Planting fruit trees on farms improves dietary quality, according to new research from Malawi that tracked nearly 1,000 households over 10 years.

The study, published in Conservation Letters, found that families who had trees on their farms ate more fruits and vegetables than those without trees. The research examined data from 936 households across Malawi between 2010 and 2020, using surveys from the World Bank’s Living Standards Measurement Study.

Families with trees on their farms had a 3% increase in vegetable consumption compared with those without trees. For every additional tree species a household owned, fruit consumption increased by 5%.

While these percentages may seem modest, they represent meaningful progress given the extremely low baseline consumption levels. The World Health Organization recommends eating 400 grams (14 ounces, or five servings) of fruits and vegetables daily, but the study found rural Malawians averaged only 51 g (1.8 oz) of fruit per person each day.

Many people in sub-Saharan Africa don’t eat enough fruits and vegetables. In Malawi, about 18% of the population is undernourished, and vitamin deficiencies are common.

“These are small effect sizes, but the positive relationship demonstrates that having on-farm trees may improve fruit and vegetable consumption for rural smallholders,” Charlotte Hall, the study’s lead author and a lecturer at the University of Stirling in Scotland, told Mongabay.

An important caveat of the study is that most households were surveyed during the dry season when trees weren’t producing fruit. However, researchers “still found a relationship between having trees on the farm and fruit and veg consumption,” Hall said. “I would expect that if we went and did the same study again, and all the households were surveyed through the rainy season, you’d see a much stronger relationship.”

Four ways trees help diets

The researchers identified four pathways through which trees can improve what people eat. The most direct way is when families eat fruits from their own trees.

“If you have a mango tree in your backyard, and there’s plenty of mangoes falling off that tree, you’re very likely to eat some of them,” Bronwen Powell, an associate professor at Penn State University, U.S., who studies the relationship between forests and nutrition but was not involved in this research, told Mongabay.

Trees also provide ecosystem services that help other crops grow better, such as improving soil quality when leaves decompose and protecting fields from extreme weather. With their deep roots, trees are better equipped to survive droughts and storms than regular crops, so they can provide food when other plants fail.

“Trees can act as a real buffer and prevent [crop loss] from happening because they’re kind of binding the soil together,” Hall said. During a visit to Malawi, for instance, she reported seeing entire crop fields wash away during a cyclone while areas with trees remained protected.

Trees can also generate income when families sell their produce, though this study found little evidence of that pathway. Finally, trees provide fuel for cooking, making it easier to prepare nutritious foods.

Declining diet

Despite finding positive effects from trees, the study revealed troubling trends. Fruit and vegetable consumption declined by 42% and 25%, respectively, over the 10-year study period.

Hall attributed this decline to several interconnected factors. Rising food prices have made nutritious foods like fruits and vegetables increasingly unaffordable. The country has also experienced dramatic currency devaluation, making food even more expensive for families with limited income.

“The most recent report from the FAO on the state of food insecurity found that for Malawi, 92% of the population can’t afford a healthy diet,” Hall said. “They just don’t have the income.”

Climate change has added another layer of difficulty. Extreme weather events like cyclones can disrupt food supplies, affecting perishable items like fruits and vegetables. Meanwhile, families facing economic hardship tend to prioritize calorie-dense staple foods over more nutritious but expensive produce.

“The biggest factor is rising food prices,” Hall said. “More nutritious foods like fruits and vegetables and perishables have become much more expensive, and so consumption is understandably lower.'”

Solutions and obstacles

Experts say addressing seasonal gaps in nutrition requires strategic planning. Powell and Hall highlighted fruit tree portfolios, or combinations of different tree species that produce fruit at different times of year to provide nutrition throughout all seasons.

However, significant barriers prevent families from planting and keeping trees. For instance, trees are often cut down for fuel. At times, people must prioritize cooking grains today over harvesting fruit in a few months.

“I saw a group of women just with large knives, hacking a tree at the side of the road,” Hall said. “If people have trees on their farm and they have no choice, they will cut them.”

Other obstacles include the expense and labor required for tree planting, lack of technical knowledge about tree care and land ownership issues that prevent people from planting trees on land they don’t own.

Policy recommendations

The researchers suggest several policy changes could help more families benefit from on-farm trees. Current tree-planting initiatives across Africa, such as AFR100 and the Great Green Wall, focus on fast-growing species for carbon storage but often ignore food-producing trees.

“Nowhere in any of those initiatives do they talk about having food-producing trees as part of the planting regimes,” Hall said. She recommends including fruit trees in reforestation programs and ensuring they are culturally appropriate, indigenous species.

Powell emphasized that agricultural policies need to value nutrition alongside calories. “Here in the U.S., we subsidize calories and not healthy foods,” she said. Similar problems exist in Africa, where policy focuses on staple grains rather than diverse, nutritious foods.

Both researchers stressed that while the effects found in this study were small, they demonstrate that trees on farms can contribute to better nutrition while also providing environmental benefits like carbon storage and biodiversity conservation.

“If we can find ways to incentivize family farms and small-scale farms and to value the labor that goes into diverse, biodiverse, agroecological farms,” Powell said, “I think that’s the big conundrum to feeding the planet and meeting everybody’s nutritional diet quality requirements.”

Banner image of a baobab tree in crop field in Mulanje district, Malawi. Image courtesy of Emilie Vansant.

Citation:

Citation: Hall, C. M., Den Braber, B., Vansant, E., Oldekop, J. A., Das, U., Fielding, D., … & Rasmussen, L. V. (2025). Trees on farms improve dietary quality in rural Malawi. Conservation Letters, 18(1), e13061.

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Liz Kimbrough is a staff writer for Mongabay and holds a Ph.D. in Ecology and Evolutionary Biology from Tulane University, where she studied the microbiomes of trees. View more of her reporting here.

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