There’s scant evidence that healthy foods prevent cancer or fatty foods cause it | Hacker News Reader

There’s scant evidence that healthy foods prevent cancer or fatty foods cause it

startribune.com

76 pointstokenadult60 comments

This shouldn't surprise anyone...

People need to realize that research publications are not textbooks. They are communications to other researchers about the way that the evidence is pointing, that helps them design new experiments, that justifies expensive and spendy clinical trials, which eventually find conclusive evidence.

The idea that one can open a science journal and find interpretable truth revealed is a pernicious one. Trust that the data is true, but do not trust the models or the conclusions. Everything is in flux, and it's science because we likely don't know what the real world is like yet.

History will go back and pick out the key experiments and construct a path of discovery, but in real time almost nobody knows what the most important experiments truly are.

This makes for difficult journalism, but one should remain true to the physical world rather than the narratives that are easy to squeeze into 500 word news blurbs.

It's not just that. There's a huge problem with selective bias here. People think that "healthy foods" automatically means good health, and bad health is automatically a result of processed foods, "bad health habits", etc. Bad health is your own damn fault for profoundly insulting mother nature by feeding your body Kraft Diner a few too many times.

News at 11: cancer is a natural occurrence. You could exclusively eat prime quality fish, raw organic fruits and veggies and still get a heart attack at 52 and cancer at 58. In other news, I seriously question the idea that paleolithic humans had incredible food wisdom and perfect health. They probably ate whatever the hell they could find at a given time of the year in their immediate environment, and that was probably hugely lacking in nutritional value when it's the winter, all the plants are dead and most animals hibernating.

I agree that making an effort to eat well is a good idea, but it doesn't make you immune to diseases, and diseases are not necessarily a result of bad habits. There is also a huge amount of conflicting information as to what is healthy food.

"News at 11: cancer is a natural occurrence."

So what? Something being "natural" has no bearing on whether it is favorable or preventable.

"You could exclusively eat prime quality fish, raw organic fruits and veggies and still get a heart attack at 52 and cancer at 58."

Of course it's possible. But if you had any amount of sense, you wouldn't be making conclusions from a single case.

"In other news, I seriously question the idea that paleolithic humans had incredible food wisdom and perfect health."

Who's making that claim? The claim most paleo advocates seem to be making is that you should eat food that the body is adapted to eating.

>> "The claim most paleo advocates seem to be making is that you should eat food that the body is adapted to eating."

In full, their claims fall closer to the following:

  P1. You should eat healthy foods.
  P2. Foods that the body is "adapted" to eating are healthy.
  P3. If paleolithic humans ate something, it means our bodies are "adapted" to it.
  C. We should eat what paleolithic humans ate.

The problems with the above line of reasoning are numerous. While most everyone would prefer to eat healthy when possible, the word "adapted" is ambiguous, and the argument that it's healthier to eat foods we're "adapted" to lacks evidence and is overly ambitious.

It's hard enough to examine healthiness on a food-by-food (or even an ingredient-by-ingredient) basis, so labeling broad categories of food as healthy or unhealthy is bound to be even harder.

Let's put that straw man logic more realistically:

  P1. If you want to have a good degree of health without requiring modern medicine, you should eat food that gives you a good degree of health without requiring modern medicine
  P2. Successfully reproducing in an environment without modern medicine requires food that supports or does not tarnish a good degree of health
  P3. Paleolithic humans successfully reproduced in an environment without modern medicine
  C. If you want to have a good degree of health without requiring modern medicine, eating what paleolithic humans ate will support or not tarnish that goal

Of course the problems with your reasoning are numerous. That's why intelligent people who eat the paleo diet don't make them. And they likely wouldn't propose the logic I did here. That's why they use studies comparing the health of hunter-gatherers to neolithic farmers. That's why they discuss scientific studies in support of meat/fat, and in opposition to grains. That's why they get angry at people who misappropriate their views.

Au contraire, plenty of intelligent people who follow the paleo diet make the flawed argument I just presented. I know a few myself.

