“Huge doses of purified methoxylated polyflavones increase insulin sensitivity and attenuate atherosclerosis in mice” is certainly not as catchy a headline as “Tangerine a Day Keeps Heart Surgeons Away” or “Superfruit Tangerines Can Reduce Heart Attack Risk.” Yes, we are once again experiencing the plague of the overly exuberant headline writer! It’s almost a daily occurrence.Â
A study appears that shows some sort of interesting finding in a Petrie dish or in some animal using some unrealistic dose of a chemical that occurs naturally in some food, and that food gets elevated to superstar status. The current golden boy is nobiletin, a chemical found in tangerines. It belongs to a family of compounds called methoxylated polyflavones that recently have garnered a great deal of chemical interest because of their potential biological activity. Laboratory investigations have shown antioxidant, anti-inflammatory, anti-carcinogenic and cholesterol lowering action. Now researchers at the University of Western Ontario have tickled headline writers fancy with their investigation of the effects of nobiletin on obese mice. Two groups of mice were treated to a calorie rich, high sugar diet designed to make them fat and prone to heart disease. One of the groups had powdered nobiletin mixed into their daily chow. The results were interesting. The mice on the nobiletin-laced diet put on less weight!Â
That was surprising, but there was more. The mice not getting the supplement accumulated higher levels of insulin and glucose in their blood, had their triglycerides and cholesterol levels rise and they were more likely to develop fatty liver. Furthermore, the treated mice had less of a buildup of plaque in their arteries. Hence the headlines about tangerines reducing heart attack risk despite the fact that tangerines were not even involved in the study. Now for a dose of reality.Â
The first point of interest in any such study is the dose of the chemical that was used. A mouse eats about 5 grams of food a day, and in this experiment about 0.2% nobiletin by weight was added to the daily meals. That translates to about 10 mgs. And how much is there in a tangerine? Roughly 1 mg, virtually all of which is in the peel and the pith, the white stuff that separates the peel from the fruit, which most people discard. The portion that we eat contains hardly any nobiletin. So there’s no justification for the headline about a tangerine a day keeping the heart surgeon away. The authors of the paper of course don’t make any such suggestion at all. They correctly conclude that “the use of nobiletin provides insight into potential targets for the treatment of abnormal lipoprotein and glucose metabolism, characteristic of insulin-resistant states and premature atherosclerosis.Â
If there is benefit to be had from nobiletin it is likely to come in a supplement form. Actually such products are already on the market. Since they are derived from a natural source they do not require a prescription. Sytrinol is a mixture of polymethoxylated flavones extracted from citrus and palm fruits and according to the manufacturer lowers cholesterol by as much as 30%. It may be one of those hyped “all natural” products that may really work. As far as the tangerines go, they do taste good, don’t they? That’s the reason to eat them. And don’t bother to take off the pith.
