Health professional resource.

The impact of nut consumption on heart disease risk has been extensively investigated since the publication in 1992 of the Adventist Health Study, which linked regular nut consumption, for the first time, with a lower risk of coronary heart disease (3).

Since then, a wealth of consistent evidence has firmly established nuts as potent cardioprotective foods.

Evidence from systematic reviews and meta-analyses shows that regular nut consumption reduces the risk of CVD by positively impacting many CVD biomarkers, and for those with CVD, reduces the risk of dying from it.

What does the research say?

A systematic review and meta-analysis of randomised controlled trials by Australian-based researchers (4) showed that regularly eating a handful of nuts, significantly reduced LDL cholesterol, total cholesterol (TC), triglycerides (TG), TC:HDL cholesterol, LDL:HDL cholesterol, and apolipoprotein B (apoB).

Another systematic review and meta-analysis, which analysed the findings of 113 randomised controlled trials, backs up these findings (6). This research was published in late 2024 in the journal Nutrition, Metabolism and Cardiovascular Disease.

As well as lowering total and LDL cholesterol, the researchers of this recent review also identified improvements in triglycerides and apolipoprotein B, with daily nut consumption.

And a third comprehensive study – an umbrella review, of systematic reviews and meta-analyses (5) – also showed heart health benefits with nut consumption.

It found eating a handful (an ounce, or 28g) of nuts a day, compared to eating no nuts, was linked with:
• 25% reduced risk for CHD
• 22% reduce risk of death from CVD
• 22% reduced risk of dying from all causes
• 21% reduced risk for CVD

How do nuts support heart health?

• Nuts contain higher amounts of unsaturated fatty acids, relative to saturated fatty acids – and this is a well-established mechanism for improving total and LDL-cholesterol. Some nuts also contain n-3 polyunsaturated fatty acids, which may decrease triglyceride levels.

• Plant phytosterols, which are found in nuts, are associated with reductions in cholesterol levels. Phytosterols decrease cholesterol absorption and increase faecal cholesterol excretion.

• Nuts are the richest plant source of the amino acid L-arginine, which is involved in the synthesis of nitric oxide – a vasodilator, which improves endothelial function and helps regulate blood pressure.

• Nuts contain a range of antioxidant phytochemicals (such as polyphenols, vitamin E, riboflavin, selenium, manganese, copper and zinc) which can positively affect lipid oxidation, oxidative stress and platelet function.

• The fibre, and particularly soluble fibre, in nuts helps lowers cholesterol reabsorption by binding to cholesterol in the small intestine.