Some Carbs are Better than Others (for Diabetics) – Part 3

INTRODUCTION: In the first article in this series on carbohydrates, I explained that Glycemic Index (GI) is a way to rate carbohydrates based how easily they raise the blood sugar of healthy people and that some carbohydrates are better than others when they cause much less of a rise in blood sugar. I wanted to know how would I react to carbohydrate-based foods now that I have been eating low carb for over a years and have seen a partial reversal of Type 2 Diabetes that I had for more than 10 years.

I decided to conduct some impromptu ‘experiments’ and the results led to some reading in the scientific literature. The information I discovered is VERY exciting for me and for others with Type 2 Diabetes or Insulin Resistance.

Once people have achieved significant reversal of symptoms following a therapeutic low carb or ketogenic diet, there is a way to logically begin to re-introduce carb-based foods in a way that doesn’t cause their blood sugar to spike.

As you may recall from the first article in this series on Carbohydrates, the Glycemic Index of a food is determine by having healthy people eat 50 grams of digestible carbohydrate of a given food, and then measure their blood glucose response over a 2 hour period (30 minutes, 60 minutes, 90 minutes, 120 minutes), plotting the curve then measuring the area under the curve (AUC) and comparing it to the AUC of pure glucose, the reference food.

The problem with the Glycemic Index or even the Glycemic Load (based on individual serving sizes) is that this data does not apply to those with Diabetes or Insulin Resistance.

Since I have been Diabetic for a long time, I decided to go about conducting my own sample-set-of-one (n=1) ‘experiment’, and one thing led to another…

The ‘Test Food’

I ate 1/2 cup of chickpeas (cooked from dried) which has 25 g of carbohydrate and measured my blood sugar response with the same meter at 30 minutes, 60 minutes, 90 minutes, 120 minutes, 180 minutes and 210 minutes.

blood glucose response to 25 g of chickpeas, cooked from dried
blood glucose response to 25 g of chickpeas, cooked from dried

At the time I did this, I hadn’t eaten in 8 hours (considered a fasted state) and my starting blood sugar was 4.8 mmol/L (86 mg.dl). The chickpeas were part of a mixed meal with some chicken (high biological value protein) and a cucumber salad with olive oil.

At the highest point, my blood sugar went up to 5.8 mmol/L (105 mg/dl),  stayed there, then started to drop at 2 hours.

I was amazed.

When I first began changing my lifestyle a year ago, even eating low GI foods such as chickpeas caused my blood sugar to jump dramatically. I recall the first few months when I would eat 1 cup of hummus, which is chickpeas with tahini (ground sesame seeds) and has even more fiber than chickpeas alone and also has only 25 g of carbs, my blood sugar would always go up to ~ 8.6 – 8.9 mmol/L (155- 160 mg/dl). What I’ve since found out (and will explain this more in detail in an upcoming article) is that intact legumes have a very different impact on blood glucose as to ground ones.  The more intact a legume or bean is, the lower the blood glucose response.  As I said, more on that in a future article.

The ‘Reference Food’

Two weeks ago, I was at a social occasion where a milk-chocolate covered cracker was served and I decided (in the interest of science, of course!) to read the nutritional label, measure out exactly 25 g of carbohydrate of this food and eat it, measuring my blood sugar at 0 minutes, 60 minutes, 90 minutes, 120 minutes, and 180 minutes.

This ‘reference food’ (high GI) was eaten after a dinner that had a fair amount of high biological value protein (steak) as well as some healthy fats (olive oil on vegetables) and fiber in the vegetables, and my starting blood sugar was 6.7 mmol/L (121 mg/dl).

Just look at the blood sugar spike!

Effect of 25 gm of carbohydrate on my blood glucose - 6.7 mmol/L to 9.8 mmol/L (121 mg/dl -177 mg/dl)

When I ate 25 gm of carbohydrate as the cracker and chocolate, my blood glucose went from 6.7 mmol/L to 9.8 mmol/L (121 mg/dl -177 mg/dl)! That is, I had eaten the SAME amount of carbohydrate (25 g of carbs) as when I ate the cooked chickpeas and had THREE TIMES the blood sugar response!!

Both the meals I ate just before the ‘reference food’ (high GI, cracker with chocolate) and the ‘test food’ (low GI, chickpeas) had a high biological value protein (chicken, steak) which slows the blood sugar response of the body, and both had the same amount of fiber (the exact same salad).

Below is a graph of the two responses (chickpeas in blue, chocolate covered cracker, orange) over 3+ hours.

It is quite evident that 25 g of carbs as high GI white flour with milk chocolate is processed VERY differently by my body than 25 g of carbs as low GI chickpeas!!

Comparison of blood glucose response of 25 g of carbohydrate as chickpeas and white flour cracker with chocolate
Comparison of blood glucose response of 25 g of carbohydrate as chickpeas and white flour cracker with chocolate (special thanks to Phil Thompson of the “Lower Insulin” Facebook group for the graph and calculations of area under the curve)

The area under the curve (AUG) was determined by lowering the cracker and chocolate curve down to sit just above the chickpea curve (grey curve) and then assessing where the respective points were and running the AUG formula relative to baseline.

The AUG of 25 g of carbs as chickpeas was 129.

The AUG of 25 g of carbs as white flour cracker with chocolate was 381.

The difference was 2.95.

The blood sugar response of the cracker with chocolate was THREE TIMES GREATER than the blood sugar response of the chickpeas – and both contained 25 g of carbs!

