Written by Greg Arnold, DC, CSCS.
CoQ10 was first identified in 1957 and was named “ubiquinone” because it is found everywhere in the body. It is found in the highest amounts in the heart, liver, kidneys, and pancreas and in lowest amounts in the lungs (1). One issue with CoQ10 supplementation is its low bioavailability, meaning it is poorly absorbed into the body by the intestines (2). This has caused many CoQ10 supplements to be combined with oils to help increase bioavailability (3). Now a new lab study (4) has found that grapefruit juice may enhance CoQ10 absorption.
In the study, researchers found grapefruit juice to “significantly increase” the uptake of CoQ10 into colorectal cells (Caco-2 cells). Specifically, the cells were bathed in a solution containing 1% grapefruit juice and CoQ10 (10 micromolar) for 2 hours. They then used High Performance Liquid Chromatography to measure the uptake of CoQ10 by the colorectal cells and found that CoQ10 uptake in the grapefruit juice solution was 50% greater compared to the placebo group.
The researchers suggested that grapefruit juice is able to increase CoQ10 uptake by lowering the activity of a cell membrane protein called P-glycoprotein (5), which directly controls CoQ10 uptake into the cell (6). For the researchers, “It is possible that co-administration of CoQ10 with grapefruit juice constitutes an easily accessible way to improve the intestinal absorption of CoQ10.” Cell studies like this need to be confirmed in animal and human studies.
It is important to know that grapefruit juice’s ability to affect cell membrane proteins also causes it to interact with prescription medications, such as those for high blood pressure and high cholesterol (7) as well as those for abnormal heartbeat (8). If you are taking prescription medications, be sure to inform your doctor if you wish to include grapefruit juice in your diet to avoid any adverse interactions.
Source: Itagaki, Shirou, et al. “Grapefruit juice enhance the uptake of coenzyme Q10 in the human intestinal cell-line Caco-2.” Food chemistry 120.2 (2010): 552-555.
© 2009 Elsevier Ltd. All rights reserved.
Posted February 24, 2010.
References:
- “Questions and answers about Coenzyme Q10” posted on the National Cancer Institute Website.
- Y. Zhang, F. Aberg, E.L. Appelkvist, G. Dallner and L. Ernster, Uptake of dietary coenzyme Q supplement is limited in rats, Journal of Nutrition 125 (1995), pp. 446–453.
- “CoQ10 Emulsions Boost Bioavailability” posted on Nutraingredients.com – April 8, 2008
- Itagaki S. Grapefruit juice enhance the uptake of coenzyme Q10 in the human intestinal cell-line Caco-2. Food Chemistry 2010; 120(2): 552-555.
- A. Dahan and G.L. Amidon, Grapefruit juice and its constituents augment colchicine intestinal absorption: Potential hazardous interaction and the role of p-glycoprotein, Pharmaceutical Research 26 (2009), pp. 883–892.
- Itagaki S. Interaction of coenzyme Q10 with the intestinal drug transporter P-glycoprotein, Journal of Agricultural and Food Chemistry 56 (2008), pp. 6923–6927.
- “Grapefruit Interactions” posted on the People’s Pharmacy website.
- “List of Drugs Affected by Grapefruit” posted on the Wikipedia website.
