Every so often the nutrition blogosphere explodes with interest and much-fevered writing about a topic for debate. Not so long ago, I wrote about one such example which broadly concerned whether ‘low-carb’ or a diet of low ‘food reward’ was more valid for the purposes of weight loss and enhanced health. As with practically everything, both these approaches appear to have merit, I think. However, as I explain in this blog post, the academic debate is not as important as what works (and doesn’t work so well) on the ground with real people living real lives.
The latest explosion of contention seems to be the concept of ‘safe starches’. I believe the idea was coined by Paul and Shou-Ching Jaminet in their book The Perfect Health Diet.
I have not read this book, though reading about it leads me to conclude that (in my opinion) the dietary principles in it are essentially sound. One recommendation that the Jaminets make in their book is that the diet should contain a certain amount of ‘safe starches’ such as potato and white rice. The idea is eating a very low carbohydrate diet can make it difficult for the body to thrive. Even though we can make glucose from protein, we have limited capacity to do this and as a result can end up deficient in glucose which can impair health and wellbeing. For example, according to the Jaminets, a lack of carbohydrate can lead to deficiency in the mucus in the gut, leading to digestive and other problems. A bit of starch (which supplies glucose to the body) can make up any shortfall and optimises health, according to the Jaminets.
The Jaminets rate white rice and potato as safe starches, but do not recommend, say, wheat. This makes sense to me as many grains (especially wheat) are common causes of ‘food sensitivity’ which can manifest in many ways including irritable bowel syndrome symptoms and fatigue. Many grains (especially wholegrains) are also rich in substances that block impair the absorption of nutrients.
Jimmy Moore (a prominent low-carb advocate) recently asked a range of bloggers, authors and researchers to give their take on the ‘safe starches’ concept, and you can read their replies here.
Jimmy kindly asked me to contribute too, but at the time I was short of time as I was in the final phase of finishing of the editing of my forthcoming book Escape the Diet Trap. However, not long ago I had an email from someone asking me about this issue, and with just a little more time on my hands, I decided I’d respond to this email in the form of a blog.
I’d like to say up front that I am a broad advocate of what might be termed ‘low-carb’ eating. I think way too much emphasis has been placed on carbohydrate in the diet by our governments, health agencies and health professionals, and this is particularly the case for starchy carbohydrates such as bread, potatoes, rice, pasta and breakfast cereals. There is little doubt in my mind that the general glut of such foods in the diet contributes significantly to weight and health issues including heart disease and type 2 diabetes.
On the other hand, I have come to recognise that people vary in their ability to tolerate carbohydrate. Some healthy, physically active individuals can, for instance, seem to tolerate quite a lot of starchy carbohydrate without any obvious ill effect in terms of their health or disease markers. Others, on the other hand, seem not to tolerate carbohydrate at all well. This is generally true for those with a weight issue, as well as those who have evidence of diabetes or metabolic syndrome. As a result, the dietary advice I’d give a slim, fit, very active 30-year-old is likely to be different to the advice I’d give a sedentary 55-year-old type 2 diabetic who weighs 240 lbs. In my view, the latter needs to be much more careful with his carbohydrate intake than the former. I’d even go so far as to say the latter should probably limit his starchy carbohydrate intake to as little as possible.
As I’ve alluded to above, I do regard some forms of starch as better than others. So, even when I am recommending a more liberal approach here I favour rice over other grains, as well as potato (white and sweet), generally speaking. For people who can tolerate carbs, a modest portion of potato or rice alongside their meat or fish and veggies seems like a reasonable addition. But I believe it’s still important to ensure that the overall emphasis is on those other, nutrient-dense and blood sugar-stabilising foods.
In short, my answer to the question about the appropriateness of ‘safe starches’ in the diet is “it depends”.
FWIW, I tried adding potatoes back into my diet. Following a suggestion from Dr. Davis, I also tried checking my blood sugar after eating a meal containing potatoes (about 4 oz, so not that much). I discovered that my BG spiked to about 140, from a normal level of about 80.
I decided that was a big jump, so switched to eating dal (essentially peas), which don’t spike my BG at all.
