health

Don’t Drink the Agave-Sweetened Kool-Aid Part I: “Natural” my foot

Mar 2 2010

UGH the subtitle. I really want Ms. Catalano to show me exactly where in "nature" she gets her agave nectar. Also, I find the use of "ultimate" to mean "exemplary" or "best" instead of "final" or "last" grating, but that's a petty battle against usage change that "Ultimate Frisbee" has clearly already won. Still, I like to think of it as "Frisbee for the End Days" Just as "wholesome" as any other hydrolyzed, refined sweetener. If you've been snarky about the Corn Refiners' Assn's recent "Sweet Surprise" marketing campaign, but have a bottle that looks like this in your cupboard, I have some delicious all-natural snake oil to sell you, good sir or madam.

This entry was nearly titled “Things That Might Not Kill You In Moderation But Certainly Won’t Make You Any Healthier Vol. I,” or “Hydrolyzed, Refined Sweeteners Masquerading as ‘Natural,’ Whole Foods,” but those seemed a little unwieldy. They do, however, capture the essence of the argument: agave is nutritionally no better than most other refined sweeteners, including high-fructose corn syrup (HFCS). If anything, it’s probably worse because it contains more fructose than table sugar or HFCS. It’s also no more or less “natural” than HFCS—it’s actually produced in a remarkably similar process that was first used on the fibrous pulp of the agave in the 1990s. While, as its proponents claim, the higher proportion of fructose has enabled people to call it a “low glycemic index sweetener,” sometimes alleged to be safer for diabetics and recommended by weight-loss programs like Weight Watchers, recent research suggests that large amounts of fructose aren’t healthy for anyone, diabetic or otherwise.

I mentioned agave nectar in passing in the HFCS post, but there’s enough conflicting information about it to merit its own post(s). A lot of the misinformation comes from agavevangelists, who can sometimes get a little sanctimonious about their avoidance of the demon HFCS and preference for “natural” sweeteners. Even this Vegfamily article that concludes “the physiological effects of all [caloric] sweeteners are similar” nonetheless claims:

Given the choice between sugar, HFCS, and agave nectar, I'll stick with organically-grown, unbleached cane sugar (evaporated cane juice) and organic raw agave nectar that are free of pesticides, herbicides, and chemical bleaching agents; not genetically engineered; and still retains some nutrients, as well as being vegan. Since HFCS is not available in organic form and is highly processed, I would never use it.

But agave nectar is just as processed as HFCS.

HFCS and Agave Nectar: One of These Things is Not Almost Exactly Like The Other

1910 magazine advertisement from http://goldcountrygirls.blogspot.com/2009/10/then-and-now-49-karo-syrup.html Like most starches, corn starch consists of large glucose polymers—70-80% the branched, non-water soluble amylopectin and 20-30% linear, soluble amylose. Normal or non-HFCS corn syrup, like Karo, is produced by breaking those polymers down into their constituent glucose molecules using acids, enzymes, and/or heat. For the history buffs: the acid hydrolysis of starch was first discovered because of the 1806 British blockade of the French West Indies. Napoleon I offered a cash reward for anyone who could come up with a replacement for cane sugar, and a Russian chemist named Konstantin Kirchhof found he could produce a sweet syrup from potato starch by adding sulfuric acid. The same process was first applied to corn in the mid-1860s, and gained popularity in the U.S. during the sugar shortages of WWI (source: The Oxford Encyclopedia of Food and Drink in America).

HFCS is produced by converting the glucose into fructose using an enzyme technology developed in Japan in the 1960s (detailed here). The resulting syrup, which contains up to 90% fructose, is then typically mixed with corn-based glucose syrup to produce HFCS-55 (the kind used in soft drinks, which has 55% fructose/45% glucose) or HFCS-45 (the kind used in baked goods, which has 45% fructose/55% glucose). Some people, like Cynthia commenting on Daily Candor, have suggested that the fructose and glucose in HFCS are absorbed into the bloodstream faster because they’re “free" instead of bound the way they are in the disacccharide sucrose, which is broken into glucose and fructose by the enzyme sucrase. Theoretically plausible, but apparently not true:

Sucrose is hydrolysed by brush-border sucrase into glucose and fructose.
The rate of absorption is identical, regardless of whether the sugar is presented to the mucosa as the disaccharide or the component monosaccharides (Gray & Ingelfinger, I 966, cited by H. B. McMichael in “Intestinal absorption of carbohydrates in man”).

