Glycemic index is not the only determining factor of a food's worth, nor has it been shown to necessarily carry much weight at all.
Glycemic load has been considered by some to be more important.
Chocolate cake has been measured to have a glycemic index of 38, while a baked potato is 85. Heck, fructose, pure sugar, has a glycemic index of 19, while brown rice is at 87.
( Numbers from "International table of glycemic index and glycemic load values: 2002" Am J Clin Nutr. 2002 Jul;76(1):5-56.)
I don't think anyone is going to say chocolate cake or pure fructose is healthier than a baked potato or brown rice.
So there is certainly more to a food's nutritional value than the glycemic index, which has been shown to be on shaky ground.
> Having normal potatoes as a staple will reduce your lifespan.
Reference please? The assertion that potatoes will reduce one's lifespan is utter nonsense. Reduce it compared to what? An Atkins diet? How well did that work out for Dr. Atkins?
Peruvians have traditionally used potatoes as a staple, and even in modern times they have 1/4 the heart disease death rate of the USA. As heart disease is the leading cause of death, this is significant. In fact, this "potato capital of the world" has obesity and diabetes rates which pale in comparison to the USA.
As we have such an abundant variety available to us today, it is possible to pick our own staples, and I personally prefer fruits or sweet potatoes to regular potatoes. However, the fact remains that even regular potatoes are a healthy choice, provided they are consumed unrefined. French fries are a disaster of a food, but nobody is advocating these highly processed potatoes as a staple food.
The below articles clearly demonstrate that potatoes are healthy and will not "reduce your lifespan". Many references are provided within.
Pretty much contradicts everything said by the page on glycemic index on www.drmcdougall.com and also addresses the points you raised above. I guess the question now is: Who do you trust? WikiPedia or a guy peddling DVDs and books?
Dr. McDougall offers for free all the information necessary to follow his program. It is linked from the front page. Direct link: http://drmcdougall.com/free.html
> Pretty much contradicts everything said by the page on glycemic index on www.drmcdougall.com and also addresses the points you raised above.
Care to enumerate any contradictions? You haven't given a single example.
Fine, I'll mark statements by Dr. McDougall with [D], WikiPedia with [W]. A few brief examples:
[D]: Worldwide, populations of hundreds of millions of people who eat high GI potatoes (Peruvians) and rice (Asians) are trim and active for a lifetime.
[W]: The high consumption of legumes in South America and fresh fruit and vegetables in Asia likely lowers the glycemic effect in these individuals. The mixing of high and low GI carbohydrates produces moderate GI values.
[D]: the American Diabetic Association dismisses the value of GI in treating diabetes.
[W]: The glycemic index is supported by leading international health organisations including the American Diabetes Association.
If you read Dr. McDougall's material carefully, you'll see him stringing together sets of unrelated facts and strawmen in such a way that it almost appears that a valid argument is being made. Like this gem:
[D]: "For the most efficient means of replenishing spent glycogen reserves, athletes have learned to choose foods that have a high GI. Selecting foods with a high GI is just as sound advice for anyone yearning to be strong and energetic throughout the day—not just for athletes."
The second statement does not follow from the first. Doing what athletes do to replenish their reserves when you haven't even used yours is incredibly bad advice. I'm speechless.
The potato consumption example is hardly a contradiction. It amounts to at most speculation by a Wikipedia author as to why the "glycemic effect" may be lower in South America, with no substantiation. Potatoes are bad for people, but in South America they are ok because they also eat fruit, beans, and vegetables? Most people don't eat only one food, so what is your point? Also, if I eat a candy bar, and then eat some fruit later, that does not lower the effect of the candy bar.
With regards to the American Diabetes Association reference by Dr. McDougall, one has to take into consideration when his article was written. Secondly, the reference you provided hardly shows much support for the glycemic index by the ADA, other than acknowledgement as a possible useful tool.
> The findings of a meta-analysis indicate that implementing a low-glycemic
> index diet lower A1C values by 0.43% when compared with a high-glycemic index diet.
0.43 PERCENT? Hardly a groundbreaking discovery.
> QUALIFYING STATEMENTS
> At this time, there is insufficient information to determine whether
> there is a relationship between glycemic index or glycemic load of diets
> and the development of diabetes. Prospective randomized trials will be
> necessary to confirm the relationship between the type of carbohydrate
> and the development of diabetes.
