Category: Sensible Science

Eight Reasons Why I’m Not Checking My Sunscreen Against EWG’s List

Sunscreencover

This topic is highly debated and frequently discussed, particularly among parents trying to make the best sunscreen decision for their families, so I jumped at the chance to have my friend and fellow native Hoosier, Professor Ruth, spend some time on the topic for this issue of Sensible Science.  ~Laura

Sunscreencover

Three years ago, I was closely following the FDA’s progress toward revamping sunscreen regulations because I knew it would be a great story to share at the Chemistry summer camp I teach, and because my first child was going to be spending more time in the sun. A big thing that I do during summer camp is teach students how to read ingredient labels, so I was also researching the active ingredients in sunscreens.

When I got an email through my playgroup mailing list about the Environmental Working Group’s list of sunscreens for that summer, I sighed… (more…)

Genetically Modified Nation, Part 1

GMO Image

What are GMOs? | Good Not Perfect

“Eating is an agricultural act.”  -Wendell Berry

Thousands of food choices surround us daily.  Organic or conventional.  Artificial sweeteners or high fructose corn syrup or sugar.  Margarine or butter.  Fat or non-fat.  And now, GMO or non-GMO.

It’s this last category that has brought an agricultural debate straight to the dinner table.  So in the spirit of Sensible Science, let’s examine GMOs (genetically modified organisms) to evaluate both sides of this controversial issue.

What are GMOs?

I certainly hadn’t given GMOs much thought until recently.  The scientist in me doesn’t find genetic modification of crops (in theory) to be automatically a bad thing.  After all, humans have been taking advantage of natural genetic mutations and cross breeding (hybridizing) plants for thousands of years. You may hear proponents of GMOs argue that these crops are more efficient, use less water and natural resources, and decrease world hunger.  Though opponents will vocally proclaim they require more pesticides and some go so far as to claim GMOs are allergenic and carcinogenic.

So, naturally, people who haven’t given GMOs much thought may not understand the hype.  Why all the recent publicity surrounding GMO labeling laws?  Bills to mandate labeling have been brought to over half the states’ legislatures, and such bills passed in Maine and Connecticut last year.  Yet another one in Washington State failed to be passed in November after agribusiness heavily funded the opposition.

So for starters, let’s understand this – what exactly is a GMO anyway?  And are there any proven health risks of GM crops?

What are Genetically Modified (Transgenic) Organisms?

Let’s take a quick tour through genetic history.

  • As we all learned in high school biology, humans have been adapting plants and animals to suit our needs since the beginning of agriculture, at least 10,000 years ago.
  • It wasn’t until the middle of the 19th century that Gregor Mendel, the Augustinian monk, famously bred pea plants by cross pollination and earned himself the title Father of Genetics.
Genetically Modified Nation | Good Not Perfect
Hybrid rose from Emily’s garden
  • Fast forward to the 1970s when transgenic organisms became possible through the insertion of genes from one (potentially completely unrelated) organism into the DNA of another.  Usually, a small snippet of DNA from one organism is put into a virus or bacteria to then be inserted into the DNA of the target organism.  It sounds science-fictionesque, but it’s not really a frightening process. None of the bacterial or viral genes end up in the final organism, just the plasmid or gene fragment does.  For a more detailed look at this process, check out this University of Nebraska site.
  • The first transgenic or GM crops were planted in the late 1980s, and today they’re ubiquitous in American fields.  In fact, 88% of corn and 93% of soy beans grown in the U.S. are genetically modified (citation here).
  • Genetically modified versions of canola, sugar beets, cucumber, tomatoes, peas, rice, and many others are also common here and around the world.

What are the advantages to genetically modifying crops?  Most of the time plants are modified to induce resistance to pests or herbicides.  For example, Roundup Ready corn produced by Monsanto is resistant to the Roundup used to kill off surrounding weeds.  Proponents of this biotechnology claim that it increases crop yield and makes the plants hardier – though this is certainly up for debate.

One thing is clear to me – there are numerous environmental consequences to these practices, which I’ll discuss in an upcoming post.  Additionally, there are possibly health-related risks (much harder to prove, but more on that later).

