A Response to the Mayo Clinic's Press Release on Overeating and MCI
UPDATE! Read the response in "comments" from the primary investigator!
UPDATE! Read the response in "comments" from the primary investigator!
 |
| Yes I'm distressed! |
I'm
perplexed. Could I really be the only one who sees the great irony in the
opening statement of this Mayo Clinic press release stating that higher calorie
intake, as self-reported by those with memory loss, ages 70-89, is
associated with greater mild cognitive impairment (MCI)? Under the title
Overeating May Double The Risk Of Memory Loss the authors conclude "Cutting calories…may …prevent memory loss as we
age." The study suggests that eating "too much" (more than 2,143
calories) may double the risk of memory loss.
Yes,
the very people assessed to have the worse cognitive function reported the
highest, sometimes extremely and unbelievably high calorie intakes. And as the
press release video reveals, we're talking significant impairment (as in “Oh
my, I've forgotten I was supposed to fly to New York yesterday" — oops!)
 |
| "Vell, I believe I had a couple of chickens, a pinch of shmaltz, a few spoons of potatoes and a pint of borsht." |
Even
self-reported food intake using a validated assessment tool has its faults. (As
in the Harvard study.) Being validated does not mean that the findings
are real, that they reflect what was truly eaten. It merely addresses
reproducibility. In this Mayo Clinic study, the only thing that was truly
confirmed (as reported in the press release) is the degree of impairment, as
assessed by more than one source. So we know participants are truly cognitively
impaired, but we don't know with certainty how much they really ate calorically
in the preceding year they were reporting on. Quite the population for
accurately reporting, retrospectively, the amount they ate!
Maybe,
given their MCI, they've forgotten how many portions they really consumed? Or
perhaps they forgot that we typically don't report these things honestly.
The
Joke is on Us
So
here's my beef. The Mayo Clinic's press release, and subsequently the media
outlets which picked it up, misled us. Even if my reasoning is off and all of
the potential places where the science seems shabby were fully explained in the
full study (which is yet to be released) there remains this problem—the media's
conclusions suggest causation when at best we have an unexplained association.
The
research summary states that higher calorie intake is associated with more
cognitive loss (but does not necessarily cause it). So to then conclude,
as most every article has, that we should be reducing our food intake, “cut out
the chips” even, limiting our calories to prevent memory loss couldn't be more
absurd! How unreasonable to manipulate us with these faulty one-liners, these
irresponsible conclusions.
The
Real Answer May Lie With BMI
The
study controls for variables that might otherwise have confounded or confused
the results. The researchers appropriately ensured that the finding, the
increase in MCI with higher calorie intake, was not the result of such
variables as diabetes, stroke, and, important to this argument, BMI. In other
words, if I understand the press release and study abstract correctly, the
increase in MCI associated with increased calorie intake at the highest intake
levels, was not due to BMI. So BMI would not have been similarly
increasing along with the cognitive impairment. Or, for that matter, with
caloric intake.
So
here's where I run into some difficulty. The study is stating that some, many
individuals ages 70-89 years, are consuming > 2,000 to 6,000 calories daily,
if we believe what they self-reported. And this is not linked with
increasing BMI? If it isn't, that means people eating a rather extraordinary
amount of food have no higher BMI than those at lower intakes. Soooo, if they
are eating so much, but don't have higher BMIs, than how do we explain this?
There
are several possible explanations. They could be expending more calories from
exercise. Yet from the abstract, there was no mention of activity level—a major
omission if we are assessing intake and making claims regarding the effects of
intake without exploring output. Maybe it's exercise
that's linked with MCI, for goodness sake, as exercisers would need to be
eating at higher calorie levels. “Exercise Causes Cognitive Impairment.” Wouldn't that make for a headline!
Or,
maybe there is some other medical explanation for such high intakes without
resultant higher BMI. Are they malabsorbing—as in such conditions as celiac
disease? This would result in nutrient deficiencies, which certainly may be
responsible for cognitive losses.
