Plant foods alter gene expression to curb inflammation

Inappropriately high levels of inflammation contribute to many of the chronic diseases of the modern world. Inflammation plays an important role in the development of atherosclerotic plaque, and inflammatory mediators have been shown to fuel tumor growth. [1] Certain characteristics of the Western diet are known to have pro-inflammatory effects – the high content of omega-6 fatty acids, for example, due to excessive oil and animal products, leads to overproduction of inflammatory molecules. Also, obesity is associated with chronic inflammation. Fat tissue produces a great number of both hormones and inflammatory molecules, and obesity-associated inflammation is said to be the link between excess body fat and chronic disease. [2]

 fruits and vegetables; Flickr: karimian

Eating more plant foods and fewer animal products and oils is advisable to avoid these pro-inflammatory effects. Omega-3 fatty acids, in contrast to omega-6 fatty acids, are known to have anti-inflammatory effects. Fruits and vegetables are known to be protective against chronic disease due to their low calorie density and high quantity of micronutrients and antioxidants, and have been associated with reduced circulating inflammatory molecules. A recent study showed that fruit and vegetable consumption alters circulating levels of inflammatory molecules by affecting gene expression in circulating white blood cells, limiting the production of inflammatory molecules by these cells.

Young adults reported their usual food intake, and the researchers correlated this to a number of inflammatory markers in blood, as well as expression of a number of pro-inflammatory genes in white blood cells. The subjects were divided into groups based on their quantity of fruit and vegetable consumption, and inflammatory markers (C-reactive protein, homocysteine, and TNFα) were 40% lower in the group with the highest (vs. lowest) fruit and vegetable consumption. Moreover, expression of four pro-inflammatory genes (ICAM1, ILR1, TNFα, and NF-κB1) were significantly lower in the circulating white blood cells of the high fruit and vegetable consumers. [3] C-reactive protein and plasma homocysteine are known risk factors for heart disease, and NF-κB is a key promoter of atherosclerosis development.[4]

This data suggests that plant foods have anti-inflammatory effects that have not yet been discovered.

We cannot underestimate the importance of high-nutrient foods. Our genes are inherited, but the expression of those genes is modified by our environment. Food components interact with our genes to affect the state of our health, and this study suggests that high-nutrient foods drive gene expression patterns that reduce inflammation and therefore risk of chronic disease.



1. Sgambato, A. and A. Cittadini, Inflammation and cancer: a multifaceted link. Eur Rev Med Pharmacol Sci, 2010. 14(4): p. 263-8.
2. Hajer, G.R., T.W. van Haeften, and F.L. Visseren, Adipose tissue dysfunction in obesity, diabetes, and vascular diseases. Eur Heart J, 2008. 29(24): p. 2959-71.
3. Hermsdorff, H.H., et al., Fruit and vegetable consumption and proinflammatory gene expression from peripheral blood mononuclear cells in young adults: a translational study. Nutr Metab (Lond), 2010. 7: p. 42.
4. Kutuk, O. and H. Basaga, Inflammation meets oxidation: NF-kappaB as a mediator of initial lesion development in atherosclerosis. Trends Mol Med, 2003. 9(12): p. 549-57.


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Comments (10) Read through and enter the discussion with the form at the end
Reg Wilkins - October 26, 2010 6:00 PM

Is there any evidence that the higher calorie plant foods such as avocado, nuts and seeds have any degree of pro-inflammatory effect?

TPHNS - October 26, 2010 9:09 PM

WRT your article, there appears to be a sound science base to much of it, apart from one critical para:

"Certain characteristics of the Western diet are known to have pro-inflammatory effects – the high content of omega-6 fatty acids, for example, due to excessive oil and animal products, leads to overproduction of inflammatory molecules"

Can you point me to any gold standard science (i.e RCTs in humans, not observational or rat studies) that proves that the "high content" of Omega 6 fatty acids in the "Western" human diet, ipso facto results from "excessive" dietary consumption of "animal products", as asserted?

I know of no evidence that in a "Western" country, such as Australia, where most animals are still grass fed, there is any strong evidence that what you assert is correct.

