Another hypothesis that has just began to be explored by the academic community is the possibility that flavonoids may alter growth factor signaling, thus limiting the ability of the cell to initiate rapid growth (8). Study into this area are just beginning to emerge and more information will be available in the next several years.
Potential Health Benefits
The key to solving the riddle of why persons that consume large amounts of fruits and vegetables can expect to have certain health benefits depends on the ability to understand the mechanisms at play. Let us first examine current hypothesis regarding the mechanisms that are responsible for the anti-carcinogenic effects of flavonoids. Research into the mechanisms by which certain flavonoids demonstrate anti-carcinogenic effects can be grouped into five categories. Currently these studies are at the in vitro stage, with a few animal studies in the present group. Therefore, it is not known how the outcome of these studies will effect clinical practice in the future.
The first group of researchers is exploring the ability of flavonoids to stimulate phase II detoxification enzyme activity (9,10). The second focuses on preservation of the components of the cell division process the regulates the ability to divide in an uncontrolled manner (11,12). Another related group of studies focuses on inducing cell death in cancer cells (13,14). Cancerous cells invade normal cells by way to enzyme action. Invasive tumors then begin to build their own blood supply (angiogenesis). One group of studies is focusing on flavonoids and their ability to prevent angiogenesis in cancer cells (15,16). Decreasing inflammation reduces the production of free radicals by inflammatory enzymes. Reducing inflammation also reduces the production of mediators that promote cell growth, angiogenesis, and inhibit aptosis (17,18,19,20).
Some of these same factors are believed to be factors in the prevention of cardiovascular disease. For instance arteriosclerosis, a contributing factor to cardiovascular disease is related to an inflammatory condition. Prevention of arteriosclerosis consists of the remainder of the group of studies involving the prevention of cardiovascular disease using flavonoids (21,22).
The third major group of academic studies focuses on the role of flavonoids in preventing neurodegenerative disease, such as Parkinson's or Alzheimer's. Many of the same factor that are responsible for the development of cancer and cardiovascular disease also play a role in neurodegenerative disease. Factors such as inflammation and oxidative stress also play a role in neurodegenerative disease. Therefore, it is not surprising that a group of studies is focusing on the use of flavonoids in the prevention of these diseases as well (23,24).
These three categories of studies are not the only uses of flavonoids that are being investigated, but they constitute a majority of the studies surrounding the role of flavonoids in the body. For instance, flavonoids are being investigated as a potential defense against microbes (the research studies presented represent only a portion of the studies currently under investigation regarding flavonoids. However, the ones mention are a representative sample of the remainder of the academic work that exists concerning flavonoids and the prevention of disease.
It should be apparent by now that flavonoids have become a topic of significant interest in the academic community. However, it should also be apparent that there is still much more work that needs to be completed before we will understand the mechanisms and actions that flavonoids contribute in the body. A majority of the research that has been performed to date have involved in vitro, or animal studies. Research still has too many questions for studies to be conducted on humans at this time. However, this will certainly be an undertaking that researchers will tackle in the future.
In vitro and animal studies provide valuable information that helps researchers to understand the mechanisms that are responsible for the actions observed in the human body. However, they still do not demonstrate the effects of flavonoids in the human bodies. Concentrations of compounds used in laboratory studies do not match concentrations of these elements as they are present in the human body. Animals can give us a better clue as to what the results will be in the human body. However, there may be key differences in the way that animals absorb and metabolize flavonoids that make them differ significantly from human results.
In conclusion, the body of research continues to grow regarding the actions of flavonoids in the human body. However, at present, there have been many reports published by some credible institutions that contain preliminary suppositions about the real benefits of flavonoids (25). There is sufficient evidence to suggest that flavonoids have some potentially significant health benefits for the health of human beings.
No one will deny that a diet containing a high level of fruits and vegetables will result in better health than one that contains few fruits and vegetables. However, one cannot make broad statements about the health benefits of flavonoids until several areas of research have been explored further. The first is that human studies need to be conducted before we can know for certain the extent with which flavonoids can stop such serious illnesses as cancer, cardiovascular...
One of the key reasons for this is that the safety of such studies must be conducted first. Research, at the present time suggests that there is a heavy indication that flavonoids can help reduce the occurrence of several serious human diseases. However, when the body of research is examined as a whole, it reveals that there is still much more to be done before broad statements can be made about the real benefits of dietary flavonoids in the human body.
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