8 ms·

Fruit and vegetable intake and the risk of overall cancer in Japanese

82 points by discombobulate 10y ago

deleted 10y ago
[deleted]
freefal67 10y ago
I really liked this. I wish more negative results such as this were published and discussed, especially when they go against general intuition and feel-good narratives.
manmal 10y ago
This is strange. Even if vegetable intake is not beneficial against cancer - should higher veg consumption not crowd out red meat (I think you eat less meat when eating more vegetables), leading to less cases of colon cancer? Also, what about vegetables with high fiber that gets converted to butyrates, and is thus anti-cancer? Is it all BS? Or is "overall cancer" a metric where high fiber might decrease colon cancer but leads to more cancers in other areas?
- dualogy 10y ago
  Have always been wondering about the supposed actual mechanism of how any meat would lead to colon cancer more/easier/likelier than fibrous foodstuffs, given that it is fibers that tend to end up in the colon whereas meat tends to be entirely liquefied in the stomach (not just softened and mashed as most plant foods are) and the resulting liquid near-on fully absorbed in the small intestines. Especially as the colon's entire purpose is to hold refuse and foreign substances. So somehow a few drops of leftover meat-liquid micro/macronutrients create more damage than roughage and seeds and such? Curious to hear from the better-informed non-epidemiologists out there ;)
  - autokad 10y ago
    possibly acids making it from the stomach to the colon?
  - desdiv 10y ago
    >There are several potential reasons to explain how red and processed meat may cause bowel cancer. Red meat contains a compound which gives it’s red colour, haem, which promotes the formation of potentially carcinogenic N-nitroso compounds. In addition when red meat is cooked at high temperatures, this results in the production of compounds (heterocyclic amines and polycyclic aromatic hydrocarbons) that can cause bowel cancer in people with a genetic predisposition. In addition processed red meat has nitrites, as well as nitrates added to it as preservatives and these are thought to cause cancer. Processing also changes the nature of the meat, which may play a role in its link to cancer. http://www.wcrf.org/int/blog/articles/2015/10/red-meat-and-bowel-cancer-risk-how-strong-evidence http://www.wcrf.org/int/blog/articles/2015/10/red-meat-and-b...
    - dualogy 10y ago
      Interesting theories! And appropriately cautiously formulated, too.. a lot more to actually investigate then: > how red and processed meat may cause bowel cancer > compounds that can cause bowel cancer in people with a genetic predisposition > nitrites, as well as nitrates and these are thought to cause cancer > which may play a role in its link to cancer.
    - TheSpiceIsLife 10y ago
      Do you know if steamed or boiled meats generate HAs and PAH? I've know about both for a while and switched to only eating meat I've steamed or boiled.
  - scythe 10y ago
    http://cancerpreventionresearch.aacrjournals.org/content/4/2/177.short http://cancerpreventionresearch.aacrjournals.org/content/4/2... >The mechanism is not known, but heme iron has a catalytic effect on (i) the endogenous formation of carcinogenic N-nitroso compounds and (ii) the formation of cytotoxic and genotoxic aldehydes by lipoperoxidation. A review of evidence supporting these hypotheses suggests that both pathways are involved in heme iron toxicity The irony is, of course, heme iron is the highest bioavailability form of iron, and is one of the main reasons to consume meat in the first place: http://europepmc.org/abstract/med/3290310 http://europepmc.org/abstract/med/3290310 > Food iron is classified as heme or nonheme. Approximately half of the iron in meat, fish, and poultry is heme iron. Depending on an individual's iron stores, 15% to 35% of heme iron is absorbed. Food contains more nonheme iron and, thus, it makes the larger contribution to the body's iron pool despite its lower absorption rate of 2% to 20%.
- autokad 10y ago
