Hello everybody....I m back...
This October and November were very hectic; I have attended 3 conferences...
They were institute of home economics (IHE) national conference, Indian dietetic association (IDA) national conference and nutrition society of India (NSI) national conference...
They were really good... but one thing was really common among all of them...
They all were talking about flavonoids, vitamin D supplementation and Anaemia prevention...
I also met a fine lady Ms. Pornima Shankar, assistant manager nutrition and health, Hindustan Unilever Limited. She was also talking about the health benefits of tea flavonoids on human body...
So this makes me to explore more on all these hot topics to find out some evident facts and researches going on around the world... and I was quite surprise specially by flavonoids which actually we are consuming everyday without analysing the beneficial effects of them on our health...
So here I am to provide u some scientific evidences and researches on health benefits of FLAVONOIDS...
FLAVONOIDSThe flavonoids are a diverse group of polyphenolic compounds widely distributed in the plant kingdom. They are a vast array of compounds found in plants, and are classified as plant pigments. These pigments, over 4000 of which have been identified, are responsible for the dazzling colors of fruits and flowers. They also play a role in protecting the plants from microbe and insect attacks. Flavonoids, also referred to as bioflavonoids, are polyphenol antioxidants found naturally in plants. They are secondary metabolites, meaning they are organic compounds that have no direct involvement with the growth or development of plants. Flavonoids are powerful antioxidants that scavenge the harmful free radicals that damage our cells, and that alter genetic DNA, accelerate the aging process, and contribute to development of many diseases.
Recent research indicates that flavonoids can be nutritionally helpful by triggering enzymes that reduce the risk of certain cancers, heart disease, and age-related degenerative diseases. Some research also indicates flavonoids may help prevent tooth decay and reduce the occurrence of common ailments such as the flu. These potential health benefits, many of which have been proven, have become of particular interest to consumers and food manufacturers.
Flavonoids may be divided into six different major classes (flavonols, flavanones, flavones, isoflavones, flavonols and anthocyanidins ) based on differences in molecular backbone structure.
Let’s now look at some of the health benefits of flavonoids....
There were number of researches done to prove the health effects of flavonoids....
Some of them are....
Antioxidant effectA research done on dietary flavonoids as antioxidants in 2009, by terao states that flavonoids are ubiquitously present in fruits and vegetables. They have attracted much attention in relation to prevention of degenerative diseases such as atherosclerosis. Their antioxidant activity should be at least partly responsible for such prevention. The mechanism of antioxidant activity of flavonoids can be characterized by direct scavenging or quenching of oxygen free radicals or excited oxygen species as well as inhibition of oxidative enzymes that generate these reactive oxygen species. The essential part of the free radical-scavenging activity of flavonoids is attributed to the o-dihydroxyl group in the B ring (catechol group) in their diphenylpropane structure. Catechol typeflavonoids therefore possess powerful antioxidant activity.
Another study done by miller on role of flavonoids as antioxidants in human organism in 2008 states that flavonoids are the ingredients of many nutrition substances and a vital diet element. They are also a group of many medicines with different influence on live organisms. The phenol compounds are used as natural drugs in the cases of various sicknesses of blood, breathing, food, and urinary circuit, and in dermatology as well. The existence of these compounds in the diet, especially maintenance of their proper consumption level, is a very important element in the prevention of many diseases, such as atherosclerosis. Phenol compounds as antioxidants may affect in many different aspects: direct reaction with free radicals, scavenging free radicals, growing dismutation of free radicals to the compounds with much lower reactiveness, chelatation of pro-oxidant metals (mainly iron), delaying or strengthening many enzymes.
Prevent atherosclerosisThe role of flavonoids in CVD is still unclear. So a study conducted by musru etal 2007 entitled as the intake of flavonoids and carotid atherosclerosis: the Kuopio Ischaemic Heart Disease Risk Factor Study. The study assessed the relation between the intakes of twenty-six flavonoids from five subclasses: flavonols, flavones, flavanones, flavan-3-ols and anthocyanidins, and the mean common carotid artery intima-media thickness (CCA-IMT). The study population consisted of 1380 middle-aged eastern Finnish men for whom the mean CCA-IMT examinations were carried out as a part of the prospective population-based Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD). After adjustment for age, variables related to CCA-IMT measurement, history of atherosclerosis, smoking, BMI, diabetes, systolic blood pressure, serum HDL- and LDL-cholesterol, VO2 max, and intakes of alcohol, SFA, folate, vitamins C and E, the total flavonoid intake was inversely associated with the mean CCA-IMT (P = 0.018). Out of different flavonoid subclasses, flavan-3-ols were inversely associated with CCA-IMT (P = 0.025) after statistical adjustment. There was a trend for an inverse association between intake of flavonols and mean CCA-IMT (P = 0.055). The study conclude that high intake of flavonoids is associated with decreased carotid atherosclerosis in middle-aged Finnish men.
