Can Diet Control Inflammation?

I was chatting with a couple of women recently, one of whom is coping with chronic back pain. The other person, unaware that I’m a registered dietitian nutritionist, started dishing out (evidence-free) advice about foods that cause inflammation:

  • Sugar
  • Gluten
  • Carbs
  • Meat
  • Dairy
  • GMOs (she was adamant about avoiding GMO wheat. Luckily we’re all doing that by default because there’s no GMO wheat in the food supply)
  • Egg yolk !? That’s a new one on me.

You know, the usual suspects. Not wanting to get into a big discussion of actual science, I kept my mouth shut. In those situations, I’m inclined to say “Do whatever you want.” If you want facts, great. If not, knock yourself out. I must add, it’s really depressing to listen to people who are so irrationally paranoid about food.

What Is Inflammation?

Inflammation is the immune system’s metabolic response to injury and infection. Your immune system mobilizes to deal with the problem, creating inflammation. Without this response, you wouldn’t survive a simple paper cut or flu infection.

Inflammation isn’t just one thing. You don’t get a diagnosis of “Inflammation” from your doctor, along with a standard treatment regimen. Instead, you get a diagnosis of a medical condition that’s characterized by inflammation, such as arthritis or intestinal disease or asthma or a broken arm. As your immune system deals with the problem, inflammation subsides as healing progresses.

Some health problems happen when your body launches an inappropriate inflammatory response against tissue that’s perfectly fine. These are called autoimmune diseases — body attacking itself. Then there’s the more recent concept of chronic inflammation: the theory that a person’s immune system is always turned on for some reason, flooding the body with mediators, which inflame tissues like blood vessel walls, intestinal lining, brain cells and joints.

Chronic inflammation is poorly understood. Is it a cause of medical problems, or an effect of one or more health conditions? For example, it’s linked to Type 2 diabetes. But does it cause diabetes, or is it a result of the diabetic process?

The popular belief is that if you simply avoid the offending foods, inflammation will go away and you’ll be fine. There’s ZERO evidence for that claim. In fact, there’s zero evidence that any particular foods cause chronic inflammation. And zero evidence that any of the popular anti-inflammatory foods suppress inflammation.

As I discuss in my book, a list of allegedly anti-inflammatory foods includes the usual good guys: various fruits and vegetables, many labeled as super foods (another meaningless term), along with a collection of herbs, spices and teas.

Inflammatory Mediators 101

Inflammatory mediator molecules govern the process of inflammation. The list of molecules includes prostaglandins, thromboxane, leukotrienes, lipoxins, resolvins and others. These can be made from omega-6 or omega-3 fatty acids. Omega-6 fatty acids are found primarily in vegetable oils, margarine, vegetable shortening and foods made with those (salad dressings, sauces, bakery items, fried foods). Omega-3s come from fatty fish; less biologically active forms are found in walnuts, flax and canola oil.

In general, when omega-6 fatty acids are used to make inflammatory mediators, the resulting molecules create a bigger response. They’re more inflammatory, so to speak. Omega-3 versions create a more subdued response. In addition, omega-3 fats are the building blocks for resolvins, which help resolve an inflammatory response to some injury. In other words, turn off the inflammation after healing is complete.

If you eat a lot of omega-6 fats, and few omega-3s, your supply of inflammatory mediators will skew to the heightened response varieties. So one thing you can do to support your immune system is include omega-3 fats in your diet. Will this eliminate chronic inflammation? Who knows, since we do not have any standard definition or tests for chronic inflammation. Nevertheless, why not do what you can to support your immune system.

Take Away Diet Advice

There’s no evidence that any particular foods cause inflammation, or that removing them from your diet prevents chronic inflammation. There’s also no evidence that particular foods are anti-inflammatory.

It’s more reasonable to make the case for an anti-inflammatory diet. Here’s my definition of what that might mean:

  • A plant-based diet, loaded with unprocessed whole foods: vegetables, grain foods, fruit, nuts, legumes, dairy, meats and fish.
  • Attention paid to omega-3 fatty acid sources, whether fish like salmon or a moderate-dose supplement or daily consumption of flax, canola and walnuts.
  • Avoidance of highly processed foods, particularly junk foods: chips, snacks, soft drinks, candy, sweets, breaded/deep fried stuff
  • Minimize added sugars
  • Use olive oil, canola oil or avocado oil for cooking rather than the higher omega-6 vegetable oils.

Will this cure back pain? No. Any medical/health issue like that has an underlying cause that’s unrelated to your diet. You have to address whatever that is. But diet can promote an appropriate inflammatory response and healing process. You can’t turn off the immune system. But you can encourage it to behave better.

UPDATE: This discussion wouldn’t be complete without mention of one of the most significant sources of chronic inflammation: body fat. In particular excess body fat. Medical researchers call it “obesity-induced inflammation”. Fat tissue is full of immune cells, and expansion of fat tissue leads to increased release of inflammatory mediators, which spread throughout the body. The solution: lose fat weight by changing your diet and lifestyle. You can’t suppress this type of inflammation by avoiding some “inflammatory” food, and you can’t fix this by eating so-called anti-inflammatory foods.