If it comes from the same plant as tequila, it can’t possibly be bad… right? The Aztecs may have seen agave as a gift from the gods, but the nectar of these spiky plants is actually extremely high in fructose — and consumption can possibly have negative effects on the liver. And it’s not exactly calorie-free (or guilt-free) either.

Bittersweet Symphony — The Need-to-Know

Just before agave plants bloom, they store up energy in the form of carbs. Those carbohydrates are extracted from the plants and processed to become sugar, or what we see on supermarket shelves as agave nectar or syrup. While agave is sometimes promoted as a better choice because it’s free of chemicals — unlike its artificial sweetener kin — natural” doesn’t necessarily mean healthy. And some argue that after the complex refinement process, agave isn’t really that “natural” at all.

As for nutrition, agave nectar isn’t really that much better than plain old sugar. The biggest difference? It’s all about fructose. Agave nectar contains a whopping 90 percent fructose. (For the record: High fructose corn syrup is 55 percent fructose and granulated sugar is 50 percent.) And while some argue agave is still a healthier sweetener, studies suggest high fructose consumption is associated with health issues like liver and kidney disease, high blood pressure, and even signs of premature agingFructose consumption as a risk factor for non-alcoholic fatty liver disease. Ouyang, X., Cirillo, P., Sautin, Y., et al. Division of Nephrology, University of Florida, Gainesville, FL, USA. Journal of Hepatology, 2008 Jun;48(6):993-9.Lipid metabolism of orchiectomised rats was affected by fructose ingestion and the amount of ingested fructose. Makino, S., Kishida, T., Ebihara, K. Department of Biological Resources, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan. British Journal of Nutrition, 2012 Mar;107(6):817-25.The impact of fructose on renal function and blood pressure. Kretowicz, M., Johnson, R.J., Ishimoto, T., et al. Department of Nephrology, Hypertension and Internal Medicine, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, ul. Skłodowskiej-Curie 9, 85-094 Bydgoszcz, Poland. International Journal of Nephrology, 2011;2011:315879..

But there’s good news, too: Agave’s high fructose content gives it a relatively low glycemic load, meaning it doesn’t drastically affect blood sugar levels‘Catalytic’ doses of fructose may benefit glycaemic control without harming cardiometabolic risk factors: a small meta-analysis of randomised controlled feeding trials. Sievenpiper, J.L., Chiavaroli, L., de Souza, R.J., et al. Department of Pathology and Molecular Medicine, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada. British Journal of Nutrition, 2012 Feb 21:1-6.. Some say this makes agave a better choice (or at least better than white sugar) for diabetics. But even non-diabetics may want to keep blood sugar constant, as more consistent levels have been associated with weight loss and improved metabolism. That still doesn’t make agave an “all the time” food; the body still needs to produce insulin to process itNo effect of a diet with a reduced glycaemic index on satiety, energy intake and body weight in overweight and obese women. Aston, L.M., Stokes, C.S., Jebb, S.A. MRC Human Nutrition Research, Elsie Widdowson Laboratory, Cambridge, UK. International Journal of Obesity, 2008 Jan;32(1):160-5.. Plus, consistently elevated insulin levels (even in those without diabetes) can have many negative health effects (like contributing to heart disease)Diets with high or low protein content and glycemic index for weight-loss maintenance. Larsen, T.M., Dalskov, S.M., van Baak, M., et al. Department of Human Nutrition, Faculty of Life Sciences, University of Copenhagen, Copenhagen, Denmark. The New England Journal of Medicine, 2010 Nov 25;363(22):2102-13.Dietary glycemic index: health implications. Brand-Miller, J., McMillan-Price, J., Steinbeck, K., et al. Human Nutrition Unit, University of Sydney, NSW 2006, Australia. Journal of the American College of Nutrition, 2009 Aug;28 Suppl:446S-449S.Hyperinsulinemia as an independent risk factor for ishemic heart disease. Despres, J.P., Lamarche, B., Mauriege, P., et al. Lipid Research Center, Laval University Hospital Research Center, Quebec, Canada. New England Journal of Medicine, 1996 April 11;334(15):952-7.. To put it simply, agave does have a lower glycemic load, but there’s no concrete proof that glycemic load makes a huge difference when it comes to overall health (or weight loss, according to Greatist expert Sherry Pagoto).

Sweet Dreams — Your Action Plan

It’s true, agave isn’t the only “healthy” food high in fructose — after all, fruits are full of it and they’re still good for you. The difference is fruits come packed with vitamins, minerals, and antioxidants, which help counteract the potentially harmful effects of fructose. And while agave may have some beneficial compounds, research is still largely in the experimental phases (aka nothing’s proven yet). Meanwhile, other natural sweeteners (like honey and maple syrup) also offer antioxidants and other benefits, giving them an upper hand in the sweetener smackdown.

But agave isn’t all bad. It is a bit sweeter than white sugar, so it takes less agave to achieve the same level of sweetness. But beware — even though we don’t need to use as much for the same level of sweetness, when foods are perceived as healthy, we might end up eating more of them, actually increasing total calorie intake (and maybe even weight gain) in the long runPerceived healthiness of food. If it’s healthy, you can eat more! Provencher, V., Polivy, J., Herman, C.P. Department of Psychology, University of Toronto, Canada. Appetite, 2009 April;52(2):340-4.. And compared to honey and maple syrup, agave has a subtler flavor, making it a popular sugar substitute in recipes where other options may change the overall taste. Unlike honey, agave is also vegan-friendly.

When going agave, be sure to read the label. Most agave nectar comes from blue agave, the sweetest variety. And while it is available in organic varieties, it’s not clear there are any additional health benefits to choosing them, though there may be environmental pluses (like fewer pesticides). More importantly, read the ingredient list on any bottle before putting it in the grocery cart. Some agave is even watered down with high-fructose corn syrup — yikes! For the best product, contact the company to ask about their refinement process. A minority of companies use techniques that actually keep agave nectar relatively healthy, like lower heating temperatures — look for one of these!

In the end, agave may be appropriate as an occasional sugar alternative, especially for diabetics and anyone else specifically avoiding glucose. But it’s far from the holy grail of sweetness some may have assumed.

This article was read and approved by Greatist Experts Sherry Pagoto and Aaron Mauck.

Photo: Caitlin Covington