Overview
About Pesto
Pesto is a composite sauce, so its triggers stack from several ingredients at once rather than coming from one.
The parmesan makes it high in free glutamate and dairy protein, the garlic makes it high in fructans, and the basil adds a moderate salicylate load. That is why people who eat plain pasta without trouble still react to pesto: a single spoonful hits an MSG-reactive or FODMAP-sensitive person harder than any one of those foods would on its own.
Sensitivities
How Pesto scores
Watch for
What trips people up
- High in free glutamates from the aged parmesan, the same naturally occurring umami compound behind MSG-style reactions such as headache, flushing and sinus congestion
- High in dairy protein from the cheese, so it is off-limits if you react to casein or whey, and it is not vegan
- High in fructans from the garlic, a common FODMAP trigger for bloating and gas even in small amounts
- Moderate salicylates from the basil, worth noting if you are salicylate-sensitive and eating it alongside other salicylate-rich foods
Diet fit
Where it fits
Swap ideas
More alternatives
FAQ
Common questions about Pesto
Why does pesto upset my stomach when plain pasta does not?
The garlic in pesto is high in fructans, a fast-fermenting FODMAP that causes bloating and gas, and it takes very little garlic to do it. Because pesto also concentrates cheese and oil, the fructan load arrives with a rich meal, which is why the same pasta feels fine plain but not with pesto.
Does pesto contain MSG or glutamates?
Classic pesto has no added MSG, but aged parmesan is naturally very high in free glutamate, the same compound that gives MSG its effect. If you get headaches, flushing or congestion from glutamate-rich foods, the cheese in pesto is the likely reason.
Is pesto dairy-free or vegan?
Traditional pesto is neither. It is high in dairy protein from parmesan (and often pecorino), so it is not suitable if you react to casein or whey and it is not vegan. Dairy-free versions exist but the classic recipe is cheese-based.
References
Read the background
Ratings reflect the Triggerbites ingredient database and may vary with portion size and preparation.