Tufts experts recommend plant protein for better health and sustainability

As more Americans reassess their eating habits for both health and environmental reasons, nutrition experts at Tufts University are encouraging a shift toward more plant-based protein sources. While most US adults already consume enough protein overall, the 2020-2025 Dietary Guidelines for Americans recommend adjusting the sources of that protein for improved long-term health.

“Any protein source will meet one’s protein needs,” commented Dr Dariush Mozaffarian, Director of the Food is Medicine Institute at Tufts’ Friedman School of Nutrition Science and Policy. “So it’s what comes with the protein that matters.”

That means looking beyond the protein content itself to assess the nutritional profile of the whole food. For example, a plant-based protein source typically comes packaged with fiber, vitamins, minerals, and phytochemicals – components that support heart and metabolic health. By contrast, processed animal proteins like cold cuts may be high in sodium and saturated fats.

Dr Mozaffarian emphasizes that while animal products do contain all nine essential amino acids – once referred to as 'complete' proteins – this doesn't mean they are necessary to meet daily protein needs. Soy, quinoa, chia seeds, and buckwheat also offer complete protein profiles. And with a well-varied diet, people can easily get all essential amino acids from a mix of plant sources over the course of a day.

“Given the variety of plant foods available in the modern diet, no one really needs to worry about matching different plant sources of protein,” Mozaffarian said. “Unless their diet is very regimented and limited to just a few specific plants.”

Common food pairings like rice and beans, pita and hummus, or peanut butter on bread naturally complement one another in ways that have long ensured nutritional adequacy across different cultures.

While increasing the share of plant-based protein in the diet is widely seen as beneficial, seafood and legumes in particular remain under-consumed in the US Meanwhile, red meat intake continues to exceed recommendations.

Alice H. Lichtenstein, a Senior Scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging and a professor at the Friedman School, points out that some consumers are cutting back on meat for more than just health reasons. “Some meat-eaters are choosing to decrease their intake, frequently for multiple reasons: the environment, sustainability, or health,” she said.

That trend has contributed to the rapid expansion of the plant-based meat alternative market. But Lichtenstein cautioned that many of these products are highly processed. “While in some ways these products are better for the environment, be aware that they are highly processed and may have a nutrient profile not all that dissimilar to meat – including added saturated fat – and may be even higher in sodium.”

She and others at Tufts suggest that instead of relying on plant-based 'meats', consumers should aim to incorporate more whole plant foods like lentils, chickpeas, walnuts, chia seeds, oats, and brown rice into their regular meals. These foods not only provide the necessary protein and nutrients, but also come with fewer downsides when it comes to processing and environmental impact.

In addition to better individual health outcomes, a shift toward more plant-based eating could significantly reduce the environmental footprint of food production. Red meat, in particular, has been shown to contribute disproportionately to greenhouse gas emissions and requires far more water and energy to produce than plant-based alternatives.

Ultimately, Tufts experts agree that a healthier diet doesn’t require giving up animal products entirely. Instead, it’s about balance and gradual shifts.

“Replacing some animal proteins with plant proteins is not only associated with positive health outcomes, it’s a better choice for the environment,” said Mozaffarian.

The advice from Tufts reflects a growing consensus in nutrition science: a varied diet rich in whole plant foods is not only adequate, but often optimal, for meeting protein needs while supporting broader public health and sustainability goals.