Obesity and diabetes: Actual epigenetics or just IVF?

This press release that appeared in my newsfeed titled "You are what your parents ate!" caught my eye because I'm a new mom of a new human and also because I study and teach human evolution.

So I clicked on it.

And after that title primed me to think about me!, the photo further encouraged my assumption that this is really all about humans.

"You are what your parents ate!"

But it's about mice. Yes, evolution, I know, I know. We share common ancestry with mice which is why they can be good experimental models for understanding our own biology. But we have been evolving separately from mice for a combined total of over 100 million years. Evolution means we're similar, yes, but evolution also means we're different.

Bah. It's still fascinating, mice or men, womice or women! So I kept reading and learned how new mice made with IVF--that is, made of eggs and sperm from lab-induced obese and diabetic mouse parents, but born of healthy moms--inherited the metabolic troubles of their biological parents. And by inherited, we're not talking genetically, because these phenotypes are lab-induced. We're talking epigenetically. So the eggs and sperm did it, but not the genomes they carry!

This isn't so surprising if you've been following the burgeoning field of epigenetics, but it's hard to look away. This fits with how we see secular increases in human obesity and adult-onset diabetes--it can't be genomic evolution, it must be epigenetic evolution, whatever that means!

As the press release says...

"From the perspective of basic research, this study is so important because it proves for the first time that an acquired metabolic disorder can be passed on epigenetically to the offspring via oocytes and sperm- similar to the ideas of Lamarck and Darwin," said Professor ...

Whole new ways of thinking are so exciting.

Except when you remember a two-year-old piece by Bethany Brookshire (because you use it to teach a course on sex and reproduction) which explained something that suggests we may have a major experimental problem with the study above.

In IVF, the sperm gets isolated (or "washed") from the semen.

You know what happens, to mice in particular, when there's no semen? Obesity and other symptoms of metabolic syndrome! There are placental differences too. This was published in PNAS.

"Offspring of male mice without seminal fluid had bigger placentas (top right) and increased body fat (bottom right) compared with offspring of normal male mice (left images)" from The fluid part of semen plays a seminal role by Bethany Brookshire.

So I went back to look at the original paper that the press release with the donut lady was about. I wanted to see if they are aware of this potential problem with IVF and whether it explains their findings, rather than the trendy concept of epigenetics...

So even though they titled it "Epigenetic germline inheritance of diet-induced obesity and insulin resistance," I wanted to see if they at least accounted for this trouble with semen, like how it's probably important, how its absence may bring about the same phenotypes they're tracking, and how IVF doesn't use semen.

But I don't have access to Nature Genetics.

Who has access to Nature Genetics, can check out the paper, and wants to write the ending of this blog post?

Step right up! Post your work in the comments (or email me holly_dunsworth@uri.edu, and please include a pdf of the paper so I can see too) and I'll paste it right here.

Update 12:19 pm
Two very good comments below are helpful. Please read those.

I'll add that I now have the pdf of the paper (but not the Supplemental portion where all the methods live and other important information resides). This quote from the second paragraph implies they do not agree with the finding of (or have forgotten about) the phenotypic variation apparently caused by sperm washed of their seminal fluid:

"The use of IVF enabled us to ensure that any inherited phenotype was exclusively transmitted via gametes."

As the second commenter (Anonymous) pointed out below, there does not appear to be a comparison of development or behavior between any of the IVF mice and mice made by mouse sex. So there is no way to tell whether their IVF mice exhibit the same metabolic changes that the semen/semenless study found. Therefore, it is neither possible to work the semen issue into the explanation nor to rule out its effects. Seems like a missed opportunity.

Completely unrelated and inescapable... I'm a little curious about how the authors decided to visualize their data like this:

Eat, drink, and be .... confused!

Is beer good for your health or is it a slow killer?  What about, say, bread, broccoli, wine, eggs, or (dare we say it?), sex?

