Flavonoids and the risk of type-2 diabetes

New research shows that anthocyanin consumption may be associated with a decreased risk of type-2 diabetes.

Flavonoids are found in plants and serve as pigments to help attract pollinators, filter out UV light, help in nitrogen fixation, and several other roles. An important class of flavonoids is anthocyanins. Anthocyanins are powerful antioxidants and can be found in blueberries, bilberries, raspberries, grapes, and many other plants. In addition to their antioxidant capacity, data also supports a beneficial effect of anthocyanins on insulin sensitivity. However few studies have looked at their effect on type-2 diabetes.

An article published this month in The American Journal of Clinical Nutrition looked at the relationship between flavonoids and type-2 diabetes. Researchers analyzed data from 70,359 women in the Nurses’ Health Study, 89,201 women in the NHS II, and 41,334 men in the Health Professionals Follow-Up Study. The mean age of the participants was 50, and all of the individuals examined were free of diabetes at baseline. Follow-up revealed that 12,611 cases of diabetes had developed since initial screening. Participants were asked how often, on average, they consumed different foods. Flavonoid content in each of the foods was analyzed to determine total flavonoid intake. Flavonoid intake was also broken down into five subcategories, they were: flavonols, flavones, flavanones, flavan-3-ols, and anthocyanins. The researchers found that anthocyanin consumption was associated with a decreased occurrence of type-2 diabetes. These results were observed consistently across all three study groups examined.

In addition to regular exercise and maintaining a healthy weight, a diet in flavonoid-rich fruits and vegetables may be a beneficial strategy to help lower the risk of type-2 diabetes.

Antioxidants Studies

As everyone knows, eating and drinking are necessary for life. Less well known, however, is the fact that the body generates what are called free radicals in the process of turning food into energy. Free radicals are chemicals that are capable of damaging cells and genetic material. But eating is not the only way free radicals spring into being. The food we eat and the sunlight we feel also generate free radicals.

To be sure, free radicals come in many shapes, sizes, and chemical configurations. The characteristic feature of this chemical is that it soaks up electrons from bodily substances that yield them, which can leave the “loser’s” structure or function radically altered. Free radical damage can change the instructions coded in a strand of DNA; it can also make a circulating low-density lipoprotein (LDL, sometimes called bad cholesterol) molecule more likely to get trapped in an artery wall. Free radicals also have the potential to alter a cell’s membrane, changing the flow of what enters the cell and what leaves it.

Fortunately, we aren’t defenseless against free radicals. The body puts up natural defenses against free radicals by making molecules that smothers the errant chemicals. We also extract free-radical fighters from food. Often called “antioxidants”, certain kinds of food give electrons to free-radicals without themselves turning into electron-scavenging substances. There are many different substances that can act as antioxidants. The most familiar ones are vitamin C, vitamin E, beta-carotene, and other related carotenoids, along with the minerals selenium and manganese. They’re joined by glutathione, coenzyme Q10, lipoic acid, flavonoids, phenols, polyphenols, phytoestrogens, and many more.

However, the term “antioxidant” can be misleading. These substances do not emit chemical properties that fight so much as they emit properties that facilitate. Indeed, some substances that act as antioxidants in one situation may be prooxidants—electron grabbers—in a different chemical milieu. Another big misconception is that antioxidants are interchangeable. This is not true. Each anti-oxidant has unique chemical behaviors and biological properties. It is believed, and has been strongly corroborated through scientific study, that anti-oxidants evolved as parts of elaborate networks, each substance having a different role to play. It follows that no single substance can fulfill the function of every other substance.

Health Benefits of Antioxidants: What’s the Buzz?

