UC Food Blog
The idea that weeds can be edible pops up periodically, with articles suggesting one person's weeds are another person's salad bar, highlighting chefs who “have a way with weeds,” discussing ways medieval gardeners encouraged weeds, and even suggesting ways to eat away at invasive species. But is this something we should take seriously?
“We call these plants weeds because of the way we interact with them. They're in our gardens, they're in our lawns, and they're competing with plants that we prefer to eat,” said Lynn Sosnoskie, a weed scientist at UC Davis. “But a lot of the plants that are weeds here in the United States were brought here purposefully—to be eaten.”
Sosnoskie's doctoral thesis was on just such a plant, with the tasty name of “garlic mustard.” She has also worked at length on Palmer amaranth, a pernicious weed found in cotton fields that can be glyphosate-resistant. In response to one Georgia farmer asking in exasperation if he should just eat the plant taking over his fields, she did some preliminary research into eating Palmer amaranth.
“It's probably not feasible to eat our way out of a serious weed problem,” she said. “But I certainly feel like we can investigate them as other potential food sources.”
In fact, the Horticulture Innovation Lab at UC Davis has a project that is researching three “indigenous vegetables” in Africa, two of which — amaranth and black nightshade — are considered weeds in the United States. The vegetables can be nutritious and profitable options for small-scale farmers in Kenya, Tanzania, Zambia and elsewhere.
Though he holds a Ph.D. in weed science, Weller is now figuring out the best ways to cultivate amaranth and black nightshade — instead of to eliminate them. Before he started working with these plants, common assumptions held that they should be easy to grow because, well, they “grow like weeds.”
“But we found out that growing them is more intensive than we were initially led to believe — similar to growing any other vegetable,” Weller said. “They need water, they need fertilizer, and pests are a problem.”
Caveat emptor: Though weedy plants can indeed be a source of food, both scientists cautioned against thinking of weeds as a “free-for-all forage buffet.” Some plants may be toxic, and weeds in farm fields may have been sprayed recently. It is important to be knowledgeable of the plants and how they've been grown before trying to eat one.
As you're ladling up country-style pinto beans for your weekend barbecue or fixing a cold three-bean salad from kidney, string and navy beans for a summer picnic, pause to remember what a long and storied history these “common bean” varieties share and the new scientific advances that promise to boost their productivity worldwide.
This week, a new genome sequencing is being reported for the common bean, which ranks as the world's 10th most widely grown food crop and includes the culinary favorites above, whose varieties together comprise a $1.2 billion crop in the United States.
“The availability of this new whole-genome sequence for beans is already paying off,” said Paul Gepts, professor in the Department of Plant Sciences at UC Davis and co-author of the new sequencing study.
Gepts, who leads the bean-breeding program at UC Davis, notes that the new sequence is being used to confirm many of the findings made earlier by his UC Davis research group, including identification of the common bean's two points of origin and domestication.
Sequencing and bean ancestry
The common bean is thought to have originated in Mexico more than 100,000 years ago, but -- as the Gepts group earlier discovered – was domesticated separately at two different geographic locations in Mesoamerica and the southern Andes.
“This finding makes the common bean an unusually interesting experimental system because the domestication process has been replicated in this crop,” Gepts said.
The sequencing team compared gene sequences from pooled populations of plants representing these two regions and found that only a small fraction of the genes are shared between common bean species from the two locations. This supports the earlier finding that the common bean was domesticated in two separate events -- one at each location -- but distinct genes were involved in each event.
The new whole-genome sequencing is also helping to identify genetic “markers” that can be used to speed up breeding of new and more productive bean varieties in the United States, East Africa and elsewhere, Gepts said.
The nitrogen connection
All of bean varieties that belong to the “common bean” group share with the closely related soybean the highly valued ability to form symbiotic relationships with “nitrogen-fixing” bacteria in the soil.
