These Foods May Lower Cancer Risk and More

People who follow a healthy plant-based diet may be less likely to develop several chronic illnesses later in life, new research suggests.

Those who ate the most vegetables, fruits, whole grains, beans and nuts had a lower risk of multimorbidity — living with two or more long-term conditions such as cancer, heart disease or type 2 diabetes. The effect was strongest in adults under 60 but was also seen in older adults.

The study, published in The Lancet Healthy Longevity, builds on earlier research showing that plant-based diets can help prevent single diseases. What’s been less clear is whether they also protect against multimorbidity, which is becoming more common as people age.To find out, researchers looked at long-term data from two of the largest health studies in Europe and the UK.

How Was the Study Conducted

The international team of researchers drew from data from two of the largest health studies in Europe and the U.K.: the European Prospective Investigation into Cancer and Nutrition (EPIC) and the UK Biobank. They focused on adults aged 35 to 70 and left out anyone who already had cancer, heart disease, type 2 diabetes or was missing diet and health information. This way, they could zero in on new cases as they developed.

In EPIC, participants filled out a detailed questionnaire about what they typically ate over the past year. In UK Biobank, people logged their diets through several 24-hour online food surveys collected over about a year, which meant some participants had more than one diet record.

From these data, the team created two measures of diet quality. The healthful Plant-Based Diet Index (hPDI) gave higher scores for eating more fruits, vegetables, whole grains, beans and nuts. The unhealthful Plant-Based Diet Index (uPDI) scored higher when diets leaned more heavily on refined grains, sugary drinks and processed plant foods.

The main question was whether these scores were linked to the risk of developing multimorbidity. The researchers also looked at whether results differed between younger adults and those over 60, and whether diet quality affected the first diagnosis of cancer, heart disease or type 2 diabetes and the progression to having more than one condition.

What Did the Study Find?

The study followed 407,618 adults, including 226,324 from EPIC and 181,294 from the UK Biobank. Over about 11 years of follow-up, 6,604 people developed cancer along with heart or metabolic disease—3,455 cases came from EPIC and 3,149 from UK Biobank. Roughly one in three cases were in women and two in three in men.

People who scored higher on the healthful Plant-Based Diet Index (hPDI) had a lower risk of developing multiple chronic diseases. For every 10-point jump in the hPDI score, risk fell by 11% in EPIC and 19% in UK Biobank. The protective effect was still there in older adults but it was stronger in those under 60.

Looking at individual conditions, healthy plant-based diets were tied to lower risks of cancer, heart disease and type 2 diabetes. For diabetes specifically, each 10-point rise in hPDI was linked to an 18% lower risk in EPIC and a 26% lower risk in UK Biobank.

On the other hand, people with higher scores on the unhealthful Plant-Based Diet Index (uPDI)—which reflects diets higher in refined grains, sugary drinks and processed plant foods—had a greater risk of these diseases in both studies, except for diabetes in EPIC.

When broken down by age, healthy plant-based diets lowered the risk of multimorbidity in both middle-aged and older adults, though the effect was strongest in people under 60. In EPIC, the benefit in adults over 60 was no longer statistically significant. In UK Biobank, unhealthy plant-based diets raised the risk in both younger and older adults.

The authors did point out some limitations. In EPIC, diet was measured only once at the start, so changes over time weren’t captured. In both studies, food intake was self-reported, which always carries the chance of some error. They also didn’t have detailed treatment information that could have affected outcomes. Even so, the results support the idea that diet doesn’t just influence single diseases—it can also affect the odds of developing multiple health problems at the same time.

How Does This Apply to Real Life?

The takeaway from this study is pretty simple: meals built around vegetables, fruits, whole grains, beans and nuts do your body a lot of good. These foods are packed with nutrients and fiber that can support your health for the long haul and may help lower your chances of developing more than one chronic condition.

But not all plant-based foods are created equal. Things like refined grains, sugary drinks and packaged snacks might be technically plant-based, but they don’t give you the same benefits as whole foods. Choosing less processed options most of the time is where the real payoff comes.

Another encouraging note is that you don’t have to go with a fully vegan diet or swear off animal products to see results. Even small, steady changes—like swapping one meat-heavy dinner for a bean dish or adding an extra serving of veggies each day—can make a difference.

And beyond personal health, there’s a bigger win. Eating more whole plant foods and cutting back on meat also helps shrink the environmental footprint of your diet, making it a choice that’s good for you and the planet.

Our Expert Take

This study is a reminder that what we eat really does add up over time. Choosing more whole plant foods—like vegetables, grains, beans and nuts—can help lower the risk of facing multiple chronic illnesses later in life. The good news is you don’t need to be perfect or cut out all animal products to see benefits. Even small changes can make a difference, and those choices help the planet too.