Fruits and vegetables win again! As CNN reports, a new umbrella study has found that most vegetarian and vegan diets significantly curb risks of life-threatening illnesses like cancer and cardiovascular disease — and can even prevent early death.

An umbrella study systematically examines large amounts of existing research. For this study, published this week in the journal PLOS, an international cohort of scientists — including from Stanford University and the University of Cambridge — looked at over 20 years of research about plant-based diets.

In doing so, as study lead author and graduate student at the Scuola Superiore Sant’Anna in Pisa, Italy Angelo Capodici told CNN, the researchers were able to determine that healthy plant-based diets — which, per the study, range from stricter vegan regimens to dairy and egg-allowing vegetarian meal plans — offer a considerable “protective effect” against cancers like “liver, colon, pancreas, lung, prostate, bladder, melanoma, kidney and non-Hodgkin lymphoma,” in addition to heart disease. The study also showed that vegetarianism and veganism reduced instances of metabolic disease and diabetes, both of which may also contribute to shorter life spans and lower quality of living.

These disease-warding effects, according to the research, appear to be the result of factors like lower cholesterol and blood pressure, lowered blood sugar, and reduced inflammation, among other risk-reducing benefits. Altogether, the research adds to the ever-growing consensus that de-emphasizing meat products and processed foods in favor of whole, plant-based foods — vegetables, fruits, whole grains, nuts and seeds, legumes, and so on — is generally a positive move for long-term human health.

But that said, there’s one major caveat: not just any vegan or vegetarian diet will yield positive outcomes.

After all, plenty of junky, processed food, from sugary white bread to potato chips to candy and even Oreos, are technically considered vegan. But processed foods like that certainly don’t contribute to long-term health, and as study co-author and medical director of the pituitary unit at Bologna, Italy’s IRCCS Institute of Neurological Sciences Federica Guaraldi told CNN, those who consume a junk food-forward vegan or vegetarian diet likely won’t reap the same benefits as peers who emphasize whole, unprocessed, plant-based foods.

“Diets that emphasize consumption of unhealthy plant foods, such as fruit juices, refined grains, potato chips, and even sodas” might effectively cancel out the potential health benefits of a plant-based diet, Guaraldi told CNN.

It’s also worth noting that some experts have suggested that those who embark on healthier plant-based diet journeys may live more holistically healthy lifestyles — exercising regularly, getting enough sleep, and so on — which may contribute to the illness-curbing effects measured in this latest study.

“What is attributed to diet here may be in part due to other lifestyle practices,” David Katz, founder of the nonprofit True Health Initiative, who was not involved in the study, told CNN.

But, Katz added, that’s a “minor concern” regarding the accuracy of the research.

“The net effect of plant-predominant dietary patterns is clearly favorable to crucial health outcomes,” he continued, “even if some of the observed benefit is attributable to other lifestyle practices.”

The umbrella study also didn’t take any diets outside of vegetarian and veganism into consideration — meaning that regimens like the Mediterranean-inspired DASH and MIND diets, which are widely considered to be heart and brain-healthy despite allowances for fish and meat, were left out of the analysis. An umbrella analysis of this kind is also inherently quite general, and as the researchers write in the study, “data should be taken with caution because of the important methodological limitation associated with the original studies.”

The researchers further caution in the study that “potential risks associated with insufficient intake of vitamin and other elements due to unbalanced and/or extremely restricted dietary regimens” — basically, embarking on an animal-free diet without prioritizing the intake of essential vitamins and minerals, and macronutrients — should also be taken into consideration.

At the end of the day, diet and nutrition are deeply personal. Access to healthy, plant-based meals also isn’t afforded to everyone, particularly those who live around or below the poverty line. It seems more than fair, though, to chalk this study up as another W for the benefits of a whole plant-forward diet. If you’re able to go meat-free even just one or two days of the week, you might want to give it a try. It’s good for the planet, and it might just be good for your body, too.

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