The plants and the bacteria work together to convert nitrogen in the atmosphere into ammonia – which includes nitrogen in a form that enriches the soil and feeds crops. Nitrogen-fixing crop plants can actually reduce or eliminate the need for farmers to apply expensive fertilizers.
One goal of the new sequencing project was to better understand the genetic basis for how such symbiotic relationships between nitrogen-fixing plants and bacteria are formed and sustained, with an eye toward increasing fuel- and food-crop productivity.
The research team successfully identified a handful of genes involved with moving nitrogen around, which could be helpful to farmers who intercrop beans with other crops that don't fix nitrogen.
Findings from this study are reported this week online in the journal Nature Genetics. The sequencing project was led by researchers at the University of Georgia, U.S. Department of Energy Joint Genome Institute, Hudson Alpha Institute for Biotechnology and North Dakota State University.
The drought is now so severe that in April Governor Jerry Brown called upon “all Californians, municipal water agencies, and anyone who uses water to do everything possible to conserve.” Just days earlier, University of California President Janet Napolitano paid a special visit to California's heartland to explore how universities could assist.
How might this drought affect food prices? Milton McGiffen, UC Cooperative Extension specialist in the department of Botany and Plant Sciences at UC Riverside, says the greatest impact would indeed be on produce coming from the Central Valley — tomatoes and melons, for example.
"Citrus prices have increased due to the big freeze last December,” he said.“With scarcity of water comes higher water cost, which could result in farmers opting to grow higher value crops, such as fruits and nuts. It's no accident that the cost of a bag of walnuts recently went up about 36 percent at Costco. Research is just beginning now on how some farmers are selling off their farms because of the adverse water situation.”
“There is a conflict between land and water use for growing food or growing cities,” he says. “It comes down to how much we want to see agriculture continuing in the state. It depends, too, on how much we want to charge farmers for water. In Riverside County, farmers got a break in water charges until the late 1980s. After that, they were charged the same amount for water as were homeowners. It became unsustainable for them, and many farmers simply left the region.”
Americans spend about 6.6 percent of their household income on food — by far one of the lowest in the world. McGiffen calculates that if food prices were to increase by 20 percent, Americans would end up spending an extra 1 percent of their household income on food.
“In real terms, will this change how we behave? I'd say probably not. Like lobsters in a slowly heated pot, we will adapt," McGiffen said. "But we cannot afford to forget that we need to produce significant amounts of food. Failing at this would put us at a major disadvantage. Currently, about half of our food comes from other countries — Latin American countries, in particular. We certainly don't want to increase that.”
It's a drizzly winter morning, and dozens of volunteers at the San Francisco–Marin Food Bank are slowly breaking down a 2,000-pound sack of whole oats into 1-pound bags, their hair tucked back in neat plastic caps. A decade ago, volunteers were more likely to be boxing up canned foods items. Today, 60 percent of everything ferried out of this warehouse is fresh produce. No soda or chips are in sight, and whole grains like these General Mills oats are standard.
For food banks nationwide to move in a similar healthy direction, coordinated efforts must increase at all levels. It will take leadership like that provided by Feeding America, the national food bank network organization; expanded support for nutrition policies at the local and regional levels; and donor efforts to supply more healthful foods. It's a tall order. But with the growing ranks of the food-insecure and obese, there is more pressure — and desire — than ever to provide low-income families with healthful food and create support for food bank nutrition policies to ensure that happens, says Patricia Crawford, UC Cooperative Extension specialist and director of UC Berkeley's Atkins Center for Weight and Health (CWH), a partnership between the College of Natural Resources and the School of Public Health.
“People managing food banks are taking charge and doing the difficult thing of modifying the healthfulness of the food donations they solicit,” says Karen Webb, a nutritional epidemiologist at CWH. “On the one hand, the food banks want an ample supply of foods to hand out, but they're also advocates for people in our most vulnerable population, so the nutritional quality of that food is important.”
