Good data (and good conclusions) on (not much) arsenic in CA wines

Short: A new article in the American Journal of Enology and Viticulture publishes data showing that California wines contain honest-to-goodness insignificant amounts of arsenic. Even if you can’t call the authors completely disinterested, they’ve published their data openly in an excellent scientific journal (and that’s a lot better than you can say for the arsenic fearmongers).


At the risk of bringing up what must surely be everyone’s least favorite wine story from 2015, I’m writing once again about arsenic in wine. I hope you’ll agree with me that, given the reason, it’s justified. A group of reasonably trustworthy researchers has published a scholarly research article demonstrating that California wines don’t have an arsenic problem, and while their work won’t put the arsenic-wine baby to bed once and for all, it goes a long way in the right direction.

My denigration of the perpetrators a year before the scandal broke is here, and my response to the scandal itself is here.

Two problems have lain at the bottom of all of the talk about arsenic in wine. One is that no one – not the US government, not the World Health Organization, and not expert toxicologists talking amongst themselves in the peer-reviewed toxicology literature – is sure how much arsenic is too much arsenic. The other is that the people talking about arsenic in wine haven’t been transparent with their data. This article doesn’t help with the first problem, but it does help with the second.

In short, two independent wine testing labs ran arsenic stats for 28 wines named in the arsenic-related lawsuit brought against California wineries, plus 73 other California wines bought essentially at random* from stores in Pennsylvania and New York. The results:

Wine category                               Mean arsenic concentration                      Standard deviation

Reds                                                6.75 µg/L**                                                    7.33 µg/L

Whites                                           10.9 µg/L                                                         11.0 µg/L

Rosés                                             27.2 µg/L                                                        16.9 µg/L

The first and most important thing to observe about these numbers is that they’re all dramatically lower than the 100 µg/L guideline Health Canada has set for wine and even more dramatically lower than the 200 µg/L the International Organization of Vine and Wine (OIV) has set for its members (of which the United States is not one, but which includes nearly every other significant winemaking country around the globe). (The United States hasn’t regulated arsenic in wine.) Even the wine with the highest concentration of arsenic in this study clocked in at 68.4 µg/L. Yes. Some of these numbers are higher than the 10 µg/L the US Environmental Protection Agency allows in drinking water. But do you drink wine the same way you drink drinking water? Compare wine to food, not to water.

The second thing to note is that, generally speaking, cheaper wines had higher arsenic concentrations. That’s both interesting and not unexpected. (Higher concentrations in rosés and whites than reds, incidentally, isn’t a factor of price. The white >> red phenomenon has been observed in other studies and is assumed to have something to do with processing, though we’re unsure what.)

The third thing to know is that the wines cited in the lawsuit had higher arsenic concentrations (25.6 µg/L) than the random wines (7.42 µg/L), but even the lawsuit-associated wines were still dramatically lower than the 100 µg/L guideline. The wines in the lawsuit were cheaper, generally speaking, than the average wines.

And the fourth thing to note, once again, is that you don’t need to be worried about arsenic poisoning from wine. These researchers did something I think is silly and calculated “average daily” arsenic exposure from average wine consumption data rather than calculating exposure for a heavy-imbiber. To generalize just a bit from their data, the average American drinking two five-ounce glasses of Californian wine a week, every week, will get no more than 10% of the arsenic in her diet from wine, even if she’s drinking the cheap stuff. Arsenic is naturally present in the environment. It’s in water, rice, meat, beer, and bread. If you smoke, you’re getting arsenic in tobacco.

I’m not willing to call this research “unbiased.” Research is never unbiased; scientists can’t escape having a point of view any more than you or I, and it colors the scientific process from the questions they ask to the methods they choose, the way they read their instruments, and the conclusions they draw even if they’re trying in all earnestness to be objective. The labs behind this paper have also run tests and provided evidence for the wine industry in the past, and it’s presumably in the authors’ best interest to conclude in the wine industry’s favor. For that matter, it’s also in the best interest of the publishers of the journal, the American Society for Enology and Viticulture, to side with California’s wineries. All of that said, everyone’s long-term reputations here are best-served by being fair and transparent and there’s every good reason to think that they’re doing just that. And that’s a lot more than can be said for the arsenic fearmongers BeverageGrades.

*The researchers used a “convenience sample,” which in this case means that instead of trying to devise some strategy for obtaining a “representative” sample, they used what they could find. Convenience samples are sometimes a real problem in research (when a psychologist uses the freshmen in his psych 101 class to represent the American public, for example), but here this strategy makes a lot of sense: these are wines you’re going to commonly find as a consumer.