Or
maybe they have some thyroid condition, or cancer, not yet diagnosed, which may
account for greater expenditure of calories, and may also impact cognitive
function. I am no expert on memory loss—that I can say with certainty. But it
appears the researchers have not done due diligence regarding their study and
its conclusions.
In
fairness, all the answers may be in the full research paper, yet to be published.
Yes, I requested it, but was only presented with the abstract and the press
release; even my questions regarding exercise were ignored.
Even
referring to the higher calorie intake as “excessive” or "overeating", leaves me scratching my
head—on what grounds? If you are more active than your peers
at 75 years old—still playing tennis, walking regularly, golfing in your
retirement years, even hiking as I've seen many a 70 and 80 year old
do—wouldn't you need to be consuming more calories? Why should they be labeling
this higher intake excessive, unless it is resulting in an undesirable weight
increase outside of their normal range? But I didn't see this addressed in
either the abstract or the press release.
And
why should you care?
You,
my readers, do not match the profile of the study participants in terms of age.
But you are being irresponsibly told that lower calorie intake may prevent
cognitive failure. And when it comes from a reputable establishment such as the
Mayo Clinic, and sealed as a reality in the written word of such media outlets
as the Wall Street Journal, Time Online, and others, you'll believe it.
You'll
believe that higher calorie intake is detrimental—regardless of your caloric
need. And then another study may arise (like the Harvard study) drawing
similarly inappropriate conclusions, and you'll buy into those senseless
conclusions, too. And soon you'll be so inundated with all this
"science" that you'll be overwhelmed about what you can eat and what
you should avoid and how much. See the problem?
What
can you do? Don't be too quick to accept the written word as fact. Await a
follow up study that might confirm findings. And be careful about where you get
your information. Sure, reputable resources are better than sites promoting and
selling something, with a financial interest in convincing you of the value of
their words. But even seemingly solid institutions and individuals can draw the
wrong conclusions. When in doubt, discuss such articles with those capable of
shedding some light on the findings.
The
unfortunate end result of early publication of scientific studies is a loss of
trust. Studies that haven't yet made it for publication in peer-reviewed
journals have no place in the hands of the public. Misinformation runs rampant,
and as consumers of this information, we are left overwhelmed and confused. And
it's a bad state of things when we can't trust science.
I get mad about studies like this too! Basic statistics, correlation does not imply causation. There was a study that found a correlation between ice cream consumption and murder rates... the actual link? Increased temperature... because of higher temps people ate more ice cream and were more agitated. Media outlets, however, usually fail to comment on the distinction between correlation and causation. I have nothing useful to offer, but I'm glad you're here poking holes in the media's portrayal of this study... perhaps the complete study will be more comprehensive.
ReplyDeleteDoesn't Ben & Jerry's lead to murder? At least if some one were to deny me my share of some ; )
DeleteI'm glad you addressed this. I saw reports about that study, and seeing the "high calorie intake" window start at less than 2200 calories was actually really triggering and guilt-inducing for me. I really wish there was a higher barrier to becoming a science/medical journalist.
ReplyDeleteI certainly got triggered, and I don't even have an eating disorder! To your last comment, I'd add research oriented MD, too!
DeleteThanks for pointing out the huge flaws in this supposedly scientific study.
ReplyDeleteIf you want another good laugh, check out this blog post (http://wholehealthsource.blogspot.com/2012/02/by-2606-us-diet-will-be-100-percent.html) where the writer asserts with a straight face that by 2606 the US diet will be 100% sugar.
Oy, hand me the bowl of schmaltz. (Actually, I'd prefer herring...)