In addition, I'd argue that the reasoning I presented falls much more closely in line with what's found on Wikipedia's "Paleo diet" article and top Paleo sites than does yours, which, strangely, seems to focus heavily on avoiding modern medicine. But this is irrelevant, since you yourself claim that "intelligent" followers of paleo likely wouldn't propose your logic, either.

So I must ask you: What reasoning would these people propose? "Using studies" is a supplement to proposing a logical framework that justifies a conclusion, not a replacement. Research isn't cited in a vacuum: it's cited to argue for or against some premise or conclusion. Also, the types of studies you refer to could just as easily be used to supplement the framework I provided as it could yours or any other. Thus, the fact that some paleo advocates would cite these studies isn't an argument for or against the accuracy of my characterization.

It seems a bit disingenuous to label one's reasoning a strawman without providing specific reasons as to why, or even providing the allegedly correct reasoning. If a group refuses/fails to articulate its position clearly and publicly, then who is truly to blame for those views being misappropriated?

>> P3. Paleolithic humans successfully reproduced in an environment without modern medicine

Many paleolithic humans did not successfully reproduce. Many died before being able to. Humans continued to exist because enough successfully reproduced.

Unless your personal health goal is that a sizable proportion of your cohort survive to reproduce successfully, this is not particularly helpful reasoning.

In any event, you are highly likely to make it to child-rearing age in economically developed countries. Our health problems occur later.

Your comment suffers from the affliction that "if it doesn't completely eradicate -foo-, then there's no point at all". If there was a magic food that cut your chance of getting any sort of cancer by a factor of 1000, your statement of 'you could still get heart attack/cancer in your 50s' would still be true.

The main article does this a little as well; there's something of a tone that says 'healthy food has all these other benefits, but since it doesn't stop cancer, it's probably not worth it'. It's weird, because I've never heard of anyone specifically choosing foods because of their reduction in cancer rates - people tend to choose foods that affect their current wellbeing, not future 'maybes'.

I'd go so far as to say that any claims of cereus types of foods being "healthier" are specious as well. As long as you're getting the required sustanence and not dying of anaphylaxis or whatever, you're good.

Everyone, even doctors, find a new food to demonize every few years, then flip and say it's the bet thing ever a decade later. Anyone remember when eggs were killing you? Or when the fad diet was low carbohydrate? Now eggs cure cancer and gluten is "literally Hitler."

Health nuts, as a rule, have no clue what they're talking about. They're just desperately looking for something to blame for their (or others') problems and using pseudoscience to justify it. (As for weight loss/gain, it's just simple thermodynamics. Caloric intake minus expenditure equals "duh.")

"Everyone, even doctors, find a new food to demonize every few years, then flip and say it's the bet thing ever a decade later."

Uh ya. New evidence comes to light, people change their minds. That's not necessarily a fault of the methodology.

This is true, so far as it goes. But obesity is unhealthy, and some food types are much more likely to make people obese than others. Specifically, "foods" (in quotes because often the worst offenders are drinks) with high caloric density and low satiability mean people take on huge amounts of calories without feeling full.

There's a great TEDx talk debunking the myths of paleo diets: https://www.youtube.com/watch?v=BMOjVYgYaG8

That video didn't debunk anything. It's just 22 minutes of straw man. It's never been about eating exactly what hunter-gatherers ate, and it has never followed any assumption that the hunter-gatherer diet is best possible diet.

It is based on evidence that hunter-gatherers showed excellent health, and those transitioning to a neolithic diet showed a health decline. Following that, it takes the sensible action and imitates the fundamentals of the diet, backed up by more cutting-edge studies starting to go against the "high-grain, low fat" spiel. It never claims to be "the best possible diet", nor the actual diet that hunter-gatherers ate. It doesn't need to be either to be a smart decision for your health.

Of course, I get the feeling that this is not really about whether or not the diet is valuable. People tend to take sides on the matter, and videos like these only worsen the problem. Most diets around are healthier than what you normally eat.