Alicia - October 26, 2010 9:41 PM

Great explanation! You took a complicated concept and made it simple for those of us without a science background to comprehend.

MIke Rubino - October 27, 2010 6:30 AM

This article really tells us why greens, beans, nuts, seeds fruits and veges.

Deana Ferreri, Ph.D. - October 27, 2010 10:37 AM

Yes, there is plenty of science to support this. Go to, and search for the author "Simopoulos AP". He has written several reviews on the subject.

TPHNS - October 27, 2010 4:36 PM

Thank you for the reference to the papers of "Simopoulos AP". I have now read four of them, including one published this year. Whilst I find them to include a recitation of the standard and emerging science regarding Omega 6/3 ratios and their interaction with genetics, I find no support for the assertions you have made, about which i challenged you.

Simply put, they do not support your view that the "Western" diet (which by definition includes USA, Europe, Australia etc.) is laden with "excessive" Omega 6 fatty acids from "animal products", that is the cause of inflammation. Again I challenge you - show me a well designed RCT that shows the causality chain you set out, viz: Western diet (i.e not just USA) has excessive Omega 6 from animal products that leads to inflammation.

The fact is, a vegan living in the USA, consuming large intakes of Omega 6 laden vegetable oils, eating wheat products and lots of fructose, with low Omega 3 intakes, may also suffer inflammation.

BTW, I have no vested interest in this debate. I just dislike poor logic.

vic305 - October 28, 2010 9:02 AM

Dr. Ferreri,

I only have access to abstracts on pubmed, but everything I'm reading seems to indicate that TPHNS was correct and that the link between the "western diet" and chronic inflammatory conditions relies on the flawed assumption that all animal products consumed MUST be of a non-grass fed nature, as these are the only animal products that exhibit such massively skewed n-6 to n-3 ratios. Grass fed meat, fowl, and milk have widely different fatty acid profiles than industrialized, grain fed meat. Clearly, westerners as a demographic DO exist (almost exclusively) on industrialzied animal products, which is why observational studies will indicate that their diet is pro-inflammatory. However, this doesn't mean that someone who adopts the typical meals and macronutrient profile of a western diet MUST consume industrialized animal products - grass fed options are available. And in this case, I'm not aware of any research indicating that the ratio of n-6 to n-3 fatty acids being ingested is still detrimental, nor am I convinced that a couple of capsules of fish oil every day wouldn't fix the ratio.

Additionally, the link between n-3 and anti-inflammation is not quite clear:

Sorry I don't have a valid source (I'm sure you can find the actual study) but this suggests that n-3 benefits are somewhat correlated to n-6 intake or at least dose-dependent.

The point of all of this is to put a stop to the defeatist and self serving attitude we sometimes see obese Americans adopt: "it's not my fault I'm 46% body fat, it's my environment and the food in the supermarket!!"

Also, to stop all the disinformation extrapolated from truthful posts like this one: "The western diet gives cancer, therefore I must not eat red meat ever!!." I'm not even exaggerating when I say I've heard this repeatedly.

patty - October 30, 2010 7:35 AM

Mahalo for the Life affirming information.


klws - October 31, 2010 11:24 PM

I know this topic is not about Halloween candy, but I can not believe what happpened! I gave out bananas and apples and had several thrown at my house later on in the night. I had several frowns as well when I handed them out. I was in shock, I thought the kids would enjoy getting some fresh fruit. I spent an enormous amount on the fruit, much more than I would have spent on bags of candy and it was NOT appreciated. Just wondering if anyone else has had any similiar experiences. Also, I saw several ADULTS, looking at least over forty years old out trick-or-treating with big pillow cases! I could not believe that either. I guess they wanted their candy as well. When I offered them the fruit, they at least said, "no thanks." Several of the kids unappreciatively took it, and later my yard was covered with mulitple bananas and apples!

Michael - November 1, 2010 9:27 AM

When I was a kid, fresh fruit given at Halloween was thrown out because there was a scare caused by some sick people who inserted needles and razor blades into apples somewhere.

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