada being notable exceptions and both countries produce olive oil. Admittedly it is not a major crop in Canada, and I understand there are a small number of olive trees thriving in the UK. What this means in practical terms for the UK consumer is that the different grades of oil referred to are not the same in IOC member countries and the US or Canada. Therefore information from USA cannot be directly compared to information from IOC countries in regard to the use of olive oils.
Apart from the obvious differences in taste, olive oil and rapeseed have different levels of the various fats, and both have their supporters. It is rather like arguing between the various types of spirits such as whisky v vodka v brandy, or red wine v white wine, beef v lamb. They are different products serving similar purposes. I always consider olive oil to be very similar to wine. There are probably more cultivars (botanically and to be pedantic they are cultivars and not varieties) of olives than there are wine grape varieties, consequently there are a vast range of flavours, not only due to the different taste of the cultivars, but also including where they are grown and the stage of ripeness at harvest.
There are two types of olive waste – water and the pomace (solid material) after oil extraction. These tend to be collectively referred to as Olive Mill Waste (OMW). Neither is toxic in a general meaning of the word. The waste water can be toxic to bacteria, but OMW can be used as a soil conditioner, biomass fuel, compost, or as starting material to obtain antioxidants, enzymes and biogas. Reuse of process water for irrigation purposes is possible. This depends on the processing of the olives to make oil. There is a tendency in modern mills to reduce the amount of water used not only because it has to be bought by the mill owner, but it is also costly to dispose of.
Pomace is primarily used as a fuel and the ash can be incorporated into blocks for building. Pomace is also used as a means of increasing soil organic matter. It does break down, but there is a lot of slowly decomposing OM in the seed covering portion of the pomace. Many will consider this slow breakdown to be a strong point in its favour. It is also used in smallish quantities in ruminant livestock feeds.
All fats and oils are damaged by excessive heat. Excessive in this case meaning being heated beyond the smoking point. When roasting in an oven, oil will get up to the oven temperature, 180°C being common. For pan frying or deep frying around 180°C is also ideal. Consequently any oil with a smoke point higher than 180ºC can be used for all normal forms of cooking. Even those sites trying to persuade you not to use olive oil will give a smoke point of 190º for EVOO. In reality it is somewhat variable but usually higher than this, over 200º. All refined oils will have higher smoking points – but do you really want to use refined oils in your cooking? It seems most folks are happy to do so, or ignorant of the fact that they are using refined oils. I am aware of oriental cooking sites that go so far as to say the oil (usually refined peanut) should be heated to beyond smoking point.
It is difficult to look up an accurate figure for other unrefined oils because these appear to differ according to the source. Anyone with a vested interest in a particular product tends to inflate that product’s smoking point and reduce others, although in general it seems that all unrefined vegetable oils have a low smoking point – many being not much over 100ºC. No doubt this is why most vegetable oils in general use are refined before being offered for sale. Butter has a higher smoking point (and clarified butter very high) and is the fat of choice for my wife when frying mushrooms or onions. I go along with that. A mix of butter and olive oil is good for other frying. Butter adds its own unique flavour.
If oils or fats are heated beyond their smoke point then, apart from a fire risk, they can form various harmful compounds, which may be carcinogenic. This is particularly true of oils that are high in polyunsaturated fats, including soy and most other vegetable oils. Saturated fat oils or monounsaturated are resistant to forming these possible carcinogenic compounds. Note resistant, not immune. Coconut oil is saturated and olive oil 70+% mono and about 15% saturated. Moral, do not overheat any oil or fat you use.
Transfats are naturally found in meat and dairy products and the general consensus of those who have done research upon the matter, is that they are harmless. On the other hand there are artificial transfats which are considered extremely bad for human health and these artificial, or hydrogenated, fats are made by chemically altering vegetable oils so that they are solid at room temperature. Interesterified fats are yet another “modified” fat, sometimes made from transfats, and have had the triglyceride molecules altered.
It is true that soy has been eaten for a very long time in various dishes in countries in the Far East, but not in the form of oil. Again, in reference to wine, grapes made into wine can be drunk in fairly large quantities, but change that wine by distilling (refining) it into a spirit and the same quantities cannot be drunk without very serious effects.
Refined oils are a different matter. The following is from something I published in 2011:- “My unscientific mind has great problems with the suggestion that seeds of plants that we may well eat frequently in small amounts will undergo an industrial process and be turned into an oil we are encouraged to consume in large doses. I am very wary about consuming an excess of anything by altering its normal form so that much larger quantities can be ingested than would be usual, or is even possible to eat when it is in its normal state. This is the sort of thing they do to lab animals to make them contract diseases – concentrate something and push it into them. How much raw soybeans or maize kernels does it take to produce the amount of oil you are being encouraged to include in your meals twice or thrice a day? Could you eat that much in its unprocessed state, and would you want to? A more scientific mind has suggested to me that concentrating the oils of such plants may also concentrate certain chemicals that are contained in only traces in the raw product, some of which may be carcinogenic or otherwise toxic, although not yet identified as such. I do not take chances so shun soybean products and only use butter, never margarine.”