I'm going to start refering to packaging like this as granola-washingJust like HFCS, agave nectar is produced by breaking down a plant-based polymer into its constituent sugars. In the case of agave, the relevant molecule is inulin, a fiber composed mostly of fructose units with a terminal glucose. Just like with corn and potato starch, there are different methods of hydrolyzing the sugars in inulin.  Blue Agave Nectar uses a thermic process. Madhava uses an enzyme process, just like HFCS.

Agavevangelists like to claim that agave nectar is a traditional sweetener used by native peoples, which appeals to the popular notion that the foodways of the past were generally healthier (e.g. Michael Pollan’s advice not to eat anything your great-grandmother wouldn’t recognize as food). Some, like Lynn Stephens of Shake Off the Sugar, merely note that the agave plant itself “has long been cultivated in hilly, semi-arid soils of Mexico.” That’s true, although it’s about as relevant as the long history of corn cultivation. Others claim that agave nectar itself has an ancient history. Flickr user Health Guy says of agave nectar: “It is 1-1/4 times sweeter than sugar, so you need less, and it has been consumed by ancient civilizations for over 5,000 years.”

Wrong. According to the website for Madhava Honey:

Agave nectar is a newly created sweetener, having been developed during the 1990's. Originally, the blue agave variety was used. This is the same plant used in the manufacture of tequila. During the late 90's, a shortage of blue agave resulted in huge increases in cost and a sweetener based on this plant became uneconomical. Further research was done and a method using wild agave was developed. Overcoming the language barrier between the Indians able to supply the nectar from the wild agave on their land and the Spanish speaking local manufacturer was the key that finally unlocked a supply of raw material and has led to our bringing this wonderful new product to market.

Still doing some native-washing (wild agave harvested by Indians who don’t speak Spanish—can’t you just feel the virtue?), but here’s what happens to the agave sap after harvesting, as described in the abstract of the 1998 patent issued for the production of fructose syrup from the agave plant:

A pulp of milled agave plant heads are liquified during centrifugation and a polyfructose solution is removed and then concentrated to produce a polyfructose concentrate. Small particulates are removed by centrifugation and/or filtration and colloids are removed using termic coagulation techniques to produce a partially purified polyfructose extract substantially free of suspended solids. The polyfructose extract is treated with activated charcoal and cationic and anionic resins to produce a demineralized, partially hydrolyzed polyfructose extract. This partially hydrolyzed polyfructose extract is then hydrolyzed with inulin enzymes to produce a hydrolyzed fructose extract. Concentration of the fructose extract yields a fructose syrup. (via Patentstorm)

Probably the healthiest sweetener pictured here and the one most shoppers in the market for a "natural sweetener" would be least likely to purchaseIt’s true that the corn used in HFCS is less likely than agave to be organically-grown, but you can get organic-certified corn syrup from the same manufacturer as the blue agave nectar pictured above and nutritionally, the main difference between that, the HFCS used in most processed foods, and agave nectar is the ratio of glucose: fructose. The regular corn syrup is 100% glucose, HFCS is usually 55/45 glucose/fructose, and agave nectar 56-90% fructose, depending on the plant and the process.

I’ve already talked a little about fructose vs. glucose here and here, but more coming soon in Agave-rant Part II concerning:

1) whether the fructose in agave is somehow better than, or indeed, different in any way from the fructose in HFCS

2) whether the fact that it’s sweeter than sugar makes it a lower-calorie alternative to sugar

3) whether its “low glycemic index” rating makes less likely to produce insulin resistance than table sugar and

4) whether it’s safer for diabetics

All of which people have claimed. I won’t keep you in suspense, especially given how long it may take me to put all of that together. The short answers are:

1) not in any nutritionally meaningful way

2) perhaps very slightly, but a <10 calorie/serving difference likely doesn’t make up for the increased risk of fatty liver syndrome and insulin resistance

3) no, it’s actually more likely to produce insulin resistance and

4) in miniscule amounts, perhaps, but recent trials involving diabetics and agave nectar were halted because of severe side effects.

Things That Won't Kill You Volume 4: Saturated Fat, Part I

Dec 14 2009

I know this is misleading because lard is mostly unsaturated, but it's been one of the major icons of "bad" fat and also, how graet is this image? from http://www.npnworldwide.com/lard

This is probably going to be an even harder sell than MSG, but I swear I'm not just trying to be contrary. It's true that all the major sources of public health and nutrition advice, including the Harvard School of Public Health, Mayo Clinic, CDC, and American Heart Association continue to refer to saturated fats as "bad fats" and suggest that people avoid them as much as possible, limit them to <7-8% of their total caloric intake, and replace them with "good," i.e. unsaturated fats, whenever possible. It's also true that there are a few studies that suggest that increased saturated fat consumption is correlated (albeit weakly) with cardiovascular disease (CVD).