For me, personally, I don’t feel that potatoes are a safe starch. I didn’t try rice because I don’t much like it.
Beth
The method of cooking potatoes effects the BG rise.
Mashed, well boiled, baked all cause considerable rise, as does the amount eaten.
About of 120 grams, 100 calories, of par boiled or raw pan fried in animal fat only takes my BG to about 6 ( 108 us)at breakfast. With baked or boiled my BG would be over 7.5 (135 us). The factor is the speed of absorption of glucose. We humans can absorb 50 calories per minute of glucose, but only about 20 of fat and protein, and they have a delay to start absorbing.
120 gm of glutinous (cooked weight, about 100 calories) rice raises my BG to close to 8 (144 US).
So for me, fried potatoes are safe, boiled etc and rice is not.
Without a bit of starch, I cannot stay on a LCHF diet due to hunger and cravings.
my understanding is that some starches are considered “safe” because they are less toxic than others, not that they’re safe for people to eat, who have blood-sugar issues. white rice, for example, doesn’t contain the anti-nutrients which brown rice does, and converts to glucose (having no fructose load for the liver to deal with)….
re: BG spiked to about 140
How long did you eat the potatoes (how many days)
Will our blood sugar creep up over time?:
http://www.lowcarbconversations.com/344/22-barbara-rose-dean-dwyer-paleo-guy-weston-price-gal-discuss-body-image-more/#comment-306963040
I wonder whether roasted chestnuts might also be considered a safe starch? They contain complete protein and some fat, and fibre, which might be qualities that keep one’s BG from spiking. Does anyone have any information on this?
The problem with chestnuts is that they have a very high carbohydrate content compared to other nuts.
Chestnuts 36% ,
Cashews 18% ,
Almonds, Peanuts 10 – 11% ,
Pistachios 8% ,
Pecans, Hazelnuts 6% ,
Brazils, Walnuts 3% .
As a type 2 diabetic, I avoid chestnuts and cashews.
to TerryJ: thanks, it appears chestnuts are chock full of starch, compared to other nuts. I’m going out and buying hazelnuts today, now that I know.
I suppose another question could be, then, how do chestnuts compare to either rice or potatoes, for if some people are ok eating either of those, might they be ok eating chestnuts? You have pointed out that chestnuts aren’t equivalent to other nuts in starch content, but maybe they’re better (?) than potatoes or rice, vis-a-vis BG?
The question of “how does food X affect my BG” is easy to answer, though expensive, time consuming and painful. Measure your BG, then eat the food, then measure BG periodically over some period of time.
That is how I determined the diff between legumes and potatoes for myself.
Beth
>re: BG spiked to about 140
>How long did you eat the potatoes (how many days)
What I meant was that my BG was about 80 before eating. About 90 minutes afterwards, it was up to 140. About 3 hours after eating, it was back down to about 80.
I realize that an excursion of 60 over about 2 hours isn’t necessarily more than others handle often, and that the normal level is reasonable, but I still would rather avoid doing this to my body.
Beth
Did you mix the potatoes with anything to lower glycemic load?
In the 2nd link I posted it says it takes 3 days to get used to pure glucose (some say you have to eat the potato for a week or two to get used to them). I like to eat them with protein, otherwise after weightlifting
“but I still would rather avoid doing this to my body.”
And do you find it ever hard to sleep through the night, or test saliva for cortisol in mornings and evenings?:
”
I’ve now started testing cortisol rhythms in patients with blood sugar irregularities that don’t make sense. Almost without exception, they have some kind of cortisol dysregulation. Sometimes high, sometimes low, but most commonly the rhythm is off: it’s low in the morning when it should be high, or high in the evening when it should be low.
Along those lines, I believe another potential cause of high fasting blood sugar is, somewhat paradoxically, low cortisol levels in the early morning hours. If blood sugar drops through the night, cortisol is supposed to kick in and raise it back up. But if there’s not enough cortisol to do that job, epinephrine will take over. And epinephrine has a much more potent effect on raising blood sugar, which would explain the high morning readings. (It also explains why these folks can’t sleep).
