Animal Protein Intake and Risk of Inflammatory Bowel Disease: The E3N Prospective Study.

Researchers wanted to study the proposed connection between animal protein consumption and increased risk for IBD.  The study consisted of 67,581 women living in France between the ages of 40-65 without major diseases at the beginning of the study. The study was conducted over 10.4 years, and questionnaires on lifestyle were given ever 24 months along with an clinical IBD assessment. During the study, a total of 77 cases of IBD were diagnosed during the study, and 458 women checked Crohn’s disease or Ulcerative Colitis on the questionnaire. (further details in link)

High protein intake, specifically animal protein, was significantly associated with increased risk of IBD (particularity for Ulcerative Colitis). Meat and fish, were particularly associated but not eggs or dairy (but eggs or dairy may not have been eaten in as large of quantities).

Specifics of the Results:

In the adjusted model, only total protein intake (not carbs or fats) was associated with an increased IBD risk. Interestingly, only animal protein exerted this IBD risk with no association observed with plant protein. Also, differences between UC (ulcerative colitis) and CD (Crohn’s Disease) were observed. CD was most correlated to total protein intake as opposed to animal or plant, while a strong association was seen with animal protein and UC.

How is moderate to high protein intake defined in this study?

Protein intake fell into three average intake groups. The first was 1.08g/kg, the second was 1.52g/kg, and the third intake group averaged in at 2.07g/kg. High protein intake saw a 3.3 fold risk of developing IBD.

Why might animal protein cause an increased IBD risk?

The small intestines do not adsorb some of the heme and amino acids contained in animal proteins. These are then passed to the colonic lumen and are metabolized by the micro-flora. Products from these reactions include hydrogen sulfide, phenolic compounds, amines and ammonia which are toxic to the colon.

Sulfide may alter the cell membrane of the intestinal wall cells leading to loss of barrier function which in turns triggers an immune response.

Even in healthy people, it has been shown that an increase in dietary protein leads to changes in colonic metabolism which is reflected by an increase in fecal ammonia, fecal volatile sulfur compounds, and urinary p-cresol.

Obviously, one limitation of this study was that it only included middle aged women, but these results highlight the need for additional studies in the younger and male population.

Influence of a five-day vegetarian diet on urinary levels of antibiotics and phthalate metabolites: A pilot study with “TempleStay” participants

Antibiotic use is widespread in the animal farming industry, human exposure to such compounds can come through water source contamination and ingestion of animal products (negating the prescription antibiotics). Detecting the major sources for unintended human antibiotic exposure is critical due to antibiotic resistance and other adverse drug interactions.

Also, phthalates are a pervasive environmental contaminates with one major source of human exposure being diet, but these chemicals are also present in many products we use. In the CNN article, “5 Toxics that are everywhere: Protect yourself“, phthalates are the second toxin listed and they report, “Virtually everyone is exposed to phthalates”.

I think the most interesting part of this study, besides the results of course, is that the people being tested only changed their diets for 5 days. Only 5 days. Do note this study was conducted in Korea, but livestock in the USA are definitely given antibiotics too. Also, in the paper is a comparison to levels seen in Korea, USA, and Germany for curious readers.

The three antibiotics tested for were: sulfamethazine (SMZ), trimethoprim (TMP), and enrofloxacin (EFX). Four phthalates often reported in human samples were also testes for; these include: diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), di-isobutyl phtalate (DiBP), and di(2-ethyl-hexyl) phalate (DEHP). A total of 25 participants (16 M, 9F) completed a 5-day vegetarian program, and levels of these antibiotics and phthalates were measured before and after the 5 day diet.

Typical Tap Water and Meat Consumption of Participants Before Diet

Antibiotics:

All 3 antibiotics were measured in the urine prior to the diet, although none were over the acceptable limit. Levels of all three antibiotics were lower after the diet, with some people reporting significant drops in certain antibiotic levels. Take a look at the numbers below:

Phthalates:

The phthalates measured before the diet were notably higher than the values often seen in the US general population, researchers noted, but some variations in the levels are present. Also, while diet is one major route of phthalate exposure, house dust, personal care products, and medications are also exposure sources in humans. So, some differences seen in reported levels for different countries could be explained by different common mechanisms of exposure.Below is the before and after measurements of phthalates for the 25 participants.

Oxidative Stress:

The researchers also measured the concentration of a urinary bio-marker for oxidative stress before and after the program, and found significant differences in the before and after values. Graph below:

Conclusion:

Based on the finding from this 5-day study, the researchers conclude that even a short-term dietary shift to vegetarianism can reduce dietary exposure to antibiotics and phthalates in the general population. In addition, oxidative stress levels were also seen to decrease.

