Comments on: Carbohydrate quality: a new model

By: Bill Shrapnel

Bill Shrapnel — Wed, 12 Sep 2012 03:44:48 +0000

Hello Frank
In March 2012, the British Medical Journal published an analysis of studies that had investigated associations between the consumption of white rice and the risk for type 2 diabetes. Here are the study’s conclusions:
“In summary, this meta-analysis suggests that higher white rice intake is associated with a significantly elevated risk of type 2 diabetes, especially among Asian populations. The recent transition in nutrition characterised by dramatically decreased physical activity levels and much improved security and variety of food has led to increased prevalence of obesity and insulin resistance in Asian countries.39 Although rice has been a staple food in Asian populations for thousands of years, this transition may render Asian populations more susceptible to the adverse effects of high intakes of white rice, as well as other sources of refined carbohydrates such as pastries, white bread, and sugar sweetened beverages. In addition, the dose-response relations indicate that even for Western populations with typically low intake levels, relatively high white rice consumption may still modestly increase risk of diabetes.”
Regards, Bill

By: Frank Birchall

Frank Birchall — Tue, 11 Sep 2012 07:54:50 +0000

I am an elderly layperson, Bill, and I would like to know if there is any evidence that Asian populations (whose rice intake per capita would be vastly higher than non-Asians) have experienced relatively degraded health as a result of eating Quadrant 4 rice.

By: Nazzah

Nazzah — Mon, 03 Sep 2012 18:10:38 +0000

Thanks Bill. In regards to the weighting you used in the model, couldn’t you weight fibre that is beta glucan a bit more so that foods like oats would move higher up where they are more likely to belong (away from the coco pops)? Otherwise, I strongly agree with the gist of promoting quadrant 1 foods and demoting quadrant 4 foods, to cut down unnecessary carb intake. Cheers!

By: Bill Shrapnel

Bill Shrapnel — Thu, 30 Aug 2012 21:24:21 +0000

Reijo, if polyphenols prove to be beneficial maybe the best way of increasing intake is through beverages (tea/coffee) consumed between meals.
Agree there is an issue with phytates in wholegrains (and nuts) in relation to iron absorption. And this is one reason that I am cautious with cereal advice to eat ‘mostly wholegrains’. For some people this may have adverse consequences. Moderation, even of wholegrain intake, is a sound nutrition principle.
Regards, Bill

By: Bill Shrapnel

Bill Shrapnel — Thu, 30 Aug 2012 21:15:16 +0000

Hello Nazzah
When Frank Hu from Harvard was in Sydney earlier in the year he presented some of their work about how it might be possible to encourage Asian populations to eat less white rice. In one study they looked at the acceptability of brown rice and the results were not that good. There were cultural barriers – brown rice was considered to be inferior. Changing rice type, as you mention, could be a way forward.
Also, as Asian populations become wealthier it would be expected that the people will eat more protein and fat, and less white rice. In nutritional terms, this may be beneficial – glycaemic load falling. But it will be accompanied by increased calorie intake so it may be a case of one step forward and one step back.
Regards, Bill
PS. Regarding rice used in the model, I would have to check. One limitation for us was the availability of both good nutritional data and good GI data.

By: Nazzah

Nazzah — Thu, 30 Aug 2012 20:24:24 +0000

Hi Bill,

I am just reblogging your findings to get your word out a bit more! I am looking at your powerpoint presentation from the IG seminar. White rice is right at the bottom with a GI of 80. Just wondering though, how about long grain rice like basmati which are moderate in GI (= 57)? Considering how rice is such a staple food in Asian cultures and people are used to having so much of it on their plate, what are your suggestions for replacing this in a culturally sensitive way. Which varieties of rice, if any, were considered good carbohydrate by the model? Thanks in advance!

By: Reijo Laatikainen

Reijo Laatikainen — Thu, 30 Aug 2012 07:39:54 +0000

“With up to a third of young women in this country with some degree of iron deficiency I’m a bit reticent to recommend lots of polyphenols for all. What are your thoughts on this? Regards, Bill”

I was not aware of the effect of polyphenols on iron absorption. It is a valid point even if I’m not sure of the magntude of the effect. Berries and fruits, major sources of polyphenols, also are high in vitamin C. Vitamin C increases the absorption of iron. Are you aware of clinical trials on blue berries, cranberries, blackcurrants, strawberries, oranges or fruits that had shown clear negative effect on iron absorption? Perhaps avoiding too much green tea and coffee would advisable among younger women, as they are almost devoid of vitamin C? Here in Finland, coffee is the biggest source of polyphenols in diet.

Iron status among Finnish young women is also rather low. So this is a real problem and dietary instructions should be adjusted on individual basis. The situation is different with males.

I think the same problem of decreased iron absorption relates also to dairy products (calcium) and whole grains (phytates). I would not generally advise my patients to use less of them because of their affect negatively iron absorption. In males, decreased iron absorption may even be of benefit, as Harvard and other prospective cohorts have suggested (red & proccessed meat studies). What do you think?

By: Bill Shrapnel

Bill Shrapnel — Wed, 29 Aug 2012 00:38:36 +0000

Hello Reijo. For our model we followed the recommendations of Drewnowski closely and one of these was to only use nutrients with accepted nutritional roles i.e. nutrients that had Nutrient Reference Values. So, fibre was in but polyphenols were out.
I have to admit that I am in two minds about polyphenols. On the one hand there are the beneficial effects that you mention but on the other hand polyphenols are also known to adversely affect mineral absorption, especially iron absorption. With up to a third of young women in this country with some degree of iron deficiency I’m a bit reticent to recommend lots of polyphenols for all. What are your thoughts on this? Regards, Bill

By: Reijo Laatikainen

Reijo Laatikainen — Sun, 26 Aug 2012 13:37:43 +0000

I’m glad you brought up polyphenols. Polyphenols of fruits and berries may be effective in reducing (post-prandial) inflammation, and glycemic & insulinemic responses, see for example Törrönen et al. 2012 (AJCN) or the recent apple vs plum RCT by Chai S et al. 2012 and orange juice plus standard meal studies. Polyphenols also increase NO production to some extent, and thereby augment arteries.

By: Bill Shrapnel

Bill Shrapnel — Thu, 23 Aug 2012 00:09:45 +0000

Hello Jeremy. The idea of this model was to use objective criteria to categorise the nutritional quality of carbohydrate-rich foods. This means one has to park preconceived ideas about what’s healthy and what’s not at the outset.
For me, one of the surprises to come out of this exercise was the poor showing of unfortified cereal foods. Over the last decade or so our message about such foods has been to ‘eat plenty’. I think we really need to re-examine this. In fact, with many unfortified cereal foods we should ask why these foods should not be restricted.
The model puts rolled oats and coco pops in the intermediate quality categories – rolled oats has low nutrient density but low GI as well; coco pops has more nutrients but a higher GI. I would not read this as advice to avoid eating rolled oats.
If I were recommending lower carbohydrate intakes (and I do) I would target those foods in carbohydrate quadrant 4 – the lowest quality quadrant. They really have no redeeming features. LOTS of our dietary carbohydrate comes from foods in this sector.
Regards, Bill