Beer; Yebisu Beer Museum, Wikipedia

The answers are:
1.  Yes!  Anything we consume will keep us alive, but that just facilitates the path to our final end.  Metabolism and conjugal energy expenditure generate waste products, heat, cell division, and so on.  That leads to death!

Or 2.  Nobody knows!  After decades of huge, expensive studies by presumably the most knowledgeable investigators doing state-of-the-art science, we know relatively little with relatively little firmness, what we eat does for or to us.

In a Times article on Sunday, nutrition journalist Gary Taubes excoriates the nutrition research mill, and we think properly so, for decades of generating ever more numerous studies on nutritional epidemiology, without garnering many firm or important conclusions.

The 600,000 articles — along with several tens of thousands of diet books — are the noise generated by a dysfunctional research establishment. Because the nutrition research community has failed to establish reliable, unambiguous knowledge about the environmental triggers of obesity and diabetes, it has opened the door to a diversity of opinions on the subject, of hypotheses about cause, cure and prevention, many of which cannot be refuted by the existing evidence. Everyone has a theory. The evidence doesn’t exist to say unequivocally who’s wrong.

Even the basic questions about foods and eating are not being answered with much rigor, including even the common-wisdom recommendations related to obesity, dietary abuses, and so on, are often on quite shaky ground.  It is a huge research establishment that has its hands on funding agencies and is not being held accountable for delivering actual goods commensurate with the public investment.

Why can't we figure out the relationship of nutrition to disease in so many cases?  Largely because we've got a reductionist science that is able to find causes of disease that have large effects -- smoking, asbestos, the cause of infectious diseases -- but lousy at explaining diseases that are due to gradual exposure to multiple interacting factors that takes place over decades.  And, when some people exposed to what looks like a risk factor -- obesity, say -- develop diabetes but others don't, or when lots of sugar in the diet seems to be associated with obesity in some people but not in others, our methods really fail us.  We see the exact parallel in genetics, as we've written many times.  Indeed, does DDT cause Alzheimer's disease, a result we blogged about just last week?

Also on Sunday, the BBC reported that vitamin C is an effective treatment for cancer.  How many times for how many decades do we still have to hear more of this-finally-is true conjecture about vitamin C?  It's been going on for many decades.  The current story appeared in a journal called Science Translational Medicine.  The very phrase' translational medicine' reflects our rather bourgeois industrialization of the research system with its business and status basis.  It is a cachet self-congratulatory catch-phrase that suggests that biomedical research in the past had no interest in preventing or combating disease.  It suggests that grants were not given by NIH for such purposes (of course, NIH does fund a lot research that's irrelevant to health), which is just plain silly.  Or, rather, as we often have suggested, an establishment's typical way of making itself sound salubrious to the taxpayer we milk for our careers.  So why is there even a Science Translational Medicine journal?  Because Nature has one?  Because there might be advertising or subscription gains to be made?  Because each science publisher has to keep up with the perceived proverbial Joneses?  Because the bloated professoriate clamors for ever-more status-sounding places to publish their work?

What we're doing in the biomedical and health research establishment is to a great extent ever more of the same kinds of studies only bigger and with more costly and sophisticated hard and software.  Anyone with a computer can get SurveyMonkey software and design a questionnaire, and if you've got a degree in public health you know how to hire a bunch of nurse-interviewers, phone-callers, data-base miners and the like, and send them out on the streets to do various sorts of random samples, test and quality-check questionnaires in a standard way, then increase samples, have lots of meetings and data-enterers, and after a few years start using push-button statistical software to pour out papers (and contact the Times and BBC 'science' journalists to trumpet your work).  And, every year or so, write new grants to follow up your important 'translational' research.

Is there anything new here?
The  state of play is well known, and well known at least to the thoughtful contingent of researchers in the game.  Taubes, who has been guilty of simplistic advocacy as even he acknowledges by confessing his personal preference for sugar as the one-size-fits-all evil, clearly identifies the nature of the problem.  He doesn't really offer a solution.