Even assuming that the intake reported is accurate (and more than these people need, despite the lack of elevated BMIs), wouldn't a much more likely scenario be that confused older adults lose touch with normal eating habits and eat more as a result? As a pharmacy tech I had older clients who thought we were shorting their medications because they ran out early month after month, when they were forgetting they'd taken them and dosing up again (family figured it out and intervened). Or does that mean taking too much of prescribed medication leads to cognitive impairment...
ReplyDelete-Tempest
Tell me about it! I'm truly floored by the fact that apparently nobody read the study abstract (which reveals the absurdity in this research) before spreading it all over the media!
DeleteThanks for reading!
Dear Mrs. Lieberman: thank you for encouraging me to share my thoughts on your blog. This is my personal opinion and I am not representing my institution.
ReplyDeleteFirst, I would like to thank you and the readers of the blog for showing an intense interest on the topic. Here are a few points that I would like to share.
1- Please note that this is only an abstract. We will present our data at the 64th conference of the American Academy of Neurology. At that meeting, we will get feedbacks and critiques. We will then publish the paper sometimes with in the coming one year. Hopefully some of the good journals may be interested in it. As you know, this is a customary process in science.
2- In our previous publications, we have explicitly admitted and discussed about the problems of recall bias in survey based studies ( Geda et al., Arch Neurol 2010, Geda et al., Neuropsychiatry and Clinical Neurosciences 2011). Ideally, one wants to use an objective measure. But in large scale population-based studies, we may still need to rely on self reported measures. By the way, on the data acquired by using FFQ ( Food Frequency Questionnaire) we have conducted a sensitivity analysis i.e. removing the data acquired from respondents who scored below 5th % ile on memory scales, did not alter the findings. We will also specifically conduct a sensitivity analysis on the Caloric data as well. We human beings are inherently biased therefore, recall bias can never be completely eliminated. Hopefully, someone will come up with a very simple and cheap technology that can be used in such large scale population-based studies in order to have valid and reliable information on caloric intake. Perhaps, on small samples, one can take hours to measure caloric intake using objective measures. It may not be feasible to use that in large scale population-based studies. Finally, bias is one of the key topics in research. The classic reference on this is [Sackett DL. Bias in analytic research. J Chronic Dis. 1979;32:51-63].
3- The bottom line is that we need to be pragmatic. We can never conduct a perfect study free of bias. Even in double blind and randomized studies, by chance alone, one may come across systematic errors. Therefore, the key is to make every effort to minimize bias; and when that is not possible then one should try to estimate the extent of the bias. That is why one conducts sensitivity analysis.
4- Regarding exercise, you are absolutely right. We got this feedback from several groups. Indeed, we will control for Physical exercise when we write the manuscript. By the way, I have already discussed this with our statistics team over the last two weeks.
5- Based on this study, we can not say much about BMI because BMI is 'out of the game' in this analysis. We treated it as a covariate. To use a sport metaphor. This means BMI was sitting at the bench along with age, education, diabetes, stoke etc. But here is what we can do. We can conduct a secondary analysis to examine the correlation between self reported one year prevalence of caloric intake and BMI. We will also bring back BMI from the 'bench back to the game' i.e. we can examine the data by making BMI as a predictor variable.
(Continued-see next comment)
(Continued from above)
ReplyDelete6- Please refer to the title of our abstract. It is carefully and deliberately stated as "Caloric Intake, Aging, and Mild Cognitive Impairment…". There was no phrase about 'over eating'.
7- In all interviews that I gave to the media, I always stated that many studies and guidelines have been released about diet, exercise and healthy life style. Based on those studies, it makes sense to consume in moderation. The quotes you mentioned should always be considered in those contexts. Perhaps, USA today has done a good job of quoting me verbatim and in context: "Bottom line: The odds of having MCI more than doubled in the highest calorie group compared to the lowest calorie group, Geda says. This is one study so "we have to be extremely careful about generalizations," he says. "The first step is that we have to confirm this finding in a bigger study. Certainly, we are not recommending starvation or malnutrition."
