When a Healthy Diet Meets a Planet in Peril

In the movie Interstellar, civilization is on the verge of collapse. Corn and okra have become the planet’s last viable crops, and even they are threatened by “blight.” While the source of the pestilence is kept vague, it isn’t hard to link this fictional disaster back to what's going on in our fields and forests today.

Extreme weather might be what keeps agronomists up at night, but it’s not just climate change that’s harming our soil and seas. From deforestation and wasteful water use to oversaturation of pesticides and fertilizers, humans have become poor stewards for planet Earth.

When a blockbuster sci-fi film depicts a desperate struggle to save civilization from impending apocalypse, we gape at the on-screen destruction but shrug our shoulders when it comes to taking action. But there are things we can do on a personal level to mitigate the effects of air, water, and soil pollution caused by factory farming.

“The good news is that, in general, a diet that’s best for the planet is also best for your health,” nutrition scientist Dr. P.K. Newby told us.

Author of National Geographic’s Foods for Health, Newby said that replacing animal products with sustainable and lean proteins and limiting highly processed foods filled with added sugar are ideal ways to support both your health and the environment. “In time, these kinds of shifts in consumption patterns toward a plant-based diet will help drive our food system toward producing a more nutritious and sustainable food supply,” she added.

Sure, I thought: I can bring a few more nuts, fruits and veggies into my diet, and I can cut back on cheeseburgers. But in researching how to reduce my environmental impact at the dinner table, a few jokers emerged—foods I knew to be traditional elements of a balanced diet that carried an unexpected environmental toll. I asked “The Nutrition Doctor” if she could suggest kinder, gentler alternatives to some of my favorite foods.

Almonds

California is the nation’s breadbasket, producing almost half of the fruits, vegetables, and nuts grown in America. But despite recent downpours, the state has not seen the end of what some are calling the “drought of the century.”

Many of California’s most famous crops are notably water-hungry, but imagine my surprise when I found that the thirstiest of all is also one of Earth’s healthiest foods. As it turns out, you need upward of 1.1 gallons of water to grow a single almond. And drought-stricken California grows 99 percent of the U.S. supply.

Dr. Newby: “Like other nuts, almonds are a wonderful source of minerals, fiber, and mono- and polyunsaturated fats. Peanuts and other less water-intensive nuts are good substitutes since they have similar health benefits. In particular, peanuts return valuable nitrogen to the soil where they’re grown and also support U.S. farmers, major growers of this crop. Walnuts, pecans, and filberts (hazelnuts) are other nutritious nuts that put less pressure on water supplies.”

Strawberries and Raspberries

Say it ain’t so! According to the Pesticide Action Network, strawberries are dosed with more pesticides than any other produce—300 pounds per acre. Raspberries are loaded with 39 different pesticides.

Though there is little evidence that pesticides directly impact consumer health, they have plenty of knock-on effects. These chemicals can be dispersed in streams and cause reproductive problems for animals; of particular concern is their probable effect on honeybees, and their possible ties to colony collapse disorder. And finally, in addition to being a burden on the environment, pesticides are a known health risk for the farmers who grow the crops.

Note that berries aren’t the worst offender in terms of pesticide residue. The Environmental Working Group reports that apples top their list of the “dirty dozen” (products that land on store shelves laced with the highest residue of bug- and weed-killers), but strawberries are close behind.

Dr. Newby: “Nothing beats a freshly-picked, summer-sweet raspberry from your neighborhood farmers market. Keep eating your berries, which are rich sources of phytonutrients (plant chemicals) critical for health—especially when they’re in season and support local businesses. But when you do, try and choose organic, a planet- and farmer-friendlier option.”

Bananas

High in potassium, vitamins B and C, and dietary fiber, bananas are the go-to fruit for many households.

Alas, when conventionally grown, bananas require the highest fertilizer usage of any crop. The Food and Agriculture Organization of the United Nations reports that banana plantations consume 427 pounds of fertilizer per acre.

