Nutrition: We don't know what we're recommending

sapalee

An interesting and broad look at many nutritional studies and beliefs. What I got from it: We just don't know much at all...

The section on caloric restriction is particularly interesting and I think pertinent to many here.

http://www.staffanlindeberg.com/OldAndNew.html

Disclaimer before a war starts out: I'm not endorsing the paper or any of it's findings, just thought it was interesting to learn about the research we base reccomendations on.

Sublog

An interesting and broad look at nutritional studies and beliefs. What I got from it: We just don't know much at all...

The section on caloric restriction is particularly interesting and I think pertinent to many here.

brb.. using imagination since you've provided no relevant info in this topic.

PaleoPath4Lyfe

An interesting and broad look at nutritional studies and beliefs. What I got from it: We just don't know much at all...

The section on caloric restriction is particularly interesting and I think pertinent to many here.

brb.. using imagination since you've provided no relevant info in this topic.

:laugh: :laugh: :laugh:

sapalee

Sorry, I was editing it to include the link, had forgotten to paste it in before posting. It's there now.

Sublog

The bottom line is we are better at nutritional science now, than we were then. Each study we have adds to that base of knowledge.

Which means you should be following current nutritional science, not old.

Of course, it's true that the things we think today will evolve over time as new studies are published, but what we have today is better than what we had 5 years ago.

sapalee

The bottom line is we are better at nutritional science now, than we were then. Each study we have adds to that base of knowledge.

Which means you should be following current nutritional science, not old.

Of course, it's true that the things we think today will evolve over time as new studies are published, but what we have today is better than what we had 5 years ago.

All good points, but it's also important to look at how the study is actually conducted as well. Newer doesn't always mean better.

If you read the paper it's surprising/interesting how much studies contradict each other or exagerate the findings but broad reccomendations are made based on them anyway. Or how beliefs cling on despite being based on old research.

neanderthin

Biased confirmation is a ***** when editorializing about any topic let along nutrition.

pixelish

From your referenced essay, "However, despite widespread consensus among nutrition experts today, there is no solid evidence of fat enrichment or fiber depletion being important causes of Western disease."

A quick search of pubmed popped up this article, among over 1500 others, on just colon cancer and fat:

Cancer Causes Control. 2012 Apr 26. A dietary pattern that is associated with C-peptide and risk of colorectal cancer
in women. Fung TT, Hu FB, Schulze M, Pollak M, Wu T, Fuchs CS, Giovannucci E.

PURPOSE: Higher serum C-peptide concentrations have shown to be associated with an increased risk of colorectal cancer (CRC). Therefore, we used diet information to identify food groups that correlated with fasting serum concentrations of C-peptide and assess the association of this dietary pattern and CRC risk. METHODS: Major food contributors to fasting C-peptide concentrations were identified with stepwise linear regression in a subsample (n = 833) of women from a large cohort. We then summed the consumption frequency of the major food contributors to form a C-peptide dietary pattern for the entire cohort (n = 66,714). Risk for CRC was computed using Cox proportional hazard model with the C-peptide dietary pattern score as the predictor. RESULTS: In up to 20 years of follow-up, we ascertained 985 cases of CRC and 758 colon cancer. After adjusting for confounders, the C-peptide dietary pattern, characterized by higher meat, fish, and sweetened beverage intake, but lower coffee, high fat dairy, and whole grains intake, showed direct association with CRC risk (RR comparing extreme quintiles = 1.29, 95 % CI = 1.05-1.58, p trend = 0.048). The same comparison was slightly stronger for colon cancer RR = 1.35, 95 % CI = 1.07-1.70, p trend = 0.009). In stratified analysis, there was no association between the C-peptide dietary pattern and colon cancer among lean and active women. However, for overweight or sedentary women, RR for the same
comparison was 1.58 (95 % CI = 1.20-2.07, p trend = 0.002) (p for interaction = 0.007). CONCLUSION: We derived a dietary pattern that correlated with C-peptide concentrations. This pattern was associated with an increase in colon cancer, especially among women who were overweight or sedentary.

The essay seems to be an opinion piece that has been rather selective of its reference of nutrition literature.

Gosser

A very interesting article, thanks for posting

wareagle8706

The bottom line is we are better at nutritional science now, than we were then. Each study we have adds to that base of knowledge.

Which means you should be following current nutritional science, not old.

Of course, it's true that the things we think today will evolve over time as new studies are published, but what we have today is better than what we had 5 years ago.

You're not being very friendly...:indifferent:

rml_16

The bottom line is we are better at nutritional science now, than we were then. Each study we have adds to that base of knowledge.

Which means you should be following current nutritional science, not old.

Of course, it's true that the things we think today will evolve over time as new studies are published, but what we have today is better than what we had 5 years ago.

I would agree, except that things like eggs have gone from good to bad to good to bad to good over time. And I've seen two studies published a week apart about the same thing that had opposing findings. Both current. Which do you follow?

I eat as whole as possible, watch my calories and exercise. I'm healthy and that's all I care about.

sapalee

Clearly the paper has faults and I'm happy to see people looking at it with a critical eye, this is what we need more of when new studies pop up avoid the mistakes of the past.

Good catch, the paper he cited with regard to colon cancer is 10 years old.

bcattoes

The bottom line is we are better at nutritional science now, than we were then. Each study we have adds to that base of knowledge.

Which means you should be following current nutritional science, not old.