There has been progress, which CWH researchers and their colleagues, at the request of the Institute of Medicine (IOM), the health arm of the National Academy of Sciences, have documented in ‘A Movement Toward Nutrition-Focused Food Banking,' an upcoming discussion paper to be released in summer 2014. The report details the evolution of food banking as the number of people served by these organizations jumped a whopping 46 percent from 2006 to 2010, according to Feeding America. Today, 12 percent of the population uses the emergency food system. Driven by increased demand, food banks have shifted from an emergency lifeline to a service filling a chronic need.
While organizations move to provide more healthful food, it's clear that pantry users, or clients, want these foods. A 2011 CWH study asked clients to rank calorie-dense snack-type foods and beverages as well as healthy options by order of preference.
“Food pantry clients ranked the most nutritious foods highest,” says Webb, a co-author of the IOM report. “Those foods are expensive, and they want to receive them. Meat, dairy, and fresh produce are at the top of their list, while soda and candy rank lowest.”
What policy looks like
Getting healthier food into clients' hands requires changes in both policy and practice, but what exactly is a nutrition-driven food policy? Many stakeholders are trying to effect change — food banks and the umbrella groups that support them, organizations and corporations that donate, and state and federal governments — but there are few cohesive policies and common standards to govern how they work together.
To start with, food banks can benefit from formal written guidelines that address the nutritional quality of the foods and beverages that they purchase or acquire from donations, according to the recommendations in the IOM report, whose authors include CWH's Elizabeth Campbell and Michelle Ross, Heather Hudson of the Food Bank of Central New York, and Ken Hecht, formerly with California Food Policy Advocates. A policy should guide the nutritional quality of the food bank's inventory as well as provide data analysis to track how successful the food bank is at distributing foods like produce and limiting unhealthful ones such as processed crackers and chips. Some 56 out of 200 food banks have a policy in place, according to a recent Feeding America survey, but more must be done.
Alameda County Community Food Bank (ACCFB) is a policy model, Crawford says. It established a written policy in June 2013, with the help of the nonprofit anti-hunger group MAZON and CWH. The project, which included several other food banks, was funded by Kaiser Permanente.
“We held focus groups with staff members and agency representatives,” says Jenny Lowe, ACCFB's nutrition education manager. “We wanted to get everyone on the same page. We asked, what are our practices? We'd been following this for a long time, but never wrote it down.”
The food bank's policy is now clear. They purchase fresh fruits and vegetables, low-sugar canned fruits, low-salt canned vegetables, low-fat milk, lean proteins, nut butters, beans, whole grains, packaged meals and soup.
“Green” foods are now more readily available at food banks across California because of the California Association of Food Banks' (CAFB) Farm to Family program, which connects state growers and packers to food banks. In 2011, CAFB, a nonprofit, membership-based umbrella group, sponsored AB152, now a state law, which enables farmers to get a 10 percent tax break on the inventory costs of fruits and vegetables they donate.
CAFB exemplifies how agriculture, advocates, and food banks can work together to create policies that incentivize the support system for healthy diets. Since 2005, the group has increased food bank produce donations by 92 million pounds of fruits and vegetables that might have otherwise been plowed under in the fields. “In California, we have a progressive agricultural community as well as progressive food bank organizers,” Crawford says. “It's that convergence that has made California a model and brought national attention to what we're doing.”
Other positive steps: Feeding America appointed a director of nutrition in 2011, and in 2012, it implemented Foods to Encourage, nutrition guidelines for promoting health—the food bank network's first-time effort at national guidelines. It's also running a pilot program that connects food-insecure clients who have Type 2 diabetes with nutrition, health education, and medical care.
Even with successes like these, there's still a long way to go.
Fresh food, new challenges
Six California food banks participated in a 2010–11 CWH study on inventory trends, funded by the Robert Woods Johnson Foundation. All six had significantly increased the amount of produce they provide to pantries, the study found, but hardy onions and potatoes made up about half of those gains. While the increase in fresh produce was dramatic, getting a variety of vitamins and minerals from different types of produce is key to good nutrition, Webb says.