Some carbs are quite clearly better than others for this Type 2 Diabetic.*

* As I will elaborate on below, people’s blood sugar response to different carbohydrate-based food is quite individual.

Objective Data

Facsimile for Glycemic Index of Cracker with Chocolate

I was able to find for purposes of estimation, that 25 g of carbohydrate as white bread with 5 g of margarine (a pretty good facsimile for 25 g of carbohydrate as white flour cracker covered with milk chocolate made with palm oil) has a GI of 70.1 when compared to the reference which was 25 g glucose in 125 ml water [1].

Studies of Effect of Eating Legumes (Pulses) Alone

A meta-analysis of 10 studies on the effect of pulses (legumes) eaten alone on blood sugar control in people with and without Diabetes [2] provided some helpful information. The pulses in the meta-analysis included chickpeas, black-eyed peas and various other beans (including red and white kidney, black, pinto, fava and white navy).

Seven of the 10 trials that looked at the effect of eating pulses alone had a crossover design (five had a washout period), studied a total of 253 participants, of which only 21 had Type 2 Diabetes, and 232 that had normal blood sugar.

Background diets were largely high-carbohydrate, low-fat diets (carbohydrate 52% of energy, protein 18% of energy, fat 29% of energy).

Due to the length of time I have had Type 2 Diabetes and the very high degree of persistent insulin resistance over the first 6 months of eating low carb but not ketogenic, the last 6 months my diet has been very low in carbohydrate (5-10% of energy), moderate in protein ~23% and 67-77% healthy fats.

It was found that fasting blood glucose following the eating of pulses alone was decreased by 0.82% (95% CI ), but there was no long term effect on HbA1C (3 month average blood sugar) or on HOMA-IR (fasting blood glucose: fasting insulin).

[Of interest, in low GI diets, eating of pulses lowered HbA1C (3 month average blood sugar) by 0.28% but had no change on fasting blood sugar or HOMA-IR. The average GI of the pulse-containing low-GI diets was 67 and as compared to the GI value of bread alone.]

The conclusions of the meta-analysis found that the strongest modifiers of benefit were in Type 2 Diabetes and that the legumes that modified blood sugar the most were black beans, white/navy beans, pinto beans, red and white kidney beans, chickpeas and fava beans.

“Specific to the pulses alone analysis, pulse species including Phaseolus vulgaris (black, white, pinto, red and white kidney beans), Cicer arietinum (chickpeas) and Vicia faba (fava beans) were also identified as significant modifiers.” [2]

Individual Glycemic Response  – role for personalized nutrition

A 2015 study from Israel[3] with 800 people who were monitored with continuous glucose monitors indicates that there isn’t a ‘universal’ blood sugar response to low GI foods or high GI carbs – that glycemic (blood sugar) response is very individual. 

“We continuously monitored week-long glucose levels in an 800-person cohort, measured responses to 46,898 meals, and found high variability in the response to identical meals, suggesting that universal dietary recommendations may have limited utility.

The study also found that an individual’s blood sugar response to different foods was able to be predicted by type and amounts of bacteria in their intestines (the ‘gut biome’ / ‘microbiome’ / ‘microbiota’) . 

Based on the data they collected, the team has since created and validated a machine-learning algorithm that combines blood parameters, dietary habits, anthropometrics (height, weight data), physical activity and gut microbiota  data that they say accurately predicts a person’s individual post meal blood sugar response to actual meals.

Applications in Dietetic Practice for Personalized Nutrition

There is a tremendous opportunity for Dietitians such as myself to help individuals with Type 2 Diabetes or pre-diabetes determine which carbohydrate-based foods cause the lowest, most gradual rise in blood sugar.

This is huge!

This means that after individuals have had significant reversal of Type 2 Diabetes / Insulin Resistance following a therapeutic low carb diet for a period of time, I can help them re-introduce carb-based foods back into their diet by selecting ones that have the least impact on their blood sugar!

There are two ways this can be done;

  1. USING EXISTING BLOOD GLUCOSE METER – I can help those with Type 2 Diabetes eat a specific amount of a ‘test food’ that contains 50 g of carbohydrate (I will calculate this for them) and have them test their blood sugar every 30 minutes for 2 or 3 hours with the blood glucose meters they already have.  Then, I can take that data, enter it into an Excel sheet just as was done with my data above, and determine their blood sugar response.

  2. USING A CONTINUOUS GLUCOSE MONITOR – continuous glucose monitors (CGMs) such as the FreeStyle Libre have become relatively inexpensive and would be ideal for this kind of testing. Test strips for most standard home blood glucose monitors are $1 a piece, so testing every 30 minutes for 3 hours costs $6. The FreeStyle Libre costs $50 for the unit, and while test patches are $90 and last only two weeks, huge varieties of carbohydrate-based foods can be tried and measured in a short time, with no effort.

As a Dietitian I can not only help individuals carry out this kind of individual testing of carbohydrate-based foods, I can help them interpret the results as we begin to re-introduced some foods back into the diet once significant reversal of insulin resistance has been accomplished.

Do you have Type 2 Diabetes or pre-diabetes and want help to determine which carb-based foods don’t spike your blood sugar? Or do you have questions about how I can help you reverse the symptoms of Type 2 Diabetes or insulin resistance ?

Please send me a note using the “Contact Me” form on this web page and I will respond to you shortly.

To your good health!