Prevent cardiovascular diseasesThere are number of studies, suggested that dietary flavonoids are helpful in the prevention of atherosclerosis and cardiovascular disease. Researches states that atherosclerosis is closely related to oxidative events such as oxidized LDL accumulation in the macrophages. So a research was conducted on tea flavonoids and cardiovascular disease 2008 published in Asia Pacific Journal of Clinical Nutrition. Drinking tea could have a significant impact on public health. Health benefits are believed to be largely due to the presence of high levels of flavonoids. Tea is a rich source of flavonoids, and often the major dietary source. Tea intake and intake of flavonoids found in tea have been associated with reduced risk of cardiovascular disease in cross-sectional and prospective population studies. In addition, flavonoids have consistently been shown to inhibit the development of atherosclerosis in animal models. The focus of this review is on the potential of tea and tea flavonoids to improve endothelial function, and reduce blood pressure, oxidative damage, blood cholesterol concentrations, inflammation and risk of thrombosis. There is now consistent data to suggest that tea and tea flavonoids can improve endothelial function. This may be at least partly responsible for any benefits on risk of cardiovascular disease. Additional studies are needed to investigate whether regular consumption of tea can reduce blood pressure, inflammation and the risk of thrombosis. The evidence for benefit on oxidative damage and cholesterol reduction remains weak.
Anti – inflammatory agentsChronic inflammation is being shown to be increasingly involved in the onset and development of several pathological disturbances such as arteriosclerosis, obesity, diabetes, neurodegenerative diseases and even cancer. Treatment for chronic inflammatory disorders has not been solved, and there is an urgent need to find new and safe anti-inflammatory compounds. So a research paper was published in inflammation research journal,2009 states that flavonoids belong to a group of natural substances occurring normally in the diet that exhibit a variety of beneficial effects on health. The anti-inflammatory properties of flavonoids have been studied recently, in order to establish and characterize their potential utility as therapeutic agents in the treatment of inflammatory diseases. Several mechanisms of action have been proposed to explain in vivo flavonoid anti-inflammatory actions, such as antioxidant activity, inhibition of eicosanoid generating enzymes or the modulation of the production of proinflammatory molecules. Recent studies have also shown that some flavonoids are modulators of pro inflammatory gene expression, thus leading to the attenuation of the inflammatory response. However, much work remains to be done in order to achieve definitive conclusions about their potential usefulness
Prevent cancerThere are only four cohort studies have examined the relation between flavonoids and pancreatic cancer risk providing inconsistent results. So a new case and control study was done in 2011 that whether flavonoids have protective effect on pancreatic cancer or not. Subjects were 326 cases with incident pancreatic cancer and 652 frequency-matched controls (admitted to the same hospitals as cases for acute non-neoplastic conditions) who answered a reproducible and valid food-frequency questionnaire. The ORs were similar in all classes of polymers with three or more mers and in their combination and did not substantially change after adjustment for fruit and vegetable consumption, and for vitamin C and folate intakes. Eating an additional portion of fruits rich in proanthocyanidins every day reduced the risk of pancreatic cancer by 25%. Finally the study concluded that dietary proanthocyanidins-mostly present in apples, pears and pulses-may convey some protection against pancreatic cancer risk.
Another review paper published in journal of environmental science and health,2011 states that Dietary flavonoids, combined with other components such as various vitamins, play an important role in cancer prevention. Flavonoids act on reactive oxygen species, cell signal transduction pathways related to cellular proliferation, apoptosis, and angiogenesis. Many studies demonstrate that flavonoids are responsible for chemoprevention, although mechanisms of action remain to be investigated. Overall, exciting data show that dietary flavonoids could be considered as a useful cancer preventive approach. This review summarizes recent advancements on potential cancer preventive effects and mechanic insight of dietary flavonoids.
Another finding was reviled at the 97th annual meeting of the American association for cancer research,2006 by Margaret .A. Gates, doctorate student at Harvard School of Public health that women with higher intake of dietary flavonoids may be at reduced risk of ovarian cancer. The finding was reviled by nurses’ health study.