“Food banks now must tackle the next challenge: adding more colorful yet hardy vegetables, such as bell peppers and broccoli," Webb said.
Part of that challenge is providing better distribution systems to pantries. Many food banks boast state-of-the-art facilities with refrigerated trucks and big walk-in refrigerators, but the pantries they serve are often basement kitchens and church halls with little access to refrigeration or storage. Policy changes must consider how to improve these conditions. For example, ACCFB provides farmers-market style distribution in parking lots to some clients, and both ACCFB and the state of New York help provide pantries with equipment grants to improve facilities.
Crawford notes that both the Central New York and Alameda County food banks have successfully implemented nutrition policies without offending donors or losing support.
Moving nutrition forward
In February 2012, anti-hunger leaders convened in Oakland, Calif., to discuss their findings from the 2010–11 Robert Wood Johnson Foundation study. There, CWH and California Food Policy Advocates called for food bank procurement policies that meet or exceed the Foods to Encourage guidelines, which were due to be released later that year.
In the most recent nudge forward, the IOM report recommends that items available through U.S. Department of Agriculture food distribution programs align with key recommendations from the 2010 Dietary Guidelines for Americans. Most food that the USDA supplies to food banks is already healthy, a recent study showed, and the agency is moving quickly to further improve nutritional quality by adding items like whole-grain pastas and brown rice. The report also recommends that food banks and advocates work with donors to find new ways to incentivize nutritious donations.
The IOM report represents a formidable increase in visibility for the issue of food bank nutrition, and Crawford wants to take advantage of the momentum. She's calling for a meeting of key stakeholders to discuss how to keep improvements to the emergency food system's nutritional quality moving forward.
Obesity and diabetes risk continue to plague the nation's health, and food banks will face big challenges in the coming year, including an expected rise in the number of clients as a result of the recent $8.6 billion in cuts to the Supplemental Nutrition Assistance Program — or SNAP, formerly known as food stamps — part of the farm bill passed in February, and as a consequence of California's drought, which is expected to bump up food prices.
“Those of us working in the field of hunger and food insecurity want the best for the people we serve,” Crawford says. “There is a moral imperative to do more than to provide just calories. We must provide foods that will help protect the health of the most vulnerable in our society.”
This article originally appeared in the spring 2014 issue of Breakthroughs, the magazine of the UC Berkeley College of Natural Resources.
UC Cooperative Extension nutrition educators in Tulare County keyed in on that point in time in a play performed for 1,600 fourth-grade students at AgVentures Farm and Nutrition Day, May 23.
The play is a scripted game show titled “What Does MyPlate Say?” which encourages the children to think about the USDA's MyPlate eating guidelines, introduced to them by UC CalFresh educators in their classrooms throughout the year, when they order a fast food meal.
Five “contestants” were selected from the audience and asked to look at a food court menu. The first contestant is asked to select a fruit from the menu, and picks a yogurt parfait. Applause and a chorus of “Healthy, healthy, healthy eyes! Healthy, healthy, healthy skin!” affirm the choice.
The second student is charged with selecting a vegetable in the food court.
“French fries from MickeyC's,” he says. “Potatoes are vegetables, aren't they?”
The brightly dressed host, Sally Strawberry, admits that's true but declares french fries a “sometimes food.” Try again.
The second response, “veggie bowl from Bear Express,” is met with music, bells and applause.
Contestant three is challenged to find whole grains in the food court.
“Turkey on whole wheat from Sideway?” he responds tentatively. “Grains give us strength and energy to play!”
The fourth child to play gets a tricky question. “Can you choose a food that is high in protein but also high in fiber?” asks Sally Strawberry.
“Bean burrito from Beeanie Bell,” the child chimes.
“Muy rico,” Strawberry says. “We now have a fruit, vegetable, whole grains and protein. We just need a drink.”
“Milk, from any place,” the last child says.
See scenes from 2014 AgVentures in Tulare County in the one-minute video below: