While endometriosis is not caused, nor “cured,” by diet alone, it’s well-regarded in research that diet can play a meaningful part in endometriosis establishment and progression, or treatment and stabilization. It’s one factor in this multi-factorial disease.

The question remaining is, “Which foods, exactly?”

Insert web and social media platforms stuffed with both confusing and conflicting information on diet and endo! There are many opinions, old science, new science, cultural differences, and ancestral wisdom, all mixed up in different “diets” that foretell doom and gloom or sparkly, glowing health. Add in a chronic health condition like endometriosis, and it gets really confusing, really fast.

So… what do we do?

I personally wrote a book on the topic, Heal Endo: An Anti-inflammatory Approach to Healing from Endometriosis. Here I delve into the research-based who, what, where, when, and why we should focus on brightly colored veggies, fruit, quality protein, and ancestral fats. There’s lots of research behind this recommendation, but that’s the simple jist of it. As far as foods to avoid? In general, anything that spikes blood sugar (added sugars or too much starch, even if in the form of grains or starchy veggies), as well as alcohol and vegetable oils.

It’s a reasonable approach to health that allows for a diet rich in antioxidants and nutrients to combat oxidative stress, balance hormones, regulates the immune system, and heal the gut, all without being overly dogmatic.

Meanwhile, in a lab far away, Dr. Suzanne Judd, a nutritional epidemiologist, had the same question about which foods to recommend for similar reasons. In a world of nutritional biases, she wanted a ranking system that looked beyond personal preferences (or lobbyist money) of what “anti-inflammatory food” is, but in an easier-to-understand format. [i.e. not a 400-page book on endometriosis]. Smart lady.

To do so, she and her team set out to identify the level of inflammation that certain foods may cause inflammation and the degree to which some foods may reduce inflammation—all based on clinical research to limit personal biases. Together they created the Dietary Inflammatory Index (DII). The DII takes into account a wide range of nutrients and foods and provides a score that can be used to guide dietary choices.

The cool thing? The DII lines up exquisitely with the recommended food protocol of Heal Endo, and research has already shown there’s a clinically significant association between endometriosis and the DII.

Curious? Read on! This blog will explore the science behind the DII, its association with endometriosis, and how you can use it to make more informed food choices.

The Best Diet for Endometriosis: The Dietary Inflammatory Index

The DII is a tool that has been developed to measure the inflammatory potential of an individual's diet. Inflammation is a critical factor in many chronic diseases such as cancer, diabetes, cardiovascular disease, and endometriosis (obviously), and research has shown that diet can play a major role in regulating inflammation in the body. Thus, by calculating a score for ourselves, we can see what deck we are stacking in our favor: pro- or anti-inflammatory? Pro-cancer or anti-cancer? Pro-endometriosis, or anti?

To create the DII, researchers analyzed the diets of individuals from various ethnic and geographical backgrounds. These participants reported how much and how often they ate 109 food items, as well as detailing their daily habits and physical activity levels. Additionally, researchers analyzed blood samples to determine the levels of inflammation markers, as well as the results of colonoscopies and polyps.

From here, they developed a mathematical formula to assess the impact of different food groups and lifestyle habits on these markers to show us which foods are more associated with provoking chronic inflammation and which foods are better at combatting it.

For ease in understanding, foods with a negative number are more anti-inflammatory, while those with a positive number are associated with increased inflammation. Some of the results include:

Anti-Inflammatory Wins

Tomatoes: -0.78
Apples and berries: -0.65
Deep yellow or orange produce: -0.57
Other fruits and veggies: -0.16
Leafy greens and cruciferous: -0.14

Benign (basically right at zero)

Fish: -0.08
Legumes: -0.04
Red meat: 0.02

Pro-inflammatory Caution

Vegetable oils, 0.31

Current Smoker: 0.50
Added sugars: 0.56
Processed meats: 0.68
Refined grains and starchy vegetables: 0.72 [Wow, I wasn’t expecting this!]

Hugely inflammatory

Overweight BMI: .89
Obese BMI: 1.57!!! [I wasn’t expecting this, either!]

Some things that surprised me from these findings included that

While very pro-inflammatory, smoking was still listed as less inflammatory than eating added sugar, processed meats, refined grains, and starchy vegetables. Brings home just how triggering these foods can be.
Just how inflammatory being unhealthily overweight is. Obesity has over 3x the inflammatory effect as sugar.
Just how much more inflammatory processed meats were than fresh meats. This is precisely the information that needs to circulate: fresh meat is healthy and balanced, and processed meats are the ones to be avoided.
Just how inflammatory blood sugar spikers are, even in the form of “healthy” grain or starchy foods. If they spike blood sugar, they’re like pouring gas on a fire.
Just how inline these recommendations are with a Heal Endo approach. Pretty cool!

How is the Dietary Inflammatory Index Associated With Endometriosis?

With this new “inflammation calculator” in hand, we can better analyze food intake with disease while leaving personal biases at home. And this is just what researchers have done with endo.