I am going to focus on Study 1, the vegan vs. omnivore study. Study 1 included 9 vegans (vegans at least 4 years with the mean of 10.2 years and a standard deviation of 4.8 years) and 15 omnivores. A total of 26 organochlorines (OC) were tested for in the plasma of the study participants and include the following:

ß-hexachlorocyclohexane
p, p’-dichlorodiphenyldichloroethane (p, p’-DDE)
p, p’-dichlorodiphenyltrichloroethane (p, p’-DDT)
Hexachlorobenzene (HCB)
Mirex
Aldrin
?-chlordane (not sure exactly what this is, the # where the ? is didn’t c/p correctly)
?-chlordane (not sure exactly what this is, the # where the ? is didn’t c/p correctly)
Oxychlordane
Polychlorinated biphenyl (PCB) #28, 52, 99, 101, 105, 118, 128, 138, 153, 156, 170, 180, 183 and 187
Cis-nonachlor
Trans-nonachlor
Aroclor 1260

For five of the OCs {Aroclor 1260, PCB 99, PCB 138, PCB 153, and PCB 180}, the researchers reported that the vegans had significantly lower plasma concentration compared to the omnivores.  Also, PCB 99 was less detectable in the vegans.

Nine OCs were completely undetectable in both groups {Aldrin, ?-chlordane, ?-chlordane, Cis-nonachlor, PCB 52, PCB 101, PCB 105, PCB 128, and PCB 183}.

Now, let’s look at the data backing this conclusion. I’m going to just post the P-values for the OCs of interest, and if you want to see the raw data just go to the post. For those of you that may not have had a probability course, the P-value used in determining data trends is representative of how likely the results are due to chance. If a P-value is less than 0.05, this is considered statistically significant, but for data with a P-value above 0.05 there is considered no significant data trend. Now, lets look at some P-values.

P-Values for Vegans vs. Omnivores, Table 2

p,p’ 0-DDE  = 0.92
HCB ====== 0.076
Aroclor ==== 0.024
PCB 138 === 0.025
PCB 153 === 0.020
PCB 180 === 0.031

P-Values for Vegans vs. Omnivores, Table 3
ß-HCH ======= 1.00
p,p’ 0-DDT  ==== 0.51
Mirex ======== 1.00
Oxychlordane === 0.092 (close)
Trans-nonachlor = 0.36
PCB 28 ====== 0.26
PCB 99 ====== 0.033
PCB 118 ===== 0.36
PCB 156 =====1.00
PCB 170 =====0.68
PCB 187 ===== 0.40

Notes from the Discussion portion of the paper:

The researchers conclude that vegans are significantly less polluted than omnivores; however they do note the small size of their study. Some reasons why they didn’t find significant differences in all the plasma OC concentrations include the fact that the vegans may have been breast fed as infants (exposing them to the OCs in their mother), and most vegans make the dietary shift in adulthood resulting in OC exposure all throughout childhood and adolescence. In addition, the vegans in this study tended to be older. Finally, contamination may come though environmental concerns in addition to diet. Location of residence, water sources, and food source as well as type are all factors in OC exposure.

There is also a positive correlation between body fat mass and OC concentration. Because OCs are fat soluble, greater fat mass on the body leads to an increased dilution space and likely retention of OCs. Also, other studies have reported that changes in OC concentration affect thyroid hormone levels. These reserachers, in a different study, reported that fat loss is related to an greater predicted decrease in T3 concentration.

As a final note, the researchers expect to see more significant data between omnivores and people who have practiced veganism for more than 10 years. Considering PCB half lives are 5-25 years, these substances could be detected in the body long after the exposure has ended.

* AGEs whether consumed (exogenous) or produced inside the body (endogenous) are correlated with declining health and aging.

* Exogenous AGEs may or may not play a big role in the cross-linking that contributes to aging, but these consumed AGEs do have negative impacts on health. A study over 4 months had people eat a similar diet except one group’s food was prepared to minimize AGE content. The study found that reduced AGE consumption had surprisingly positive health benefits. (link)

* A study of CRed mice found that given the same diet with the exception of AGE content, the CRed mice with high AGE ingestion didn’t even live as long as the control group of mice. Link

The SENS Foundation will be conducting research to find ways to break these cross-links, but until  we have a solution, we must find a way to minimize cross-link formation. AGEs are responsible for the majority of cross-linking, so if we can reduce AGE accumulation in our body, we can theoretically delay one step of the aging process. AGEs can either be consumed or can be produced within the body. Understanding these two routes of AGE accumulation is important if we want to minimize their effects in our body.

