TL;DR: Sustained Mediterranean eating was estimated to lower 20-year cardiovascular risk to 28.2% versus 35.9% under low-fat eating in high-risk United States adults, according to a June 20, 2026 target-trial emulation reported in the American Journal of Clinical Nutrition.

What the 20-year comparison estimated

The central answer from the new analysis is that both the Mediterranean diet and the food-based American Heart Association-2020 dietary goals were estimated to produce a lower 20-year risk of cardiovascular disease than a low-fat diet among United States adults, as reported in the American Journal of Clinical Nutrition.

The pooled absolute risk over 20 years was 35.9% with a 95% confidence interval from 33.1% to 38.5% under the low-fat strategy, 28.2% with a 95% confidence interval from 25.8% to 31.4% under the Mediterranean strategy, and 31.2% with a 95% confidence interval from 29.1% to 33.4% under the food-based American Heart Association-2020 strategy.

Compared with the low-fat diet, the estimated risk ratio was 0.79 with a 95% confidence interval from 0.70 to 0.91 for the Mediterranean diet and 0.87 with a 95% confidence interval from 0.79 to 0.96 for the American Heart Association-2020 dietary goals.

The investigators also reported estimates for a general population that was not selected for age, diabetes, or cardiovascular risk factors, where the corresponding risk ratios were 0.90 with a 95% confidence interval from 0.84 to 0.95 for the Mediterranean diet and 0.94 with a 95% confidence interval from 0.90 to 0.99 for the American Heart Association-2020 goals.

The published conclusion stated that sustained adherence to the Mediterranean diet and to the American Heart Association-2020 dietary goals is estimated to have a lower 20-year risk of cardiovascular disease than a low-fat diet in United States adults.

The background for the project noted that the Mediterranean diet reduces cardiovascular disease risk in European populations, but its long-term effectiveness in United States adults, particularly relative to the American Heart Association-2020 dietary goals, remained uncertain before this emulation.

Who was included and how follow-up was done

The emulation used data from the Nurses' Health Study and the Health Professionals Follow-up Study, two long-running United States cohort studies named as the data sources in the American Journal of Clinical Nutrition report.

The high-risk target-trial population included 12,197 United States adults aged 55 to 80 years who had diabetes or three or more major cardiovascular risk factors at the start of the emulated trial.

Diet was assessed every four years with validated food frequency questionnaires, providing repeated measures that the researchers used to represent sustained eating patterns rather than a single baseline recall.

The primary outcome was cardiovascular disease defined as nonfatal myocardial infarction, coronary revascularization, stroke, and cardiovascular death, with events confirmed by medical records.

The authors applied the parametric g-formula to estimate 20-year cardiovascular risk under each dietary strategy, a statistical approach designed to emulate sustained adherence while accounting for time-varying diet and risk factors.

Over 20 years of follow-up in the high-risk group, 3,469 cardiovascular cases occurred, including 1,451 cases among men and 2,018 cases among women.

The author group was led by Yi Li with Dalia Stern, Miguel Ángel Martínez-González, Shuyuan Yang, Jorge E. Chavarro, JoAnn E. Manson, Eric B. Rimm, Robert William Platt, and Yu-Han Chiu as corresponding author, with affiliations including McGill University, Instituto Nacional de Salud Pública, Instituto de Salud Carlos III, Brown University, and Brigham and Women's Hospital.

The paper appeared in the American Journal of Clinical Nutrition on June 20, 2026, and listed support from the National Institute of General Medical Sciences.

What each eating strategy represented

The objective described three sustained strategies: a low-fat diet, a Mediterranean diet, and the food-based American Heart Association-2020 dietary goals, with the low-fat diet serving as the reference for the risk-ratio comparisons.

A Veterans Affairs Evidence-based Synthesis Program management brief characterized the Mediterranean diet by high intake of olive oil, fruits and vegetables, whole grains and cereals, legumes, fish, and nuts, with low intake of red meat, dairy products, and sweets and moderate intake of red wine with meals.

That same brief described the comparison Western diet as rich in red meat, dairy products, processed and artificially sweetened foods, and salt, with minimal intake of fruits, vegetables, fish, legumes, and whole grains.

The brief said epidemiologic studies have shown that cardiovascular disease incidence in populations consuming Mediterranean-type diets is lower than in populations consuming a more typical Western diet.

The American Journal of Clinical Nutrition emulation specifically compared the food-based version of the American Heart Association-2020 dietary goals, rather than a nutrient-only score, against the Mediterranean and low-fat approaches.

Readers seeking practical food selection can discuss questionnaire-based patterns with a clinician or registered dietitian and consider general adherence tracking, because the study measured diet with repeated food frequency questionnaires and modeled sustained adherence.