I think what caused such robust health among paleolithic humans is they didn't drive. They had to walk everywhere. Literally miles to find food.

What evidence is there that paleolithic humans had robust health?

I suspect there was a real (literal!) survivor bias is the healthiness of paleolithic humans while they were alive. In a hunter/gatherer society you had to remain healthy enough to be mobile. If you didn't you were probably left behind, and then you died pretty quickly.

Does the high levels of "fitness" of those alive mean they had "robust health" in general? I'd question that: I think cause and effect has been switched, and the only paleolithic humans left alive were those who remained in "robust health".

Bingo. Hunter gatherer societies are far less forgiving of the weak and sick.

I remember reading a study on paleolithic humans that said that even they had atherosclerosis.

This is all true, but the atricle says something quite different than what you are commenting on. The "original findings" which are being reversed were based on 4,000 pieces of peer-reviewed research.

After reviewing more than 4,000 studies, the [1997] authors were persuaded that green vegetables helped ward off lung and stomach cancer.

It's easy to dismiss a single instance as an arbitrary data point. When you can dismiss a large portfolio of such points--you have another problem. That problem is a core-weakness in methodology/approach/and institutional incentives. That seems to be the larger issue highlighted here.

Well, the sentence immediately preceding that one gets it right:

>The situation seemed very different in 1997, when the World Cancer Research Fund and the American Institute for Cancer Research published a report, thick as a phone book, concluding that diets loaded with fruits and vegetables might reduce the overall incidence of cancer by more than 20 percent.

With "might" being the most important word there. These 4,000 studies were all retrospective analyses, and retrospective analyses only find conclusions of the "might" sort, which is well understood by the scientists, but not so well communicated by journalists.

Still, a 20% "might" is a an absolutely enormous amount of potential upside in cancer prevention, even a "maybe" of this magnitude justifies great excitement. Which is why they embarked on the prospective study, which is the real story here.

It is absolutely ridiculous to conclude that there are methodology or misaligned institutional incentives based on this case, it's exactly how things should work. It's just another example of scientists being blamed by bad reporting that they have no control over.

That said, there are many other cases where methodology is wrong or institutional incentives are wrong.

You need to weight them by quality, from experience in my field of E&M the papers with 2k citations are correct and the ones with 4 citations aren't.

Also 4k papers is too much to go through by hand, so something else was done.

This newspaper article states "In 2007, a major follow-up [to the 1997 AICR report] all but reversed the findings." They don't cite the study or provide a link, but it's almost certainly the 2007 AICR report.

Fortunately you can take a look for yourself [0]. The published research findings are pretty much the opposite of the Star Tribune's claims that eating healthy has no effect on cancer.

These are the AICR recommendations:

    Be as lean as possible without becoming underweight.
    Be physically active for at least 30 minutes every day.
    Avoid sugary drinks. Limit consumption of energy-dense foods.
    Eat more of a variety of vegetables, fruits, whole grains and legumes such as beans.
    Limit consumption of red meats (such as beef, pork and lamb) and avoid processed meats.
    If consumed at all, limit alcoholic drinks to 2 for men and 1 for women a day.
    Limit consumption of salty foods and foods processed with salt (sodium).
    Don't use supplements to protect against cancer.

[0] http://www.aicr.org/research/research_science_expert_report....

Edit: formatting.

That's odd. The same article was in New York Times, do you know how did they manage to get the opposite conclusions? Maybe it's a different study after all?

"Cures Cancer" is a high bar for anything.

Eat healthy food because you'll have a better life if you do.

Hell, just try it for a month. Don't eliminate carbs, reduce them. Don't skip meals, shrink portion sizes. Add veg that you've never used before. Instead of mashed potatoes, go for mashed cauliflower or (even better imo) celery root puree. Toss veggies in EVOO, salt, pepper and roast on a baking sheet at 425* until tender. Get high quality proteins and cook in a little fat with simple seasonings. Eat less than you do now. Just because you're not full doesn't mean you're hungry. I found that last lesson hard to learn.