Joy

 

References

  1. Aston LM, Gambell JM, Lee DM, Bryant SP, Jebb SA. Determination of the glycaemic index of various staple carbohydrate-rich foods in the UK diet. European journal of clinical nutrition. 2008;62(2):279-285.
  2. Sievenpiper, J.L., Kendall, C.W.C., Esfahani, A. et al. Effect of non-oil-seed pulses on glycaemic control: a systematic review and meta-analysis of randomised controlled experimental trials in people with and without diabetes. Diabetologia (2009) 52: 1479.
  3. Zeevi D, Korem T, Zmora N, et al. Personalized Nutrition by Prediction of Glycemic Responses. Cell. 2015 Nov 19;163(5):1079-1094.

Copyright ©2018  BetterByDesign Nutrition Ltd. 

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.


 

Are Some Carbs Better Than Others – Part 2

Introduction

In Part 1 of “Are Some Carbs Better Than Others”, I explained that Glycemic Index (GI) is a way to rate carbohydrates based on how easily they raise blood sugar. Low GI foods (those with a value of 55 or less) are more slowly digested, absorbed and metabolized and cause a lower and slower rise in blood glucose levels. Very high GI foods (>70) are digested very rapidly, causing a large spike in blood sugar. High GI foods (>55) result in a fairly rapid rise in blood sugar.

The GI value of a food is determined by comparing how healthy people’s blood sugar responds over a two-hour period to a food containing 50 grams of digestible carbohydrate from that food compared to 50 grams of glucose (pure sugar). The drawback to this rating scale is that the values are only known for a serving that has 50 grams of carbs in it.  That is, they compare the ability of different foods containing the SAME amount of carbohydrate (50 g) to raise blood sugar.

The problem with the Glycemic Index is that it’s hard to compare foods because one serving of a food may have considerably less than 50 g of carbs in it.  For example, the Glycemic Index of watermelon is 76, which is as high as the Glycemic Index of a doughnut, but one serving of watermelon (1/2 a cup) has 11 g of carbohydrate in it, while a medium doughnut (one serving) has 23 g of carbs.

Glycemic Load

This is where the concept of Glycemic Load (GL) is much more helpful, because it tells us how a healthy person’s body will respond to the carbs in one serving of a food. 

How to Determine Glycemic Load

To determine the Glycemic Load  (GL) of a serving of a food, what needs to be known is:

The Glycemic Index (GI) of that food (found by referring to a table of Glycemic Indexes)

The number of grams of carbohydrate in the quantity of food considered to be one serving.

  • GL  = GI x (amount of carbohydrate per serving) / 100

For purposes of comparison,  let’s look at the Glycemic Load of the same foods we looked at the Glycemic Index for in the first article.

One slice of white bread has a Glycemic Load of 10, and so does one slice of whole wheat bread, which is considered low. Both have 15 g of carbs per slice.

white spaghettiOne 1 cup of cooked white spaghetti has a Glycemic Load of 25, which is considered very high and while 1 cup of whole grain spaghetti only has a Glycemic Load of 14, this is still not low, just lower than white spaghetti.

bowl of white riceA cup of boiled white rice has 53 g of carbs in it and has a very high Glycemic Load = 35. A cup of white spaghetti has 44 g of carbs in it and also has a very high Glycemic Load at 25. These foods are high in carbohydrates and will cause a rapid rise in blood sugar in healthy people. To those who are already Diabetic or pre-diabetic, this is a big problem.

whole grain spaghettiOne cup of cooked whole grain spaghetti has a Glycemic Load of 14, which is still not low, and has 37 g of carbs in it.

 

brown riceA cup of boiled brown rice has a Glycemic Load of 20, which is still considered very high, and has 42 g of carbs.  These foods are high in carbohydrates and will cause a fairly rapid rise in blood sugar in healthy people, let alone those who are already having problems.

Where is the Problem?

Eating a high Glycemic Load diet over a period of years will result in blood sugar after meals (called “postprandial blood glucose”) being high. This puts a huge demand on the body to keep releasing insulin to try to move all that glucose into the body’s cells and get it out of the blood.

Over time, a high Glycemic Load diet causes the body’s pancreas β-cells (beta cells) to decrease in function or, in many cases, to die – resulting in a diagnosis of type 2 diabetes. As illustrated above, even eating the “whole grain” version of favourite foods does not necessarily reduce the insulin demand on our pancreas.

Our β-cells are under continual pressure to release insulin every time we eat – from our breakfast toast or cereal, to our mid-morning muffin, to our pasta lunch. Eating a lower-carb diet is an effective way to lower the demand on our pancreas to keep producing and releasing insulin to deal with the constant spikes in our blood sugar due to eating carbohydrate-containing foods. 

While Glycemic Load will tell us how much a serving of food will increase our blood sugar,  it doesn’t tell us how much insulin our body releases as a result of eating a food. That is, GL does not explain how big a demand we are putting on our pancreatic β-cells.

For those who have been eating a high-carbohydrate diet for years or have a family history of type 2 diabetes, it is important to know how much insulin is required to process carb-based food. That way, we can choose to eat foods that put a smaller demand on our pancreatic β-cells. 

For those who already have type 2 diabetes, it is especially important to eat in such a way as to preserve whatever β-cell function that is left.

In a future article, I will explain the Insulin Index, which enables us to choose carb-based foods that put less of a demand on our β-cells.

More Info

I can help you learn to choose foods that result in significantly less insulin being released, putting much demand on your β-cells. You can learn about the packages I offer under the Services tab, above.

To your good health!

Joy

Reference

Oregon State University, Linus Pauling Institute, Micronutrient Information Centre, Glycemic Index and Glycemic Load  http://lpi.oregonstate.edu/mic/food-beverages/glycemic-index-glycemic-load#glycemic-index

 

Copyright ©2018  BetterByDesign Nutrition Ltd. 