8- On the issue of 'excessive caloric intake'. We arbitrarily divided the "n" into three equal groups. This is what statisticians refer to as “analysis in tertiles”. You can also conduct your analysis in quartiles. For example, a New York group conducted analyses in quartiles. ( Luschinger JA et al., Arch Neurol. 2002;59:1258-1263 Caloric Intake and the Risk of Alzheimer Disease). Therefore, these numbers have nothing to do with recommended daily caloric intakes. We labeled the top third tertile as "excessive" or "highest caloric' and the lowest third tertile as the reference. Then we compared the highest with the lowest. The highest tertile group ( 'excessive caloric' intake group) had doubled odds of having MCI than the reference group ( the lowest tertile). The middle group did not have an increased odds of having MCI. In the manuscript, we will remove the word “excessive” in order to avoid misunderstanding.
9-Indeed, in the past when we published a paper on diet, aging and MCI, we have involved a dietician. [Roberts RO et al., Vegetables, unsaturated fats, moderate alcohol intake, and mild cognitive impairment. Here is a quote from one of our papers.] "The Food Processor SQL nutrition analysis software program (version 10.0.0, ESHA Research, Salem, Oreg., USA) was used to calculate the total nutrient, food group, and energy (caloric) intake per day, under the supervision of a registered dietician (H.M.O.)." The initial H.M.O. refers to the name of the dietician. Please refer to the paper for information.
In summary, my colleagues and I have benefitted from your remarks as we will be taking specific steps as discussed above to enrich the manuscript.
Cordially,
Yonas E. Geda, MD, MSc
Scottsdale, Arizona.
This comment has been removed by a blog administrator.
ReplyDeleteDear Mrs. Lieberman: thank you for encouraging me to share my thoughts on your blog. This is my personal opinion and I am not representing my institution.
ReplyDeleteFirst, I would like to thank you and the readers of the blog for showing an intense interest on the topic. Here are a few points that I would like to share.
1- Please note that this is only an abstract. We will present our data at the 64th conference of the American Academy of Neurology. At that meeting, we will get feedbacks and critiques. We will then publish the paper sometimes with in the coming one year. Hopefully some of the good journals may be interested in it. As you know, this is a customary process in science.
2- In our previous publications, we have explicitly admitted and discussed about the problems of recall bias in survey based studies ( Geda et al., Arch Neurol 2010, Geda et al., Neuropsychiatry and Clinical Neurosciences 2011). Ideally, one wants to use an objective measure. But in large scale population-based studies, we may still need to rely on self reported measures. By the way, on the data acquired by using FFQ ( Food Frequency Questionnaire) we have conducted a sensitivity analysis i.e. removing the data acquired from respondents who scored below 5th % ile on memory scales, did not alter the findings. We will also specifically conduct a sensitivity analysis on the Caloric data as well. We human beings are inherently biased therefore, recall bias can never be completely eliminated. Hopefully, someone will come up with a very simple and cheap technology that can be used in such large scale population-based studies in order to have valid and reliable information on caloric intake. Perhaps, on small samples, one can take hours to measure caloric intake using objective measures. It may not be feasible to use that in large scale population-based studies. Finally, bias is one of the key topics in research. The classic reference on this is [Sackett DL. Bias in analytic research. J Chronic Dis. 1979;32:51-63].
3- The bottom line is that we need to be pragmatic. We can never conduct a perfect study free of bias. Even in double blind and randomized studies, by chance alone, one may come across systematic errors. Therefore, the key is to make every effort to minimize bias; and when that is not possible then one should try to estimate the extent of the bias. That is why one conducts sensitivity analysis.
4- Regarding exercise, you are absolutely right. We got this feedback from several groups. Indeed, we will control for Physical exercise when we write the manuscript. By the way, I have already discussed this with our statistics team over the last two weeks.