Antioxidants came to public attention in the 1990s. It was then that scientists began to understand that free radical damage was involved in the early stages of artery-clogging atherosclerosis, and that the chemicals may contribute to cancer, vision loss, and a host of other chronic conditions. A number of studies stated that people with low intakes of antioxidant-rich fruits and vegetables were at greater risk for developing these chronic conditions than were people who ate sufficient amounts fruits and vegetables. Clinical trials tested the impact of single substances, especially beta-carotene and vitamin E, on cancer, heart disease, and similar maladies. But even before the results of these trials were in, the media, and the dietary supplement and food industries began promoting the benefits of “antioxidants.” Foods such as frozen berries and green tea were hyped as being rich in antioxidants. The consequences of this publicity were predictable: certain foods were labeled as rich in antioxidants and were marketed as such in stores; the makers of dietary supplements began touting the disease-fighting properties of all sorts of antioxidants.

In the meantime, the results of the actual trials were mixed. Most have not found the hoped-for benefits. And research teams reported that vitamin E and other antioxidant supplements didn’t protect against heart disease or cancer. One study even showed that taking beta-carotene may actually increase the chances of developing lung cancer in smokers. However, some of the trials reported benefits. One such study found that taking beta-carotene is associated with a modest reduction in the rate of cognitive decline.

The rather most, if not downright disappointing, results of the antioxidant trials have not stopped the commercial interests from misrepresenting the benefits of antioxidants in order to make money. Antioxidant supplements are a $500 million dollar industry that continues to grow. Antioxidants are still added to breakfast cereals, sports bars, energy drinks, and other processed foods, and they are promoted as additives that can prevent heart disease, cancer, cataracts, memory loss, and a host of other conditions. The claims made by the food and dietary supplement industries often distort the data. It is true that the package of antioxidants, minerals, fiber, and other substances found naturally in fruits, vegetables, and whole grains help prevent a variety of chronic diseases; but there is no solid evidence that high doses of antioxidants can accomplish the same feat. The conclusion is clear: randomized, placebo-controlled trials—which, when performed well, provide the strongest evidence—offer little support that taking vitamin C, vitamin E, beta-carotene, or other single antioxidants provides substantial protection against heart disease, cancer, or other chronic conditions. The results of the largest such trials have been mostly negative.

Heart Disease and Antioxidants

Vitamin E, beta-carotene, and other so-called antioxidants are not a panacea for heart disease and should not be promoted as such. In the Women’s Health Study, 39,876 initially healthy women took 600 IU of natural source vitamin E or a placebo every other day for 10 years. The results of the study showed that the rates of major cardiovascular events and cancer were no lower among those taking vitamin E than they were among those taking the placebo; however, a 24 percent reduction in total cardiovascular mortality was observed, which can be considered a quite significant result.

Earlier large vitamin E trials, conducted among individuals with previously diagnosed coronary disease or at high risk for it, generally showed no benefit. In the Heart Outcomes Prevention Evaluation (HOPE) trial, the rates of major cardiovascular events were essentially the same in the vitamin E (21.5 percent) and placebo (20.6 percent) groups, although participants taking vitamin E had higher risks of heart failure and hospitalization for heart failure. (3) Another trial, the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico (GISSI), showed mixed results; there were no preventive effects after more than three years of treatment with vitamin E among 11,000 heart attack survivors. Nevertheless, some studies suggest potential benefits among certain subgroups. A recent trial of vitamin E in Israel, for example, showed a marked reduction in coronary heart disease among people with type 2 diabetes who have a common genetic predisposition for greater oxidative stress. In any case, Beta-carotene, as was shown in the Physicians’s Health Study, does not provide any protection against heart disease or stroke.

There have been combinations, but the findings are complicated and unclear. In the Supplementation en Vitamins et Mineraux Antioxydants (SU.VI.MAX) study, 13,017 French men and women took a single daily capsule that contained 120 milligrams of vitamin C, 30 milligrams of vitamin E, 6 milligrams of beta-carotene, 100 micrograms of selenium, and 20 milligrams of zinc, or a placebo, for seven and a half years. The vitamins had no effect on overall rates of cardiovascular disease. In the Women’s Antioxidant Cardiovascular Study, vitamin E, vitamin C, and/or beta-carotene had much the same effect as a placebo on myocardial infarction, stroke, coronary revascularization, or cardiovascular death, although there was a modest and significant benefit for vitamin E among women with existing cardiovascular disease.

