Do you know why potato salad is great for your beneficial gut bacteria? And cold potatoes can be better for your blood sugar than hot ones? It’s all to do with something called resistant starch.
Potato salad in a blue-glazed bowl. New pink potatoes in a box with a handwritten price label.
When cooked potatoes cool, some of the starch contained in them converts to resistant starch. We can’t digest resistant starch, so it passes through our digestive system to our large intestine where most of our microbiome lives. When gut bacteria feast on resistant starches, they produce beneficial compounds — such as butyrate that feeds the cells that line our gut and decreases inflammation in the gut and elsewhere in the body.
When we digest starches in our food, it’s converted into sugars that we absorb into our bloodstream. Because some of the starch content in potatoes is converted to resistant starch through the cooling process, eating cold potatoes is less likely to spike our blood sugar. (Our microbiome actually plays a major role in our blood sugar balance but that’s another blog post!)
My approach as a Microbiome Analyst and food-first practitioner is always to look at foods we can add in to your week to support microbiome health. So I often recommend cold potatoes, cooked and cooled rice, as well as soaked oats or slightly unripe bananas – as these are all great sources of resistant starch.
I made the potato salad pictured above with Jersey Royals together with some new season Rudolphs — for some dietary diversity and their wonderful pink colour. I kept the skins on to benefit from the fibre as well as the pink polyphenols.
For some ‘probiotic’ bacteria, I made an easy but delicious mayo-style dressing from live yoghurt, mixed with olive oil and a large teaspoon of wholegrain mustard. I used soya yoghurt, but any dairy or non-dairy yoghurt would work well.
For more ‘probiotic’ goodness, I also added fermented red onions and gherkins, as well as some chives.
A perfect side for a hot summer's day!
Viola Sampson BSc is a Microbiome Analyst practising in London UK and online. You can book a consultation, or get in touch to find out more.