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything you have read or heard in our content.

Are Some Carbs Better Than Others – Part 1

Introduction

Not all carbohydrate foods (“carbs”) are created equal. Some are broken down very quickly into simple sugars, while others are broken down very slowly. In the past, the terms “simple sugar” and “complex carbohydrate” were used to imply this concept. There are newer terms that enable us to know how much eating these foods will raise blood glucose in healthy people. The “in healthy people” is important, as the ability to tolerate carbohydrate in those with insulin resistance (“pre-diabetes”) or type 2 diabetes is significantly affected.

Glycemic Index

The Glycemic Index (GI) is a way of rating carbohydrates based on their ability to raise blood sugar. Low GI foods (those with a value of 55 or less) are more slowly digested, absorbed and metabolized and cause a lower and slower rise in blood glucose levels, and very high GI foods (>70) are digested very rapidly, causing a large spike in blood sugar. High GI foods (>55) result in a fairly rapid rise in blood sugar.

Many foods that people eat a lot of in our society, such as bread, rice, pasta and cereal, even vegetables, are high GI foods. When healthy people eat these foods on a regular basis, they put a high demand on their bodies to produce and release insulin to bring all that glucose into their cells. Insulin is released from the beta cells of the pancreas, so people who frequently eat high GI foods result in their beta cells releasing insulin multiple times all day. Over time, this frequent demand on the beta cells results in the cells throughout their body becoming insulin-resistant. That is, they no longer respond to insulin’s signal, so more and more insulin is released, which over time can burn out their beta cells, resulting in type 2 diabetes.

Type 2 Diabetes as Beta Cell Dysfunction

By the time most people are diagnosed with type 2 diabetes, they already have beta cell dysfunction for a long time, and have a certain amount of beta cell death or a decrease in beta cell mass. Once beta cells die, they’re gone. Our once healthy body is no longer healthy. 

When we eat foods with significant carbohydrates, especially high GI carbohydrates, our ability to release insulin is significantly impacted, and in time, we are no longer able to tolerate carbs like we used to.  The length of time that someone had type 2 diabetes before they were diagnosed, or how long they had it before they changed their eating habits, will factor into how much carbohydrate they can handle. For this reason, each person’s carbohydrate tolerance is different.

Carbs aren’t Inherently “Bad”

It’s not that carbs are inherently “bad”. It’s that our bodies are no longer able to process some of them the way we could when we were still healthy. In these cases, the sugar stays in the blood longer than it would if insulin were working well, and this can damage tissues throughout the body.

Knowing which carbs are high GI is important, because these are the foods that tax our already overtaxed beta cells if we are not Diabetic and limiting these foods significantly, or avoiding may be the best way for healthy people to remain healthy.

The good news is that there are some types of carbohydrates that some people can not only tolerate, but may actually improve their blood sugar control, and that’s the topic of an upcoming article.

How the GI of a Food is Determined

GI Graph

The GI value of a food is determined by feeding a group of healthy people the amount of a food that contains 50 grams of digestible (available) carbohydrate and then measuring the effect on their blood glucose levels over the next two hours. The area under their two-hour blood glucose response (glucose AUC) for this food is then measured.

At another time, the same group of healthy people eat 50 grams of glucose (which is the reference food) and their two-hour blood glucose response is also measured.

The GI value for the test food is calculated for each person in the group by dividing their glucose AUC for the test food by their glucose AUC.

The final GI value for the test food is the average GI value all the people in the group.

Too Much of a ‘Good’ Thing

Many of the foods that people in the West enjoy and eat a lot, such as bread, rice and noodle,s are High GI foods – these are ones that are rated at  ≥ 55 (compared to pure glucose, which is rated at 100).

slice of bread

White bread has a GI of 75 ± 2, and whole wheat bread isn’t much better, at 74 ± 2.

 

basmati white rice

Boiled white rice is high GI at 73 ± 4, and while somewhat better, boiled brown rice is still high GI at 68 ± 4.

white spaghetti

White spaghetti has a GI of 49 ± 2, and whole grain spaghetti has a GI of 48 ± 5.

 

rice noodles in PhoRice noodles, such as those in Pho (Vietnamese Beef Noodle soup), are even higher, at 53 ± 7.

 

Breakfast cereals, whether boxed or cooked, are also high GI.  Here is a table that summarizes some of these [1];

BREAKFAST CEREALS  Glycemic index (glucose = 100)
Cornflakes 81 ± 6
Wheat flake biscuits 69 ± 2
Porridge, rolled oats 55 ± 2
Instant oat porridge 79 ± 3
Muesli 57 ± 2

Many people include vegetables such as potatoes, sweet potatoes and squash, such as pumpkin, in their “vegetable quota” for the day, but let’s look at the Glycemic Index for these;

VEGETABLES  Glycemic index (glucose = 100)
Potato, boiled 78 ± 4
Potato, instant mash 87 ± 3
Potato, French fries 63 ± 5
Carrots, boiled 39 ± 4
Sweet potato, boiled 63 ± 6
Pumpkin, boiled 64 ± 7

People in our culture eat a lot of bread, rice, pasta, starchy vegetables and cereal, but eating them with a good source of protein slows down how quickly they affect blood sugar. Oftentimes, bread and cereal form the basis of breakfast, perhaps with a high GI glass of juice and frequently, people eat pasta with a tomato sauce for supper (or leftovers for lunch), and this kind of meal will spike their blood sugar. We also know that the fibre content of a mixed meal will also slow down the rate at which blood sugar rises from these carbs, so there are ways to ‘tone down’ the response.