Now this is what I call dogfooding your own recommendations:

That evening at a reception hosted by the M.D. Anderson Cancer Center, guests partook of a sumptuous buffet that included thick slabs of roast beef, a variety of rich cheeses and generous servings of wine. Afterward came the cancer research association’s grand celebration known for its dessert buffet.

Yeah, it had been 10 years since the first convention which got all preachy about healthy diets. So these folks had all that pent up diet-rebellion, and then the convention says, "Nevermind." They promptly went and pigged out.

This article (and some people here) seem to be mixing up the conclusion that particular so-called "super foods" are viewed with skepticism by oncologists. And a poor high fat high sugar diet is very clearly associated with cancer, diabetes and heart disease. In between these is a grey area of whether a slightly more healthy than merely adequate balanced diet is good.

Its pretty clear though that poor diet is associated with cancer.

No evidence, sources or credibility. Sorry but this article is just silly. This is an old world corporate fed point of view that is obviously incorrect.

What's with a news source promoting misinformation?

I get the same feeling.

I don't understand what's being reported on here.

"The reason for the change was more thorough epidemiology. The earlier studies tended to be "retrospective," relying on people to remember dietary details from the distant past."

So what? Which are the studies that are invalid? If none of them are invalid, then why disregard any information they might give us? 4000 studies with similar observations is not "scant evidence", unless you can rule out every single one. And are these 4000 the only studies which have similar conclusions? Probably not.

"These results were often upended by "prospective" protocols, in which the health of large populations was followed in real time."

I don't know what this means.

In a "retrospective" study, you look at the past - for instance, you interview people and ask them what they recall eating over the last year, and see how that tracks with their current health condition. But memories are faulty and selective and easily influenced, so you might be operating from bad data. And the associations you find could be spurious for other reasons. So you can quickly reach some conclusions with this type of study, but they might just reinforce what people already believed rather than tell you what is actually true.

In a "prospective" study, you look at the present - for instance, you could ask a group of people to keep a food journal, measure their health at regular intervals, encourage some of them to make some changes, and see if the advice ends up making them healthier. The advantage is that you have MUCH more accurate data. The disadvantage is: (a) you have to wait many years before you can reach any conclusions, (b) most of the time the conclusion you discover is that the advice didn't help.

Retrospective studies can generate hypotheses but you have to TEST those hypotheses with prospective studies.

Ah ok. Had no idea how far back people were expected to remember. A few days might be fine. A year seems crazy.

Also I don't know why the author put prospective and retrospective in quotes. "Prospective study" and "retrospective study" are terms.

Certain kinds of fat are likely healthy. Certain population s of indigenous people thrived on high fat diets.

The title of the article really annoys me. Not all fat is unhealthy. What is especially bothersome is that food companies are creating "low fat" foods by replacing fat with sugar, making them much less healthy than the original yogurt or sour cream or whatever.

No mention of the demonization of fat and promotion of artificial sweeteners and additives promoted and used to "fix" the fat problem.

Eating less and exercising more has worked pretty well for me, but that's not for everyone. I've also learned to see which foods give me more, sustained energy over time and which ones don't or even drain me. But, once again, I doubt that will work for everyone.

I'm also very skeptical of a lot of studies that discount things that are clearly working for me. For example, a lot of studies that discount fish oil tend to not take an enteric coating and proper absorption into account. Actually, after many years, I'm still waiting for those studies. In the meantime, I've seen the positive effects myself and will continue to use enteric coated fish oil as a supplement.

I've also watched countless friends, family and acquaintances try the Atkins diet only to yo-yo and see later problems develop. So, I'm not going to consume buckets of lard to lose weight. But, if the Atkins thing works for you, more power to you!

My conclusion is what works for me may or may not work for anyone else and vice versa. But, that said, I still look at some studies over time and try to glean some slight insight into what works and doesn't work for others and experiment here and there.

