You’ll no doubt have heard the buzz around Resistant Starch (RS) lately, with the likes of Dr Michael Mosley extolling the benefits on our TV screens.
If you’ve only just got your head round the idea of controlling carb intake, this latest health craze may be in danger of exploding your brain! So how can you have all the benefits of a higher fat, higher protein, lower carb diet, and still get enough RS? And do you even need it?
First of all lets have a look at what RS even is. Starch is a name for carbohydrates in a string or a web or just a bunch of glucoses holding hands if you will. So when you see terms like amylum (glucose lined up) and amylopectin (glucose in a web) and glycosidic bonds (holding hands), don’t panic! Starch is how most plants store their sugar.
Glucose in a web (amylopectin) has a larger surface area and can be quickly broken down by the digestive enzyme amylase. This raises your insulin levels and that signals your cell doors to open and the loose glucoses leave your blood and go into the cells for and are stored.
Glucoses in a line can slip through this digestive process still holding hands. When they reach the large intestine (aka bowel), they are fermented by our gut bacteria into Short-Chain Fatty Acids, or SCFAs.
SCFAs then feed the good bacteria, and prevent the build up of bad bacteria. Happy bacteria means a better, more balanced immune system. They increase blood flow in the bowel, which means the cells get plenty of oxygen, which circulates to the liver. SCFAs also bind with minerals crucial to bone health, enabling them to be absorbed in the gut rather than passing all the way through.
And because SCFAs don’t get digested, they don’t make us put on weight. In fact they do the opposite by filling us up and causing the release of our satiety hormones. (Remember, they’re not the only things that can do this!)
What are the types of Resistant Starch?
Resistant starch is the indigestible starch we have been talking about and there are four types of Resistant Starches. Those that are:
1- The physically indigestible coating around legumes and grains
2- Resistant before cooking (found in green bananas, raw spuds)
3- Cooked and cooled starch (cold potatoes, rice)
4- Chemically altered, modified starch, used in processed foods.
Increasing the amount of indigestible starch in the diet won’t be for everyone!
The foods that contain resistant starch are the ones we were all encouraged to eat masses of in the 80s and 90s: whole grains, pulses and root vegetables, such as potato. In fact, all the foods that in more recent years, we’ve been avoiding as they contain gluten and lectins, which can cause inflammation and immune chaos, not to mention weight gain.
Any regular reader of my blog will have an inkling as to what I’m going to say next…it’s all about BALANCE!
Don’t start guzzling RS!
If you’re doing just fine on a paleo type diet, there’s no reason to start guzzling raw potato starch (which by the way isn’t potato flour) or noshing on unripe bananas. There are plenty of foods you’re probably enjoying already that contain RS, such as cashews, seeds, plantains etc, and if you’re feeling well, then we can safely assume your guts are doing just fine.
There are many ways to the top of the mountain, and there are other ways for your guts to get their all important SCFAs.
Fruit pectin is another source (apples, blackberries and most berries, carrots, apricots, cranberries, oranges), as are fructo-oligosaccharides aka FOS and inulins (no not insulins) from foods such as Jerusalem artichokes, onions, leeks, asparagus to name a few. Milk fat is a great source of butyrate, and I count grassfed butter as a health food!
Arabinoxylan is a soluble fibre found in grains, most healthfully in brown rice and oats. It too is broken down in the guts to become gas and SCFAs.
There are legions of studies to suggest a low-carb diet is preferable for the balance and health of the gut flora. Similarly there are studies, which show that feeding RS can inadvertently disrupt the balance of the microbiota, and cause overgrowth of some strains – leading to a large range of unpleasant symptoms. You can have too much of a good thing.
Is your gut a rainforest?
A lean mean gut where the bacteria compete has been likened to a rainforest; whereas a gut where the inhabitants are selectively fed, is compared to the algal bloom from agricultural run-off. If you’re starting from a position of imbalance, there’s a chance it could help. There’s also a chance it could make a bad situation worse! And if you’re ticking along nicely without supplementary starch, you’d have to say if it ain’t broke…
However there is also anecdotal evidence that certain types of RS can dramatically improve symptoms for some people. If you decide to try supplementing resistant unmodified potato starch, the most important thing to remember is to listen to your body. If you find your symptoms are worsening, STOP.
Of course there are occasions where you have to eat ‘directionally’, when there is no other way to address a health concern – and I’d always advise you to seek professional help with this to avoid unintended consequences. For most conditions, eating a varied diet with plenty of veggies, fats and protein, with very little refined carbohydrate, will elicit an improvement in wellbeing, energy and immunity. And at the end of the day, that’s all anyone wants isn’t it?!