**µg/L = micrograms of arsenic per liter of wine

Arsenic, BeverageGrades, and the Power of Withholding Information

UPDATE: Kevin Hicks brought a class action lawsuit against multiple California wineries for selling wine containing undisclosed high concentrations of arsenic in March 2015. I’ve posted about that here.

I received an unusual “story” by way of Palate Press this week. It looked like this:


Alcoholic beverage testing company, BeverageGrades has discovered lead
and arsenic present in wine at levels that exceed the Environmental
Protection Agency (EPA) standard Maximum Contaminant Levels for
drinking water.
Independent laboratory testing has been conducted on the top selling
white wines in the United States. Approximately one in every three
bottles tested was found to contain either arsenic or lead levels that
exceed the Maximum Contaminant Level.
Regular consumption of these elements, even at low levels, can present
a serious health risk.

Topic (wine, food, wine pairing, travel, etc.)
Wine Science

Suggested Title
High Levels of Arsenic and Lead Detected in Wine

Approximately one third of the top selling wines in the United States
found to contain lead and arsenic.

Your Website or Other Writing Sample

Preferred payment method:

Mailing Address (Check)
7000 Broadway
Suite 307
Denver, CO

PayPal email

BeverageGrades, it seems, is a young company creating a private database of beverage health information, summarized in their trademarked “grades.” They say that they run a bottle – of wine at the moment, of beer, spirits, and coolers in the future – through a pile of lab tests to create a profile for each product. Users can see calories, sugar, and carbohydrates per serving, plus a set of “grades” that are supposed to indicate how healthy a wine is overall, how “skinny” it is, how “pure” it is, how likely it is to trouble your allergies, and how likely it is to give you a headache. The problem with HealthyPour™, SkinnyGrade™, and the rest of these ratings is that if you’re looking for more information on how they’re calculated, you’re out of luck. New users have to click “I do” to having read BeverageGrade’s methodologies page, but those “methodologies” say nothing more detailed than “we take lots of measurements of lots of stuff.” And, rather than showing numbers for any of these measurements, wines are rated as average or better or worse than average.

Concerns about proprietary details aside, that’s not enough information. What in tarnation does “pure” mean? What counts as a “contaminant” or an “additive” in BeverageGrade-speak? How do they summarize how healthful a wine is when a whole pile of scientists are still trying to figure out how and why and whether wine is healthy? They list sodium and “vitamins and minerals,” but should I care about sodium in wine, and is wine a good source of “vitamins and minerals” in the first place?

Instead of seeking to educate consumers, BeverageGrades is patronizing them with overly simplistic branded products while hiding information. And that brings us back to arsenic.

Arsenic is found in wine. Recent studies in New Hampshire and France have shown higher arsenic concentrations (in toenails and urine) in wine drinkers versus non-wine drinkers (fish, beer, and Brussels sprouts were similarly implicated, as has been rice in studies based in Asian countries). Arsenic is found in water and soil; drinking water remains, in fact, our most significant source of arsenic exposure. Grapevines and some other plants seem to take up and concentrate it and other heavy metals. The FDA has set maximum limits on how much arsenic can be present in apple and pear juices in the US and is working on similar limits for rice; wine very well may be next on the list. If we stop here, things look bad. 

But stopping there means withholding important information. Saying that arsenic is found in wine is, crucially, different from saying that arsenic in wine poses a significant health risk. Arsenic in wine and arsenic as a health risk in general aren’t things we understand well yet. We don’t yet have a clear picture of how much arsenic is too much arsenic (the same is true for a lot of environmental toxins, including lead).

The several recent studies I found all indicate that arsenic in wine probably doesn’t pose a significant risk to most drinkers. The “probably,” “significant,” and “most” hedges in the previous sentence are all a nod to that yet-unsolved “how much arsenic is too much” problem. But an analysis of arsenic in wine, sake, and beer for sale in Central Europe concluded that it’s not a significant risk to consumers. A comparative risk assessment of fifteen “known and suspected human carcinogens” judged that ethanol was the only really significant carcinogen in alcoholic beverages; the rest, including arsenic, “may pose risks below thresholds normally tolerated for food contaminants.” In other words, these fish are too small to bother frying.

I suspect that BeverageGrades isn’t counting alcohol itself against a wine’s HealthyPour™ rating – though I don’t know for sure, since they’re not sharing that information. In any case, I appreciated a comment made by one reader of a popular press story about arsenic in wine, who suggested that not just drinking, but eating and breathing and sleeping were hazardous to our health, too, and that we should probably stop doing all of those things. Wine, unlike breathing, isn’t a necessity. But if we try to eliminate every risk from our way of life, we’ll end up not living at all.