In an article reviewing research carried out so far into the effects of CoQ10 on the progressive debilitating disease, published in the July issue of Pharmacology & Therapeutics, (Elsevier, vol 107, pp 120-130), Dr Clifford Shults of the Department of Neurosciences at the University of California in San Diego revealed that a new phase III trial is scheduled to commence this year.
In the past three years, demand for CoQ10 has escalated, causing soaring prices and reports of fake products entering the market.
Although there is no means of qualifying the connection, the increase in demand is thought to have been triggered by the publication of Shults' earlier phase II study, published in 2002 in the Archives of Neurology (59, pp 1541-1550) , which showed a "positive trend for coenzyme Q10 to slow progressive disability that occurs in Parkinson's disease."
The most recent figures obtained by NutraIngredients.com at the end of March set the on-the-spot price of CoQ10 at around $4,000 per kg. Some European suppliers have reported that availability has since improved and that prices could have fallen to the region of $3000 per kilo.
Japanese supplier Kaneka, which has produced natural CoQ10 since 1977 through a yeast fermentation process, currently supplies between 60 and 70 percent of the CoQ10 sold in the US. The US has been estimated to account for up to two thirds of global demand.
Kaneka doubled its capacity to 150 tons last year and is adding a further 30 tons this year, followed by an additional 100 tons at a new plant next year.
Shortages in the early part of this year are thought to have been caused by regulatory changes in its home market of Japan, which opened up the use of CoQ10 in food supplements and pharmaceuticals, resulting in less availability for international markets.
Shults' new phase III research will compare placebo and two dosages of CoQ10 (1200 and 2400 mg/day), with 200 patients in each treatment arm.
"The study should answer many of the questions regarding the short- and longer term effects of coenzyme Q10 in Parkinson's disease," he wrote.
In the phase II study, Shults compared a placebo with three doses of CoQ10 - 300, 600 and 1200 mg/day. Each group consisted of 20 patients in the early stages of the disease, who had not received any medication. All patients also received 1200IU/day of vitamin E.
The patients' were evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS) at one, four, eight and 12 months, then with 16 visits either up until the point when the patient's condition meant that they required medication, or up to a maximum of 16 months.
Where + indicates a worsening of the condition, the adjusted mean UPDRS changes were +11.99 for the placebo group, +8.81 for the 300mg/d group, +10.82 for the 600mg/day group and +6.69 for the 1200 mg/d group.
Not only were the high doses of CoQ10 seen to be safe and well tolerated, they were also the most effective. This observation has led Shults to deem it "important that any phase III study evaluate a higher dosage".
The safety of doses up to 3000mg/day was evaluated in a 2004 study (Experimental Neurology 188, 2), and adverse effects were considered to be unrelated to CoQ10. The highest effective dose was seen to be 2400mg/day.