Flavonoids and bone healthFrom a nutritional point of view, several factors are involved in ensuring optimal bone health. The most documented of these are calcium and vitamin D. However, it is now well acknowledged that some phytochemicals, also known as phytonutrients, which are plant-based compounds that are present in our daily diet, can positively regulate a number of physiological functions in mammalian systems involved in chronic diseases such as osteoporosis
A recent observational study was conducted to investigate whether dietary flavonoid intake was associated with bone mineral density (BMD) and bone resorption in a large group of perimenopausal Scottish women published in journal of bone and mineral research, 2011. Over 3000 women completed a food frequency questionnaire as part of an osteoporosis screening study. The diets were analyzed for flavonoid intake using a food composition database. BMD was measured at the femoral neck (FN) and lumbar spine (LS) by dual-energy X-ray absorptiometry (DXA). Free pyridinoline (PYD) and deoxypyridinoline (DPD) were measured by high-performance liquid chromatography (HPLC) in second early morning fasted urine samples. Associations were found between energy-adjusted total flavonoid intakes and BMD at the FN and LS. Annual percent change in BMD was associated with intakes of procyanidins and catechins (p ≤ .05), and flavanones were negatively associated with bone-resorption markers. It was concluded that dietary flavonoid intakes are associated with BMD, supporting the evidence from animal and cellular studies.
Another study was done to evaluate the efficacy of green tea polyphenols (GTPs) at mitigating bone loss and microstructure deterioration along with related mechanisms in androgen-deficient aged rats, a model of male osteoporosis. A 2 (sham vs. orchidectomy) × 2 (no GTP and 0.5% GTP in drinking water) factorial design was studied for 16 weeks using 40 aged male rats. An additional 10 rats (baseline group) were killed at the beginning of study to provide baseline parameters. There was no difference in femoral mineral density between baseline and the sham only group. GTP supplementation resulted in increased serum osteocalcin concentrations, bone mineral density, and trabecular volume, number, and strength of femur; increased trabecular volume and thickness and bone formation in both the proximal tibia and periosteal tibial shaft; decreased eroded surface in the proximal tibia and endocortical tibial shaft; and increased liver glutathione peroxidase activity. They concluded that GTP supplementation attenuates trabecular and cortical bone loss through increasing bone formation while suppressing bone resorption due to its antioxidant capacity.
Anti ulcer effectA peptic ulcer is an ulcer of an area of the gastrointestinal tract that is usually acidic and thus extremely painful. Majority of peptic ulcers are associated with helicobacter pylori, a spiral-shaped bacterium that lives in the acidic environment of the stomach. Quercetin seems to play a very important role in the prevention and treatment of peptic ulcer. It acts by promoting mucus secretion, thereby serves as gastroprotective agent, also quercetin has been shown to inhibit the growth of helicobacter pylori bacterium in in-vitro studies. Among other flavonoids, methyl-3-(+)-catechin interferes with the formation of histamine in gastric mucosa and hence produces the protective effect.
Anti viral effects
Flavonoids of many types have antiviral effects in humans. First Cutting and his co workers described the antiviral effect of quercetin against rabies virus. Quercetin was later found to show inhibiting effects against herpes simplex virus. All the other flavonoids except rutin too show anti viral effects against herpes simplex virus, respiratory syncytial virus, parainfluenza virus, and adenovirus. Another fact which was observed was that when quercetin was added to cultures of several viruses associated with human maladies, viruses with an envelope were inhibited while those lacking such an envelope (like polio virus) were moderately or completely resistant to flavonoids.
MY VERDICT• Atleast consume two portion of fruits salad everyday which must includes apple, orange, red blue and purple berriers, and strawberries. (please don’t exclude the other fruits)
• Squeeze lemon on your salads everyday if it’s possible. Incorporate broccoli and carrots in your salads.
• Try to consume onion, garlic and ginger as possible as u can, as there can be a religious or regional restriction.
• Consumption of tea 2 times a day is not harmful, try to consume green tea.
That’s for now....
But my discussions and articles are always open for more comments, suggestions and advice...... so that we can together create good informative articles...
Context courtesy: http://www.ncbi.nlm.nih.gov/pubmed/19367113
Images courtesy: lurj.org, realage.com, masterpsychicerica.com, kriskris.com, healingdaily.com, topnews.net.nz, smart-diner.com, alternative-cancer.net, takdhinadhin.in, faqs.org.
