This week another large study added to the body of known cardiovascular benefits of eating almonds. Every ounce eaten daily was associated with a 3.5 percent decreased risk of heart disease ten years later. Almonds are already known to help with weight loss and satiety, help prevent diabetes, and potentially ameliorate arthritis, inhibit cancer-cell growth, and decrease Alzheimer's risk. A strong case could be made that almonds are, nutritionally, the best single food a person could eat.

Almonds recently overtook peanuts as the most-eaten "nut" (seed, technically) in the United States, and Americans now consume more than 10 times as many almonds as we did in 1965. The meteoric rise of the tree-nut is driven in part by vogue aversions to meat protein and to soy and dairy milks, and even by the unconscionable rise of the macaron. But the main popularity driver is almonds' increasingly indelible image as paragons of nutrition.

This week's research, led by the eminent David Jenkins, professor and research chair in nutrition and metabolism at the University of Toronto, suggests that in addition to almonds’ idyllic monounsaturated fats, the cardiac benefits may be due to vitamin E, fiber, antioxidant phytochemicals (phenols, flavonoids, proanthocyanidins, and phytosterols), or arginine—and that’s just a partial list of almondic virtues.

This follows a massive study released last fall from Harvard that found eating nuts decreased mortality rates by 20 percent, and it builds on Jenkins’ work done more than 10 years ago which suggested, in the American Heart Association’s journal Circulation, “Almonds used as snacks in the diets of hyperlipidemic subjects significantly reduce coronary heart disease risk factors.”

That's all wonderful, but coverage of almond-nutrition research necessarily affords a narrow vantage on health. It seems like every day someone asks me to dichotomize a health trend: good or bad. Almonds are a great example of why I'm terrible at doing that.

It was around the time of Jenkins' prior study, and amid the broader "actually, fat isn't categorically bad" movement in the U.S. that almonds really got traction. We eat about the same amounts of other nuts as we did decades ago, but almond consumption singularly soared. (Pistachios are on the rise, but they are nowhere near almonds.)

The only state that produces almonds commercially is California, where cool winter and mild springs let almond trees bloom. Eighty-two percent of the world’s almonds come from California. The U.S. is the leading consumer of almonds by far. California so controls the almond market that the Almond Board of California’s website is Its twitter handle is @almonds. (Almost everything it tweets is about almonds.)

California’s almonds constitute a lucrative multibillion dollar industry in a fiscally tenuous state that is also, as you know, in the middle of the worst drought in recent history. The drought is so dire that experts are considering adding a fifth level to the four-tiered drought scale. That's right: D5. But each almond requires 1.1 gallons of water to produce, as Alex Park and Julia Lurie at Mother Jones reported earlier this year, and 44 percent more land in California is being used to farm almonds than was 10 years ago.

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That raises ecological concerns like, as NPR’s Alastair Bland reported last weekend, that thousands of endangered king salmon in northern California’s Klamath River are threatened by low water levels because water is being diverted to almond farms. Despite the severe drought, as of June 30, California's Department of Agriculture projected that almond farmers will have their largest harvest to date. If more water is not released into the river soon, Bland reported, the salmon will be seriously threatened by a disease called gill rot. If there's one disease I never want to get, it's gill rot.

Even as almond production increases in California, demand is driving prices ever higher. Other producers are getting into the game. In England, for example, the cost of almonds has almost doubled over the past five years, and sales of almond milk increased 79 percent in a year. "The value of each kernel has gone up dramatically, and growers are looking for the best return on their investment, so they're still planting almond trees at an alarming rate," one farmer told BBC’s Peter Bowes. "If you decided to plant an orchard right now, you would wait two years for available root stock to actually plant."

The crop is so valuable in the U.K., Bowes reported in February, there had been a spate of thefts and missing almond trucks. He wrote, "Nut-nappers, as they have become known, have been making off with produce by the lorryload." A truck loaded with nuts can be worth more than $160,000.

Almond theft is not a major issue in California, but as almond skeptic Tom Philpott put it in Mother Jones, the ecological implications of almond farming during a drought are “potentially dire.” Over-pumping of aquifers threatens infrastructure like roads, which stand to collapse into sunken ground. Farmers can fallow vegetable fields during droughts, but almond trees need steady supplies of water.

California's almond industry is also completely reliant on honeybees to pollinate its almond trees. The industry requires 1.4 million bee colonies, according to the USDA, most of which are brought to the state from across the country. Because of colony collapse disorder, honeybees are a commodity. The almond farmers' requirements represent approximately 60 percent of the country's managed colonies. This year many of the mercenary pollinating bees brought to California died due to exposure to pesticides.

Anyway, when I buy almonds, I don't think about having a hand in killing bees or salmon, or getting someone's truck stolen or collapsing a road. It's just a jumble of what's "good for me," what I feel like eating, and how much things cost. Michael Specter’s feature on GMOs in last week's New Yorker gets into how seven billion people on the planet will be 10 billion by the end of the century, and feeding that population might well be the greatest challenge to humanity ever. Thinking about going easy on almonds is sort of analogous to GMO dilemmas or buying organic, where the point isn’t really nutrition, it's environmental consciousness and sustainability, which always come back to water. Thinking about that side of food makes it hard to write about nutrition in isolation. Anyway, almonds are good for our hearts.