Soy and Your Heart: The Truth Behind the Hype

Soy products have been a subject of regular discussion, and wide debate down through the years, and it seems that confusing claims about the benefits of soy are in abundance.

So, what exactly are soy products?

Soy is a complete source of protein containing essential amino acids. They also contain high levels of polyunsaturated fats, fiber, vitamins, and minerals, antioxidants, and low levels of saturated fat.

In the mid-90s the cholesterol-lowering effect of soy, and its role in heart disease, was widely believed. However, future studies have failed to show a particularly strong link to its cholesterol lowering effect.

Scientific evidence

To date, the message seems a little confused, with some agencies claiming soy to be hugely beneficial, while others recommend its avoidance.

In a 2003 meta-analysis, which looked at lowering cholesterol using soy, the authors concluded that although the use of soy may exert a smaller risk reduction at the individual level than a pharmaceutical intervention, risk reduction is considerable at a population level.

In a 2005 meta-analysis, published in the American Journal of Clinical Nutrition, the authors concluded that consuming soy protein resulted in a significant decrease in total cholesterol, LDL cholesterol and triglycerides, and a significant increase in HDL cholesterol.

In response to numerous studies in 2005 regarding soy, the American Heart Association reviewed 22 studies. They found that large amounts of dietary soy protein merely reduced LDL cholesterol by 3%, with no effect on HDL cholesterol, or blood pressure. As a result, the American Heart Association no longer recommends eating soy to lower cholesterol.

However, a 2007 study published in the Archives of Internal Medicine, concluded that soy could be a practical, and safe way to reduce blood pressure. If the findings can be repeated in a larger group they may have important implications for reducing cardiovascular risk at population level.

Check out my previous article, Do Soy Products Help Lower Blood Pressure?

According to the British Dietetic Association “Recent evidence indicates that the combined use of soy protein, soluble fiber, almonds and plant sterols have the potential to decrease LDL cholesterol by 20%, equivalent to a first line statin drug. This approach cannot replace statins, but can provide a useful adjunct to statin therapy in motivated patients, as well as an approach for those who cannot or do not wish to take statins.

Continued research is needed in this area, before specific claims can be made. However, soy products do contain many other beneficial components, and as we’ve seen they have potential (however small) to reduce cardiovascular risk.

Advice: Try to include soy products regularly into your diet, as a healthy replacement for meats and other high fat foods.

Different sources of soy protein:

• Calcium-fortified soy milk
• Tofu
• Tempeh
• Textured vegetable protein
• Miso
• Soy burger
• Soy cheese
• Soy beans
• Soy yogurt
• Soy nuts
• Soy flour