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UC findings suggest supplements not helpful

By Priyanka Sharma-Sindhar Special to the Daily Pl
Monday October 23, 2000

Ever since Martyn Smith, professor of toxicology at UC Berkeley and graduate student Christine F. Skibola, published their findings in the “Free Radical Biology and Medicine” journal, they’ve been inundated with phone calls and e-mails from very worried people.  

Their studies showed that an excessive intake of certain components of plant food, called flavonoids, in the form of supplements, could be toxic. High concentrations of flavonoids are present in popular products such as ginkgo pills, quercetin tablets, grape seed extract and flax seed.  

“People want to improve their own health, and unfortunately believe the wild claims made for these supplements. They believe that their memory is going to be sharpened by Gingko Biloba. There is absolutely no evidence for that in normal people. So, they’re trying to improve themselves, but in the effort, they may be doing more harm to themselves than good.”  

Smith and Skibola embarked on this study because they got tired of hearing only about the beneficial effects of flavanoids, which according to them are actually in fruits and vegetables. “The companies selling these compounds are touting the good things. But people have to be aware of the dangers they’re exposed to,” said Skibola.  

Smith points to the example of a supplement called Quercetin, which is widely advertised as an antihistamine, and is supposed to have anti-inflammatory properties. “The bottle of Quercetin in our lab has a skull and cross bones ‘poison’ sign on it. We handle it only with protective clothing. You can go to a health food store and buy it, and they recommend that you take a gram a day. There’s no warning on it. The first studies at Berkeley on that compound and others, which showed that it produced generic damage were done in 1977, and published in ‘Science’ on the Berkeley campus. People seem to have forgotten that. They seem to think that it’s a harmless natural substance, and that’s just not true.”  

Smith and Skibola don’t doubt that flavonoids are potentially very useful compounds. The duo say the benefits are in eating flavonoid-rich foods, like green teas, apples, onions, and other fruits and vegetables, and not in taking supplements with high flavonoid concentrations. “What is good for you in nature is not necessarily good for you in a concentrated form,” said Skibola. 

Smith said the crux of the problem is the 1994 Dietary Supplement Health and Education Act of 1994. With the passage of this act, the dietary ingredients used in dietary supplements were no longer subject to the pre-market safety evaluations required of other new food ingredients or for new uses of old food ingredients. “The supplements can only be taken off the market if the Food and Drug Administration can prove that they are unsafe. The burden of proving that they are unsafe is on the government, and not on the manufacturer,” said Smith.  

But manufacturing companies insist that this doesn’t give them any leeway to do as they please. “The FDA does regulate us. Certain label claims have to be approved by the FDA. We have to adhere to their guidelines. We have a legal department and a regulatory department to deal with label claims,” said Jim Sword, director of corporate communications at Twin Labs. 

And it appears that many consumers would rather believe the labels than the studies. 

Andrew Saito, 21, an ethnic studies student at UC Berkeley, likes to use grapefruit extract and black currant oil. He believes that they help with acne and eczema. He wasn’t sure if the findings would make him stop using these supplements.  

“There are conflicting theories about everything. So, I don’t know what to believe,” said Saito. 

Many consumers agreed with him. So did the people on the other side of the counter. “A lot of people are doing research. One says one thing. Another says some thing else. I look at a lot of reference books, before I decide what to keep in my store. And my reading tells me that flavonoids are good, because they are a part of the natural environment.” said Baoul Scavullo, the owner of a health food store that sells various dietary supplements. “When people say that to me, I tell them that arsenic, mercury, benzene and lead are all perfectly natural,” said Smith. “There are all these poisons you can think of, which are perfectly natural, and there’s no demonstration that with time, that you become more resistant to them.”  

Smith and Skibla are worried that too many people are self-medicating themselves with these supplements, and not telling their doctors about it. This could confuse matters when the doctor is trying to make a diagnosis or prescribe treatment. The only way out, according to Smith, is legislation.  

“You can combat this only with new legislation, requiring the manufacturers to establish safe levels of intake and to demonstrate that their products are safe. I think the burden should be on the manufacturer, and not on the government.”