Harldy a strong endorsement.
> FINANCIAL DISCLOSURES/CONFLICTS OF INTEREST
> Janette C. Brand-Miller, PHD is on the board of directors of Glycemic Index Limited.
That report is not free of conflicts of interest.
Here is an article about the glycemic index currently at the ADA website.
> The Glycemic Index debate: Does the type of carbohydrate really matter?
> by Janine Freeman, RD, CDE
> As the low-carbohydrate-diet fad slowly loses steam, another may be moving in to take its place: the glycemic index fad.
...
> Some studies show small improvements in A1Cs among people who are attentive
> to the glycemic index. But reducing calories, weight loss, and basic
> carbohydrate counting have been shown to be more effective in improving
> A1Cs among people with type 2 diabetes than basing diet decisions on the GI.
> I don't suggest eliminating "high GI" foods in favor of "low GI" foods to
> gain better blood glucose levels for two reasons. First, there is not
> enough evidence yet to show that such an action actually will improve your
> blood glucose levels; and second, choosing foods based solely on GI will
> compromise healthy eating.
So it is evident that the ADA does not outright support and recommend the glycemic index.
Your final criticism is simply ridiculuous. Dr. McDougall writes of athletes and follows up with a recommendation for "anyone yearing to be strong and energetic". Hardly unrelated. I am speechless at your incredulity here. Secondly, he is not referring to old sports myths, such as carb loading, but replensihing glycogen reserves, which should be done after substantial activity, such as for one who is yearning to be "strong and energetic throughout the day."
Lastly, this has veered off topic - please provide a reference for your claim above that potatoes will "reduce your lifspan." I provided historical evidence of societies that lived on potatoes as a staple, with better health than the USA. You have done nothing other than nitpick and provide a Wikipedia URL that does not back up your claim, pretending that it contradicts an entire article by Dr. McDougall, without showing a single example.
Secondly, he is not referring to old sports myths, such as carb loading, but replensihing glycogen reserves, which should be done after substantial activity, such as for one who is yearning to be "strong and energetic throughout the day."
The feats of logic required to go from after substantial activity to such as for one who is yearning to be "strong and energetic throughout the day." are just too much for me to bear.
To get back on topic, just by citing the original article that this post is about, I can tell you that eating sweet potato instead of normal potatoes will extend your life, unless the change excludes some very important nutrients (unlikely).
Glycemic load has been considered by some to be more important.
Chocolate cake has been measured to have a glycemic index of 38, while a baked potato is 85. Heck, fructose, pure sugar, has a glycemic index of 19, while brown rice is at 87.
( Numbers from "International table of glycemic index and glycemic load values: 2002" Am J Clin Nutr. 2002 Jul;76(1):5-56.)
I don't think anyone is going to say chocolate cake or pure fructose is healthier than a baked potato or brown rice.
So there is certainly more to a food's nutritional value than the glycemic index, which has been shown to be on shaky ground.
http://www.drmcdougall.com/misc/2006nl/july/glycemic.htm ( Glycemic Index - Not Ready for Prime Time )
> Having normal potatoes as a staple will reduce your lifespan.
Reference please? The assertion that potatoes will reduce one's lifespan is utter nonsense. Reduce it compared to what? An Atkins diet? How well did that work out for Dr. Atkins?
Peruvians have traditionally used potatoes as a staple, and even in modern times they have 1/4 the heart disease death rate of the USA. As heart disease is the leading cause of death, this is significant. In fact, this "potato capital of the world" has obesity and diabetes rates which pale in comparison to the USA.
As we have such an abundant variety available to us today, it is possible to pick our own staples, and I personally prefer fruits or sweet potatoes to regular potatoes. However, the fact remains that even regular potatoes are a healthy choice, provided they are consumed unrefined. French fries are a disaster of a food, but nobody is advocating these highly processed potatoes as a staple food.
The below articles clearly demonstrate that potatoes are healthy and will not "reduce your lifespan". Many references are provided within.
http://www.drmcdougall.com/misc/2008nl/may/potato.htm ( International Year of the Potato, 2008 )
http://www.nealhendrickson.com/mcdougall020400pupotatoesarep... ( Potatoes Are Pillars of Worldwide Nutrition )