Annatto tocotrienols support metabolic and bone health according to two animal studies

Sep 10, 2018

Two similar but separate animal studies found that supplementation with tocotrienols from annatto beans (DeltaGold from American River Nutrition; Hadley, MA) in rodents with induced metabolic syndrome and type 2 diabetes not only supported blood sugar but also bone health. There is a link between bone loss synonymous with diseases like osteoporosis and blood sugar disorders such as metabolic syndrome and diabetes.

Researchers of the study published in Bone1 explain, “Systemic hormonal changes have been proposed as an underlying mechanism governing the relationship between metabolic syndrome and bone health.” Chronic inflammation, a hallmark of metabolic syndrome and diabetes, is also recognized as a cause for bone loss, Wong et al. explain further. “In chronic inflammatory
condition, inflammatory cytokine networks stimulate an uncoupling process of bone formation and resorption,” they write.

The Bone study divided 30 rats into five groups: A baseline group, a normal diet group consisting of standard rat chow and tap water, and three groups fed a high-carbohydrate, high-fat diet (HCHF) with fructose supplemented water. Each HCHF group had a different daily regimen that included either tocopherol-stripped corn oil, 60 mg/kg of annatto tocotrienol, or 100 mg/kg of annatto tocotrienol after eight weeks of HCHF diet. The study lasted 20 weeks total.

Results showed that the HCHF diet increased abdominal circumference, blood pressure, fasting blood glucose, glucose intolerance, triglyceride, total cholesterol, LDL cholesterol, fat mass, and percentage of fat in animals compared to control. Supplementation with annatto tocotrienols however, significantly reduced blood pressure, fasting blood glucose, triglycerides, and total cholesterol in HCHF rats, with only the 100 mg/kg tocotrienol group showing significantly reduced LDL cholesterol.

When it came to bone health, the HCHF rats experienced significant deterioration in trabecular bone microstructure, significantly narrower femur width, lower ultimate load in their femurs, and higher ultimate strain in their femurs. Supplementation of annatto tocotrienols at 100 mg/kg significantly reversed negative parameters of trabecular bone microstructure, and significantly improved ultimate load, elasticity and ultimate strain in their femurs.

The other study, published in Scientific Reports2, divided 58 mice into five groups: A low-fat diet group, a high-fat diet (HFD) group, and high-fat diet groups given either 400 mg/kg annatto tocotrienols, 1,600 mg/kg annatto tocotrienols, or 200 mg/kg of metformin for 14 weeks. Metformin is an anti-diabetic medication.

After 14 weeks, the HFD group without supplementation exhibited hyperglycemia after fasting and glucose intolerance indicative of diabetes. Supplementation with 1,600 mg/kg of annatto tocotrienols and metformin, however, significantly decreased four-hour fasting blood glucose levels in mice with HFD. All treatment groups improved glucose tolerance as well.

In terms of bone health, 1,600 mg/kg of annatto tocotrienols significantly increased the level of a serum bone formation biomarker and decreased the level of a serum bone resorption biomarker compared to HFD alone. Both doses of tocotrienols also mitigated the HFD-induced deterioration of trabecular bone microstructure (similar to results published in Bone) and prevented obesity-induced loss of femoral cortical thickness, while metformin did not improve trabecular or cortical microstructures in obese mice.

According to Wong et al. tocotrienol derived from annatto beans are unique because they are made up of 90% delta-tocotrienol and 10% gamma-tocotrienols and no alpha-tocopherol. “The absence of alpha-tocopherol from annatto tocotrienol is an advantage because it interferes with them bioavailability of tocotrienols due to the preferential binding of alpha-tocopherol to alpha-tocopherol transfer protein (alpha-TTP),” they write.

“These independent studies show for the first time that DeltaGold annatto tocotrienol as a single agent can target both metabolic and bone health,” commented Barrie Tan, PhD, president of American River Nutrition in a press release. “With more than a third of all Americans being pre-diabetic or diabetic and bearing an increased risk of osteoporosis, these results are welcome news to those battling both ailments, and support clinical data espousing DeltaGold benefits to metabolic health as we age and the aging bone.”

Because these are animal studies, these findings require further investigation in human subjects.

References: 

1. Wong SK et al. “Exploring the potential of tocotrienol from Bixa orellana as a single agent targeting metabolic syndrome and bone loss.” Bone, vol. 116 (July 2018): 8-21

2. Shen C et al. “Annatto-extracted tocotrienols improve glucose homeostasis and bone properties in high-fat diet-induced type 2 diabetic mice by decreasing the inflammatory response.” Scientific Reports, vol. 8 (July 2018): 11377