Six key foods linked with lower risk of heart disease, finds study

A major new study has found a diet comprised of higher amounts of six key foods – fruit, vegetables, nuts, legumes, fish, and dairy – is linked with lower risk of heart disease and death from any cause in adults (1).

About the research:

The research, just published in the European Heart Journal, combined findings from the Prospective Urban Rural Epidemiology (PURE) study, and also five other international studies (1,2).

Together, these comprised 244,597 people, both with and without prior cardiovascular disease (CVD), across 80 countries, who were tracked for an average (median) of 8.3 years.

Using data from the PURE study, the researchers developed a ‘healthy diet score’ and then explored the link between this and risk of major cardiovascular events (including heart attack, stroke, and heart failure) and death from any cause.

The PURE healthy diet score was based on intake levels of six protective foods – fruit, vegetables, nuts, legumes, fish, and (mainly regular-fat) dairy, which are all known to be linked with a significantly lower risk of death.

The healthy diet score ranged from 0 (worst) to 6 (best) points – that is, higher scores indicated a healthier diet. And participants were categorised into five ‘quintiles’ based on their healthy diet scores.

What did the study find?

A 20% (1 quintile) higher PURE healthy diet score was associated with a 6% lower risk of major cardiovascular events, and an 8% lower risk of death.

The average (mean) PURE healthy diet score was 2.95.

The highest PURE healthy diet score (that is, a score of 5-6, compared with a score of 0-1) was linked with:

• 28% lower risk of total mortality
• 19% lower risk of major CVD
• 15% lower risk of heart attack
• 17% lower risk of stroke.

Each quintile increase in the PURE healthy diet score was linked with:

• 8% lower risk of total mortality
• 6% lower risk of major CVD
• 6% lower risk of heart attack
• 6% lower risk of stroke.

The findings applied to people with and without vascular disease or diabetes, and in all world regions. But the associations were significantly stronger in South Asia, China, and Africa – regions where the PURE healthy diet score was low.

Lower consumption of healthy foods, including fruit, vegetables, nuts, legumes, fish, and dairy, contributes to an increase in cardiovascular risk globally, especially in countries with lower income.

The ‘most healthy’ diet (that is, a PURE healthy diet score of ≥5; or the highest quintile) translates to:

• Fruits and vegetables: 4-5 servings daily
• Legumes: 3-4 servings weekly
• Nuts: 7 servings weekly
• Fish: 2-3 servings weekly
• Dairy: 14 servings weekly
• Whole grains: Moderate amounts
• Unprocessed meats: Moderdate amounts

The ‘most healthy’ diet included 28.2g of nuts every day, and the ‘least healthy’ 3.9g nuts per day. In Australia, the average daily intake of nuts is chronically low, at just 4.6g (3).

The World Health Organisation estimates nearly 18 million people died from CVD in 2019, representing 32% of all global deaths. Of these deaths, 85% were due to heart attacks and strokes.

AIHW: Heart, stroke and vascular disease – Australian facts

Implications for nutrition policy

The study authors note:

• Diet-related chronic diseases continue to rise globally. Nutrition research, such as this, and modern dietary guidance highlight the power of protective foods, like nuts, to help address this.
• But the public’s understanding of healthy eating and relevant global policies has not yet caught up to this science. For instance, consumers remain cautious of some protective, energy-dense foods (such as nuts), and policy actions are still heavily focussed on reducing intake of certain nutrients, including fats.
• By contrast, there are almost no national or international strategies and policies to increase protective foods.

The bottom line:

This study adds to the body of research showing that healthy dietary patterns – including fruit, vegetables, nuts, legumes, fish, and dairy – can help protect again chronic disease, including CVD.

Nuts are fundamental within many healthy dietary patterns, with strong evidence for their role in reducing the risk of CVD. But daily nut intake is chronically low. To help bridge the gap between actual intake and the health-protective target of 30g/day, nuts need to be more prominent in dietary guidelines and within dietary advice.

Elevating nuts in dietary guidance

Nuts and CVD: What does the science say?

New research: Eating nuts reduces six factors for CVD

References

1. Mente, A., et al. Diet, cardiovascular disease, and mortality in 80 countries. European Heart Journal, 2023. ehad269: https://doi.org/10.1093/eurheartj/ehad269
2. Mozaffarian, D., et al. Identifying nutritional priorities for global health: Time for a more PURE focus on protective foods. European Heart Journal, 2023. ehad325: https://doi.org/10.1093/eurheartj/ehad32
3. Nikodijevic, CJ., et al. Nut consumption in a representative survey of Australians: A secondary analysis of the 2011-2012 National Nutrition and Physical Activity Survey. Public Health Nutr, 2020. 23(18):3368-78.