GMOs and Our Health: Do They Make the Grade?

Europeans have been labeling GM foods since the passage of the 1997 Novel Food Regulation, which was made even stricter in 2004.  After 2004, any food product to be sold in Europe that is made with a GMO ingredient must be labeled as such (see here).  In Europe, GMOs (either seeds or foods) must also get authorization before entering the market.

Also by law in Europe, Canada, and the U.S., 100% certified organic food must be non-GMO.  So it follows that if you don’t live in a state with a GMO labeling law, eating organic food is one way to avoid GMOs.

With all this controversy surrounding genetically modified crops, one of my first thoughts was, “Let’s all back up a hot minute, here.  Where’s the data?  Are these things even bad for us?”

As it turns out, like many controversial scientific topics, the health effects of GMOs have not yet been studied extensively.

  • A 2007 review of GMO safety studies showed a number of brief animal studies, some with negative effects like intestinal cell changes, but others with no known harmful effects.
  • Most of these studies were conducted over short periods of time with small numbers of animals, and none of them conclusively demonstrated cancer or premature death.
  • There have been a number of similar animal studies since that time, but no large studies in humans to my knowledge.

So how do we put this data into context?  As I sorted through what research is available (and not available), I was reminded of the guidelines for safety of medications in pregnancy (FDA rule here).  If you’ve ever been pregnant, you might be familiar with these categories.  Most obstetricians prefer to use medications in category A or B for their pregnant patients when possible.  Using similar guidelines, how might we classify GMOs in terms of risk to us?

GMOPregnancyCategories

The data we have on GMOs puts them into category C at best.  We simply don’t have enough data to rule out a risk to humans.

Despite this seeming indictment of GMOs, I’m not convinced we’ll ever find health risks from the organisms themselves.

  • Though there are potential health risks of GMOs, it’s impossible to know for sure if any harm has already been done.  With the widespread dissemination of GM food products throughout the world, narrowing down any adverse health effects to one GMO would be exceedingly difficult.  And for all we know, genetically modified organisms might have zero negative effects on our health.
  • Until we know for sure, being aware of the origins of our food is our best defense.  But that’s a discussion for another day (Part 3, to be exact).

Checking for Safety

In the meantime, GMOs need, at the very least, a safety check before they make it to the table.  In the opinion of the author of the review article mentioned above, every GMO needs to have safety assessed on a case-by-case basis to evaluate:

  1. Toxicity – Is the inserted gene or new organism that has been created toxic in any way?
  2. Allergenicity – The newly-inserted gene could contain an allergenic component of its parent organism that would pose a danger to the unaware consumer with a food allergy.**
  3. Stability of the inserted gene – Could it potentially become something toxic or allergenic if unstable?
  4. Nutritional effects associated with gene modification.

And I would add:

5.  Pesticide residue – Because of GMOs’ designed resistance to pesticides, more pesticides are often used on GM crops.

**Though there has been an increase in food allergies since the 1990s, it is impossible to prove GMOs are the cause, though perhaps it’s possible. 

Final Exam:  Grade C

The bottom line about GM crops is that there isn’t enough data to prove they have directly harmed humans.  Though there isn’t necessarily any data to prove their safety either.  And to me, their safety is inextricably linked to their impact on the environment, which isn’t favorable, to say the least.

In the next part of the series, we will address these environmental effects.

Mary Sig

 

 

 

 

Upcoming in the series:

  • Part 2:  The Environmental Impact of GMOs
  • Part 3:  The Responsibility of Eating – Things We All Should Be Doing

Sensible Science | Good Not Perfect

maryheadshot

Mary is a regular guest contributor to Good Not Perfect.  Mary grew up in Kansas City – raised by two science lovers – and met Laura and Emily during her stint as a Hoosier in college.  She currently lives in Denver with her husband and two daughters and works as a physician in internal medicine.  She aspires to be one of those women still running 10Ks in their 70s, and her bucket list includes visiting all 59 U.S. National Parks.

Examining Wheat Belly – Sensible Science

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Dear Laura,

I read your letter and am here to help.  With all the recent hype about Wheat Belly and gluten-free diets, it is hard not to think there must be real science supporting the trend.