  i think the most important take away with nutrition is eat what your ancestors ate. you're probably not japanese so its less likely that the results apply to you. I myself switched from drinking soda to OJ. my health declined slowly for a long time until I found out my body doesnt like oranges. fruit can be healthy but i doubt we are supposed to eat all fruit diets. Astin Kutcher took on Steve Job's all fruit diet and ended up in the hospital with pancreatitis. And we all know what happened to Steve Jobs.
  - griffinmmahon 10y ago
    OJ is just sugar water though, the value of fruit is (I think) the whole fruit.
    - autokad 10y ago
      true, but i have an even stronger alergic reaction to the fruit :) its also worth noting that fruit is sugar water. its 98-99% water + 2% sugar and fiber
      - griffinmmahon 10y ago
        Hm. I've heard lots of different angles on not eating fruit but never got these numbers. Thanks!
        deleted 10y ago
        [deleted]
      - dxhdr 10y ago
        > its also worth noting that fruit is sugar water. its 98-99% water + 2% sugar and fiber Oranges, apples, etc are only 85% water. Grapes 80%. The rest is fiber and is likely why your body tells you to stop eating them. Two and a half apples is a lot less appealing than a can of soda (actual sugar water). The whole percent water thing is completely meaningless though, human brains are 85% water and babies are 80%.
- tnmrnis 10y ago
  AFAIK is red meat not causing cancer per se. While there has been a correlation between red meat intake and colon cancer shown, the studies that have shown this didn't differentiate between highly processed products made out of red meat (think of sausage) and rather natural meat (think of steak) itself. The processed stuff is packed with all kinds of sugar, preservatives, flavor enhancer and colouration which might be the cause for the higher rates of colon cancer. To my knowledge these highly processed meat products are not common in Japan.
yesbut 10y ago
This study doesn't account for strict plant-based diets. There isn't a single reference to animal product portion size. It just lumps everyone together. Some groups had larger fruit and vegetable portions. But all had animals.
- aminok 10y ago
  The study wasn't trying to account for strict plant-based diets. It was attempting to find a correlation between fruit/plant intake and cancer rates.
  - yesbut 10y ago
    It would be unfortunate if someone reads the headline and thinks this means that this study negates the meat consumption-cancer risk correlation studies. Though, when considered in regards to the large body of plant based diet studies, this study does add more evidence to the notion that to benifit from plants we probably need to omit the animal products altogether.
  - spraak 10y ago
    But imagine if you did a study about lungs of runners, but did not account for who smoked.
reefwalkcuts 10y ago
Anyone, is there also a study like this where the consumption of red meat (or meat in general) affects the risk of overall cancer?
- DanBC 10y ago
  We know that processed red meat causes cancer. The quality of the evidence is very very good. The strength of the effect is weak. Because the quality of the evidence is now very good (as good as for smoking) the WHO information was widely misreported as "red meat as bad as smoking". This is likely to make web searches less useful. Here's something from the English NHS about it: http://www.nhs.uk/news/2015/10October/Pages/Processed-meat-causes-cancer-warns-official-report.aspx http://www.nhs.uk/news/2015/10October/Pages/Processed-meat-c... > A key statistic provided by the infographic is that if everyone stopped smoking, there would be 64,500 fewer cases of cancer a year in the UK, compared with 8,800 fewer cases if everyone stopped eating processed or red meat.
  - alister 10y ago
