Top 5 Foods That Can Help You Live Longer

• A new study indicates that several foods can contribute to long-term health in humans and the planet.
• The study’s author hopes the research informs policy decisions, but dieticians say it can also help people with meal planning and grocery shopping.
• Experts recommend focusing on progress, not perfection when trying to eat for better outcomes for your health and the planet.

Healthy you, healthy planet? Research suggests the two may be closely linked.

In a new study, presented in July at NUTRITION 2023, the flagship annual meeting of the American Society for Nutrition in Boston, researchers used a tool they created called the Planetary Health Diet Index (PHDI) to review foods and their impacts on human and environmental health.

The results show that individuals consuming a more environmentally sustainable diet were 25% less likely to die within a 30-year follow-up period than those following a less sustainable diet.

“This diet index will help public health workers understand the current healthiness and sustainability of their population’s diet and serve as an indicator for dietary intervention effect,” said study author Linh Bui, a PhD candidate in the Department of Nutrition at Harvard T.H. Chan School of Public Health.

“Furthermore, policymakers can use such evidence to make decisions on prioritizing strategies that aim to increase the PHDI to achieve the global carbon neutrality goal by 2050.”

5 foods that benefit human health and the planet

Lui told Healthline she’s always had a keen interest in mitigating human impacts on the environment. Her research team identified five key foods that positively impact human health and could increase lifespan. These include:

• whole grains
• fruit
• non-starchy vegetables (i.e., cauliflower, broccoli, mushrooms, and tomatoes)
• nuts
• unsaturated oils (i.e., olive, peanut, walnut, sunflower, rapeseed, and corn oil)

“These healthy plant-based foods were associated with both low risk of chronic diseases, like coronary heart disease, colorectal cancer, diabetes, stroke, and total mortality, and low impacts to the environment, like water use, acidification, eutrophication, land use, greenhouse gas emissions,” Lui said.

Connecting healthy food and longevity

The new study was inspired by a report led by Dr. Walter Willet and published in the Lancet in 2019.

In the report, the authors indicated that much of the world was not adequately nourished and that food production was pushing environmental systems and processes beyond safe boundaries. They called for a global overhaul of the food system.

“I was very astonished by the powerful impact of diet choices on the environmental capacity of the planet,” Lui said.

Willett became Lui’s academic advisor at the Harvard T.H. Chan School of Public Health. He later helped her develop the PHDI, which became the impetus for this new longitudinal study that follows 63,081 women and 44,275 men in the U.S.

The PHDI “gives folks a diet ‘score’ and then correlates those scores with folks’ risk of death from various causes, during a 30+ year follow-up period,” explains Maddie Pasquariello, MS, RDN.

“Notably, they integrated what they know about planet-friendly foods from a dietary reference guide called the EAT-Lancet reference, [the 2019 report authored by Willett]. which focuses on foods that are particularly sustainable from an environmental perspective.”

Lui said that the goal was to estimate the effect of adherence to a planetary-health diet on the risk of death.

The research suggests that eating more planet-friendly foods, such as plant-based proteins instead of red meat, lowers an individual’s chances of dying from conditions like cancer and heart, respiratory, and neurogenerative diseases.

“This result confirmed our hypothesis that higher PHDI was associated with lower risk of mortality,” said Lui.

Pasquariello said the findings can help healthcare providers, policymakers, people, and the planet.

“They provide stark implications for the importance of a diet balanced with certain foods, namely whole grains, fruit, non-starchy vegetables, nuts, and unsaturated oils, in promoting overall health and lessening disease risk,” Pasquariello said. “These findings also underscored how, in doing so, we can be thoughtful of our environmental impact as well.”

Trista Best, MPH, RD, LD, of Balance One Nutrition agrees with this assessment of the findings but offers one critical caveat.

“The study does not provide detailed information on the specific barriers or challenges individuals may face in adhering to a sustainable diet,” Best said.

“It mentions that factors like health conditions, religious restrictions, socioeconomic status, and food availability can influence a person’s ability to follow such a diet. However, it does not delve deeply into the strategies to overcome these barriers.”