Unless an article compares various studies using a meta-analysis methodology (see https://en.wikipedia.org/wiki/Meta-analysis), I'm probably not going to give it much attention.

To summarize one key problem: journalists (and even some scientists) are prone to say two studies "disagree" if one demonstrates an effect and another does not. This is a problematic style of argument, because this kind of "disagreement" may be caused by random variation in sample sizes and/or differences in thresholds. You have to dig in to make an honest comparison and synthesis. This requires some basic statistical understanding, which apparently is lacking in many educational programs (but that is another thing!).

Please, if you do this kind of work or care about interpreting a set of studies collectively, go read the first few chapters from "Introduction to Meta-Analysis" by Borenstein, Hedges, Higgins, and Rothstein.

The primary thrust of the article seems to be that because (1) the American Association for Cancer Research conference had a very small number of sessions on diet and cancer, and (2) a single follow-up study in 2007 concluded there was little link between diet and cancer that it must be true.

This is only one view and hardly comprehensive. If you read http://www.drfuhrman.com/library/vegetables_cancer.aspx by Joel Fuhrman, MD, you'll get a perspective on why the devil is in the details with many of these studies and why broad sweeping headlines like this one are often inaccurate.

Based on everything I've read on this subject -- The China Study, Eat to Live, and a few others -- I side with the Fuhrman article over the one published in the Star Tribune, a statewide newspaper for Minnesota.

So, interesting follow-up as I researched this further. First, this article was just published last week in the New York Times (http://www.nytimes.com/2014/04/22/science/an-apple-a-day-and...). The Star Tribune was merely syndicating it.

Second, it looks like the Joel Fuhrman, MD wrote a direct response to this article: http://eathealthyandthrive.wordpress.com/2014/04/26/the-nutr...

It's on a random Wordpress blog here, but this was sent out to his eNewsletter earlier this week (though not posted on his website).

I don't think any credible health organisation or government body has ever claimed that what you eat has a serious effect on cancer incidence. I'm sure there are plenty of random books written by self-appointed experts who claim that though. They probably recommend coffee enemas for cancer treatment, too.

OTOH, heart disease has long been thought to be associated with eating high levels of saturated fat. Recent evidence is beginning to challenge that though[1].

[1] http://www.nhs.uk/news/2014/03March/Pages/Saturated-fats-and...

Cancer is like a random process. When enough mutated cells gets into a certain neighborhood of events which lead to cancer, that's how it starts.

When I went to Aruba with my friend, a sailor there told us that most sailors eventually got melanoma from being out allthe time. That's what made me realize this.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2515569/

Only 5–10% of all cancers are due to an inherited gene defect. Various cancers that have been linked to genetic defects are shown in Fig. 2. Although all cancers are a result of multiple mutations (9, 10), these mutations are due to interaction with the environment (11, 12).

That 5% figure is much less interesting when you realize they mean _inherited_ genetic defects.

Doesn't this contradict the original article?

> Cancer is like a random process.

> most sailors eventually got melanoma from being out allthe time

These two statements seem in conflict to me.

Why?

It's lke saying "Craps is a random. If you roll the dice at Vegas all the time, eventually you will lose your bankroll."

Because they are in conflict. "Cancer is like a random process" is saying that it can happen equally to anyone. "Most sailors eventually got melanoma from being out all the time" is showing that it does not happen equally to anyone. Your example isn't accurate.

Random means unpredictable/non deterministic, it does not have to be equally distributed. Normal dice throws 6 with the same probability as 1. Biased dice that throws 6 twice as much as 1 is still random, but it does not throw numbers equally

Smokers have significantly higher chance to get cancer then non-smokers, but they are not guaranteed to have it. Both smokers and non-smokers can get lung cancer and it is biased random whether you will get it or not.

I don't think saying cancer is random means anyone can get it. It could also mean when you are exposed to a carcinogen, the impact is random.

