Compounds in Spinach, Almonds and Sweet Potato May Worsen Gut Inflammation in Crohn's

Naturally occurring compounds found in spinach, almonds and sweet potato may aggravate intestinal inflammation in people with Crohn's disease, according to new laboratory work. The foods involved are ones usually recommended without qualification.

The compounds in question

The foods share a class of naturally occurring plant compounds, present in the raw material rather than added during processing. These are not contaminants and they are harmless to the general population -- the finding is specific to an inflamed and permeable intestinal lining, where substances that would ordinarily pass through without incident can reach tissue they do not normally contact.

What the research showed

In experimental systems modelling Crohn's-affected intestine, exposure to these compounds increased markers of inflammation. The effect was tied to the compromised barrier rather than to the compounds being toxic in themselves, which is why it would not be expected in a healthy gut.

Why this is difficult territory

Diet in inflammatory bowel disease is one of the most frustrating areas in gastroenterology. Patients consistently report that food affects their symptoms; controlled trials have struggled to demonstrate that any particular diet changes the disease course. Part of the difficulty is that IBD is heterogeneous and patients differ in what troubles them, and part is that restricting a diet is easy to start and hard to undo.

The specific risk here is malnutrition. People with Crohn's are already at higher risk of nutritional deficiency through impaired absorption, previous surgery and reduced intake during flares. Spinach, almonds and sweet potato are nutrient-dense foods, and removing them on the strength of a laboratory result would be a poor trade.

What the study does not show

It was not conducted in patients. No one has demonstrated that eating these foods worsens disease activity in a person with Crohn's, or that avoiding them improves it. Cooking, portion size and what else is eaten alongside all affect what actually reaches the intestinal lining, and none of that was tested.

What is reasonable to do

Keep a record if you suspect a food. A symptom diary kept over several weeks is more informative than an elimination started on a single result, and it is the approach a gastroenterology dietitian will use. Any significant dietary restriction in IBD is worth planning with one.

Bottom line

Interesting mechanism, not clinical advice. Do not strip nutrient-dense foods out of a diet that is already difficult to keep adequate.