Heart health

Eating a plant-based diet is a simple and easy way to look after your heart. Plant-based foods such as fruit, vegetables, legumes, whole grains, nuts and seeds are lower in saturated fat and many are a source of fibre. A diet low in saturated fat is important for maintaining a healthy cholesterol level as part of a healthy balanced diet and lifestyle.

Plant foods such as almonds, oats and soya have a specific cholesterol lowering effect. 

In the US the FDA has approved a heart health claim for both soya protein and nuts (almonds, hazelnuts). Soya foods can lower cholesterol in a number of ways. Nuts mainly contain unsaturated fats and very little saturated fats.

In Europe the blood cholesterol lowering effect of beta-glucans from oat and barley has also been recognized.

Cardiovascular disease (CVD - which includes both coronary heart disease (CHD) and stroke) is the single most important cause of death in Europe and causes 4.3 million deaths per year, representing 48% of all deaths.
The most important behavioral risk factors are an unhealthy diet, physical inactivity and tobacco use. Together these three risk factors are responsible for about 80% of CHD and stroke.
One of the most important modifiable risk factors is raised blood cholesterol. The World Health Organisation (WHO) estimates that over 60% of CHD and 40% of stroke in developed countries is due to total blood cholesterol levels in excess of the theoretical minimum, 3.8mmol/L. People with abnormal blood lipids have a three-fold greater risk of heart attack compared to those with normal levels. The WHO calculated that each 1% reduction in Low Density Lipoprotein-cholesterol (LDL-cholesterol) in the population, could lead to a 2%–4% reduction in CVD.
Plant-based eating patterns and plant-derived foods have a number of characteristics that may contribute to their role in heart health.
  • Plant-based foods and eating patterns tend to be lower in fat, especially saturated fat. It’s widely accepted that a reduced saturated fat intake is associated with lower total blood cholesterol and LDL-cholesterol.
  • Plant-based diets are high in fibre, both soluble and insoluble, which results in a lower energy density diet and improvements in satiety. Furthermore, soluble fibre binds to bile salts and cholesterol in the intestines, reducing the amount that is reabsorbed and causing bile salts to be excreted. This loss results in an increased synthesis of bile salts from cholesterol in the liver which in turn reduces blood cholesterol.
  • Specific plant foods or plant-derived components have been shown in scientific publications to reduce blood cholesterol, namely soy protein, nuts, oat/barley beta glucans and plant stanols or sterols.
Eating more fruit, vegetables, legumes, whole grains, nuts and seeds is a simple and easy way to support a healthy heart.
Under controlled conditions soya foods directly lowers blood LDL-cholesterol by 4-6% compared to diets with the same macronutrient content. This has been confirmed by a systematic review and meta-analysis showing that consumption of 15-25g soya protein daily, has been scientifically proven to lower LDL-C by 4.3%. This is due to the direct action of soya protein on LDL-C receptors in the liver- where it down regulates LDL-C synthesis.

In real life, soya foods displace other foods in the diet: soya drink replaces dairy milk, soya dessert replaces dairy-based desserts, tofu mince replaces meat … . As such, swapping foods that are high in saturated fat, such as meat and dairy, with soya foods that contain polyunsaturated fats, reduces the amount of saturated fat and cholesterol in the diet. It’s been estimated that in a typical western diet, the displacement of meat and dairy foods by soya is likely to lower LDL-cholesterol by a further 3.6-6%.
 
Overall soya can therefore reduce LDL-cholesterol by between 4.3-10.3%. This has clinical significance, as it’s been suggested by the WHO that each 1% reduction in LDL-cholesterol in the population could lead to a 2 to 4% reduction in cardiovascular diseases.



Figure:  effects of soya on LDL
There is some evidence suggesting that soya foods may lower blood pressure. It’s been proposed that a 1% reduction in blood pressure in the population could prevent around 1500 deaths from cardiovascular disease a year.

Findings from clinical studies show that supplementing the diet with soya reduces systolic and diastolic blood pressure in hypertensive individuals. A meta-analyses of 11 studies found that soya isoflavones lowered blood pressure in hypertensive subjects, but not in normotensive subjects.

Soya isoflavones appear to have a beneficial effect on the endothelium (the inner lining of cells in blood vessels). Isoflavones may also increase the elasticity of the aorta and so can improve vascular function.
The Ultimate Cholesterol Lowering Plan© is a revolutionary and practical approach to cholesterol lowering developed by HEART UK in collaboration with Alpro. It combines the latest scientific evidence for dietary modifications to actively lower cholesterol and integral to its application utilizes motivational interviewing to tackle compliance issues – the common stumbling block to the success of lifestyle therapies.
Harland JI, Haffner TA. Systematic review, meta-analysis and regression of randomised controlled trials reporting an association between an intake of circa 25g soya protein per day and blood cholesterol. Atherosclerosis 2008;200:13-27.
 
Jenkins DJ, Mirrahimi A, Srichaikul K et al. Soy Protein Reduces Serum Cholesterol by Both Intrinsic and Food Displacement Mechanisms. J Nutr 2010.

Anderson JW, Bush HM. Soy protein effects on serum lipoproteins: a quality assessment and meta-analysis of randomized, controlled studies. J Am Coll Nutr 2011;30:79-91.

Liu XX, Li SH, Chen JZ et al. Effect of soy isoflavones on blood pressure: A meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis 2011.

He J, Gu D, Wu X et al. Effect of soybean protein on blood pressure: a randomized, controlled trial. Ann Intern Med 2005;143:1-9.

Taku K, Lin N, Cai D et al. Effects of soy isoflavone extract supplements on blood pressure in adult humans: systematic review and meta-analysis of randomized placebo-controlled trials. J Hypertens 2010.