You could smoke cigarette's and never get lung cancer. You could spend your whole life in the sun and never get skin cancer.

I think what he is trying to say is that the baseline for getting cancer is random, and there really isn't much you can do you reduce the chances of it happening.

However, you can increase the chances of happening through things like excessive sun exposure.

If you read the actual title which seems much less misleading than the subtitle it tells a different story.

Foods aren't 'good' for you.

But it seems to fail to mention is the important bit. Some foods aren't bad and some food help stop you eating as much bad foods.

Well, there's this: http://www.clinicalepigeneticsjournal.com/content/3/1/3#B1

A sensationalist title with no links to any studies cited.

Why the misinformation? Are we, the readers, expected to be so ignorant to think that foods grown in our gardens are equal (in health) to those found at our local fast food restaurant?

No mention of the relationship between genetically modified foods, artificial sweeteners, organic food, oxygen, etc to disease.

Another failure of the fourth-estate to inform the public.

#FAIL

I find the evidence for your claims to be lacking. GM foods? Are you kidding me? There's no evidence that GM foods are bad for your health. Perhaps some evidence will turn up. (It's possible; I doubt it will happen.) But there is none. And organic foods? Come on, you're thinking like some ancient Greek who took Aristotelean "essential natures" seriously. Like you're going to paste bird feathers on your flying machine because birds fly so surely the feathers will help.

There's quite a bit of evidence that organic foods have higher levels of antioxidants. (This is not a first source, but it references quite a few) http://www.altmedrev.com/publications/15/1/4.pdf

"Organic strawberries had significantly higher total antioxidant activity (8.5% more), ascorbic acid (9.7% more), and total phenolics (10.5% more) than conventional berries (Table 2), but significantly less phosphorus (13.6% less) and potassium (9.1% less) (Table 1)." Organically managed surface soils also supported significantly greater microbial biomass (159.4% more), microbial carbon as a percent of total carbon (66.2% greater), readily mineralizable carbon (25.5% more), and microbial carbon to mineralizable carbon ratio (86.0% greater) (Table 6). These indicate larger pools of total, labile, and microbial biomass C and a higher proportion of soil total and labile C as microbial biomass. All measures of microbial activity were significantly greater in the organically farmed soils, including microbial respiration (33.3% more), dehydrogenase (112.3% more), acid phosphatase (98.9% more), and alkaline phosphatase (121.5% more). The organically farmed soils had a significantly lower qCO2 metabolic quotient, indicating that the microbial biomass in the organically farmed soils was 94.7% more efficient or under less stress than in the conventionally farmed soils [40]. These same differences, except for qCO2, alkaline phosphatase, iron, boron, and sodium, were also observed in soils from the bottom of the mounds (20–30 cm depth). http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...

Glyphosate, used with GM soy, adversely affects good gut bacteria in poultry at levels of 5ppm while bad bacteria are highly resistant to it. http://www.netwerkvlv.nl/downloads/2012-Krueger,%20M-glyphos...

I'm just pointing out that none of these topics can be or were addressed head on by the author. He instead chose to infer by generalization that food is food, with no supporting documentation just a tactically written "scientific" opinion piece.

For evidence look into the work of Jeffrey Smith. Here's just a 2min clip of some of what you seek, http://www.youtube.com/watch?v=TvopGRiPHdE. Also check out Joel Salatin. Best of luck on your journey.

Off to the right there's a picture of a bathroom scale. When you click on it it opens up to ... a larger picture of a bathroom scale. I don't know why I found that so funny but I laughed for a good solid minute.

complete bunk

Diets are easy.

Don't eat anything that is advertised on TV. If an actor in a televised 30 second play convinced you to eat it, you probably shouldn't.

Apart from that, invest in good quality scales. When the numbers go up, change your behaviour until the numbers go back down again.

Oh, and quit making endless excuses in your head. They are just lies you tell yourself. If you really want to be healthier, than just go ahead and do it.

I thought it was sugar that makes your body acidic and that causes cancer...

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