Cancer and Antioxidants

There is also no conclusive proof that antioxidants help prevent cancer. Scientists need more time to determine the impact of antioxidants on the risk of getting cancer. In the long-term Physicians’ Health Study, cancer rates were similar among men taking beta-carotene and among those taking a placebo. Other trials have also largely showed no effect, including HOPE. The SU.VI.MAX trial showed a reduction in cancer risk and all-cause mortality among men taking an antioxidant cocktail but no apparent effect in women; it is possible that this is a result of the men in the study having low blood levels of beta-carotene at its beginning. A randomized trial of selenium in people with skin cancer demonstrated significant reductions in cancer and cancer mortality at various sites, including colon, lung, and prostate. The effects were strongest among those with low selenium levels at baseline.

Age-Related Eye Disease and Antioxidants

The effects of antioxidants on age-related eye disease may be one of the most hopeful leads scientists have. A six-year trial, the Age-Related Eye Disease Study (AREDS), found that a combination of vitamin C, vitamin E, beta-carotene, and zinc provided some protection against the development of advanced age-related macular degeneration in people who were at high risk of the disease. Lutein, a naturally occurring carotenoid found in green, leafy vegetables such as spinach and kale, may also protect vision. It is too early to tell what the impact of lutein supplements may be. The trials of such substances have been relatively short, and their ability to slow or prevent age-related macular degeneration has not been ascertained. A new trial of the AREDS supplement regimen plus lutein, zeaxanthin, and fish oil is underway, and it could yield better information.

Potential Hazards of Antioxidants

There have been a few studies which showed that the consumption of antioxidants, as opposed to being beneficial in all instances or at least harmless in fact can interfere with the health of the consumer. The first trial which showed this possible negative effect was undertaken in Finland where heavy smokers were fed beta-carotene. Because of their smoking habits there was a already a lung cancer risk but it was noticed that a significant increase in the incidence of lung cancer amongst the trial group as opposed to the placebo. The trial was stopped so conclusive results are hard to deduce.

A different test which was conducted with heavy smokers exposed to asbestos being fed beta-carotene and vitamin A. This too shows an increase in the incidence of Lung cancer. It must be emphasized that not all trials of Beta-carotene have been negative. A physicians health study which only had a few smokers did not show any significant differences even when followed up after 18 years.

In a separate study showing possible negative effects of a variety of health supplements showed a higher incidence of skin cancer in women being fed supplements of Vitamins C & E, Beta-carotene, selenium and zinc.

Conclusions to be drawn from the above studies, amongst others, is that it is known that although free radicals have been shown to contribute to the incidence of heart disease, cancer, Alzheimer’s and even vision loss, there is no automatic conclusion that can be drawn that antioxidants will fix the problem. And certainly not when consumed away from their normal context.

Studies to date do not show conclusive evidence one way or another but there is certainly no strong evidence to suggest that antioxidants are effective against disease. A rider must be mentioned and that is that the trials conducted till now have been short in duration, conducted with people some of whom had an existing disease.

There has been a noticeable benefit to the consumption of beta-carotene on cognitive ability after 18 years. This is exceptional as it is the only study to have continued so long. (Physicians health follow up study) Nevertheless there is abundant evidence suggests that eating whole fruits, vegetables, and whole grains—all rich in networks of antioxidants and their helper molecules—provides protection against many of these scourges of aging.

Clarification with regard to supplemental studies

There are any number of studies conducted on any number of vitamins and other dietary supplements that are often contradictory. The picture presented to the consumer is confusing and will often seem frustrating in that instead of clarifying things these studies muddy the waters.

Examining exactly what the vitamins trial study did will often go some way to explaining the varying results. Here are a few items to check when looking at apparently conflicting vitamins studies.