5- Based on this study, we can not say much about BMI because BMI is 'out of the game' in this analysis. We treated it as a covariate. To use a sport metaphor. This means BMI was sitting at the bench along with age, education, diabetes, stoke etc. But here is what we can do. We can conduct a secondary analysis to examine the correlation between self reported one year prevalence of caloric intake and BMI. We will also bring back BMI from the 'bench back to the game' i.e. we can examine the data by making BMI as a predictor variable.
(Continued as next post)
(Continued from above)
ReplyDelete6- Please refer to the title of our abstract. It is carefully and deliberately stated as "Caloric Intake, Aging, and Mild Cognitive Impairment…". There was no phrase about 'over eating'.
7- In all interviews that I gave to the media, I always stated that many studies and guidelines have been released about diet, exercise and healthy life style. Based on those studies, it makes sense to consume in moderation. The quotes you mentioned should always be considered in those contexts. Perhaps, USA today has done a good job of quoting me verbatim and in context: "Bottom line: The odds of having MCI more than doubled in the highest calorie group compared to the lowest calorie group, Geda says. This is one study so "we have to be extremely careful about generalizations," he says. "The first step is that we have to confirm this finding in a bigger study. Certainly, we are not recommending starvation or malnutrition."
8- On the issue of 'excessive caloric intake'. We arbitrarily divided the "n" into three equal groups. This is what statisticians refer to as “analysis in tertiles”. You can also conduct your analysis in quartiles. For example, a New York group conducted analyses in quartiles. ( Luschinger JA et al., Arch Neurol. 2002;59:1258-1263 Caloric Intake and the Risk of Alzheimer Disease). Therefore, these numbers have nothing to do with recommended daily caloric intakes. We labeled the top third tertile as "excessive" or "highest caloric' and the lowest third tertile as the reference. Then we compared the highest with the lowest. The highest tertile group ( 'excessive caloric' intake group) had doubled odds of having MCI than the reference group ( the lowest tertile). The middle group did not have an increased odds of having MCI. In the manuscript, we will remove the word “excessive” in order to avoid misunderstanding.
9-Indeed, in the past when we published a paper on diet, aging and MCI, we have involved a dietician. [Roberts RO et al., Vegetables, unsaturated fats, moderate alcohol intake, and mild cognitive impairment. Here is a quote from one of our papers.] "The Food Processor SQL nutrition analysis software program (version 10.0.0, ESHA Research, Salem, Oreg., USA) was used to calculate the total nutrient, food group, and energy (caloric) intake per day, under the supervision of a registered dietician (H.M.O.)." The initial H.M.O. refers to the name of the dietician. Please refer to the paper for information.
In summary, my colleagues and I have benefitted from your remarks as we will be taking specific steps as discussed above to enrich the manuscript.
Cordially,
Yonas E. Geda, MD, MSc
Scottsdale, Arizona.
Dear Mrs. Lieberman: thank you for encouraging me to share my thoughts on your blog. This is my personal opinion and I am not representing my institution.
ReplyDeleteFirst, I would like to thank you and the readers of the blog for showing an intense interest on the topic. Here are a few points that I would like to share.
1- Please note that this is only an abstract. We will present our data at the 64th conference of the American Academy of Neurology. At that meeting, we will get feedbacks and critiques. We will then publish the paper sometimes with in the coming one year. Hopefully some of the good journals may be interested in it. As you know, this is a customary process in science.
2- In our previous publications, we have explicitly admitted and discussed about the problems of recall bias in survey based studies ( Geda et al., Arch Neurol 2010, Geda et al., Neuropsychiatry and Clinical Neurosciences 2011). Ideally, one wants to use an objective measure. But in large scale population-based studies, we may still need to rely on self reported measures. By the way, on the data acquired by using FFQ ( Food Frequency Questionnaire) we have conducted a sensitivity analysis i.e. removing the data acquired from respondents who scored below 5th % ile on memory scales, did not alter the findings. We will also specifically conduct a sensitivity analysis on the Caloric data as well. We human beings are inherently biased therefore, recall bias can never be completely eliminated. Hopefully, someone will come up with a very simple and cheap technology that can be used in such large scale population-based studies in order to have valid and reliable information on caloric intake. Perhaps, on small samples, one can take hours to measure caloric intake using objective measures. It may not be feasible to use that in large scale population-based studies. Finally, bias is one of the key topics in research. The classic reference on this is [Sackett DL. Bias in analytic research. J Chronic Dis. 1979;32:51-63].