    > If everyone stopped smoking, there would be 64,500 fewer cases of cancer a year in the UK, compared with 8,800 fewer cases if everyone stopped eating processed or red meat. Even that statistic greatly overstates the risk of red meat as compared to smoking. Because it's not adjusted for the percentage of the population that smoke vs the percentage that eat processed or red meat. In the UK, only 16.9% currently smoke[1] but I believe that the great majority eat meat[2]. (I'm surprised how few people smoke now -- I remember a time when most people smoked.) The statistic makes it sound like you're 7 times more likely to die from smoking than from processed or red meat (64500/8800 = 7). But if my math is correct, the death ratio should be more like smoking being 39 times worse (64500/16.9%) / (8800/90%) = 39). [1] https://en.wikipedia.org/wiki/Prevalence_of_tobacco_consumption#United_Kingdom https://en.wikipedia.org/wiki/Prevalence_of_tobacco_consumpt... [2] I didn't find a statistic specifically about red meat or processed meat, but only 10% of the population are "meat-avoiders" according to this: https://en.wikipedia.org/wiki/Vegetarianism_by_country#United_Kingdom https://en.wikipedia.org/wiki/Vegetarianism_by_country#Unite...
  - 10y ago
Alex3917 10y ago
How are they controlling for deaths from other causes, e.g. cardiovascular disease? If you're not dead from some other cause then you're going to be more likely to die from cancer, even if vegetables are actually conferring a significant anti-cancer benefit. I see that they are using people years to track followup, but I'm not clear from the methodology whether this is enough to fully control for this issue.
- wapz 10y ago
  Are you stating that death from cardiovascular disease would be higher (or lower) from people who don't eat fruits/vegetables which means they have a "lower" chance of getting cancer? My guess would be that they didn't take that into account and that the deaths from cardiovascular (or other diseases) would be ignored in the assumption they are "similar" between the two sides.
  - Alex3917 10y ago
    To rephrase, I'm suggesting that eating vegetables may lower the risk of cardiovascular disease. If you don't die from cardiovascular disease, then it's more likely that cancer is the thing you do die from. So even if eating vegetables reduces your risk of cancer, you could actually be more likely to die from cancer if you eat vegetables.
    - wapz 10y ago
      Ahh thanks for the clarification. Your logic makes a lot of sense. I believe there was a study that showed pesticides may cause cancer (it was probably done in mice or something) from a long time ago but this is just the top of my head so I don't know if there's any relation to fruit/veggie consumption.
hartator 10y ago
Studies that invalidate common beliefs are really interesting.
- aminok 10y ago
  It shows how unreliable scientific consensus about a theory that cannot be subject to controlled experimentation, like any medical theory, is.
- mrfusion 10y ago
  Keep in mind that's the only reason we're hearing about this study. If they found what would be expected it wouldn't be as interning. Man bites dog and all that. There are probably lots of studies that say the opposite if you look for them.
- erikpukinskis 10y ago
  The study didn't invalidate anything.
miguelrochefort 10y ago
Every day, the case for eating plants gets weaker. I'm starting to believe that plants aren't necessary for human health, and are possibly harmful. This website has been eye-opening: https://zerocarbzen.com https://zerocarbzen.com
- PerfectElement 10y ago
  I think you are suffering from confirmation bias.
  - miguelrochefort 10y ago
    Doesn't change the facts. Why should I believe that plants are necessary for health?
    - spraak 10y ago
      Confirmation bias means they aren't strictly facts you're believing
- cgh 10y ago
  Thank you for posting this link. Interesting stuff that parallels my own experiences with vegetarianism and veganism, the adoption of which I consider one of the great mistakes of my life. I've never gone 100% meat and water though I do eat red meat 4+ times a week.
- cgh 10y ago
  Thank you for posting this link. Interesting stuff that parallels my own experiences with vegetarianism and veganism, the adoption of which I consider one of the great mistakes of my life. I've never gone 100% meat and water though I do eat red meat 4+ times a week.
neves 10y ago
This is for Japan, doesn't they already eat a lot better than the Western world, that is, less red meat, less processed foods, more high oily fish etc.?
- mikekchar 10y ago