Wheat’s biggest foe for the last two years has, without a doubt, been Dr. William Davis, cardiologist and author of the book Wheat Belly: Lose the Wheat, Lose the Weight and Find Your Path Back to Health.

What’s so wrong with wheat, anyway?  We all recognize that the Mediterranean countries have successfully been eating wheat as part of a healthy, balanced diet for centuries.  I thought it was worthwhile to put Wheat Belly to the test and take a closer look at the claims in the book.

Wheat Belly – The Good

Wheat Belly does contain some interesting and accurate scientific information.

WheatBellyTruths

  • We’re a carb nation – Most Americans (probably myself included) eat far too many carbohydrates, including wheat, and don’t come close to eating enough fruits and vegetables.  When I ask my obese patients to take me through their daily diets, most eat 1-2 servings of fruits or vegetables a day, which is far less than the recommended 5-13 servings.  If you’re eating a 2000 calorie diet, you need 9 servings (about 4 ½ cups) of fruits and veggies a day. And no, ketchup does not count as a vegetable.
  • We eat too much – As the book points out, too many calories and carbs contribute to obesity, diabetes and high cholesterol – all of which contribute to the #1 cause of death in women (and men, for that matter) – heart disease (see here).  So it follows that cutting back on calorie-dense carbs will certainly lead to weight loss and improvements in cholesterol and blood glucose numbers.  Though this could also be done just by decreasing portions of all foods, not just carbs or wheat.
  • Celiac Disease is attributable to wheat – This is the one disease mentioned in the book that actually IS attributable to wheat but is rare (U.S. prevalence is 0.71%) (see here).  Most people do not have this condition, characterized by diarrhea and malabsorption, which can be diagnosed on a simple blood test.  Irritable bowel syndrome (IBS) and other GI woes are unlikely related to wheat, though there may be a non-celiac IBS-like condition that responds to a gluten-free diet (see here).  But before you decide to eliminate wheat, check with your doctor.

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Wheat Belly – The Bad and The Ugly

Dr. Davis makes numerous outrageous health claims about wheat in his book, and here is just a sampling:outrageouswb

The first two claims above are completely unfounded, and Dr. Davis takes huge leaps of logic to reach these conclusions.  Simply put, the science does not support those two particular arguments.

The other claims in the list above are all related to carrying excess body weight and cannot be attributed to wheat alone.  And here lies the major flaw of the book – it’s being overweight, not wheat, that is actually wreaking havoc on our bodies.

Let’s take inflammation as an example.  Dr. Davis points out visceral (belly) fat functions as an organ in the body – an inflamed organ that releases inflammatory cytokines into the bloodstream.  These cytokines are cell signaling molecules that invoke a number of responses.  For starters, they worsen arthritis and add to pancreatic injury that is already occurring in diabetics and pre-diabetics.

magic inflammationThere are many more examples of this sort of logic in Wheat Belly.  But the bottom line is, wheat ≠ inflammation ≠ obesity ≠ the root of all evil.

My most recent patient success story actually didn’t have anything to do with wheat.  I have a patient who was drinking 130 ounces of Dr. Pepper a day. That’s 1625 calories per day of liquid love handles!  Not surprisingly, when he cut that out and stopped eating fast food, he lost 13 pounds in two months.  And even with this relatively small absolute weight loss, his cholesterol improved and his pre-diabetes vanished.

WBTestFail

 

The Whole Story about Whole Grains

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Unfortunately, Dr. Davis leaves out an important part of wheat’s story – the proven health benefits of whole grain wheat and other whole grains.