Exogenous AGEs
These are AGEs we consume. Animal studies show positive correlation to AGE consumption and health problems, but it is unknown whether exogenous AGEs actually cause cross-linking. To reduce our AGE consumption, we must know what to avoid. The Inhuman Experiment blog post on AGEs gives a great generalization on exogenous AGEs (original post HERE):

* Fats and meat products contain the most AGEs
* Carbohydrates are relatively low in AGEs
* Higher cooking temperatures increase AGEs
* Longer cooking times increase AGEs
* The presence of liquids in cooking reduces AGEs
* Processed foods have more AGEs than natural or homemade food

The author of this blog has some very interesting related posts. One post is on comparing serum AGE levels in vegetarians and omnivores, which surprisingly finds that vegetarians/vegans have higher AGE levels despite having diets lower in exogenous AGEs. This suggest that endogenous AGEs are more important to AGE levels in the body.
Studies & Articles to Check Out:
Advanced glycoxidation end products in commonly consumed foods

Reducing Consumption of Glycotoxins From Heat-Processing Of Foods Reduces Risk Of Chronic Disease

Food Preparation May Play A Big Role In Chronic Disease

Endogenous AGEs
These are AGEs produced inside our bodies. The primary cause of AGE formation within the body is excess sugar in the blood. Specifically, fructose and galactose are prone to glycation. However, there is no hard evidence on the dietary relationship between serum AGE levels and intake of AGEs or sugars, but some type of relationship does seem to exist. This area is really lacking in data, so more research needs done. There is evidence that taurine many protect against AGEs, which could help explain why omnivores have lower serum AGE levels than vegetarians.
Studies & Articles to Check Out:
Advanced glycation end products and nutrition

AGEs and Aging – Frequently Asked Questions

Glycotoxins and cellular dysfunction. A new mechanism for understanding the preventive effects of lifestyle modifications

Reducing AGEs
Dietary consumpton of AGEs and production of AGEs in the body is still not well known. We can hopefully minimize AGEs by watching our blood sugar, fructose consumption, and exogenous AGE consumption, but we need to be aware of how to reduce AGEs presently in the body (at least as much as we can until the cross-linking cure is available). Until anti-aging therapies come out, we may be able to do a few things to help ourselves:

Green tea has actually shown promising results in reducing AGEs. Check out THIS post on the Inhuman Experiment blog.

Taurine acts as a glycation inhibitor:  Effect of taurine on advanced glycation end products-induced hypertrophy in renal tubular epithelial cells

In Summary
Obviously there is a real concern for lowing AGEs in the body from both a health and aging perspective. Until we have proper anti-aging therapies, we can hopefully manage the accumulation rate of AGEs by dietary practices and reduction methods.

What am I going to do?
Keep reading about AGE research, try not to cook the crap out of my food, drink green tea, and hope the taurine in my meats (selected and prepared with AGEs in mind) does do some good! :-)

CR Cranberry Green Smoothie (serves 2)

2 Bananas (~200g)
5 Kale Leaves (~90g)
100g Cranberries
1 Scoop Raspberry Protein Powder
1-2t stevia powder
1 1/2C Water

I didn’t have the variety of ingredient choices I usually have, but I did have a big bunch of bananas and a bag of cranberries in my freezer. So, I went to work. I weighed out the cranberries, microwaved then for 2 minutes, and put them in the freezer to cool. Then I cut the leafy part off of 5 of the kale leaves, put them in a big bowl, microwaved for 45 seconds, and placed them in the freezer to cool. While those were cooling, I measured out the other ingredients.

Now for the creation. I placed the water and kale in the blender first. I blended it until I didn’t think the kale could blend any more. Then I added the cranberries and bananas and blended well. I added the powder last.
I divided the smoothie into two glasses, and put them in the freezer for a few minutes to cool. I would have preferred them over ice, but I was all out. I like my smoothies cold.

But, what did QB say? And I quote, “I would rather eat a salad, you must like the taste of green”. Lol. Well, yes I do as long as it doesn’t taste too strong. Personally I liked the smoothie. If you are used to green smoothies, I think this is a decent one. Not the best, but definitely not the worst.

Here is the nutrition. Each serving has 19.8mg of Lutein+Zeaxanthin, and the protein powder is just for protein and flavor (doesn’t have any added nutrients).