3- The bottom line is that we need to be pragmatic. We can never conduct a perfect study free of bias. Even in double blind and randomized studies, by chance alone, one may come across systematic errors. Therefore, the key is to make every effort to minimize bias; and when that is not possible then one should try to estimate the extent of the bias. That is why one conducts sensitivity analysis.
4- Regarding exercise, you are absolutely right. We got this feedback from several groups. Indeed, we will control for Physical exercise when we write the manuscript. By the way, I have already discussed this with our statistics team over the last two weeks.
5- Based on this study, we can not say much about BMI because BMI is 'out of the game' in this analysis. We treated it as a covariate. To use a sport metaphor. This means BMI was sitting at the bench along with age, education, diabetes, stoke etc. But here is what we can do. We can conduct a secondary analysis to examine the correlation between self reported one year prevalence of caloric intake and BMI. We will also bring back BMI from the 'bench back to the game' i.e. we can examine the data by making BMI as a predictor variable.
(Cont)
(Continued from above)
ReplyDelete6- Please refer to the title of our abstract. It is carefully and deliberately stated as "Caloric Intake, Aging, and Mild Cognitive Impairment…". There was no phrase about 'over eating'.
7- In all interviews that I gave to the media, I always stated that many studies and guidelines have been released about diet, exercise and healthy life style. Based on those studies, it makes sense to consume in moderation. The quotes you mentioned should always be considered in those contexts. Perhaps, USA today has done a good job of quoting me verbatim and in context: "Bottom line: The odds of having MCI more than doubled in the highest calorie group compared to the lowest calorie group, Geda says. This is one study so "we have to be extremely careful about generalizations," he says. "The first step is that we have to confirm this finding in a bigger study. Certainly, we are not recommending starvation or malnutrition."
8- On the issue of 'excessive caloric intake'. We arbitrarily divided the "n" into three equal groups. This is what statisticians refer to as “analysis in tertiles”. You can also conduct your analysis in quartiles. For example, a New York group conducted analyses in quartiles. ( Luschinger JA et al., Arch Neurol. 2002;59:1258-1263 Caloric Intake and the Risk of Alzheimer Disease). Therefore, these numbers have nothing to do with recommended daily caloric intakes. We labeled the top third tertile as "excessive" or "highest caloric' and the lowest third tertile as the reference. Then we compared the highest with the lowest. The highest tertile group ( 'excessive caloric' intake group) had doubled odds of having MCI than the reference group ( the lowest tertile). The middle group did not have an increased odds of having MCI. In the manuscript, we will remove the word “excessive” in order to avoid misunderstanding.
9-Indeed, in the past when we published a paper on diet, aging and MCI, we have involved a dietician. [Roberts RO et al., Vegetables, unsaturated fats, moderate alcohol intake, and mild cognitive impairment. Here is a quote from one of our papers.] "The Food Processor SQL nutrition analysis software program (version 10.0.0, ESHA Research, Salem, Oreg., USA) was used to calculate the total nutrient, food group, and energy (caloric) intake per day, under the supervision of a registered dietician (H.M.O.)." The initial H.M.O. refers to the name of the dietician. Please refer to the paper for information.
In summary, my colleagues and I have benefitted from your remarks as we will be taking specific steps as discussed above to enrich the manuscript.
Cordially,
Yonas E. Geda, MD, MSc
Scottsdale, Arizona.