We can't either, but we do say, that what is not being done is making better use of our wet ware: our brainpower.  Taubes' story was on nutrition research, and we have been harping on the same issues with respect to genomics, and have also critiqued epidemiology (including nutritional epidemiology) in past posts.

There is no magic answer for ginning up real insight and creativity.  But there may be ways of numbing or mesmerizing the part of society that might produce creativity.  A huge factory-like establishment of drone workers who need the factory to keep spewing out 'product' may have just that effect.  Our own idea that part of what is needed is to at least make the soil -- the research environment ecology -- more likely to engender innovation.  That would mean to down-size, slow down, think more and return research to being more of a profession than an industry.  There are too many professors, too pressured to grind out too many papers or hustle too many grants to keep the administrators and careerists happy.  Too many administrators who, dependent on the cream, need to keep the factory humming.  Time to think, or re-think, or be inspired creatively by odd facts is hard to come by when the pressure is get grants or lose your job.

Better synthetic rather than narrowly technical education is needed, but we haven't been generating the kinds of people who can teach it.  Instead, we have trained a body of academic professors who have been brought up and entrained in, depend on, and hence perhaps can't see or can't afford to see what is actually happening. But despite at least some people pointing the problems out, there is nothing on the horizon that seems yet able to stimulate real change.

All of this is true.  It is also true that the problems are difficult, many if not most faculty have a sincere drive to help public or individual health, high technology is at least somewhat effective and more than just expensive showy toys, and administrators are needed for big, expensive systems.  The methods are often canned in ready-made software, but that doesn't make them wrong, even if we clearly are thinking wrongly in some way.  Until we're shown better, while we do act like fad-following sheep, we do that because that's what we, collectively, know how to do.  And until our jobs and self-esteem are not constructed around the impatient, short-term factory mentality, one cannot expect us to act very differently. 

We do, after all, need to eat, drink, and try to be merry, for tomorrow we die whether or not we like to accept that.

Fruit and diabetes - a cocktail of results

Do you remember how much fresh fruit you ate last year?  Or, ok, in the last three months?  Or even last week?  What about differentiating between fruits; strawberries vs cantaloupe vs blueberries?  And how many??

We ask because a new study published in the British Medical Journal ("Fruit consumption and risk of type 2 diabetes: results from three prospective longitudinal cohort studies," Muraki et al.), that's getting a lot of news play, reports that eating a serving of blueberries at least three times a week protects against type 2 diabetes (t2d).  Blueberries are best, but grapes and raisins are second best and apples and pears are third.  Cantaloupe, on the other hand, seems to be a risk factor, as does drinking your fruit as juice rather than eating it whole. 

The study looked at food questionnaire data from a ton of people; "66 105 women from the Nurses’ Health Study (1984-2008), 85 104 women from the Nurses’ Health Study II (1991-2009), and 36 173 men from the Health Professionals Follow-up Study (1986-2008)."  So the data must be robust--yes?

Food questionnaires are a well-established tool for eliciting dietary information, and they are used all the time.  But they are also notoriously unreliable, for reasons that are easy to understand; it's really hard, first, to think in terms of standardized portion sizes and, second, to remember how often you eat a food, particularly if it's seasonal.  And there's the subtle possibility of responder bias--knowing what the study is looking for.

An anecdote, for what it's worth.  My mother has been filling out food questionnaires as a subject in the Nurses' Health Study for decades.  I remember her reaction to the first one she was asked to complete because I was a graduate student in public health at the time, learning in epidemiology classes about state-of-the-art tools like diet surveys, so the fact that they might be seriously flawed was an eye opener.  Suffice it to say, she did a lot of guessing. It's not good science to extrapolate from a single case, I know, but the following, from the paper, suggests it might actually be valid in this instance.

