The study published this week, in the International Journal of Sports Nutrition and Exercise Metabolism, looked at quercetin’s effects on endurance in healthy nonathletes. For seven days, 12 volunteers received either 500 mg of quercetin dissolved in Tang or a placebo. Their cycling performance was recorded, and then they repeated the experiment with the other substance, serving as their own control group. Quercetin supplementation was associated with a 13.2 percent increase in the amount of time subjects could ride before getting too tired to continue, as well as a nearly 4 percent increase in V02 max, a measure of aerobic fitness.

J. Mark Davis, director of the exercise biochemistry laboratory at the University of South Carolina’s department of exercise science and author of the new study, says quercetin may aid performance through its anti-inflammatory properties or because it increases the number and function of mitochondria, the energy-producing factories found in cells. It may also provide a caffeinelike boost to the central nervous system. Davis suspects quercetin is similar to resveratrol, another plant-derived chemical that’s gotten much attention for its beneficial effects in animal studies. (Results of the study will need to be replicated to be confirmed.)

Another researcher studying quercetin, David Nieman, in the department of health and exercise science at Appalachian State University, is taking a different approach. Rather than studying its use alone, he’s combining it with green tea extract and fish oil, a mixture of flavonoids he believes is better absorbed by the body. “There is more and more evidence mounting that we need to find three, four, or even five unique plant molecules and get the right dose,” he says. The mixture he’s now studying, or some yet-to-be-concocted formulation, he says, might serve as an anti-inflammatory and might boost performance more than quercetin alone, particularly in the un-fit.

Putting potential effects in context, if somebody who isn’t already an athlete just exercises hard, “after a couple of months, you can get a 50 percent to 100 percent improvement in mitochondrial density,” he says. Caloric restriction can produce about a 25 percent improvement. And some kind of flavonoid supplementation, he says, might eventually yield gains of between 10 and 20 percent in the untrained athlete. Gains will be tougher to come by for elite athletes and are likely to be on the margins, though they are possible, he says.

Shoskes warns against “megadoses” of the supplement, saying antioxidants at high doses can actually have pro-oxidant effects and produce symptoms such as pain in small joints. Quercetin in general seems safe, says ConsumerLab.com, though it advises pregnant women to avoid the supplements and says maximum doses for children, nursing women, or people with serious liver or kidney disease haven’t been established.

One problem: Not only is quercetin tough for the body to absorb orally, but that absorption is variable depending on whether the source of the substance is whole foods or purified extracts, says Kathleen Wesa, a physician specializing in integrative medicine at Memorial Sloan-Kettering Cancer Center. So even if there are beneficial properties, the body may simply not have the ability to access them at the level required to achieve results seen in the lab. Researchers are looking at how to make quercetin more bioavailable and whether the substance is both safe and effective, but there are no answers yet, she says.

Fortunately, there are many available sources of quercetin. Quercetin is naturally found in almost all plant foods. Many of the best sources of quercetin are fruits with dark pigments (think red apples, red onions, and most berries).

The easiest way for most people to increase their intake of quercetin is to eat more apples and onions. Red wine is also a convenient source of quercetin, which provides other benefits as well.

Fruits with dark pigments may be the best known source of quercetin, but quercetin is also found in other fruits and vegetables such as broccoli, spinach, and citrus fruits.

In addition to these natural sources of quercetin, you can also add quercetin to your diet with supplements. Quercetin is often packaged with bromelain (an enzyme found in pineapple), which is thought to increase the absorption of quercetin.

Quercetin is a substance that is commonly found in many brightly colored foods such as the skins of apples and can be very beneficial to your overall health. However in recent years the health benefits that come from this powerful substance have been made more accessible to the average person with the use of dietary supplements that have isolated quercetin. This allows people to consume this beneficial substance in supplements and benefit from the results of this phyochemical.

Quercetin is categorized as an antioxidant, which can be very beneficial in promoting overall good health and preventing many of the common health issues such as heart disease. It is also considered to be a natural anti inflammatory and anti histamine making an extremely powerful substance in aiding in the effort to prevent a ton of extremely common health threats such as prostate cancer and cardiovascular disease. These are the main reasons why so many people have been talking about quercetin lately and are also the reason that so many herbal medicine suppliers have begun selling quercetin in the form of supplements. These are also the reasons that you should be taking these great supplements in order to increase your chances of preventing these common health problems.

There are many different people that will be able to greatly benefit from quercetin because of different factors. For example, due to the fact that quercetin is anti histamine, some of the people that will be able to greatly benefit from this substance include those who suffer from asthma and different allergies. There are also many different benefits that come from the natural anti-inflammatory aspect of quercetin. For instance, this aspect of the substance can be very beneficial in reducing the pain associated with many different common health issues such as arthritis. It has also been known to help relieve the symptoms that are associated with many other health issues such as anxiety, depression, and fatigue. However the fact of the matter is that studies have shown the people that can benefit most from quercetin are men that are concerned about prostate problems as the substance has proven to be effective in reducing the risk of this common health threat.

For those of you who are interested in learning more about where to find quercetin supplements and different products containing this extremely powerful substance, you’re in luck. There are many different local and online herbal medicine suppliers these days that are making these effective quercetin supplements available to those who want to take advantage of all of the benefits that come from doing so.