Does Whole Grain Consumption Lower Cholesterol?
Title: Whole-grain and blood lipid changes in apparently healthy adults: a systematic review and meta-analysis of randomized controlled studies
Author: Hollaender et al.
Journal: American Journal of Clinical Nutrition
Objective: “Using a meta-analytic approach, they assessed the effect of whole-grain compared with non–whole-grain foods on changes in total cholesterol (TC), LDL cholesterol, HDL cholesterol, and triglycerides.”
According the Center for Disease Control and Prevention:
- kills 610,000 people die every year from heart disease, that’s 1 in 4 deaths
- Leading cause for death in men and women
- Coronary heart disease (disease of the arteries that supply the blood to the heart), is the most common, making up 370,000 of those deaths
- About 735,000 americans have heart attacks annually,
The are many known risk factors for cardiovascular disease, including diabetes, overweight and obesity, diet, lack of physical activity, excessive alcohol use.
Elevated serum cholesterol is another known risk factor cardiovascular disease. Again, according to the CDC, having high cholesterol:
- Doubles your risk of a heart attack
- 71 million Americans have elevated LDL cholesterol, the bad kind
- Only 1 out of 3 with elevated cholesterol has it under control and less than half get treatment
Many different methods have been researched and proposed to lower your cholesterol, including dietary changes, increasing physical activity, smoking cessation, weight loss, and if that all fails, medication.
One dietary consideration has been whole grain, complex carbs. Whole grain foods are nutritionally dense, with significant amounts of vitamins, minerals and fibers. The relationship between whole grain consumption and blood levels of total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides is not clear. There have been multiple studies of varying quality with mixed results. The authors of this meta analysis and systematic review sought to shed some light on this.
A systematic review and meta-analysis, while technically different, are functionally similar. The goal is to combine and summarize the results different studies on a given subject in the hope of identifying patterns among study results. It is the gold standard among scientists and medical professionals for interpreting research results from multiple studies.
A total of 6069 articles were screened for eligibility, ultimately 24 studies were included for analysis.
They used advanced statistical analysis to allow them to compare the different studies and combine the results.
Whole-grain intake, when compared to control, lowered
- LDL cholesterol (weighted difference: 20.09 mmol/L; 95% CI: 20.15, 20.03 mmol/L; P , 0.01)
- Total cholesterol (weighted difference: 20.12 mmol/L; 95% CI: 20.19, 20.05 mmol/L; P , 0.001)
Whole-grain oat had the greatest effect on total cholesterol (weighted difference: 20.17 mmol/L; 95% CI: 20.10, 20.25 mmol/L; P , 0.001).
Whole grain foods did not have an effect on HDL cholesterol (the healthy cholesterol).
Whole-grain foods tended to lower triglycerides compared with the control, although this difference was not statistically significant.
Consumption of whole-grain diets lowers LDL cholesterol and total cholesterol, but not HDL cholesterol or triglycerides.
Whole-grain oats appears to be the most effective whole grain for lowering cholesterol.
These findings provide a foundation for recommending whole grains as part of a comprehensive diet plan aimed at improving your lipid profile.
Hollaender, P. L., Ross, A. B., & Kristensen, M. (2015). Whole-grain and blood lipid changes in apparently healthy adults: a systematic review and meta-analysis of randomized controlled studies. American Journal of Clinical Nutrition, 102(3), 556-572. doi:10.3945/ajcn.115.109165