The food frequency questionnaires were validated against diet records among 173 participants in the Nurses’ Health Study in 1980 and 127 participants in the Health Professionals Follow-up Study in 1986. Corrected correlation coefficients between food frequency questionnaire and diet record assessments of individual fruit consumption were 0.80 for apples, 0.79 for bananas, and 0.74 for oranges in women, and 0.67 for total whole fruits, 0.76 for fruit juice, 0.95 for bananas, 0.84 for grapefruit, 0.76 for oranges, 0.70 for apples and pears, 0.59 for raisins and grapes, and 0.38 for strawberries in men.

So portion size and frequency are hard to remember, and that's a problem.  But maybe there's something else influencing the results of this study.  We're betting it's a lot easier to remember when you consume something every day, like a glass of orange juice, or banana on your cereal, but harder to remember when you have something that is more likely to be only seasonally available, like plums, or apricots.  This could explain why there seems to be such variation in the accuracy with which people remember different fruits and juice.

But probably more significantly, we'd bet that people who are already at lower risk of t2d because they exercise, or watch their diets, are thinner and so forth, are the same people who include more fruits and vegetables in their diets.  So, blueberry consumption may be indicative of a low-risk lifestyle rather than nutritional components that protect against t2d.  And this is what was found.

In all three cohorts, total whole fruit consumption was positively correlated with age, physical activity, multivitamin use, total energy intake, fruit juice consumption, and the modified alternate health eating index score, and was inversely associated with body mass index and current smoking. Whole fruit consumption was associated with an increased probability of using post-menopausal hormones in the Nurses’ Health Study and with a reduced probability of using oral contraceptives in the Nurses’ Health Study II.

The investigators corrected for these correlations -- that is, essentially asked the question, "In the lower risk group in the study, are those who eat X fruit at even lower risk?".  These adjustments weakened the associations, which isn't surprising, and in fact adjusting for other things like gestational diabetes or cancer also attenuated the associations.  But they still found that blueberries, raisins, grapes, pears and apples were correlated with lower risk, and cantaloupe with higher.  Methodological questions aside, could blueberries really be protective against type 2 diabetes, but not cantaloupe?

The idea is that fruits are rich in fiber, antioxidants and phytochemicals, all of which are presumed to be protective.  But, some are sugary, which might instead be a risk factor.  Results of studies of the role of specific fruits in risk of t2d have varied, with different fruits sometimes implicated in risk and sometimes with protection. "In eight previous prospective studies, the association between total fruit consumption and risk of type 2 diabetes was examined, and the results were mixed."

And, the study found that association of risk with glycemic load was inconsistent, and varied by cohort; "...a significant, inverse association was found in the Nurses’ Health Study, but not in the other two cohorts."  Indeed, this wasn't the only outcome that varied by cohort.    

In the Nurses’ Health Study II and Health Professionals Follow-up Study, banana consumption was associated with a lower risk of type 2 diabetes, whereas in the Nurses’ Health Study a non-significant positive association was found. The association for strawberry consumption was significantly positive in the Health Professionals Follow-up Study but was non-significant and inverse in the Nurses’ Health Study.

The authors conclude about their findings that most, but not all, "were quite consistent among three cohorts." We would suggest, however, that despite the large cohort sizes, methodological issues, particularly recall issues with the food questionnaires, are significant enough that you shouldn't make your decisions about which fruit to put on your cereal based on these results.

The issues are mainly examples of data (recall) error, and confounding:  so many factors go together in this society, bombarded by health-advice 'news' (and 'scientific' reports like the blueberry study), that it is very difficult to disentangle them.  Usually, then each individual factor has low effect on its own.

You can make your own judgement about whether these kinds of study are worth reading, publishing, or funding.  You might, for example, classify them with GWAS and other 'Big Data' studies, and say that when many different factors are at play, with individually minor effects, and people know what the latest advice is and adjust their behavior (often subtly) accordingly, that we're just asking to be confounded when we ask about the wisdom of exposure to individual factors.

Unless, of course, you're from New England and you're partial to blueberries.  In that case: go ahead and dose up!  Otherwise, read something more worthwhile than massive, inconclusive, weak-factor studies.