Some Final Thoughts…

If you have a family history of type 2 diabetes, are overweight or have high blood sugar, it’s important to understand that what you eat matters and to eat in a way that does not put high demand on your beta cells to keep releasing insulin to process all that glucose.

The time to consider the effect on your body is now – before you get sick by having overtaxed your pancreas’ beta cells and experience beta cell death or mass loss, and are diagnosed with Type 2 Diabetes.

Once we’ve crossed that threshold, once our once healthy body is no longer healthy, we need to learn to eat in a way that does not put high demand on our beta cells, that does not require our body to process large amounts of glucose at a time, to preserve whatever beta cell mass and function we have left.

Determining which carb-containing foods we can tolerate and in what quantities will enable us to eat in a way that keeps us from getting worse and keeps us from developing the very serious consequences of not doing so, which can include blindness, toe and foot amputations and more.

In coming articles, I’ll explain Glycemic Load and the Insulin Index, and I’ll also touch on the role for legumes (pulses) such as chickpeas and sources of “resistant starch” in a moderate carb ‘Mediterranean-style’ diet.  Stay tuned.

More Info

If you just found out you are pre-diabetic, now is the time to do something about it. Waiting will not make it better.

If you’ve been recently diagnosed with type 2 diabetes, it’s not too late. Studies have shown that changing eating habits and lifestyle soon after diagnosis makes it possible for some people to reverse their symptoms and to have their type 2 diabetes go into remission.

One thing is certain. Doing nothing will bring meaning to the phrase that “diabetes is a chronic, progressive disease”.  It doesn’t have to be.

Several of the packages that I offer can be tailored to help you lower blood sugar and restore insulin sensitivity. Visit the Services tab to learn more.

To your good health!

Joy

 

References

  1. https://www.health.harvard.edu/diseases-and-conditions/glycemic-index-and-glycemic-load-for-100-foods

Also see: Atkinson FS, Foster-Powell K, Brand-Miller JC, “International tables of glycemic index and glycemic load values”, Diabetes Care 31(12); 2281-2283

Copyright ©2018  BetterByDesign Nutrition Ltd. 

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything you have read or heard in our content.

Concerns with Polyunsaturated Vegetable Oils – Part 2

This article is Part 2 in a two-part series on concerns with Polyunsaturated Vegetable Oils. Part 1 can be read here.

There are a few key things about polyunsaturates vegetable oils that need to be understood to understand this article, so I’ll keep the science simple.

There are two class of polyunsaturated fats; (PUFAs); omega 3 (ρ‰-3 also written n-3) and omega 6 (ρ‰-6 / n-6) which compete with each other for enzymes, and which becomes significant at one branch point (marked with the red and green box).

At that junction point (where the red box is at Arachidonic acid and green box is at Eicosapentanoic acid) if there is more n-6 fats than n-3 fats, then the pathway will favour the n-6 pathway. If there are more n-3 fats than n-6 fats, then the pathway will favour the n-3 pathway. The issue, as I will elaborate on below, is that in the Western diet, the n-6 pathway is always favoured.

Of significance, the n-6 polyunsaturated fats are pro-inflammatory and the n-3 polyunsaturated fats are anti-inflammatory. This is important to understand why eating lots of foods high in n-6 fats can lead to health consequences.

When people take low-dose Aspirin® for example, to lower the risk of heart attack or stroke, it acts on Arachidonic acid in the n-6 polyunsaturated fat pathway, to keep it from making certain inflammatory products that can lead to heart attack or stroke.

In our evolutionary history it was thought that n-6 fats (from nuts and seeds that were gathered in the wild) and n-3 fats (from the fish and meat we hunted) were eaten in close to a 1:1 ratio – providing the two essential fatty acids from both classes. When man began domesticating grain and growing beans and lentils and nuts and seeds for food (all high in n-6 fats), the shift towards a diet higher in n-6 fats occurred. The modern Western diet is estimated to have an omega-6 to omega-3 fatty acids of 15—20:1 in favour of n-6 fats [6].

Many people take omega-3 fish oil capsules in an effort to protect their body from inflammation, but because the amount of n-6 fats in the diet is so much higher than the amount of n-3 fats, the n-6 pathway is still favoured.

Unless we significantly lower the amount of n-6 fats in the diet, taking fish oil doesn’t really help as the n-6 pathway will always be favoured.

Changing the Makeup of Cell Components

Industrial seed oils have very high levels of linoleic acid which is at the top of the n-6 pathway.  These industrial seed oils are pro-inflammatory and will elongate to Arachidonic acid, resulting in many pro-inflammatory products being produced.

When we eat a lot of food made with soybean oil or fried in soybean oil we eat way more linoleic acid then our body has evolved to handle.

A major problem with polyunsaturated fatty acids such as linoleic acid are that they are very unstable fats that are easily oxidized (similar to a fat becoming ‘rancid’ or a metal ‘rusting’). Even if we never buy these industrial seed oils to cook with at home, when we buy French fries at restaurants they are fried in either soybean or canola oil. When we pick up a donuts, same thing.  Bottle salad dressing and mayonnaise (even the one that is called ‘olive oil mayonnaise’) are made with one of these industrial seed oils. These oils are found in products one would never expect to find them, including peanut butter! Start reading labels and you will be shocked how many products they are in – or rather, how few products they are NOT in.

Industrial seed oils are in most of the prepared food we buy and almost all of the food we eat out in fast-food restaurants.