Consuming whole grains has been associated with:

  • Lower cholesterol
  • Decreased risk for diabetes
  • Lower risk of heart disease and all-cause mortality

Why are whole grains (including wheat) superior to refined grains?  It most likely has to do with glycemic index, the rate at which blood sugar rises after eating certain foods.  Whole grains still contain the bran and germ (fiber) that are removed in the grain refining process.  While refined grains – white flour, white rice – have a high glycemic index (rapidly spike blood sugar levels), whole grains are generally lower glycemic index.  A good rule of thumb – the more fiber in a food, the lower the glycemic index.  Spikes in blood sugar associated with ingestion of high glycemic index foods lead to metabolic syndrome – high cholesterol, insulin resistance, and obesity.  And the reverse is also true – eating lower glycemic index foods like whole grains, fruits, and vegetables lowers this risk of these conditions (see here).

wbgradeincomplete

Sources:

http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/health-gains-from-whole-grains/

http://summaries.cochrane.org/CD006061/whole-grain-foods-for-the-prevention-of-type-2-diabetes-mellitus

Wheat Belly – Final Exam

In my book, there’s nothing wrong with incorporating whole wheat as part of a healthy diet.  In Dr. Davis’s book, on the other hand, there are plenty of anecdotes of miraculous “cures” for his patients who eliminate wheat from their diets.

I don’t doubt the Wheat Belly stories, just the reasons behind them.

So why might people feel better after eliminating wheat?

  • They lose weight – Restricting anything you are prone to overeat (Cheez-Itz, Oreos, pasta) will help you lose weight.
  • They get a higher proportion of their calories from protein – What’s left after you eliminate the bread from your lunchtime sub?  A salad with lean protein. This increase in the proportion of calories from protein leads to greater satiety.  Simply put, protein fills you up more than carbs.
  • They increase fiber intake – Because of their fiber and water content, fruits and vegetables also make you feel full, similar to protein.  For example, which do you think would fill you up more – four Oreo cookies -OR- five cups of romaine lettuce topped with a carrot, a tomato, and a cucumber with an apple on the side?  (They both have approximately 220 calories.)  Fiber also helps relieve constipation and IBS symptoms.

220 calories

Final Exam:

WBTestFail

 

 

 

 

Extra Credit

I would be remiss without mentioning another fashionable argument against wheat.  Yes, “Wheat contains antinutrients” seems to be quite the common catch phrase these days.

  • It’s true.  Wheat contains phytic acid, aka phytate, the storage form of a plant’s phosphorus.  As do all plants.  When something that contains pyhtate is eaten, phytic acid binds to certain minerals in the gastrointestinal tract, and too many bound minerals can lead to mineral deficiencies (severe mineral deficiencies could eventually result in osteoporosis or rickets).
  • By dry weight, nuts (particularly brazil nuts, almonds, and walnuts) generally contain more phytic acid than similar amounts of grains and legumes (see here).  Phytic acid is also present in coconut meat.
  • Research is constantly evolving regarding the healing compounds of plants.  Despite all the bad PR surrounding phytic acid, it may have some potential health benefits.  Phytochemicals have been known to exhibit potent antioxidant activity (see here).  Preliminary research also shows that it can stop growth of certain breast cancers (see here).

The anti-nutrient argument is an argument against excessive ingestion of wheat, legumes, or nuts, not an argument against these foods in absolute terms.  You will likely maintain a balance between high-phytate foods versus the nutrients affected by phytate if you are eating a wide variety of foods in your diet.

In fact, the risk that any adult in the U.S. would suffer severe manifestations of nutritional deficiencies is exceedingly rare.  In my eight years of interacting with patients, I have only seen one case of severe nutritional deficiency – we diagnosed a patient with scurvy (vitamin C deficiency) and later found out his diet consisted of only the meat portion of Salisbury steak TV dinners.

Above all, keep in mind that “wheat-free” is one in a long line of America’s fad diet obsessions.  And diets are only effective so long as you can maintain them your entire life.

A more sustainable approach is balance – a variety of fruits, vegetables, whole grains, and lean proteins.

Michael Pollan says it best: “Eat food.  Not too much.  Mostly plants.” … including whole grains.

Mary Sig

Sensible science complete

maryheadshot

Mary is a regular guest contributor to Good Not Perfect.  Mary grew up in Kansas City – raised by two science lovers – and met Laura and Emily during her stint as a Hoosier in college.  She currently lives in Denver with her husband and two daughters and works as a physician in internal medicine.  She aspires to be one of those women still running 10Ks in their 70s, and her bucket list includes visiting all 59 U.S. National Parks.