Eat green, live longer: New research links planet-friendly foods to lower mortality risk

The data showed that those with higher PHDI scores had a 15% reduced risk of death from conditions like cancer or heart disease.

Vegetables are seen in vegetarian restaurant "Green Cuisine" in Minsk, Belarus February 1, 2018 (photo credit: VASILY FEDOSENKO / REUTERS)
Vegetables are seen in vegetarian restaurant "Green Cuisine" in Minsk, Belarus February 1, 2018
(photo credit: VASILY FEDOSENKO / REUTERS)

A study from Harvard University's TH Chan School of Public Health has found a promising correlation between our diet choices and both our lifespan and the well-being of our planet. 

Presented at the NUTRITION 2023 conference in Boston, the research reveals that individuals opting for "planet-friendly" foods could have a 25% reduced risk of death over a 30-year period.

These beneficial, eco-conscious foods encompass whole grains (like wheat and rice), fruits, vegetables, nuts, and unsaturated oils—these oils are healthier fats, often found in foods like olives and certain fish. 

On the contrary, red and processed meats are shown to be less advantageous both for personal health and the environment.

The PHDI evaluates the broader consequences of our food choices 

To help understand and quantify the impact of these dietary choices on health and the environment, the researchers introduced the Planetary Health Diet Index (PHDI). 

FRESH PRODUCE is stacked in a store in Jerusalem’s Mahaneh Yehuda market (credit: MARC ISRAEL SELLEM/THE JERUSALEM POST)
FRESH PRODUCE is stacked in a store in Jerusalem’s Mahaneh Yehuda market (credit: MARC ISRAEL SELLEM/THE JERUSALEM POST)

Linh Bui, a PhD student at Harvard, shed light on the concept, stating, "The PHDI integrates the latest scientific findings on how different foods impact our health and our planet."

This PHDI scoring system isn't just about individual wellness. It evaluates the broader consequences of our food choices. The index considers factors such as how much water is consumed in the production of food (water use), the amount of land needed (land use), the contamination of water sources due to runoff from fertilizers (nutrient pollution), and gases released during food production that contribute to global warming (greenhouse gas emissions).

With this new tool, the research team analyzed the data of over 100,000 US participants spanning from 1986 to 2018. Unfortunately, within this timeframe, more than 47,000 of these individuals passed away. 

Those with higher PHDI scores had less risk of disease

The data, however, yielded compelling results: those with higher PHDI scores had a 15% reduced risk of death from conditions like cancer or heart diseases, a 20% reduction from ailments affecting the brain called neurodegenerative diseases, and a 50% reduced risk from respiratory diseases, which affect breathing and lung function.

Bui accentuated the PHDI's flexibility but also highlighted potential adjustments based on the cultural or religious contexts of different countries. She further pinpointed that some individuals, due to specific health conditions or limited access to certain foods, might find it challenging to fully embrace this planet-friendly diet.

The unveiling of the PHDI signals hope for policymakers and public health entities. This dual-focus tool can guide strategies to uplift public health while also mitigating the harmful effects of climate change. By understanding and adopting such dietary patterns, individuals can potentially secure a healthier future for themselves and the planet.

Please note that this scientific study has yet to undergo the peer-review process.