Not all fertilizers today are chemical, but when used in abundance the nutrients pollute waterways and result in coral reef destruction and aquatic die-off. Further, most Central American plantations continue to rely on highly toxic pesticides. That means the cheerful Chiquita banana lady may not be all she’s dressed up to be.

Dr. Newby: “Bananas are an American favorite, and choosing Rainforest Alliance–certified will ensure your potassium-rich snack protects the farmers, the soil, and animal habitats where they’re grown. Selecting seasonal fruits like apples in autumn and peaches in summer instead of bananas will bring in more nutrients to your diet and boost local food production.”

Corn

Corn is grown for a huge variety of purposes, from ethanol production, to livestock feed, to corn syrup. The crop also requires heavy fertilizer use, consuming 40 percent of all commercial fertilizers sold in the U.S.

As with bananas, the runoff carries a heavy toll. When excessive nutrients flood water systems, algae flourishes and it begins to consume the oxygen that other sea life depends on. Corn-related fertilizer runoff is a factor behind the growing “dead zones” found in the Gulf of Mexico and Chesapeake Bay—habitats now so depleted of oxygen they cannot sustain life.

Dr. Newby: “Summer-sweet corn-on-the-cob can be part of a healthy and planet-friendly plant-based diet. But avoiding foods that rely on corn for production (e.g, beef, pork, poultry) and choosing those that don’t include corn syrup or corn oil are changes you can make to lower your environmental impact and encourage biodiversity. Swapping in oils like safflower, sunflower, or hemp for corn oil and consuming less meat from animals mainly fed corn are more sustainable choices.”

Sugarcane

Not long ago, eliminating corn syrup as a sweetener became a priority for families across the U.S. Soon, savvy manufacturers of sodas and cereals began switching back to cane sugar as their primary sweetener.

Not so fast, guys. Thanks to agro-chemical runoff, soil erosion, air pollution, and intensive water use, sugar cultivation leaves a bitter aftertaste. In sum, sugarcane is said to be responsible for the greatest biodiversity loss attributable to a single crop.

Dr. Newby: “Sugarcane is the world’s largest crop, and the demand for sweet foods and drinks is what drives production. Americans consume way more sugar than is good for their health; it’s found in everything from baked goods to beverages and yogurt. Substituting foods like vegetables, fruits, and nuts for snacks instead of processed foods high in added sugar will in time help direct production toward a more diverse array of crops that are healthier for people and the planet.”

Milk

Milk is said to “do a body good,” but the planet doesn’t get a similar benefit from dairy farming. Dairies have a high carbon footprint due to their use of processed feed, along with, yes, cow belching and flatulence—a major source of methane gas in the atmosphere.

Worse yet, the alfalfa that farmers feed dairy cows soaks up a larger percentage of California’s water than any other crop. Add in heavy use of antibiotics, which some argue is fueling the rise of drug-resistant “superbugs,” and we’re not so sure we want milk in our fridge.

Dr. Newby: “There are a lot of good reasons to limit consumption of milk from animals or omit it entirely. Milk is a great source of nutrients, but it’s a less sustainable choice than non-dairy milks. From soy to rice to coconut, there are planet-friendlier options to pour on your cereal, and water is a better go-to beverage when you’re filling your glass.”

Red Meat

It’s hardly news that cattle production has a huge environmental toll. A study by the Proceedings of the National Academy of Sciences found that beef production requires 28 times more land, uses 11 times more water, and produces five times the greenhouse gas emissions per calorie compared to the average of other livestock categories (pork, chicken, lamb, etc.).

Although per-capita consumption of beef has been on a decline in America, it’s on the rise in the developing world. What are the alternatives?

Dr. Newby: “Turning to vegetable-based protein sources with a smaller environmental footprint will go a long way toward increasing the sustainability of our planet. Foods like nuts and legumes, soy-based proteins like tofu, and sustainable seafoods that are low on the food chain are a more efficient and planet-friendly way to meet human protein needs compared to beef and pork, as well as poultry.”