Two very recent studies (released within the past few months) demonstrate a clinically significant association between DII foods and the risk of endometriosis. Each analyzed the food intake of people with and without endometriosis (one from the Nurses Health Study, the other from the NHANES). They found that the more your DII score was in the negative (i.e., prioritizing anti-inflammatory or benign foods), the less likely you were to have endometriosis. Conversely, the higher your score (i.e., focus is on pro-inflammatory foods), the higher your chance of having endo. [2,3]

Since I realize few people want the specifics in this research as much as me (read the literature if you like, cited below), I instead made some graphs to demonstrate the big-picture results. As you can see, there’s a considerable jump in endometriosis cases the further away from zero you get toward the right (pro-inflammation):

What Foods/Activities are Associated with Endo (or not)

Weight and endometriosis: Being overweight, in general, is not directly associated with endometriosis (not like diabetes, for example, where chances are you’re overweight if you have it). However, if you are overweight and you have endometriosis, chances are you’re in deeper trouble than your slimmer endo-sister. In fact, the more overweight you are, the higher your chances are for severe endo, and the less likely you’ll have minimal stage I. This could be linked to the incredible inflammatory burden of being overweight. [4]
Phytonutrients and endometriosis: Eating more phytonutrients is a specific treatment approach to reduce oxidative stress and something I talk about at length in my book to help support endo stabilization and regression. The foods richest in phytonutrients are deeply and brightly pigmented fruits and veggies (the ones that are all super anti-inflammatory here on the DII)—perhaps why eating more of these foods (per the DII) is associated with less endo. [5]
Move more, move better: As I detail in my book, moving more, and moving better, are both imperative for lowering inflammation, increasing nutrient accessibility, and healing from endo. Here we can see that the more you move your body, the farther away from inflammation you get, while the more sedentary you are (and more overweight), the more you stack your deck toward inflammation.
Blood Sugar is King: I was actually surprised with the DII results that lumped blood sugar-provoking refined foods together with “healthier” grains and whole foods starches (like potatoes or peas). This group was more inflammatory on the DII than processed meats, sugar, or smoking! But… in a world of blood sugar imbalance, it does makes sense (why I also recommend limiting these foods even though they’re healthier than pure sugar). If you’re on a blood sugar rollercoaster, be it from soda and candy or sweet potato and organic granola, you will induce systemic inflammation every day. If you want to read about how blood sugar fosters endometriosis (yes, really), read this here. There’s also some fascinating research on how reducing blood sugar (and its associated problems) is associated with endometriosis regression. [6]

Endometriosis Diet Focus 101: Anti-Inflammatory and Nutrient Dense

As a nutritional therapist, I believe the DII is a helpful tool. While not entirely perfect (they only looked at 109 foods out of THOUSANDS), it’s a great step in the right direction when needing to mitigate chronic inflammation, as we with endometriosis do! It also helps us see that there’s a scale of inflammation, so eating sugar or french fries with friends once in a while won’t substantially impact your overall scores long as you overall are prioritizing the anti-inflammatory and benign spectrum of foods.

The great thing about understanding how the chronic inflammation fire is stoked is that we can do so much to calm it down. One way is through food choices. That is, by eating anti-inflammatory foods! And now we have this cool tool.

If you want a picture carousel of what DII eating looks like in my own daily life, check out 100 images here!

If you want to implement a dietary strategy like this in your own home, check out my cookbook here!

If you want to read more about what endometriosis is and why diet and lifestyle MATTERS, read my new book here :)

1) Byrd DA, Judd SE, Flanders WD, Hartman TJ, Fedirko V, Bostick RM. Development and Validation of Novel Dietary and Lifestyle Inflammation Scores. J Nutr. 2019 Dec 1;149(12):2206-2218. doi: 10.1093/jn/nxz165. PMID: 31373368; PMCID: PMC6887697.

2) Liu, P., Maharjan, R., Wang, Y., Zhang, Y., Zhang, Y., Xu, C., Geng, Y., & Miao, J. (2023). Association between dietary inflammatory index and risk of endometriosis: A population-based analysis. Frontiers in nutrition, 10, 1077915. https://doi.org/10.3389/fnut.2023.1077915

3) Hu PW, Yang BR, Zhang XL, Yan XT, Ma JJ, Qi C, Jiang GJ. The association between dietary inflammatory index with endometriosis: NHANES 2001-2006. PLoS One. 2023 Apr 26;18(4):e0283216. doi: 10.1371/journal.pone.0283216. PMID: 37099512; PMCID: PMC10132696.

4) Liu, Y., & Zhang, W. (2017). Association between body mass index and endometriosis risk: a meta-analysis. Oncotarget, 8(29), 46928–46936. https://doi.org/10.18632/oncotarget.14916

5) Gołąbek, A., Kowalska, K., & Olejnik, A. (2021). Polyphenols as a Diet Therapy Concept for Endometriosis-Current Opinion and Future Perspectives. Nutrients, 13(4), 1347. https://doi.org/10.3390/nu13041347

6) Kimber-Trojnar Ż, Dłuski DF, Wierzchowska-Opoka M, Ruszała M, Leszczyńska-Gorzelak B. Metformin as a Potential Treatment Option for Endometriosis. Cancers (Basel). 2022 Jan 24;14(3):577. doi: 10.3390/cancers14030577. PMID: 35158846; PMCID: PMC8833654.