  In my experience, this is generally true, but the Japanese diet is changing rapidly. I came to Japan almost 10 years ago and I remember seeing quite traditional lunch boxes (called bento) in the convenience stores. Now everything is deep fried, or comes with fairly large portions of meat. Unless you go to a specialised bento store, it's pretty difficult to get a bento with a piece of fish, vegetables and rice. Also, with the reduced restrictions on imports, I've seen a veritable explosion of steak restaurants and yaki niku places (Korean barbeque). Now that they can get cheap pork from Canada and cheap beef from Australia, meat has gotten very popular. The meat sections of the grocery stores in my area are about the same size as the fish section. And even the small town I live in has the same number of butchers as they do specialty fish stores. Having said that, it's still not difficult to eat a traditional Japanese diet and certainly older people tend to eat that way. Not sure what will happen in the next generation or two, as the culture is shifting (to my eyes, anyway). It may be for the best, though, as global fish stocks are shrinking in an alarming way.
- saryant 10y ago
  Having seen the giant ice cream-stuffed crepes they sell in Harajuku, I'm not sure how true that is anymore...
thomyorkie 10y ago
Perhaps pesticide consumption offsets fruit and vegetable benefits.
SwetDrems 10y ago
I thought we were under the consensus that these large scale associative studies were not accurate/effective in predicting causal effects, especially in nutrition. I can't find any studies right now, but I remember reading about mechanistic explanations for plant compounds such as isothiocyanate and resveratrol in reducing and even completely suppressing tumour growth.
ramblenode 10y ago
Did anyone else read the statistical analysis section? There were some "interesting"/unclear choices made, but I'm going to pick on one in particular that could affect the outcome: the decision on how to weight the individual cohort studies on which this study is based (pg 6). > A random-effects model was used to obtain a single pooled estimate of the HRs from the individual studies for each category. The study-specific HRs were weighted by the inverse of the sum of their variance and the estimated between-studies variance component. First note that there is no citation which motivates this weighting scheme. There may be a valid reason for doing it this way, but that's not clear from the paper. Second, "the sum of their variance" I take to mean the sum of the variance components of the regression model. That's interesting because the components mean very different things. In the simple case of least squares, there's the "explained variance": the "strength" of the relationship between Y and X, and there's also the residual variance: the variance in X that isn't explained by Y. Aside from the fact that they mean different things, their sum is not a constant and so are not directly comparable across models/studies. Third, weighted by the "between-studies variance component" has the effect of down-weighting studies that show a large difference from the mean study result and up-weighting studies which are similar. Now, what would you say if I conducted an experiment and transformed the raw data points according to this same procedure? "That's not fair because that's not the data we collected!"[0] And herein lies the problem: the purpose of this meta-analysis is to assess whether we can draw any consistent conclusions from the results of the individual cohort studies, but by weighting studies toward the mean the authors are taking it as a forgone conclusion that the mean study is ground truth. I'm by no means an expert on meta-analysis so someone please chime in if you think I'm off base, but this all strikes me as a very peculiar and unjustified set of steps being taken before the model is even fit. [0] Yes, there are cases for data transformation, motivated either by theory or meeting regression assumptions, but this is neither.
minusf 10y ago
Forks over knives (https://en.wikipedia.org/wiki/Forks_Over_Knives https://en.wikipedia.org/wiki/Forks_Over_Knives) quite clearly argues that meat increases cancer risks manyfold. T. Colin Campbell and Caldwell Esselstyn are no quacks either and the document makes a solid argument for minimizing meat intake, at least for adults.

