Are there studies supporting the use of black and red rice for lowering cholesterol?

Black and Red Rice for Lowering Cholesterol: Evidence Review

There is insufficient evidence from high-quality clinical guidelines to recommend black and red rice specifically for lowering cholesterol. Current dietary guidelines for cholesterol management focus primarily on reducing saturated and trans fats rather than on specific rice varieties 1.

Current Dietary Recommendations for Cholesterol Management

Established Dietary Approaches

• For individuals with elevated LDL cholesterol, saturated fatty acids and trans-unsaturated fatty acids should be limited to <10% and preferably to <7% of energy intake 1
• Dietary cholesterol intake should be limited to <300 mg/day, with further restriction to <200 mg/day for those with LDL cholesterol ≥100 mg/dl 1
• LDL cholesterol lowering can be enhanced by adding plant stanols/sterols (2 g/day) and increasing soluble (viscous) fiber (10-25 g/day) 1
• For every gram increase in soluble fiber, LDL cholesterol would be expected to decrease by an average of 2.2 mg/dl 1

Dietary Fat Considerations

• When saturated fat is replaced with carbohydrates or monounsaturated fats, most studies show improvements in plasma LDL cholesterol 1
• For every 1% of energy from saturated fat that is replaced by 1% of energy from carbohydrate, MUFA, or PUFA, LDL-C is lowered by an estimated 1.2,1.3, and 1.8 mg/dL, respectively 1
• Incorporation of two to three servings of fish per week provides dietary n-3 polyunsaturated fat and can be recommended for cardiovascular health 1

Evidence on Black and Red Rice

Black Rice Research

• One laboratory study demonstrated that black rice extracts may inhibit cholesterol absorption through multiple mechanisms, including inhibition of pancreatic lipase, decreasing micellar cholesterol solubility, and suppressing cholesterol uptake in intestinal cells 2
• The cholesterol-lowering effects were positively associated with anthocyanin content (cyanidin-3-glucoside and peonidin-3-glucoside) in black rice 2
• However, this was an in vitro study, and clinical evidence in humans is lacking 2

Red Rice Research

• It's important to distinguish between red rice and red yeast rice, which are different products
• Red yeast rice (a fermented product containing monacolins) has demonstrated cholesterol-lowering effects in multiple studies 3, 4, 5
• Red yeast rice supplementation reduces LDL-C levels by approximately 15-34% versus placebo, with effects similar to low-dose statins 3
• In a small case series of 18 patients, a proprietary product combining red yeast rice and phytosterols reduced total cholesterol by 19% and LDL by 33% after 6 weeks 4
• In patients intolerant to statins, red yeast rice decreased total cholesterol by 13% and LDL cholesterol by 19% 5

Limitations and Caveats

• Most studies on red yeast rice are focused on supplements rather than dietary consumption of natural red rice 3, 4, 5
• There is a lack of high-quality clinical trials specifically examining the effects of dietary black or red rice on cholesterol levels 1
• Current dietary guidelines for cholesterol management do not specifically mention black or red rice as recommended foods for cholesterol lowering 1
• The cholesterol-lowering effects observed in laboratory studies may not translate to clinically significant benefits when consuming these foods as part of a regular diet 2

Practical Recommendations

• Focus on established dietary approaches for cholesterol management, including limiting saturated and trans fats, increasing soluble fiber, and incorporating plant stanols/sterols 1
• While black and red rice may be incorporated into a heart-healthy diet, they should not be relied upon as primary interventions for cholesterol management 1
• For significant cholesterol lowering, consider evidence-based approaches such as reducing saturated fat intake, increasing physical activity, and if necessary, pharmacological interventions 1
• If interested in nutraceutical approaches, red yeast rice supplements (not to be confused with dietary red rice) have better evidence for cholesterol-lowering effects than dietary consumption of colored rice varieties 3, 6