Autophilia: Where morality ends....science begins?

Autophilia:  Not, it's not a sex term.  But it is a term we like to use for our human love for ourselves, that makes us act as if the world was made for us to exploit and abuse.   Some, of course, think that a kindly (to humans, not pigs or cows or mice) God set it up this way. Of course, life evolved in such a way that we have to eat, and what we have to eat is or was once alive.  Pigs don't want their throats slit nor carrots to be eaten alive, in order that we may have satisfyingly filled post-prandial naps on the couch.

Sometimes, we decide that for scientific as well as for gustatory objectives, inflicting death, or even disease, on other species, including mammals like rodents and even primates, is justified.  Our autophilia over-rides other aspects of ethics.  But there should be limits....

The fat monkey
There is a story in the NY Times about funded science that uses monkeys to experiment with the health risks of 'couch potato' behavior--obesity, diabetes, and the like.

The corpulent primates serve as useful models, experts say, because they resemble humans much more than laboratory rats do, not only physiologically but in some of their feeding habits. They tend to eat when bored, even when they are not really hungry. And unlike human subjects who are notorious for fudging their daily calorie or carbohydrate counts, a caged monkey’s food intake is much easier for researchers to count and control.

To allow monitoring of their food intake, some of the obese monkeys are kept in individual cages for months or years, which also limits their exercise. That is in contrast to most of the monkeys here who live in group indoor/outdoor cages with swings and things to climb on.

To us, this work is thoroughly disgusting, if not immoral. While institutions purportedly have review boards that must approve every research project proposed by their employees (such as university faculty), this is largely nowadays based on CYA (protect yourself from lawsuit) criteria rather than whether the research really is not cruel to animal or human subjects, and/or whether the experimentation is scientifically justified.

From the Times: At 45 pounds, Shiva
 is twice his normal weight and carries
 much of it in his belly. He can eat all
 the pellets he wants and snack on
 peanut butter, but gets barely any exercise. 

It is perfectly legitimate to want to reduce morbidity and impaired quality of life due to our lazy, McFood-laden lifestyles.  Certainly one should treat those who suffer.  But we don't need animals to be made sick--even rodents, and certainly not primates!--to shows us what we already know.  We know how to address this problem and it has to do with education, income and neighborhood equity, and regulation.  It is not a matter of lack of knowledge.

Of course, now we have people experimenting, and doubtlessly doing extensive genomewide mapping, 'epigenetics', expressomics, nutrigenomics, and all sorts of other made-up types of work to glamorize their value to society. And of course we must acknowledge that so long as that is the reward system, one cannot blame the professoriate for going for it!

But, we know how to solve the obesity related chronic disease problem, we just don't have the resolve to do it.  How about rationing hours spent on video games or TV, intake of fast foods, mileage driven vs mileage walked, and so on?  How about providing wholesome shopping and affordable cost for areas that now are only McServed?  Or banning tobacco.  Banning leaf-blowers by subsidizing the price of rakes.  Outlawing golf carts for those under 65.  And so on.

Or, more drastically: if even then you don't follow decent lifestyle, you are on your own when it comes to health care costs.

Fat monkeys, fat people, professor welfare: what would we learn anyway?
The Times reports that at least one weight loss drug has been shown to be effective on these monkeys, and that gastric bypass surgery can be a treatment for diabetes.  They've also found a drug that makes monkeys gain weight, though it reduced appetite in rodents.  Whether or not these results justify keeping monkeys alone in small cages, and unable to exercise for years at a time is your call.  The story also reports that monkey research has taught us that it's total calories, not type of calorie, that makes us fat.  We've known that for decades.

In the long run, fat monkeys can't make a complex trait simple.  These monkeys are not inbred, a longstanding advantage of lab mice and rats, even though they are less similar to humans than monkeys are.  In fact, 40% of the monkeys don't get fat, which means there's something different about those that do.  Will researchers do GWAS now to figure out what that is?  With as much success as they've had explaining the genetics of obesity in humans?  