deleted 10y ago

[deleted]

I really liked this. I wish more negative results such as this were published and discussed, especially when they go against general intuition and feel-good narratives.

manmal 10y ago

This is strange. Even if vegetable intake is not beneficial against cancer - should higher veg consumption not crowd out red meat (I think you eat less meat when eating more vegetables), leading to less cases of colon cancer? Also, what about vegetables with high fiber that gets converted to butyrates, and is thus anti-cancer? Is it all BS? Or is "overall cancer" a metric where high fiber might decrease colon cancer but leads to more cancers in other areas?

dualogy 10y ago
Have always been wondering about the supposed actual mechanism of how any meat would lead to colon cancer more/easier/likelier than fibrous foodstuffs, given that it is fibers that tend to end up in the colon whereas meat tends to be entirely liquefied in the stomach (not just softened and mashed as most plant foods are) and the resulting liquid near-on fully absorbed in the small intestines. Especially as the colon's entire purpose is to hold refuse and foreign substances. So somehow a few drops of leftover meat-liquid micro/macronutrients create more damage than roughage and seeds and such? Curious to hear from the better-informed non-epidemiologists out there ;)
- autokad 10y ago
  possibly acids making it from the stomach to the colon?
- desdiv 10y ago
  >There are several potential reasons to explain how red and processed meat may cause bowel cancer. Red meat contains a compound which gives it’s red colour, haem, which promotes the formation of potentially carcinogenic N-nitroso compounds. In addition when red meat is cooked at high temperatures, this results in the production of compounds (heterocyclic amines and polycyclic aromatic hydrocarbons) that can cause bowel cancer in people with a genetic predisposition. In addition processed red meat has nitrites, as well as nitrates added to it as preservatives and these are thought to cause cancer. Processing also changes the nature of the meat, which may play a role in its link to cancer. http://www.wcrf.org/int/blog/articles/2015/10/red-meat-and-bowel-cancer-risk-how-strong-evidence http://www.wcrf.org/int/blog/articles/2015/10/red-meat-and-b...
  - dualogy 10y ago
    Interesting theories! And appropriately cautiously formulated, too.. a lot more to actually investigate then: > how red and processed meat may cause bowel cancer > compounds that can cause bowel cancer in people with a genetic predisposition > nitrites, as well as nitrates and these are thought to cause cancer > which may play a role in its link to cancer.
  - TheSpiceIsLife 10y ago
    Do you know if steamed or boiled meats generate HAs and PAH? I've know about both for a while and switched to only eating meat I've steamed or boiled.
- scythe 10y ago
  http://cancerpreventionresearch.aacrjournals.org/content/4/2/177.short http://cancerpreventionresearch.aacrjournals.org/content/4/2... >The mechanism is not known, but heme iron has a catalytic effect on (i) the endogenous formation of carcinogenic N-nitroso compounds and (ii) the formation of cytotoxic and genotoxic aldehydes by lipoperoxidation. A review of evidence supporting these hypotheses suggests that both pathways are involved in heme iron toxicity The irony is, of course, heme iron is the highest bioavailability form of iron, and is one of the main reasons to consume meat in the first place: http://europepmc.org/abstract/med/3290310 http://europepmc.org/abstract/med/3290310 > Food iron is classified as heme or nonheme. Approximately half of the iron in meat, fish, and poultry is heme iron. Depending on an individual's iron stores, 15% to 35% of heme iron is absorbed. Food contains more nonheme iron and, thus, it makes the larger contribution to the body's iron pool despite its lower absorption rate of 2% to 20%.
autokad 10y ago
i think the most important take away with nutrition is eat what your ancestors ate. you're probably not japanese so its less likely that the results apply to you. I myself switched from drinking soda to OJ. my health declined slowly for a long time until I found out my body doesnt like oranges. fruit can be healthy but i doubt we are supposed to eat all fruit diets. Astin Kutcher took on Steve Job's all fruit diet and ended up in the hospital with pancreatitis. And we all know what happened to Steve Jobs.
- griffinmmahon 10y ago
  OJ is just sugar water though, the value of fruit is (I think) the whole fruit.
  - autokad 10y ago
    true, but i have an even stronger alergic reaction to the fruit :) its also worth noting that fruit is sugar water. its 98-99% water + 2% sugar and fiber
    - griffinmmahon 10y ago
      Hm. I've heard lots of different angles on not eating fruit but never got these numbers. Thanks!
      - deleted 10y ago
        [deleted]
    - dxhdr 10y ago
      > its also worth noting that fruit is sugar water. its 98-99% water + 2% sugar and fiber Oranges, apples, etc are only 85% water. Grapes 80%. The rest is fiber and is likely why your body tells you to stop eating them. Two and a half apples is a lot less appealing than a can of soda (actual sugar water). The whole percent water thing is completely meaningless though, human brains are 85% water and babies are 80%.
tnmrnis 10y ago
AFAIK is red meat not causing cancer per se. While there has been a correlation between red meat intake and colon cancer shown, the studies that have shown this didn't differentiate between highly processed products made out of red meat (think of sausage) and rather natural meat (think of steak) itself. The processed stuff is packed with all kinds of sugar, preservatives, flavor enhancer and colouration which might be the cause for the higher rates of colon cancer. To my knowledge these highly processed meat products are not common in Japan.

yesbut 10y ago

This study doesn't account for strict plant-based diets. There isn't a single reference to animal product portion size. It just lumps everyone together. Some groups had larger fruit and vegetable portions. But all had animals.

aminok 10y ago
The study wasn't trying to account for strict plant-based diets. It was attempting to find a correlation between fruit/plant intake and cancer rates.
- yesbut 10y ago
  It would be unfortunate if someone reads the headline and thinks this means that this study negates the meat consumption-cancer risk correlation studies. Though, when considered in regards to the large body of plant based diet studies, this study does add more evidence to the notion that to benifit from plants we probably need to omit the animal products altogether.
- spraak 10y ago
  But imagine if you did a study about lungs of runners, but did not account for who smoked.

reefwalkcuts 10y ago

Anyone, is there also a study like this where the consumption of red meat (or meat in general) affects the risk of overall cancer?