I am not inclined to denounce Ancel Keys because his work was sound. It may not be generally known to TFF members that the modern notion of the Mediterranean diet originated as the diet of the people of Crete and was promulgated by Keys (who developed the US military K-rations) and others because the Cretans had the lowest rate of deaths from heart disease that he found in his extensive travels. This diet includes very large quantities of olive oil, also animal protein. Crete has for millennia been recognised as a source of quality sheep and goats in particular, but also other livestock, including poultry (meat and eggs).
The much publicised “Diet” and its offshoots (Pyramid, Healthy Plate, etc) put forward by Harvard University about 30 years ago was supposedly based upon Keys’ work, but I have a sceptics view of these diets and here is a small extract from a blog I made in 2014 (before the time I used a mill where I had my own fruit returned to me as oil). Full article https://www.blogger.com/blogger.g?b...onClosedMenu=allposts;postNum=16;src=postname
“To go back to the original source of the MD, Crete, it is estimated that there were over one million goats and sheep on the island in 1990 just before the MD was widely publicised. And people were supposed to eat very little red meat? There were also “large” numbers of pigs whatever “large” means, and “some” cattle.”
The local populace kill these animals at home and they never appear in official statistics. It still happens – nobody has ever asked me how many home-killed animals I have eaten, but it is a lot over the last 70 odd years.
I do not have a note of whether it was Keys or someone else writing at the same time who remarked upon the high intake of animal protein (meat, fish, cheese, eggs) of the farmers. They also drank wine. Given the extreme interest of Keys and his wife in the Med diet and the fact they lived (subject to extensive travel) in Italy until shortly before Keys’ death, I would expect that they followed the real diet in full. Keys was a couple of months short of his 101st birthday when he died, his wife living for another couple of years and dying at the age of 97. A good reason to follow what seems to be the normal diet of country folk around here.
Very interesting and comprehensive- thank you for the clarifications, especially about smoking point. Just to explain my comment about the Ancel Keys 7 countries Study - it was not to deny his findings in those countries but he lost credibility because I have read that he actually studied 22 countries and only chose to publish data from the seven that suited his preconceived agenda - if that is indeed true, cherry picking data is not good science. It’s interesting that he lived to extreme old age, but so did my husband’s grandfather who smoked and drank all his life and ate a diet full of fat - I believe that disease and lifespan are mainly due to genetics rather than diet.
Old McDonald
Member
- Location
- Harray, Orkney
I am not particularly supporting Keys. In fact, as I have pointed out in various places on numerous occasions I believe he fell into the same trap as everyone else who reports on the diet of those in the Mediterranean/East Atlantic (Portugal & parts of France) area – they seriously underestimate the amount of animal fat consumed. As you posted on this thread “you don't have to be an academic to have a gut feeling that what people write in a food questionnaire is likely to be rubbish!”
At the same time I am of the opinion that those who later criticised his Seven Countries Study (e.g. Yudkin, Lustig and Taubes) had a vested interest in condemning sugar rather than fat. Interestingly enough there was a Taubes in the 19th Century who decided sugar was the culprit. Perhaps he was an ancestor of the later one. My overall impression is that Keys was as honest a researcher as anyone else. He was researching soon after WWII and I am sure there were an awful lot of country folks who were extremely suspicious of anyone asking too many questions. I understand he was prevented from using Portugal as one of his countries because the then dictator Salazar did not want to be associated with what he considered to be a study of a “poor people” diet. I am not convinced that Keys cherry picked, so I give him the benefit of the doubt. From your previous posts I think you might be interested to read this article by him https://ahajournals.org/doi/pdf/10.1161/01.cir.5.1.115
As a non-scientist and non-doctor my belief is that the main problems with obesity, and possibly therefore problems with heart disease and other illnesses, is too high an intake of sugar, salt and vegetable fats – key ingredients in just about every processed and “fast” food. Soya, the reason for the commencement of this thread, has to be high on the list of vegetable suspects. I am unable to speak for other countries but in Portugal there seems to have been an exceptionally high intake of salt (bacalhau or dried salted cod) and sugar for a very long time, so perhaps it is the vegetable fat that is the problem, and not the others. Anyone who has visited Portugal must be aware of the mid morning snack and lanche (mid afternoon snack) which include sickly sweet small cakes such as Pasteis de Nata. It is notable too to see the number of people in supermarkets who buy vegetable oils. No doubt believing the hype that these are “good” for you. This would never have happened in the past.
I tend to agree with you about genetics being the most important factor in reaching old age. I have mixed age deaths on both sides, so can only hope. Interestingly the head cardiologist at the hospital where I was prior to being transferred for my operation spent a fairly lengthy time with me discussing my life history and particularly lifestyle because as she said “I cannot understand why you have such major problems with your heart and arteries. You are not obese, you are not diabetic, you do not have a cholesterol problem, you have never smoked.” I have always had a very low intake of sugar, being a youngster whilst sugar was rationed I never acquired sweet tooth. I have always consumed a large quantity of animal fats, but it seems these have not been transferred into a cholesterol problem.
primmiemoo
Member
- Location
- Devon
There's been mention of phyto-oestrogens from soya playing a part in cushioning the effects of menopause in cultures that have high intakes of soya in their diet, so might there be a long-term, cumulative effect? They're stored in human body fat, after all.