A handful of berries a day could help cut heart disease risk, major Queen’s study suggests

Regularly eating berries and other deeply coloured fruits and vegetables could significantly reduce the risk of heart disease, heart attacks and type 2 diabetes, according to major new research led by Queen’s University Belfast.

The study found that people with the highest intake of anthocyanins – natural compounds found in many red, blue and purple foods – had a 26% lower risk of developing cardiovascular disease compared with those consuming the least.

Researchers say the findings add to growing evidence that simple, achievable dietary choices could have a meaningful impact on long-term health, even among people who are otherwise healthy.

Published in The American Journal of Clinical Nutrition, the study analysed all available high-quality human evidence on anthocyanins and heart health, bringing together findings from 18 long-term population studies and 65 randomised controlled trials involving healthy participants.

Why this matters

Heart disease remains one of the leading causes of death across the UK, while rates of type 2 diabetes continue to rise.

Although no single food can prevent these conditions, researchers say their findings suggest that regularly consuming anthocyanin-rich foods may help lower risk over time.

Anthocyanins are naturally occurring plant compounds that give many fruits and vegetables their rich red, blue and purple colours. They belong to the flavonoid family of compounds, which have long been associated with health benefits including improved blood vessel function and reduced inflammation.

Foods rich in anthocyanins include berries, cherries, grapes, plums, red cabbage and aubergines.

The study was led by Professor Aedín Cassidy, Co-Director of the Co-Centre for Sustainable Food Systems at Queen’s University Belfast, in collaboration with researchers from Tufts University in Boston and the University of East Anglia.

Lower risks of major diseases

Across the population studies reviewed, people with the highest anthocyanin intake experienced:

• 26% lower risk of cardiovascular disease

• 18% lower risk of heart attack or coronary heart disease

• 11% lower risk of type 2 diabetes

• 9% lower risk of cardiovascular-related death

• 8% lower risk of developing high blood pressure

The researchers stress that these figures represent associations rather than guarantees, but they were consistent enough across large populations to suggest a meaningful relationship between anthocyanin-rich diets and better health outcomes.

Benefits seen at everyday intake levels

One of the most encouraging findings was that potential benefits appeared at intake levels that most people could realistically achieve through normal eating habits.

The clinical trials included in the review found improvements in cardiovascular and metabolic health markers at anthocyanin intakes as low as 50mg per day.

That could be achieved through a serving of berries, cherries or other richly coloured fruits and vegetables rather than specialised supplements.

Professor Cassidy said:

“By pooling all the data from high quality population-based studies and randomised controlled studies, our data suggests that higher habitual intakes of anthocyanins are associated with a lower risk of developing illnesses such as cardiovascular disease, hypertension, and type 2 diabetes.

“These benefits were backed up by the available data from randomised controlled trials which showed that readily achievable anthocyanin intakes, as low as 50 mg/d, improve cardiometabolic biomarkers in healthy participants.

“Our study shows clinically relevant improvements in blood flow, elasticity of the arteries and insulin levels in the combined trial data and these improvements could translate into significant long term health benefits.”

Healthier blood vessels may be driving the benefits

Interestingly, the strongest evidence from the clinical trials was not related to weight loss, cholesterol levels or blood pressure.

Instead, the most consistent improvements were seen in blood vessel function.

Researchers found anthocyanins improved the ability of blood vessels to relax and widen, helping blood flow more efficiently around the body.

They also found improvements in arterial elasticity and reductions in insulin levels, both of which are considered positive markers for long-term cardiovascular and metabolic health.

In simple terms, the findings suggest these foods may help keep blood vessels healthier and more responsive as people age.

The best foods to put on your shopping list

While anthocyanins are found in a wide range of foods, some sources provide particularly high amounts.

Among the richest everyday options are:

• Blackcurrants

• Blackberries

• Blueberries

• Cherries

• Red and purple grapes

• Plums and damsons

• Red cabbage

• Cranberries

• Raspberries

Researchers note that frozen berries can be just as useful as fresh varieties and are often a more affordable way to increase intake year-round.

What the study did not find

The research also provides an important reminder that healthy foods are not miracle cures.

Among healthy participants, anthocyanins did not produce significant improvements in several commonly measured health markers, including:

• Blood pressure

• Cholesterol levels

• Blood glucose

• Body weight

• Waist circumference

• General inflammation markers

Instead, the strongest evidence pointed towards long-term improvements in blood vessel health and metabolic function, which may help explain why people who regularly consume more anthocyanin-rich foods appear to experience lower rates of heart disease and diabetes over time.

A simple change that could add up over time

The researchers conclude that increasing intake of colourful fruits and vegetables rich in anthocyanins is a practical and achievable step that may support long-term heart and metabolic health.

For most people, that could be as simple as adding a handful of berries to breakfast, choosing cherries or grapes as a snack, or including more red cabbage and other colourful produce in everyday meals.

While the findings do not suggest any single food can prevent disease, they reinforce a growing body of evidence that small dietary habits, repeated consistently over many years, can make a meaningful difference to future health.