  • What was the precise dosage taken by the participants and how long was the study’s duration. This is significant as few studies will have identical dosages and identical time spans. A study in Vitamin D showed that a dosage of 700 plus IU per day had a significant protection against fractures whereas a study of people taking only 400 IU per day showed no such effect. The same applies to the duration as the build up of the protective mechanisms is not a short process.
  • The age, health and life styles of the participants. Studies drawn from young, active gym going participants is likely to differ significantly from heavy drink and smoking office workers. Exercise and other lifestyle choices such as diet affect out health and how the body responds to vitamins.
  • At what stage is was the supplement fed to a study participant. If studying the effect of a supplement on someone already suffering from a disease it may be found that something taken at the onset has a differing effect from something taken when a disease is far advanced. An example being that Folate supplements are only effective against neural tube defects in the early stages of pregnancy.
  • How were the results tabulated and calculated. This is a significant problem as measurement as to benefit may and probably will vary widely. Heart disease is a wide subject and a measurement of coronary thrombosis may miss out on the incidence of strokes.


For thousands of years, garlic (Allium sativum) has been known to have a variety of medicinal benefits. It contains amino acids, vitamins, trace minerals, flavonoids, enzymes, and 200 additional compounds. Garlic’s main active ingredient is allicin, an antibacterial compound that is produced when the garlic is crushed or chopped. Because allicin is most effective immediately after its production, garlic should be eaten soon after it is prepared.

Functions of Garlic

• Balances blood sugar
• Boosts natural killer cell activity (which helps prevent cancer)
• Boosts your immune system
• Decreases LDL (bad) cholesterol
• Increases nitric oxide
• Lowers blood pressure
• Lowers triglycerides
• May lower risk of prostate cancer
• Natural blood thinner
• Raises HDL (good) cholesterol

Recommended dosage

Garlic products are described in terms of fresh or whole garlic equivalent. An average daily dose is 1,500 to 1,800 milligrams of fresh garlic equivalent, which equals approximately one half a clove of fresh garlic.

Side effects and contraindications

Garlic is a blood thinner. If you are taking a blood thinner, therefore, check with your physician before ingesting large amounts of garlic. Do not take large doses of garlic if you are pregnant because they may cause uterine contractions.

Diseases/disorders that garlic can treat or protect against

Atherosclerosis, Cancer (colon, esophageal, and stomach), Heart disease, High blood pressure and High cholesterol levels

Your Daily Meal Pattern

MyPyramid Basics

In 2005, MyPyramid was unveiled to replace the Food Guide Pyramid. MyPyramid provides Americans age 2 and above with an outline for how to eat in a more healthful way each day.

MyPyramid is based on the 2005 version of the Dietary Guide for Americans. Together, they are designed to help Americans consume an appropriate amount of calories to support a healthy body weight and, at the same time, maximize nutrient intake.

MyPyramid emphasizes three key principles:

• Variety – Consume items from all the basic food groups (fruits, vegetables, grains, meat and beans, milk, and oils) and subgroups (including dark green, deep orange, and starchy vegetables as well as legumes such as beans and peas).
• Proportion – Consume more fruits, vegetables, whole grains, and fat-free or low-fat milk or milk products and eat fewer foods rich in saturated or trans fats, added sugars, cholesterol, salt, and alcohol.
• Moderation – Choose foods that offer lower amounts of saturated and trans fats, added sugars, cholesterol, salt, and alcohol.

Daily Food Guide

MyPyramid provides 12 daily meal patterns to meet individual calorie needs for Americans age 2 and above. Calorie levels range from 1,000 to 3,200 calories; individual calorie recommendations are based on age, sex, and activity level.