DanBC 10y ago
We know that processed red meat causes cancer. The quality of the evidence is very very good. The strength of the effect is weak. Because the quality of the evidence is now very good (as good as for smoking) the WHO information was widely misreported as "red meat as bad as smoking". This is likely to make web searches less useful. Here's something from the English NHS about it: http://www.nhs.uk/news/2015/10October/Pages/Processed-meat-causes-cancer-warns-official-report.aspx http://www.nhs.uk/news/2015/10October/Pages/Processed-meat-c... > A key statistic provided by the infographic is that if everyone stopped smoking, there would be 64,500 fewer cases of cancer a year in the UK, compared with 8,800 fewer cases if everyone stopped eating processed or red meat.
- alister 10y ago
  > If everyone stopped smoking, there would be 64,500 fewer cases of cancer a year in the UK, compared with 8,800 fewer cases if everyone stopped eating processed or red meat. Even that statistic greatly overstates the risk of red meat as compared to smoking. Because it's not adjusted for the percentage of the population that smoke vs the percentage that eat processed or red meat. In the UK, only 16.9% currently smoke[1] but I believe that the great majority eat meat[2]. (I'm surprised how few people smoke now -- I remember a time when most people smoked.) The statistic makes it sound like you're 7 times more likely to die from smoking than from processed or red meat (64500/8800 = 7). But if my math is correct, the death ratio should be more like smoking being 39 times worse (64500/16.9%) / (8800/90%) = 39). [1] https://en.wikipedia.org/wiki/Prevalence_of_tobacco_consumption#United_Kingdom https://en.wikipedia.org/wiki/Prevalence_of_tobacco_consumpt... [2] I didn't find a statistic specifically about red meat or processed meat, but only 10% of the population are "meat-avoiders" according to this: https://en.wikipedia.org/wiki/Vegetarianism_by_country#United_Kingdom https://en.wikipedia.org/wiki/Vegetarianism_by_country#Unite...
- 10y ago

Alex3917 10y ago

How are they controlling for deaths from other causes, e.g. cardiovascular disease? If you're not dead from some other cause then you're going to be more likely to die from cancer, even if vegetables are actually conferring a significant anti-cancer benefit. I see that they are using people years to track followup, but I'm not clear from the methodology whether this is enough to fully control for this issue.

wapz 10y ago
Are you stating that death from cardiovascular disease would be higher (or lower) from people who don't eat fruits/vegetables which means they have a "lower" chance of getting cancer? My guess would be that they didn't take that into account and that the deaths from cardiovascular (or other diseases) would be ignored in the assumption they are "similar" between the two sides.
- Alex3917 10y ago
  To rephrase, I'm suggesting that eating vegetables may lower the risk of cardiovascular disease. If you don't die from cardiovascular disease, then it's more likely that cancer is the thing you do die from. So even if eating vegetables reduces your risk of cancer, you could actually be more likely to die from cancer if you eat vegetables.
  - wapz 10y ago
    Ahh thanks for the clarification. Your logic makes a lot of sense. I believe there was a study that showed pesticides may cause cancer (it was probably done in mice or something) from a long time ago but this is just the top of my head so I don't know if there's any relation to fruit/veggie consumption.

hartator 10y ago

Studies that invalidate common beliefs are really interesting.

aminok 10y ago
It shows how unreliable scientific consensus about a theory that cannot be subject to controlled experimentation, like any medical theory, is.
mrfusion 10y ago
Keep in mind that's the only reason we're hearing about this study. If they found what would be expected it wouldn't be as interning. Man bites dog and all that. There are probably lots of studies that say the opposite if you look for them.
erikpukinskis 10y ago
The study didn't invalidate anything.

miguelrochefort 10y ago

Every day, the case for eating plants gets weaker. I'm starting to believe that plants aren't necessary for human health, and are possibly harmful. This website has been eye-opening: https://zerocarbzen.com https://zerocarbzen.com

