Pesticide exposure: separating facts from fears

An advocacy group called Friends of the Earth has been publicizing the results of a new study demonstrating that when people switch from a regular diet to one containing only organic foods, their exposure to pesticides is reduced.

The study recruited four families from different corners of the country.  Each family ate a non-organic diet for six days and an all-organic diet for six days. The researchers found that the organic diet “rapidly and dramatically reduced exposure to pesticides.” 

That’s not terribly surprising.  In fact, it’s so unsurprising, it’s a little hard to imagine why the researchers felt the need to do this study.

The far more important question (not answered in this study) is: Is this something we need to worry about?

Relatively major but absolutely minor

In reporting their findings, the Friends of the Earth present the difference in exposure in relative terms. “Levels of all detected chemicals dropped an average of 60.5 percent with a range of 37 percent to 95 percent depending on the compound.”

But they don’t give us any information about the absolute levels of exposure.  This is at least as important as the relative exposure. Celery has 40 times as much sodium as cucumber. It’s still a low sodium food.

Did those higher levels of exposure pose any sort of threat? Or were they (as I suspect) well below the threshold of concern?

Good Riddance to Bad Rubbish

Secondly, the coverage repeatedly talks about the “pesticide levels in the bodies” of the subjects. But the study didn’t test the subjects’ blood or tissues. They tested their urine, which is where the body discards things it doesn’t want or need.  Furthermore, what they found in the urine were compounds formed when the pesticides were broken down by the liver.

In other words, what they found was evidence that the body’s detoxification systems were working exactly as they are supposed to, breaking down and excreting potentially harmful compounds. The pesticides these families were being exposed to by eating a non-organic diet were apparently being eliminated from their bodies.

So I have to ask once again: Is this really something that we need to worry about?

One of these things is not like the other

The organization points out that one of the pesticides monitored in this study is frequently linked to farmworker poisonings.  That’s a great argument for farmers using more care when working with agricultural chemicals (and that goes for synthetic as well as organic chemicals). But it doesn’t really have anything to do with risks that families might be exposed to by eating conventional produce.  And yet, by juxtaposing these two facts in the press release, it implies that eating non-organic foods increases your risk of chemical poisoning.  There is absolutely no data to support this implication.

Good news is no news?

Meanwhile, the press reports don’t mention that a third of the compounds they were testing for were undetectable in the urine samples after the non-organic diet. You have to wonder whether they were, perversely, somewhat disappointed by this.  They certainly didn’t seem very eager to publicize the fact that some of the most common pesticides used in conventional agriculture apparently pose little risk to eaters.

So, what’s the upshot of all this?

The Friends of the Earth concludes that “these results show that eating organic works.”  Works how, exactly? Yes, eating organic  reduces your exposure to certain (but not all) pesticides. But does it reduce your risk of disease or harm? I don’t see any evidence of that here.

This is Important. Let’s Get it Right

Lest you think I am pro-pesticide, or anti-organic, let me assure you I’m not. I’m just against this sort of sloppy communication and manipulative “science.”

Conventional farmers don’t use pesticides because they’re lazy, ignorant, or uncaring. They use them, as sparingly as they can get away with, in order to maximize yields and lower the cost of food.  If they can figure out a way to use less, they are eager to do so.

Organic farmers use pesticides and herbicides, too, by the way. Some of these organic pesticides are highly toxic to beneficial insects and, if mishandled, can be harmful to humans, as well.  But organic farmers are also working to increase yield and reduce the cost of their products. And pest control is part of that.

Instead of pitting organic growers (and eaters) against conventional, why not work together to make progress on all of these important fronts? Let’s use the best technology, the best practices and, yes, the best chemistry, to create a safer, more abundant, and more sustainable food supply.

To that end, let’s assess the risks and impacts of chemical use (both synthetic and organic). Let’s weigh the costs and benefits of various options. But let’s debate the issues on their scientific merits instead of resorting to sensational, misleading, and manipulative “research” and rhetoric.