MyPyramid breaks down foods and beverages into specific food categories. Here’s what’s included in each one:

• Fruits – All fresh, frozen, canned, and dried fruits and fruit juices made or prepared without added sugars or fats.
• Vegetables – All fresh, frozen, and canned vegetables and vegetable juices made or prepared without added sugars or fats. Subcategories include dark green, deep orange, and starchy vegetables as well as legumes (beans and peas; these can also be counted in the Meat and Beans category).
• Grains – Whole grains and foods made with whole grains (for example, wheat, oats, cornmeal, barley, or other cereal grains) and refined grains (for example, white flour, degermed cornmeal, white bread, and white rice).
• Meat and Beans – Meats and poultry (lean), fish, eggs, legumes (beans and peas), tofu and other soy foods, nuts, nut butter, and seeds.
• Milk – All low-fat or fat-free milks, yogurts, frozen yogurts, dairy desserts, cheeses, and lactose-free and lactose-reduced products and made or prepared without added sugar.
• Oils – Vegetable oils; mayonnaise; some salad dressings; and vegetable oil spreads and soft margarines that are added to foods during processing, cooking, or at the table.
• Discretionary Calories – Calories from added sugars, solid fats, or alcohol, or calories from the extra fat or sugar in foods made wit or that naturally contain more fat and sugar (for example, high-fat meats or fruit made with added sugar)

The Food Guide Pyramid was the nutrition guide of the United States Department of Agriculture used before the development of MyPyramid in 2005.

The Dietary Guide for Americans is a set of science-based guidelines published every 5 years by the United States Department of Health and Human Services (DHHS) and the United States Department of Agriculture (USDA). They’re used to create national nutrition policies, and a new version is expected in 2010.


Fruits contain several key nutrients and other beneficial substances. They provide simple carbohydrates and are naturally low in fat and sodium and contain no cholesterol. Because of their high water and fiber content, fruits tend to filling and can therefore be useful allies if you’re trying to lose or manage your weight. They’re also relatively low in calories. Studies show that consuming fruits and vegetables as part of a healthful, nutritious diet can reduce the risk for cardiovascular diseases (including strokes), type 2 diabetes, and some cancers.
Although all fruits are healthful, some are standouts. Whole fruits typically contain fewer calories and more fiber than more concentrated – and more caloric – varieties such as dried fruits or fruit juices. Some high-fiber fruits include pears, raspberries, strawberries, bananas, and guava.

Many fruits provide good source of vitamins and minerals. Some fruits that are high in vitamin A include mango, cantaloupe, and apricots. Vitamin C-rich fruits include guava, papaya, oranges, and orange juice. Fruits rich in potassium include bananas, plantains, and organs.

Some fruits are also rich sources of phytochemicals such as carotenoids (beta carotene, lutein, and zeaxanthin), flavonoids (anthocyanidins, flavanols, flavonones, and proanthocyanidins), and phenols (caffeic acid, ferulic acid, and resveratrol); following are examples.

• Carotenoids – Citrus fruits, peaches, apricots, pink grapefruit, watermelon, pumpkin, and guava
• Flanonoids – Strawberries, blueberries, raspberries, cherries, red grapes, apples, and citrus fruits
• Phenols – Apples, pears, citrus fruits, and purple grape juice

Daily Recommended Amounts

MyPyramid recommends between 1 and 2 ½ cups of fruit each day depending on your individual daily calorie allotment.

Each of the following counts as approximately ½ cup of fruit (or about 60 calories):

• ½ cup cut up, raw, cooked, or frozen fruit
• 1 piece of fruit (1 small orange, peach, or banana)
• ½ cup 100% fruit juice (orange juice, cranberry juice, or grape juice)
• ¼ cup dried fruit (1 small box of raisins, 1 ½ ounces)

Carotenoids are a group of compounds naturally found in plant foods (including fruits and vegetables) that provide their deep yellow, orange, and red colors. Carotenoids convert to vitamin A in the body and can work as antioxidants, boosting immunity, promoting heart health, and supporting vision.

Flavonoids are a group of compounds found naturally in plant foods (including fruits and vegetables). They can act as antioxidants, supporting heart health, helping maintain brain function, and supporting health of the urinary tract.

Phenols are compounds found naturally in plants and plant foods. They can work as antioxidants, supporting a healthy heart, and helping maintain vision.