However, many other studies have found no increase in CVD associated with saturated fat consumption. And several recent review articles have concluded that the evidence for a connection between saturated fat consumption and CVD is inconsistent, insufficient or nonexistent.

There are basically three things that have convinced me that saturated fat isn't independently responsible for heart disease or death:

1) groups of people who eat vastly more saturated fat than most Americans frequently have lower rates of CVD—or no apparent CVD at all

2) the study that first inspired many people to think saturated fat was a bad thing had a lot of obvious flaws and has been thoroughly discredited

3) there's no good evidence that the proposed mechanism actually works—briefly: saturated fat supposedly causes heart disease by raising serum cholesterol levels because cholesterol is what clogs arteries and causes heart attacks and strokes, but serum cholesterol turns out to be a really poor predictor of CVD 

1) The French (and Polynesian and Melanesian and Masai and Fulani and Sri Lankan) Paradox 

photo by Arun Ganesh http://en.wikipedia.org/wiki/User:PlaneMadThe most confounding phenomenon for the theory that saturated fat consumption causes heart disease (sometimes called the lipid hypothesis or lipid-heart hypothesis or diet-heart hypothesis) is the virtual non-existence of CVD in multiple populations that eat way more saturated fat than most Americans. This has primarily been documented in the Pacific islands where coconuts, which are very high in saturated fat, are a staple food. For example, before the 1970s, the inhabitants of the island Tokelau got an estimated 55% of their calories from saturated fat, but heart disease was virtually unknown (according to Gary Taubes and Stephen Guyenet; notably, since their diet has shifted to include less saturated fat but more sugars and refined carbohydrates, many health indicators have worsened). Read more

Things That Won't Kill You Volume 3: MSG

Oct 14 2009

From Flickr user "The Other Dan" taken in Corktown, Toronto 

Unlike juice, which has sort of a mixed reputation even among contemporary nutritionists and doctors, MSG has been consistently demonized. Most people can't tell you why, they just know that it's bad. If pressed, they might tell you that it's "unnatural," that food manufacturers put it in processed foods to con people into eating "junk," that it's basically salt (which I'll address in a future post in this series), or that it gives some people headaches. Or they might just gesture to the fact that it's common knowledge that MSG is basically some kind of poison—after all, why would Chinese restaurants be so eager to reassure you that they don't use it if it were completely benign?

A recent commercial for Campbell's New Select Harvest Light (which is the sort of self-satirizing product name I'd expect to find in David Foster Wallace's fiction) suggests that even if people don't know what MSG stands for, they know that it's bad—potentially bad enough to deter people from buying a particular brand. Reading from a Progresso Light can, blonde #1 gets through "monosodium" but stumbles on "glutamate"—fortunately, the rainbow coalition includes an Asian woman who can translate that jargon into something we all understand: "That's MSG."

Although people may still associate it primarily with Chinese restaurant cooking, the Campbell's ad hints at its broader prevalence—MSG and other forms of glutamic acid are omnipresent in processed foods. They're especially likely to be found in foods designed to taste like things that have a lot of naturally-occurring glutamate (or similar molecules like inosinate or guanylate). Stock, broth, and bouillon often contain MSG, as does anything cheese-flavored or ranch-flavored, like Doritos, which actually contain five different forms of glutamate. I taste it the most in instant ramen and Chex Mix, but even though I know what it tastes like on its own, I can't always tell when something contains it or not. When used sparingly, it may not even be possible to discern because whether the glutamate in a dish comes from a mushroom or a salt, once it's dissolved in liquid or on your tongue, it's the exact same molecule:

from Wikipedia, showing up weirdly gray here

So even people who think it's "bad" and expect to feel bad after eating it probably eat MSG, at least from time to time, without even knowing it, and without suffering any negative effects.Read more

Against the Soda Tax

Oct 6 2009

awesome depth of field courtesy of Stephane Pompougnac http://www.flickr.com/photos/vox_efx/3063389109/

Although many states already tax soda (usually a fraction of a penny per ounce), a recent article in the New England Journal of Medicine on the potential benefits of a $0.01 per ounce tax on "soft drinks, energy drinks, sports beverages, and many juices and ice teas" has re-ignited the debate about whether or not we need a national soda tax. Back in July, Obama said a sin tax on soda was "an idea we should be exploring" in an interview with Men's Health although in the recent panic about industry profits and personal liberties, the White House has been quick to note that they haven't yet and have no plans to propose anything like it. 