PerfectElement 10y ago
I think you are suffering from confirmation bias.
- miguelrochefort 10y ago
  Doesn't change the facts. Why should I believe that plants are necessary for health?
  - spraak 10y ago
    Confirmation bias means they aren't strictly facts you're believing
cgh 10y ago
Thank you for posting this link. Interesting stuff that parallels my own experiences with vegetarianism and veganism, the adoption of which I consider one of the great mistakes of my life. I've never gone 100% meat and water though I do eat red meat 4+ times a week.
cgh 10y ago
Thank you for posting this link. Interesting stuff that parallels my own experiences with vegetarianism and veganism, the adoption of which I consider one of the great mistakes of my life. I've never gone 100% meat and water though I do eat red meat 4+ times a week.

neves 10y ago

This is for Japan, doesn't they already eat a lot better than the Western world, that is, less red meat, less processed foods, more high oily fish etc.?

mikekchar 10y ago
In my experience, this is generally true, but the Japanese diet is changing rapidly. I came to Japan almost 10 years ago and I remember seeing quite traditional lunch boxes (called bento) in the convenience stores. Now everything is deep fried, or comes with fairly large portions of meat. Unless you go to a specialised bento store, it's pretty difficult to get a bento with a piece of fish, vegetables and rice. Also, with the reduced restrictions on imports, I've seen a veritable explosion of steak restaurants and yaki niku places (Korean barbeque). Now that they can get cheap pork from Canada and cheap beef from Australia, meat has gotten very popular. The meat sections of the grocery stores in my area are about the same size as the fish section. And even the small town I live in has the same number of butchers as they do specialty fish stores. Having said that, it's still not difficult to eat a traditional Japanese diet and certainly older people tend to eat that way. Not sure what will happen in the next generation or two, as the culture is shifting (to my eyes, anyway). It may be for the best, though, as global fish stocks are shrinking in an alarming way.
saryant 10y ago
Having seen the giant ice cream-stuffed crepes they sell in Harajuku, I'm not sure how true that is anymore...

thomyorkie 10y ago

Perhaps pesticide consumption offsets fruit and vegetable benefits.

SwetDrems 10y ago

I thought we were under the consensus that these large scale associative studies were not accurate/effective in predicting causal effects, especially in nutrition. I can't find any studies right now, but I remember reading about mechanistic explanations for plant compounds such as isothiocyanate and resveratrol in reducing and even completely suppressing tumour growth.

ramblenode 10y ago

Did anyone else read the statistical analysis section? There were some "interesting"/unclear choices made, but I'm going to pick on one in particular that could affect the outcome: the decision on how to weight the individual cohort studies on which this study is based (pg 6). > A random-effects model was used to obtain a single pooled estimate of the HRs from the individual studies for each category. The study-specific HRs were weighted by the inverse of the sum of their variance and the estimated between-studies variance component. First note that there is no citation which motivates this weighting scheme. There may be a valid reason for doing it this way, but that's not clear from the paper. Second, "the sum of their variance" I take to mean the sum of the variance components of the regression model. That's interesting because the components mean very different things. In the simple case of least squares, there's the "explained variance": the "strength" of the relationship between Y and X, and there's also the residual variance: the variance in X that isn't explained by Y. Aside from the fact that they mean different things, their sum is not a constant and so are not directly comparable across models/studies. Third, weighted by the "between-studies variance component" has the effect of down-weighting studies that show a large difference from the mean study result and up-weighting studies which are similar. Now, what would you say if I conducted an experiment and transformed the raw data points according to this same procedure? "That's not fair because that's not the data we collected!"[0] And herein lies the problem: the purpose of this meta-analysis is to assess whether we can draw any consistent conclusions from the results of the individual cohort studies, but by weighting studies toward the mean the authors are taking it as a forgone conclusion that the mean study is ground truth. I'm by no means an expert on meta-analysis so someone please chime in if you think I'm off base, but this all strikes me as a very peculiar and unjustified set of steps being taken before the model is even fit. [0] Yes, there are cases for data transformation, motivated either by theory or meeting regression assumptions, but this is neither.

minusf 10y ago

Forks over knives (https://en.wikipedia.org/wiki/Forks_Over_Knives https://en.wikipedia.org/wiki/Forks_Over_Knives) quite clearly argues that meat increases cancer risks manyfold. T. Colin Campbell and Caldwell Esselstyn are no quacks either and the document makes a solid argument for minimizing meat intake, at least for adults.