Coming soon--the response from Dr Geda!
ReplyDeleteOk, here it is in 2 parts. My short response will follow:
ReplyDeleteDear Mrs. Lieberman:
Thank you for encouraging me to share my thoughts on your blog. This is my personal opinion and I am not representing my institution.
First, I would like to thank you and the readers of the blog for showing an intense interest on the topic. Here are a few points that I would like to share.
1- Please note that this is only an abstract. We will present our data at the 64th conference of the American Academy of Neurology. At that meeting, we will get feedbacks and critiques. We will then publish the paper sometimes with in the coming one year. Hopefully some of the good journals may be interested in it. As you know, this is a customary process in science.
2- In our previous publications, we have explicitly admitted and discussed about the problems of recall bias in survey based studies ( Geda et al., Arch Neurol 2010, Geda et al., Neuropsychiatry and Clinical Neurosciences 2011). Ideally, one wants to use an objective measure. But in large scale population-based studies, we may still need to rely on self reported measures. By the way, on the data acquired by using FFQ ( Food Frequency Questionnaire) we have conducted a sensitivity analysis i.e. removing the data acquired from respondents who scored below 5th % ile on memory scales, did not alter the findings. We will also specifically conduct a sensitivity analysis on the Caloric data as well. We human beings are inherently biased therefore, recall bias can never be completely eliminated. Hopefully, someone will come up with a very simple and cheap technology that can be used in such large scale population-based studies in order to have valid and reliable information on caloric intake. Perhaps, on small samples, one can take hours to measure caloric intake using objective measures. It may not be feasible to use that in large scale population-based studies. Finally, bias is one of the key topics in research. The classic reference on this is [Sackett DL. Bias in analytic research. J Chronic Dis. 1979;32:51-63].
3- The bottom line is that we need to be pragmatic. We can never conduct a perfect study free of bias. Even in double blind and randomized studies, by chance alone, one may come across systematic errors. Therefore, the key is to make every effort to minimize bias; and when that is not possible then one should try to estimate the extent of the bias. That is why one conducts sensitivity analysis.
4- Regarding exercise, you are absolutely right. We got this feedback from several groups. Indeed, we will control for Physical exercise when we write the manuscript. By the way, I have already discussed this with our statistics team over the last two weeks.
5- Based on this study, we can not say much about BMI because BMI is 'out of the game' in this analysis. We treated it as a covariate. To use a sport metaphor. This means BMI was sitting at the bench along with age, education, diabetes, stoke etc. But here is what we can do. We can conduct a secondary analysis to examine the correlation between self reported one year prevalence of caloric intake and BMI. We will also bring back BMI from the 'bench back to the game' i.e. we can examine the data by making BMI as a predictor variable.
(Continued on next post)
(Continued from above)
ReplyDelete6- Please refer to the title of our abstract. It is carefully and deliberately stated as "Caloric Intake, Aging, and Mild Cognitive Impairment…". There was no phrase about 'over eating'.
7- In all interviews that I gave to the media, I always stated that many studies and guidelines have been released about diet, exercise and healthy life style. Based on those studies, it makes sense to consume in moderation. The quotes you mentioned should always be considered in those contexts. Perhaps, USA today has done a good job of quoting me verbatim and in context: "Bottom line: The odds of having MCI more than doubled in the highest calorie group compared to the lowest calorie group, Geda says. This is one study so "we have to be extremely careful about generalizations," he says. "The first step is that we have to confirm this finding in a bigger study. Certainly, we are not recommending starvation or malnutrition."