Most people probably already know how the two sides shake out: promoters argue that soda makes people fat (which allegedly makes people sick and thus incurs social costs) so the tax would have the dual benefit of reducing the costs associated with obesity and generating money that would help cover health care costs (or balance state budgets). Opponents argue that soda isn't morally distinct from many other elective behaviors that sometimes (but not always) contribute to disease and health care costs, and as soda consumption is inversely correlated with income, taxing it would disproportionately burden those least able to pay.

All of those are actually pretty complicated claims, some of which I'll try to unpack below the jump but here's the short version: even promoters admit that the tax isn't likely to meaningfully reduce obesity or the diseases associated with it (note: not caused by it, as there's still no reliable evidence that fatness causes any disease besides osteoarthritis, and anyone who wants to hear more about that should consult Paul Campos' The Obesity Myth, J. Eric Oliver's Fat Politics, Glen Gaesser's Big Fat Lies, and/or Michael Gard and Jan Wright's The Obesity Epidemic). That means the only real argument in favor of the tax is that it would raise money. But everyone agrees that it would be a regressive tax. So unless you think that collective costs like state budget deficits and health care reform should be disproportionately shouldered by the poorest citizens, there is no good reason to support the soda tax (and this goes double for ill-considered suggestions that we just axe corn subsidies instead—also after the jump).Read more

Things that won't kill you Vol. 2: Fruit juice

Sep 17 2009

This may seem like a strange thing to argue about, because the popular consensus still seems to be that juice is healthy. Jamba Juice markets itself as "the category-defining leader in healthy blended beverages, juices, and good-for-you snacks." They even use Jamba as an adjective to mean the opposite of high fructose corn syrup and trans-fats (adding those things to juice ""just wouldn't be Jamba"), which again, constructs the brand as healthy vs. the demon poisons that make people fat. Even if it's foolish to go looking for truths in advertising, I don't think Jamba Juice's branding generally occurs to people as a massive irony or lie. Advocates of banning or restricting soda vending machines in schools often claim that the soda should be replaced with 100% fruit juice with no added sugars, and for many people, a glass of orange juice still represents "part of a nutritious breakfast" strongly with desirable nutrients like Vitamin C.

The Case Against Juice

But a number of health trends have begun cast suspicion on juice, especially the (impartial and incomplete) shift from primarily low-fat to primarily low-calorie and low-carb dieting in mainstream weight-loss culture, and the growing concern about the role sugars (especially fructose) play in personal and national obesity.

On the low-calorie front, people who believe that losing weight or maintaining a healthy weight is all about the basic algebra of calories-in vs. calories-out often end up axing all caloric beverages from their diets because they have a bad satiety-to-calorie ratio—I mean, obviously, right? Fruit juice is just fruit with some or all of the filling fiber removed. If the goal is maximum satiety on minimum calories, you're better off eating whole fruit and drinking water or artificially sweetened beverages.

On the low-carb front, people who believe that what's important is not how many calories you eat but what kind are also going to see juice (and sometimes most fruits and vegetables as well) as "unhealthy." It does seem to be true that diets high in carbohydrates drive up insulin levels, slowing metabolism and encouraging the body to store fat. And the overwhelming majority of the calories in most fruit juices are in the form of carbohydrates. Some green vegetable juices have protein content approaching 50% of the carbohydrate content, but that just makes it 75% bad rather than 100% bad, at least as true carbophobes are concerned.

And finally, there are some non-carbophobes who might avoid juice because they're wary of sugar qua sugar, rather than sugar qua carbohydrate. The carbohydrates in fruit juice primarily take the form of fructose—wikipedia has a handy chart of the kinds of sugars in common plant foods. It doesn't seem like there's a true consensus yet about whether or not fructose is especially bad—despite recent studies linking fructose to obesity, even within the medical community, some people still advocate fructose as a "low glycemic" sugar that's better for diabetics. It basically all comes down to whether you think the fact that fructose is digested in the liver and doesn't trigger insulin production is a good thing or a bad thing. To link it to other sugar purveyors: pro-agave nectar people should also think that fruit juice is healthy and people who think hfcs is bad because they think it's "high fructose" compared to other sugars are, well, a) wrong, but b) should also be advocating hfcs-sweetened sodas over fruit juices, which are even richer in sugar.

Personally, I think the evidence that fructose in large amounts causes equivalent blood sugar spikes to other sugar, increased "bad" cholesterol and triglycerides and signs of insulin resistance compared to glucose, and can cause non-alcoholic fatty liver disease consumed in vast quantities suggests that it is certainly no better and possibly much worse for human health than glucose or sucrose. But "worse for human health" is relative, not absolute, and depends a lot on amount, kind, and context.  Read more