According to a 2011 journal article published in the American Journal of Clinical Nutrition;

“The most striking modification of the US food supply during the 20th century was the >1000-fold increase in the estimated per capita consumption of soybean oil from 0.006% to 7.38% of energy.” [7]

When the linoleic acid content of the diet is high because we are eating foods made with industrial seed oils, important components of our cells membranes incorporate higher amount of linoleic acid into them.

For example, cardioleptin is a phospholipid component found in the inner mitochondrial membrane, which is where all energy metabolism in our body occurs. Cardioleptin plays an important role in the function of several enzymes involved in mitochondrial energy metabolism.

When we eat a lot of pre-made and processed foods and food made in fast-food restaurants, cardioleptin’s fatty acid content becomes 90% linoleic acid, making it easily oxidized, affecting its function. If the diet is high in coconut oil and olive oil, cardioleptin will be higher in stearic and oleic acids and these fats are more stable fats than linoleic acid.

Literally, we are what we eat!

Cooking with Industrial Seed Oils

When industrial seed oils are heated such as they are in the making of commercial foods using them, they undergo rapid oxidation which means that they react with oxygen in the air to form toxic substances, including aldehydes and lipid peroxides.  Aldehydes are known neurotoxins and carcinogens, and are documented to contribute to DNA mutations, inflammation and hypersensitivity [8].

Heating polyunsaturated vegetable oils for just 20 minutes produces 20 times the permitted levels of ldehydes recommended as a maximum limit by the World Health Organization [8].

Keep in mind that at fast-food restaurants and in the preparation of commercial donuts and other fried food products, these industrial seed oils are used for frying everything from French fries to donuts and are heated over and over for extended periods of time, creating alarming levels of aldehydes and lipid peroxidation products.

Concentrations of aldehyde per litre of oil when heated to 180 C (from Groosvelt et al, 2015)

When heated, industrial seed oils produce oxidized metabolites known as oxidized linoleic acid metabolites (OXLAMs) which have been also been implicated in the development of non-alcoholic fatty liver disease (NAFLD)[9].

In the body cell components such as cardioleptin with high amounts of linoleic acid are easily oxidized producing an oxidation product known as 4-hydroxynonenal (4-HNE) which has been implicated in the development of cancer [10].

Increasing Appetite

The high linoleic acid content of industrial seed oils also act on two endo-cannibinoids in the body (2-AG and Anandamide) which results in us feeling hungry, even when we have recently eaten –  in much the same way as cannabis (marijuana) does [11-12].  As a result, these industrial seed oils are believed to contribute to obesity and the associated health risks such as Type 2 Diabetes and high blood pressure.

Final Thoughts…

For fifty years, the public ate industrially-created trans fats in place of natural saturated fats and we only found out later that they were a major contributor to heart disease.

For the last forty years we have been eating industrial seed oils in greater and greater quantities place of natural saturated fat, but (a) given how these industrial seed oils are produced (solvents, high heats for extended period of time, bleach, etc.) and (b) given what is known about the very toxic products they produce when heated in production and how they are oxidized in the body and oxidized through heating when cooking, it is warranted to be very cautious about eating prepared foods made with them.

To avoid these industrial seed oils will take a concerted effort as they are in virtually everything we buy ready-made and many of the foods we eat out, but one solution is to cook real food using healthy sources of fat and to avoid these industrial seed oils that were created and marketed to us as supposedly healthy substitutes for natural fats.

The butter, lard and tallow of years gone by were made from animals that were pasture raised, not fed soybeans and corn as commercial animals are now, but in light of the mounting number of studies that indicate that saturated fat is not associated with increased risk of cardiovascular disease, perhaps it might be preferable to buy grass fed butter or render tallow or lard from the fat of pasture-raised animals for some cooking applications – rather than use these industrial seed oils that were created as substitutes.  Butter, lard and coconut oil (a vegetarian saturated fat) are all very low in linoleic acid and thus are very stable.  They are not easily oxidized in the body or by heating and produce very low levels of aldehyde and lipid peroxidation products when heated, compared with many of the industrial seed oils.

These are all factors we need to consider when deciding which fats our food should be made with.

The chart below shows the linoleic content of some common fats in blue.  Keep in mind that fats with the smallest amount of linoleic acid are the most stable and the least prone to oxidation (either in the body or when heated).

Comparison of Dietary Fats – linoleic acid content

A personal note: For non-heating uses, I use natural sources of monounsaturated fat such as cold pressed macadamia nut oil, hazelnut oil, avocado oil, and extra virgin olive oil and for cooking and heating uses I use a mixture of olive oil and coconut oil (to raise the smoke point), clarified butter (ghee) at higher temperatures and butter at lower temperatures and for baking. I read labels of all products I buy and deliberately avoid purchasing any food products that contain soybean oil, canola oil or sunflower oil and when I eat out, I ask that my food be prepared with coconut oil, butter or ghee.

While the jury is still “out” when in comes to saturated fat, it is my opinion that with the mounting evidence that eating saturated fat does not contribute to heart disease, using moderate use of butter, ghee (clarified butter) and coconut oil seems to me to be a more acceptable risk than eating foods made with, or fried in industrial seed oils.

I trust having the information contained in this article will help you make an informed choice for yourself and for those you cook for.

If you have questions about how I might be able to help you follow a low carb lifestyle -including selecting appropriate fats for use in your own cooking, please feel free to send me a note using the “Contact Me” form located on the tab above.