” Chris Kresser http://wholehealthsource.blogspot.com/2010/11/glucose-tolerance-in-non-industrial.html?showComment=1290316937587#c2661901957076291994
Dr Briffa,
You failed to note that the anti-nutrients in grains are deactivated via cooking.
Oats and brown Rice are the most acidic of the grains, while Wheat is one of the least acidic. There is no reason to avoid wheat unless you are celiac or have sensitivity.
Have you actually look at Dr Davis and Loren Cordain… they are not exactly pictures of health, they look sick and bloated.
>And do you find it ever hard to sleep through the night, or test >saliva for cortisol in mornings and evenings?
I have had trouble sleeping though the night sometimes, yes (though it has been good lately). I have not tested cortisol, I might try that.
> I believe another potential cause of high fasting blood sugar
I don’t have any reason to think I have high fasting BG. OTOH, I have only tested it before eating (when it is low), not when I get up. I can try that too, since I have some test strips left.
Beth
>Did you mix the potatoes with anything to lower glycemic load?
Meat (including the fat at the edges) and vegies. The veggies would add lots of fiber, the meat adds protein and fat.
I had been eating the potatoes about a month or maybe 3 months when I did the testing.
Beth
sam said:
>>Have you actually look at Dr Davis and Loren Cordain… they are not exactly pictures of health, they look sick and bloated.<<
They look like perfectly normal older people to me not sick and bloated at all. What makes you say they don't?
” Even though we can make glucose from protein, we have limited capacity to do this and as a result can end up deficient in glucose … according to the Jaminets, a lack of carbohydrate can lead to deficiency in the mucus in the gut, leading to digestive and other problems. A bit of starch (which supplies glucose to the body) can make up any shortfall and optimises health, according to the Jaminets.”
What is the evidence for such an idea. Where is the limitation on gluconeogenesis? What is deficiency in glucose? In any case, nobody eats zero carb. Even meat has some carbohydrate. The ‘safe starch’ idea is supposed to supplant the numerous studies that show total dietary carbohydrate is the key variable if you are overweight, insulin resistance or diabetes.
Looking back at the long run of evolution I should think we have a long backward legacy of affiliation (almost certainly, I’d guess, to a point of dependency by degree) with carbohydrate in the diet, but only a short and very recent reliance upon certain classes and/or groups of carbohydrate rich food sources. I tend to a view that carbohydrate is essential to the human diet while acknowledging we’re not especially well suited to the high GL food types that have become modern staples.
Eating food of low energy density once determined our time was spent gathering, masticating and digesting a diet that left little free time for much else. In contrast we are now so involved in so many other activities we have little time left for eating, which means we are reliant upon a diet of high energy density. We’re fortunate that our physiology gives us some versatility and that our bodies cope well with variations in macro-nutrient composition. And we’re fortunate our physiology can ‘buffer’ postprandial surpluses of energy (roughly, what? 2000 cals as glycogen) to carry us several hours to the next meal, but the indications are that lifestyles are asking more versatility and flexibility of our physiology than evolution and adaptation has determined it can (consistently and chronically) offer.
A plot of physiological demand for macro-nutrients against the passing of hours in the day would be fairly flat. Eating patterns that most closely match exogenous supply with physiological demand would seem to place less load upon supportive systems. If people are driven to provide a ‘peaky’ supply of macro-nutrients via a couple of rushed energy dense meals each day the habit seems to overload the bodies ability to ‘buffer’ the surplus. The potential for ‘overload’ seems the greater if more carb is included (while highly suitable fats may be excluded upon ubiquitous but erroneous advice) and if much of that carb is ‘fast’ carb.
Safer carbs are supplied by patterns of eating that more closely match exogenous supply with physiological demand, and the nature of these carbs, being slower carbs that are not digested so quickly, helps match supply with demand. The reasons people find it difficult to have habits in keeping with this are not without cause(s). In my book peonage has a big part in causality.
“They look like perfectly normal older people to me not sick and bloated at all. What makes you say they don’t?”
Click video play button below for Cordain:
http://www.amazon.com/Paleo-Diet-Cookbook-Breakfasts-Beverages/dp/0470913045
Does he look out of shape: yes or no?
Lance,
I don’t know how you can tell what shape Cordain is in by that video.