8- On the issue of 'excessive caloric intake'. We arbitrarily divided the "n" into three equal groups. This is what statisticians refer to as “analysis in tertiles”. You can also conduct your analysis in quartiles. For example, a New York group conducted analyses in quartiles. ( Luschinger JA et al., Arch Neurol. 2002;59:1258-1263 Caloric Intake and the Risk of Alzheimer Disease). Therefore, these numbers have nothing to do with recommended daily caloric intakes. We labeled the top third tertile as "excessive" or "highest caloric' and the lowest third tertile as the reference. Then we compared the highest with the lowest. The highest tertile group ( 'excessive caloric' intake group) had doubled odds of having MCI than the reference group ( the lowest tertile). The middle group did not have an increased odds of having MCI. In the manuscript, we will remove the word “excessive” in order to avoid misunderstanding.
9-Indeed, in the past when we published a paper on diet, aging and MCI, we have involved a dietician. [Roberts RO et al., Vegetables, unsaturated fats, moderate alcohol intake, and mild cognitive impairment. Here is a quote from one of our papers.] "The Food Processor SQL nutrition analysis software program (version 10.0.0, ESHA Research, Salem, Oreg., USA) was used to calculate the total nutrient, food group, and energy (caloric) intake per day, under the supervision of a registered dietician (H.M.O.)." The initial H.M.O. refers to the name of the dietician. Please refer to the paper for information.
In summary, my colleagues and I have benefitted from your remarks as we will be taking specific steps as discussed above to enrich the manuscript.
Cordially,
Yonas E. Geda, MD, MSc
Scottsdale, Arizona.
I can't thank Dr. Geda enough for taking the time to very thoroughly respond to the concerns raised in this post. A few points worth highlighting:
ReplyDelete-the media messes with the message. From my understanding, the abstract as prepared by the researcher, was not infused with judgement about "excess" calories, or any reference to the quality of the reported intake. But if you read most articles on this research they described 2000+ calories as overeating, and made judgements about having too much french fries--not the summary presented by the author.
-that said, the Mayo Clinic should NOT have titled their press release "Overeating May Double Risk of Memory Loss"!
-I urge researchers to be more selective, more conservative in their release of preliminary findings. Clearly there is much to be revisited in Dr. Geda's study--exercise, BMI, issues of bias. I so appreciate his acknowledging this! Promoting such incomplete associations to the public leads to much confusion. Confusion makes people overwhelmed. Being overwhelmed with conflicting information leads to not trusting, not believing in science. And that leaves us providers in the trenches working to regain trust in what's really true, to help support a move toward healthier lifestyles.
Your thoughts?
I happen to think that it’s not the number of calories eaten that may cause problems with memory, but the quality of food people are consuming. Spend your life eating junk and a junked up, garbled brain is the result. Antioxidants from fresh produce, cholesterol, EPA, and DHA are all vitally import to brain function and memory, and the older the brain gets, the more important healthy, nutrient dense food becomes. No study of this nature is valid without a critical examination of diet and food quality. An analysis of the effects of yo-yo dieting on brain function (which wrecks metabolism and hormone function) is also in order. From my own experience with my mother, I have a strong suspicion that yo-yo dieting (which I watched my mother do to EXTREMES while I was growing up) has a strong effect on memory function.
ReplyDeleteYes, further evaluation of dietary quality is worth exploring! There has been much research in support of individual foods and their antioxidant and lycopene content and benefit on cognitive function.
ReplyDeleteAs for yo-yo dieting, the only problem would be who to use for controls!
How about those of us who have never dieted? Have never restricted calories? Yes, we are out there! According to BMI standards, I am overweight, but I’ve been relatively the same weight since I was a teenager, and I’m almost 34 years old. My weight has never fluctuated more than 10 # in either direction, and that’s proven in my medical records. I also do not suffer from metabolic problems, most likely because I don’t diet. A long term study of individuals like me who purposely don’t diet and may or may not be overweight would be extremely beneficial and enlightening to the medical community, I think. The only dietary changes I’ve ever made is to include abundantly more nutrient dense foods and to moderately decrease my sugar intake. I also do not rely on processed foods for the bulk of my diet. I love to cook and eat fresh food, and I think that makes a world of different with health.
ReplyDelete