This is not an us vs. them situation. We’re all us.

Quick Guide to Complementary Protein Sources

In this week’s Nutrition Diva podcast, I talk with protein researcher Douglas Paddon Jones about whether or not there’s any benefit to combining complementary plant-based protein sources at the same meal. Contrary to a lot of the conventional wisdom, which claims that it’s sufficient to get all of the essential amino acids over the course of a single day, Dr. Paddon Jones argues  that a meal-based approach to protein nutrition will enhance the ability to build and maintain lean muscle tissue.

This doesn’t mean you have to tally up and micro-manage each individual amino acid. The following chart shows how to choose meal components that will ensure complete proteins at a meal.

If you consume only plant-based proteins, you may also want to increase your total protein intake by 10-20% to compensate for the lower digestibility of these plant-based protein. 

The Recommended Daily Allowance for protein is 0.8 g per kg of body weight (or 0.36 g per pound). Strict vegetarians may want to aim for a minimum of 1 g per kg (or 0.45 g per pound).

These are these are minimum recommended intakes. Research suggests that there may be benefits to higher protein diets, especially for athletes, the elderly, those recovering from surgery or illness, or during weight loss. If you’re in any of these groups, you might want to aim for something closer to twice the recommended minimum.

 

What are the best and worst kinds of fruit?

In this week’s Nutrition Diva podcast, I debunked the myth that you should avoid certain types of fruit, either because they are higher in sugar or higher in fructose.   All fruit can be part of a healthy diet–especially if you are eating fruit in place of other less healthy choices. 

But if you’re curious to see how various types of fruit stack up in terms of total sugar content as well as fructose and glucose content, here’s a chart of some common fruits. You can click on any column to sort by that value.

Fruit (1 cup serving)Total Sugars (g)Fructose (g)Glucose (g)
Source: USDA National Nutrient Database for Standard Reference
Raisins1085750
Dates, medjool864244
Figs, dried713437
Apricots, dried691643
Plums, dried (prunes)662244
Bananas281111
Grapes231211
Mangos2383
Tangerines2154
Cherries1879
Plums1658
Pineapple1643
Kiwi1687
Grapefruit1644
Blueberries1577
Apricots, fresh1414
Oranges1443
Cantaloupe1433
Honeydew1455
Pears1494
Peaches1323
Papaya1156
Apples1162
Nectarines1122
Watermelon1052
Strawberries743
Blackberries733
Raspberries532
Cranberries514

 

Can we all calm down about coconut oil?

I’ve gotten several emails from readers asking me to respond to a viral video in which a Harvard (Harvard!) professor asserts that coconut oil is “pure poison.”

It’s hard to imagine how someone with such a prestigious pedigree could make such as silly and sensational statement in public. Presumably she was pushed over the edge by the ridiculous claims that some people have been making about coconut oil lately.

Can we all just calm down about coconut oil?

Coconut oil is not pure poison. On the other hand, it’s also not going to make you smarter, thinner, younger, or fold your laundry for you.

Proponents of coconut oil make a big deal out of the fact that coconut oil is rich in medium chain triglycerides (MCTs). But, as I discussed in my podcast episode on MCTs, claims for these specialty fats tend to be exaggerated or unproven.

Coconut oil haters such as this Harvard (!) professor mostly object to the fact that coconut is is almost 100% saturated fat. But, as I discussed in my recent podcast episode on butter, saturated fat in moderation may even have some heart health benefits.

Despite saturated fat’s rehabilitated reputation, I still think it makes sense to limit saturated fat intake to around 10-15% of calories, if for no other reason than to leave room in the diet for other healthy fats. But if you want to spend your sat fat allowance on coconut oil, I see no reason to call in Poison Control.

Where does fat go when you lose it?

Pride goeth before a fail.

When I saw this headline earlier this morning, I clicked through (Mission accomplished, headline writers) and skimmed the article, which seemed to contradict the basic facts that we all learn in nutritional biochemistry. Having not yet had my coffee (yes, I’m making lame excuses), I impulsively posted it on Facebook with a “Shame on you, CNN” comment.