References

(continued from Part 1)

6. A.P. Simopoulos, Evolutionary aspects of the dietary omega-6:omega-3 fatty acid ratio: medical implications,World Rev Nutr Diet, 100 (2009), pp. 1-21

7. Tanya L Blasbalg, Joseph R Hibbeln, Christopher E Ramsden, Sharon F Majchrzak, Robert R Rawlings; Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century, The American Journal of Clinical Nutrition, Volume 93, Issue 5, 1 May 2011, Pages 950—962.

8. Grootvelt M, Rodada VR, Silwood CJL, Detection, monitoring, and
deleterious health effects of lipid oxidation products generated in culinary oils during thermal stressing episodes, Lipid Oxidation, November/December 2014, Vol. 25 (10)

9. Maciejewska, Dominika & Ossowski, Piotr & Drozd, Arleta & Karina, Ryterska & Dominika, Jamioł & Banaszczak, Marcin & Małgorzata, Kaczorowska & Sabinicz, Anna & Wyszomirska, Joanna & Stachowska, Ewa. (2015). Metabolites of arachidonic acid and linoleic acid in early stages of non-alcoholic fatty liver disease-A pilot study. Prostaglandins & other lipid mediators.

10. Zhong H, Yin H. Role of lipid peroxidation derived 4-hydroxynonenal (4-HNE) in cancer: Focusing on mitochondria. Redox Biology. 2015;4:193-199. doi:10.1016/j.redox.2014.12.011.

11. Alvheim AR, Malde MK, Hyiaman DO et al; Dietary Linoleic Acid Elevates Endogenous 2-AG and Anandamide and Induces Obesity, Obesity (2012) 20;1984-1994

12. Alveim AR, Torstensen BE, Lin YH et al, Dietary Linoleic Acid Elevates the Endocannabinoids 2-AG and Anandamide and Promotes Weight Gain in Mice Fed a Low Fat Diet, Lipids (2014) 49:59—69


Copyright ©2018 BetterByDesign Nutrition Ltd.

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

Concerns with Polyunsaturated Vegetable Oils – Part 1

INTRODUCTION: Both the US and Canadian Dietary Guidelines encourage us to limit saturated fat in order to reduce the risk of heart disease and to eat unsaturated fat, including polyunsaturated vegetable oils instead but what are these fats, where do they come from and what role might these play in development of obesity, Type 2 Diabetes, non-alcoholic fatty liver disease and even cancer?  This article is part 3 in the series titled Bad Fats and Enduring Beliefs.


“Polyunsaturated vegetable oils” is really a misnomer, as neither soybeans nor rapeseed / Canola are “vegetables”.  More accurately these should be called “industrial seed oils”, as they are seed crops that have been deliberately engineered for food use.  These are created oil products which are quite unlike natural oils that can be easily expressed from nuts, seeds and fruit using a millstone, as has been done since the Bronze Age [1].

Image result for ancient olive press
Ancient olive oil press

If you simply press olives, almonds, sesame or poppy seeds between your fingers you will be able to express a little bit of their oil on your fingers.

Not so with soybeans!

You can squeeze a soybean as hard as you like and for as long as you like and you are not going to get any oil out of it!

The first attempt at trying to express oil from soybeans occurred in the United States, a few years after the creation of Crisco® shortening in 1911.  For 3 long years (1922 – 1925) scientists tried over and over again to extract oil from soybeans  imported from Manchuria using hydraulic presses,  and time and time again they failed. Finally, in 1925 scientists turned to the use of chemical solvents  to get oil from soybeans and solvent extraction of soybean oil has been used ever since.

Trans Fats and Industrially Produced Shortening

In days gone by, deep-fat frying in restaurants (e.g. for French fries) was done in beef tallow, sometimes in lard. Pastry crusts were made with lard or butter, and baked goods such as cakes and brioches were usually made with butter – that is until 1911 when Crisco® shortening was invented. When it was noticed that hardened cottonseed oil used in the soap-making industry had an appearance like lard, scientists decided to further process it to remove the strong odor inherent with cottonseed oil, and market it to housewives as the ‘modern’ way to bake.

Beginning in the 1950s, trans fats (which occurs naturally in very small quantities) were industrially produced from other industrial seed oils such as soybean oil for use in other natural fat substitutes, including  margarine, fat for commercial baked goods and fat for deep-fat frying in the fast food industry [2]. Unfortunately, it was only in the late 1990s and early 2000s that it became widely-accepted by the scientific community that eating foods made with trans fats or fried in trans fats raised LDL-cholesterol while lowering protective HDL cholesterol, and also raised triglycerides; promoting systemic inflammation and contributing to the development of heart disease.

How ironic that the fats that were created to replace naturally-occurring saturated fats ended up being so detrimental to health!

After trans fats were discontinued due to their adverse health effects, industrial seed oils such as soybean oil and canola oil became the number one and number two oils of the food industry. These unsaturated (liquid) industrial seed oils have replaced saturated (solid) trans fat industrial oils in our food supply, however there is considerable evidence emerging which should cause us to question whether these fats are any safer (more on that below).

The Created Market for Industrial Seed Oils

The market for industrial trans fats and liquid industrial seed oils was itself created based a belief that ‘dietary saturated fat led to heart disease’.  Much  of what we have come to believe about this originated with a pathologist named Ancel Keys who proposed his ‘diet-heart hypothesis’ in the 1950s.

In 1967, Keys published his “Seven Country  Study” that reported that populations that consumed large amounts of saturated fats in meat and dairy had high levels of heart disease but when data from 22 countries that was available since 1957 was plotted, it was a great deal more scattered, indicating a much weaker association than Keys’ Seven Country  Study data indicated.