Of course, it's true that the things we think today will evolve over time as new studies are published, but what we have today is better than what we had 5 years ago.

All good points, but it's also important to look at how the study is actually conducted as well. Newer doesn't always mean better.

If you read the paper it's surprising/interesting how much studies contradict each other or exagerate the findings but broad reccomendations are made based on them anyway. Or how beliefs cling on despite being based on old research.

Some old beliefs hang on because they have been verified by further studies. Some hang on because people think they have the truth and can't or won't consider conflicting evidence. This is why when MFP posters start posting one or even a few studies to support a claim I think it's nonsense. They may have a perfectly valid point, but one or two or even five studies don't prove anything when it comes to nutrition. I prefer to find sources I respect and take advice from there, rather from any one study or the media's portrayal of it.

I choose resources that don't claim to have all the answers, are willing to site references to back up their recommendations as well as present conflicting data. And they must be open-mided enough to change if further research proves them wrong. Anyone that claims to have it all figured out is not a good resource. Becoming so rigid in your recommendations or beliefs that you can't/won't change when new information presents itself is dangerous and stupid.

Nutrition is a fascinating field. Nothing is ever set in stone. Even if something 100% true today, factors beyond food itself can alter that truth in the future.

pixelish

The other thing to remember about nutrition research is that individual studies typically focus on one or a handful of nutrients (some of my own research has focused on protein malnutrition - yes, I'm a phd). For "conflicting" results about something like eggs, what you are really seeing is one group determining the cholesterol amounts could be unhealthy, while another lab demonstrates that the fatty acids are beneficial. Those aren't in conflict - the cholesterol can be too high simultaneously with benefits derived from fatty acids.

Food is exceptionally complicated and that's why it is best to have a variety of lots of different foods in your diet. Not too much "bad" from any single source, and a wide (healthy) diet increases the likelihood of gaining your required nutrients from food.

Another point I will add, many of the studies of "calorie restriction" in laboratory animals used standard ad lib food amounts for the controls. It's been demonstrated in many studies that lab animals are over-fed, relative to their native counter-parts. As one author has stated, our laboratory animal stocks are sedentary and over weight, and not a good representation of the biology of animals in their native environment.

imnotyourpal

Oh pixie, I heart pubmed. Haven't visited it in some time, but I do love me some publications.

130annie

Hi....You can bring out all the studies you like....There has been many food information books brought out.....In fact, I pick up lots of them from the secondhand store....To me, that in itself speaks volumes......Until you change on what goes in between the ears, nothing will change......

1a1a

Michael Pollen describes nutrition science as being like medicine was in the 16th century. Plenty of room for improvement.

ahamm002

From your referenced essay, "However, despite widespread consensus among nutrition experts today, there is no solid evidence of fat enrichment or fiber depletion being important causes of Western disease."

A quick search of pubmed popped up this article, among over 1500 others, on just colon cancer and fat:

Cancer Causes Control. 2012 Apr 26. A dietary pattern that is associated with C-peptide and risk of colorectal cancer
in women. Fung TT, Hu FB, Schulze M, Pollak M, Wu T, Fuchs CS, Giovannucci E.

PURPOSE: Higher serum C-peptide concentrations have shown to be associated with an increased risk of colorectal cancer (CRC). Therefore, we used diet information to identify food groups that correlated with fasting serum concentrations of C-peptide and assess the association of this dietary pattern and CRC risk. METHODS: Major food contributors to fasting C-peptide concentrations were identified with stepwise linear regression in a subsample (n = 833) of women from a large cohort. We then summed the consumption frequency of the major food contributors to form a C-peptide dietary pattern for the entire cohort (n = 66,714). Risk for CRC was computed using Cox proportional hazard model with the C-peptide dietary pattern score as the predictor. RESULTS: In up to 20 years of follow-up, we ascertained 985 cases of CRC and 758 colon cancer. After adjusting for confounders, the C-peptide dietary pattern, characterized by higher meat, fish, and sweetened beverage intake, but lower coffee, high fat dairy, and whole grains intake, showed direct association with CRC risk (RR comparing extreme quintiles = 1.29, 95 % CI = 1.05-1.58, p trend = 0.048). The same comparison was slightly stronger for colon cancer RR = 1.35, 95 % CI = 1.07-1.70, p trend = 0.009). In stratified analysis, there was no association between the C-peptide dietary pattern and colon cancer among lean and active women. However, for overweight or sedentary women, RR for the same
comparison was 1.58 (95 % CI = 1.20-2.07, p trend = 0.002) (p for interaction = 0.007). CONCLUSION: We derived a dietary pattern that correlated with C-peptide concentrations. This pattern was associated with an increase in colon cancer, especially among women who were overweight or sedentary.

The essay seems to be an opinion piece that has been rather selective of its reference of nutrition literature.

While I agree that the essay was biased (like virtually all essays about nutrition), you seem to have missed its point. The point being that while there are EPIDEMIOLOGY studies that show that fat is bad, there are also EPIDEMIOLOGY studies that do not show it's bad. Furthermore, most real studies (i.e., RTC) have failed to demonstrate that fat, even saturated fat, is unhealthy. Meta-analysises of RTC's have supported this.

The study you linked doesn't seem to show anything bad about fat either. Indeeed, according to your linked study, diets high in high-fat diary have a LOWER amount of CRC. But that was just an epidemiology study anyway.