Is making monkeys sick much more than yet another playground for the professor class who can't think of more cogent things to do?  Is it much more than something that will give us something to do in between lattes, organic salads, and our time at the Nautilus club, where we can watch TV, yes, but only while treadmilling?

If we had a sane, moral research establishment and health care system, we would take care of these health issues first behaviorally, through lifestyle changes that we already know actually increase quality and length of life, on a large scale.  Then, those who still have morbid levels of obesity or diabetes etc. would be easier to identify. They would be the ones for which genetic, or sophisticated surgical or other approaches would be appropriate, would more likely be truly transformative, or might actually make a difference that the victims can't make on their own.

But that would mean we'd have to get our autohpilia under control, and not justify absolutely everything in our own self-interested terms.  But that doesn't seem on the horizon.  How could it be curbed if we haven't even recognized that the autophilia is a (or the) problem?  And, since it seems characteristic of our species, it may actually be a GWASable genetic problem that our professor class could opportunistically seize upon to justify the next round of Omics!

Meanwhile, it may be a strong thing to say that many will object to, but have the project reviewers, funders, and investigators no sense of shame about what they are doing to these innocent monkeys?

What? No request for more grant money??

Here's a rare science/medicine story that doesn't end with a plea for more money for further study. Indeed, the answer is clear -- but it has been for decades.

"No quick drug fix for diabetes risk", the BBC story is entitled. (There's a different take on this story in the NYTimes, in which Gina Kolata concentrates on potential harm from the drugs under investigation.) A study published in two parts the New England Journal of Medicine (here and here) of 9300 people defined as 'pre-diabetic' (meaning they are beginning to stop responding to insulin) comparing two medications with a placebo showed no difference in the proportion of either group who went on to develop diabetes and subsequent heart disease. "Researchers said the results showed the only way to ensure future health in people at high risk of diabetes was exercise and a healthy diet." And, rather than asking for more money for an even larger study, they call for an increase in money for preventive care.

Why are they sure that prevention is the best cure? We were interested to note that part of the treatment for people in this study in either the group receiving drugs or the group receiving placebo was 'lifestyle intervention'. That is, they asked all subjects to add a 5% reduction in weight and 150 minutes of exercise per week to their drug regimen. Rigorously done, from what is known from other studies about the significant effects of lifestyle changes on risk of obesity and diabetes, this could have made interpretation of the results of drug intervention difficult. But in fact in this study, subjects were followed up only once a year, and, as the accompanying NEJM editorial suggests, lifestyle changes must have been minimal, since, contrary to expectation, risk of diabetes was not significantly lowered in this study.

Ironically, that inference itself assumes what's being tested -- a real no-no in science!, namely, that lifestyle is the cause. That may be right, but it's not right to assume!

And, indeed, the researchers' conclusion that lifestyle modification was more effective at reducing risk of diabetes and cardiovascular disease than the two tested compounds was based on these other studies, not their own -- something they couldn't have shown, given their study design.

So, in fact what we learn from this large and expensive study are things we already knew. Once or twice, such confirmation is a powerful tool for science. But enough repetition is enough!

It is pretty clear, based on what previous studies have shown, that diabetes and its complications are best prevented by diet and exercise.  But, lifestyle changes are easy to explain but hard to implement. We repeat what a colleague once told us; it might well be cheaper to give everyone at risk of diabetes a personal trainer than to continue doing studies that show, in effect, that everyone should have a personal trainer.

But maybe there's progress -- at least the researchers aren't asking for more money to confirm their results.

**Update:  As we've said before (e.g., here), it's looking as though inflammation may be the underlying process behind more and more chronic diseases.  Today's NYTimes reports that this may be true for type 2 diabetes, as well.  Study subjects taking a cheap generic anti inflammatory related to aspirin were able to lower their blood glucose levels far more than those on placebo.  The idea is that obesity may induce inflammation, which then induces insulin resistance. In this case, however, the researchers conclude that "more research is needed."