Two potential risk factors that may increases the risk of inflammatory bowel diseases (such as ulcerative colitis and Crohn's disease) are animal protein and nanoparticles such as titanium dioxide.
Of all dietary factors, animal protein from meat and fish is most associated with a higher risk of inflammatory bowel disease. As you can see in my 6-min video Titanium Dioxide & Inflammatory Bowel Disease, the researchers think it may be the blood in meat which is degraded to carbon monoxide, or some of the toxins created by cooking muscle or added to processed meats, or the pro-inflammatory omega-6 arachidonic acid.
Meat may also contain certain bacteria that have been linked to inflammation, but then again maybe it's the antibiotics in meat mucking with people's intestinal flora. Whatever the reason, the study concluded that a diet high in animal protein may not only be associated with increased risk of getting inflammatory bowel disease in the first place, but also a higher relapse rate if you already have it. This is consistent with the data I presented last year that even a semi-vegetarian diet was highly effective in preventing flares in Crohn's disease (see my video Dietary Treatment of Crohn's Disease).
One potential risk factor that I had never heard of, though, was micro- or nanoparticles. Foodstuffs in developed countries contain increasing quantities of microscopic particles such as titanium dioxide. Titanium dioxide is used by the millions of tons as a whitening or brightening pigment to make white-colored paint, but also as an additive to make white-colored food. It's added to food so much so that people eating conventional diets may be ingesting a trillion particles of titanium dioxide every day!
Who cares, though? Well a few years ago researchers found evidence of micro and nanoparticles in all 18 out of 18 samples of diseased colons they looked at--either colon cancer or inflammatory bowel, but none in the 3 healthy colons they looked at from folks who died in a car accident or from a heart attack. That's a tiny sample but it got people thinking, and more importantly, inspired scientists to put it to the test.
Researchers took intestinal biopsies from people and added some titanium dioxide to see if it would cause inflammation. Watch my video Titanium Dioxide & Inflammatory Bowel Disease to see the results, but basically they concluded that titanium dioxide may transport inflammatory substances like endotoxin into the gut wall via a 'Trojan horse'-type mechanism.
What happens in a petri dish, however, may not happen in a person. How are you going to test the theory in people, though? You can't go around trying to give people inflammation, but you can take a bunch of people actively suffering from Crohn's and take microparticles out of their diet to see if they get better. A study was performed in which of 18 patients with active Crohn's, 9 were kept on their regular diet and 9 were placed on a low microparticle diet. Within a month, those on the low microparticle diet had a significant decrease in disease severity, and by the end of the study 7 of the 9 were in remission, whereas none were in remission in the regular diet group.
In addition to removing things they expected to contain titanium dioxide-coffee whitener, white cheese, powdered sugar-they also removed processed meats and fish, fearing that there were microparticles in them too. This complicates things, though. Just cutting down on meat alone is one of the most powerful Crohn's interventions, so maybe that's why they got better and perhaps the titanium dioxide had nothing to do with it. Indeed a larger trial in which both groups were told to cut down on processed meat and seafood found no benefit to also cutting microparticles. This is consistent with another study that did not find that Crohn's patients were eating significantly more white foods--like crispy shell chewing gums, marshmallows, and powdered doughnuts.
So where are we now? Well, high concentrations of dietary microparticles should not be completely ruled out as potential contributors to intestinal inflammation, but there's little evidence at this point suggesting they're harmful. Note, though, that the most concentrated sources (out of nearly 100 products tested that I feature in the video) aren't any good for you anyway, so if you want another excuse to avoid Hostess donuts, there you go!
For more on that list of concerning compounds they noted in animal products, see Estrogenic Cooked Meat Carcinogens for the heterocyclic amines, Chicken, Eggs, and Inflammation for arachidonic acid, Meat Additives to Diminish Toxicity for heme iron, Yersinia in Pork for the inflammation-linked bacteria, and Lowering Dietary Antibiotic Intake on some of the drugs fed to animals. I'd also add to that list The Inflammatory Meat Molecule Neu5Gc and Dead Meat Bacteria Endotoxins.
Some of my other videos on food additives include:
- Is Carrageenan Safe?
- When Nitrites Go Bad
- Artificial Coloring in Fish
- Is Sodium Benzoate Harmful?
- Aluminum in Vaccines vs. Food
- Are Artificial Colors Bad for You?
- Is Potassium Sorbate Bad for You?
-Michael Greger, M.D.
Image credit: adamdachis/ Flickr