In August of 1967, just as Ancel Keys published his study, Stare, Hegsted and McGandy, 3 Harvard researchers paid by the sugar industry published their reviews in the New England Journal of Medicine which vindicated sugar as a contributor of heart disease and laid the blame on dietary fat and in particular, saturated fat and dietary cholesterol (previous article on that topic here). Sponsorship of this research by the sugar industry certainly casts a dark shadow over their findings.

These 3 researchers insisted in their conclusion that there was a link between dietary cholesterol and heart disease and that there was “major evidence” which suggested that there was “only one avenue for diet to contribute to hardening of the arteries and the development of heart disease”,  but as covered in the previous article, it is known that a year after their publications (1968), the report of the Diet-Heart Review Panel of the National Heart Institute made the recommendation that a major study be conducted to determine whether changes in dietary fat intake prevented heart disease because such a study had not yet been done.

Just 10 years after the sugar industry paid Stare, Hegsted and McGandy to write their reviewsHegsted was directly involved with developing and editing the 1977 US Dietary Guidelines which recommended that Americans decrease intake of saturated fat and cholesterol and increase dietary carbohydrate – entrenching the belief that saturated fat caused heart disease into American public health policy. That same year (1977), based on the same body of literature, Canada adopted very similar dietary guidelines around saturated fat…and the rest is history.

Public Health Policy Based Rooted in a Belief

For the last forty years Americans and Canadians have shunned natural fats such as butter, cream and lard in place of man-made margarine, non-dairy creamer and Crisco® – all in the enduring belief that ‘saturated fat is “bad” and leads to heart disease’.  Given that published reports vilifying saturated fat were funded by the sugar industry and that Ancel Keys study left out 2/3 of the nutrition and health data available at the time, it has become evident that public health policy was founded on what is now questionable data.

In addition, more and more current peer-reviewed published studies are concluding that saturated fat is not associated with an increased risk of developing cardiovascular disease.

If saturated fat is not associated with increased risk of heart disease then should we be eating industrial seed oils that were created and marketed as a replacement for them?

Creation of Industrial Seed Oils

Inexpensive soybean oil has been the leading oil used in food production in the United States since 1945 [3]. It was previously made into a hard fat through hydrogenation and sold to consumers as trans-fat based shortening and margarine and came into wide-spread use as both synthetic hard fat and as a food-based oil product in the late-1960s.

In Canada, soybean oil is just behind canola oil in terms of the most used, and canola is another industrial seed oil that was created by science. In 1978 rapeseed, a prairie weed was specially bred in Canada to produce a novel plant that was lower in erucic acid (a toxin found in rapeseed) and this new plant was named “canola” (‘Canadian Oil’).

A 2015 study on Canadian vegetable oil purchased and eaten in Canada found that in 2013, 42% was canola oil (a Canadian bio-engineered industrial seed oil) and 20% was soybean oil, an industrially-engineered seed oil developed in the US [4]. Keep in mind this figure excludes food products available in Canada that are manufactured in the US, which uses predominantly soybean oil.

Soybean Oil is a Modern, Industrial Product

According to an article titled “Soybeans Are Ancient; Oil Is Not” published in the Wall Street Journal in 2011 [5], soybeans as the basis for tofu and soy sauce is an ancient food in China, but soybean oil was virtually unknown until global food oil shortages during World War I created an interest to extract the fatty part of the soybean for oil. Soybean oil is a modern creation.

How is oil made from seeds such as soybean and canola?

“Soybeans are first crushed into crude oil and then refined to remove impurities like free fatty acids. Over days, the crude is ”neutralized” of acidity with phosphoric acid, ”winterized” through filters that remove wax, bleached at high heat to lighten the color and finally vacuum ”deodorized” to eliminate impurities.” [5]

Related image
soybean extraction plant

The extraction of soybean oil involves the industrial processing of soybeans with solvents at very high heats over an extended length of time in order to have the soybean give up its small amount of oil.

Solvent extraction of canola oil occurs in a similar method, beginning with an hour or more ‘wash’ of the rapeseed with a hexane solvent, then a sodium hydroxide wash. Bleach is then used to lighten the cloudy color of the processed oil and then it is steamed injected at high temperatures to
remove the bitter smell.

Yummy! Now this oil is ready to sell to the public to cook with and eat!

Should we even be eating these industrial seed oils?

Are they any safer than trans fats that were approved for consumption for 50 years and later found to contribute to heart disease?

Part 2 of this article will continue in Concerns with Polyunsaturated Vegetable Oils – Part 2.

References

  1. Alfred Thomas (2002). “Fats and Fatty Oils”. Ullmann’s Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH.
  2. “Tentative Determination Regarding Partially Hydrogenated Oils”. Federal Register. 8 November 2013. 2013-26854, Vol. 78, No. 217.
  3. Dutton, HJ. Journal of the American Oil Chemists Society, Vol. 58, No.3 Pages: 234-236 (1981),  https://pubag.nal.usda.gov/pubag/downloadPDF.xhtml?id=26520&content=PDF
  4. Schaer, L., Grainews, Canola gets competition from soybeans, Feb 01, 2016, https://www.grainews.ca/2016/02/01/canola-gets-competition-from-soy/
  5. Wall Street Journal, “Soybeans Are Ancient; Oil Is Not”, 2011, https://blogs.wsj.com/chinarealtime/2011/01/03/soybeans-are-ancient-oil-is-not/

Copyright ©2018 BetterByDesign Nutrition Ltd.

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.