There has been controversy surrounding soy protein and its effect on cholesterol. A new meta-analysis delved into existing data and concluded that protein can indeed reduce “bad” cholesterol levels.
Soy protein comes from soybeans. It has high protein content, but does not contain cholesterol and only contains low levels of saturated fat. It is one of the few plant foods containing all essential amino acids.
Currently, the US Food and Drug Administration (FDA) includes soy protein in its list of foods that can lower cholesterol.
Of the 46 studies selected by the FDA, 43 provided enough data to be added to the scientist’s analysis. A total of 41 studies specifically looked at low-density lipoprotein (LDL) cholesterol, commonly referred to as bad cholesterol.
LDL cholesterol has a bad reputation because it increases the risk of stroke and heart disease when it accumulates in the arteries. Any food that can reduce this risk is very interesting.
The authors recently published their analysis results in the “Journal of Nutrition.” They concluded:
“Soy protein significantly reduces low-density lipoprotein cholesterol by about 3-4% in adults. Our data supports the international public’s recommendation to increase plant protein intake.”
Soy protein can reduce low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) cholesterol in harmful cholesterol, but cannot reduce the good cholesterol high-density lipoprotein (HDL) cholesterol. Studies have shown that after consuming soy protein, the concentration of total cholesterol in serum is reduced by 9.3%, LDL cholesterol is reduced by 12.9%, the concentration of total triglycerides in serum is reduced by 10.5%, and the concentration of high HDL cholesterol in serum is increased by 2.4%. Therefore, consumption of soy protein can cause cardiovascular and cerebrovascular diseases.
The lowering effect of soy protein on cholesterol is related to the initial concentration of cholesterol. Studies have shown that after consuming soy protein, LDL cholesterol for people with normal blood cholesterol levels is only reduced by 7.7%, and for people with high plasma cholesterol levels, it is reduced by 24%. It can be seen that the higher the cholesterol concentration, the better the reduction effect of soy protein.
Although the size of the effect seems small, the result is significant. The author also believes that in the real world, the effect may be stronger. They argue that when someone adds soy protein to their diet, in most cases, it will replace other protein sources that contain high levels of LDL cholesterol, such as meat and dairy products.
Dr. David Jenkins, who led the study, explained, “When people replace high-saturated fat and cholesterol-rich meat with a diet that contains soy, the cholesterol reduction may be even greater.”