Fortunately, my followers are smarter than I am…and are not afraid to tell me so. So, let me try this again, appropriately humbled.

Let’s Play Biochemistry Gotcha!

Had I been one of those-who-should-know-better surveyed by the authors, I too would have fallen into the trap and said that fat is converted into energy (with water and CO2 as byproducts). But this is not quite accurate. Continue reading “Where does fat go when you lose it?” >

Can collagen supplements make your skin younger?

There’s a lot of buzz about collagen peptide supplements these days. Collagen is a structural protein present in the skin, joints, hair and nails. The gradual loss of collagen as we age can make the skin look less plump. The idea is that collagen supplements can replace some of that lost collagen and improve the look of the skin.

Assessing the effectiveness of skin care products or supplements is notoriously difficult. For one thing, it’s difficult to isolate the effects of any particular cream or pill. The condition of our skin surface can be affected by diet, hydration, sun exposure, temperature and humidity. It’s also really hard to be objective about what we’re seeing in the mirror.  So how do we know whether these supplements are actually working? Continue reading “Can collagen supplements make your skin younger?” >

Is IV Nutrition Worth a Try?

Will IV Therapy improve your health?

If you have a confirmed deficiency of a specific nutrient, or a condition that prevents you from absorbing nutrients  delivered orally, IV nutrition might make sense. And if you were severely dehydrated, an IV can be an efficient way to deliver fluids.

But I have grave reservations about these “IV therapy” clinics that are springing up and pumping people full of nutrient cocktails.  Although it’s promoted as everything from a hangover cure to energy booster to anti-aging therapy, most of the claims are not supported by evidence and may even be unsafe.

IV fluids may help relieve some of the acute symptoms of a hangover (many of which are due to dehydration), but won’t counteract the other harmful effects of drinking too much. More questionable are the alleged benefits of the vitamins, minerals, and other compounds used in IV therapy.

Supplying nutrients in excess of the body’s needs will not make your cellular processes work better or faster, any more than over-filling your gas tank will make your car run faster. High doses of antioxidants can even shut down the body’s own antioxidant mechanisms.  There are also general risks associated with any IV therapy, such as infection or hematoma.

Those administering IV therapy may be well-meaning but uninformed, or they may simply be out to make a buck. Given the lack of regulation and oversight (and research), I think I’d steer clear.

What is the Sirtfood Diet?

Will there ever be an end to silly new diet trends?

The Sirtfood Diet is the latest to cross my desk and, boy, is it a doozy.

The premise is that certain foods increase the activity of sir ruins in your body. Sirtuins are special proteins which allegedly have all sorts of beneficial effects, everything from fighting inflammation to preventing cancer and neurodegenerative diseases, all the way to reversing aging and extending lifespan.

The Sirtdiet protocol consists of lots of green smoothies and other meals made from “sirtfoods,” which include capers, celery, cocoa powder, green tea, kale,  parsley, onions, strawberries, turmeric, and walnuts.

Nothing wrong with those foods.  But there is a lot wrong with this diet.

First, the claims for this diet are not only unproven, they verge on the preposterous. Although sirtuins are an area of promising research, what we don’t know about them far exceeds what we do know about them.

Even if we did know more about how sirtiuns promote health and longevity, the idea that these foods will increase sirtuin activity is pure speculation.  These foods are rich in poloyphenols, compounds that might boost sirutin activity. Then again they might not. We’ll have to get back to you on that.

The other problem with this diet is that it is designed to produce extreme (and extremely fast) weight loss. As you’ve heard me say before, dieting is counter-productive. Extreme dieting is extremely counter-productive.

I bet a lot of these so called “sirtfoods” are already in your diet. Stay the course! And some of the “sirtfood” recipes I’ve seen look delicious. Feel free to add them to your repertoire. But the actual Sirtfood Diet protocol? I’d pass on that if I were you.