Why United States data were needed

European trial and cohort evidence had already linked Mediterranean eating to lower cardiovascular risk, but the authors framed uncertainty about long-term effectiveness in United States adults and about performance relative to the American Heart Association-2020 goals.

The Veterans Affairs brief identified the PREDIMED trial, described as Prevention with Mediterranean Diet, as the only large randomized controlled trial that tested effects of an intensive Mediterranean diet with five of seven components on clinical outcomes.

In that trial, either a Mediterranean diet supplemented with extra virgin olive oil or a Mediterranean diet supplemented with nuts was associated with a significant 30% reduction in major cardiovascular events, which was the primary endpoint, compared with a low-fat control diet, according to the Veterans Affairs synthesis.

The synthesis also reported that the trial documented significant reductions in incident diabetes, but only in the group assigned to the diet supplemented with extra virgin olive oil.

The Women's Health Initiative Dietary Modification trial, discussed in the same synthesis, found no difference in major cardiovascular events or diabetes between its two diet groups, although investigators did not consider that fat-lowering intervention with two of seven Mediterranean components a true Mediterranean diet.

For secondary prevention, the synthesis said data from three randomized controlled trials indicate that a Mediterranean diet is associated with a significant reduction in new myocardial infarction, but no reduction in cardiovascular mortality, stroke, or other cardiovascular events.

The new United States emulation therefore addressed what the authors called a gap concerning sustained Mediterranean adherence outside Europe and direct estimation against both low-fat eating and the food-based American Heart Association-2020 goals.

What 20-year European follow-up showed alongside

A separate 20-year analysis from the ATTICA Study, published in the European Journal of Nutrition on June 19, 2026, examined habitual dietary patterns in a Mediterranean population-based cohort and their links to cardiovascular risk factors and outcomes over two decades.

That study enrolled 3,042 cardiovascular-disease-free adults in 2001-2002 and derived posteriori dietary patterns with principal component analysis based on intake assessed with a validated food frequency questionnaire.

Complete cardiovascular data were available for 1,988 individuals after 20 years, and the investigators calculated cardiovascular incidence, lifetime risk, and disability-adjusted life years.

Three dietary patterns were identified that together explained 46.5% of variance in consumption: a plant-based sustainable pattern, a Western pattern rich in animal-sourced and processed foods, and a high-calorie, low-white-meat pattern.

Higher adherence to the plant-based pattern was associated with a 26% lower 20-year cardiovascular risk, with a hazard ratio of 0.74 and a 95% confidence interval from 0.55 to 0.99, in multivariate Cox proportional hazards analysis.

The high-calorie, low-white-meat pattern was linked to increased lifetime risk with a beta coefficient of 0.066 and a p-value below 0.001 and to higher disability-adjusted life years with a beta coefficient of 0.13 and a p-value of 0.009.

No significant associations were observed for the Western pattern after adjustments in that analysis, while beta and gamma regression models were used alongside Cox models to examine pattern-outcome relationships.

The ATTICA authors concluded that a plant-based dietary pattern was protective against long-term cardiovascular outcomes, while a high-calorie, low-white-meat pattern was detrimental, and they emphasized culturally acceptable sustainable patterns for reducing risk and supporting environmental sustainability.

Viewed together, the European Journal of Nutrition cohort findings and the American Journal of Clinical Nutrition emulation both point toward lower long-term cardiovascular risk with plant-forward Mediterranean-type adherence when followed over 20 years.

How to interpret the estimates for personal choices

The risk numbers are modeled estimates of what 20-year risk would be under sustained adherence to each strategy, not observed rates among people who were randomly assigned to eat that way for two decades.

The parametric g-formula estimates adjusted for measured time-varying factors captured in the Nurses' Health Study and Health Professionals Follow-up Study, but emulation cannot establish the same certainty as a decades-long randomized feeding trial.

People with diabetes or multiple major risk factors, matching the 55-to-80-year-old high-risk group, may wish to review the absolute risks of 35.9%, 28.2%, and 31.2% with their clinician because absolute differences matter alongside the reported risk ratios of 0.79 and 0.87.

People without those selection characteristics may focus on the general-population risk ratios of 0.90 for the Mediterranean diet and 0.94 for the American Heart Association-2020 goals, which were closer to one than the high-risk estimates yet remained below one with confidence intervals that excluded one.

Because diet was measured every four years by questionnaire and outcomes required medical-record confirmation of myocardial infarction, revascularization, stroke, or cardiovascular death, day-to-day eating and symptom evaluation still require individualized medical guidance rather than self-classification.

Sources referenced