Flavonoids are gaining international attention for their diverse array of powerful health benefits. In the old days they were mostly thought of as antioxidants. In the new era involving epigenetics and gene expression they are potent regulators of health, reducing the risk for age-associated disease and extending lifespan.
Three new human studies evaluating dietary intake patterns of various types of flavonoids showed that higher intake of flavonoids was associated with better health and a longer life.
The first study followed 2915 members of the Framingham Offspring cohort who were free of type 2 diabetes at the start of the study for an average for 12 years. These individuals were over 50 and most were overweight. Those with the highest intake of one type of flavonoid (flavonol) were 26 percent less likely to develop type 2 diabetes, indicating that flavonoids could help reduce the slide from inefficient metabolism into type 2 diabetes.
A second study evaluated the existing scientific literature on flavonoid intake and the risk for cardiovascular disease. The results showed that six different types of flavonoids were all associated with a risk reduction for cardiovascular disease – the higher the intake the better the protection. Risk reduction ranged from 10 - 13 percent, depending on the type of flavonoid. The researchers concluded that intake of these flavonoids “significantly decrease the risk of cardiovascular disease.”
A third study looked at all-cause mortality over a 12-year period in a group of 807 men and women aged 65 and older from the Chianti region of Tuscany, Italy. The researchers evaluated dietary intake and urinary excretion of total polyphenols. Flavonoids are the main dietary polyphenol. By measuring urinary excretion the researchers were able to gauge true intake, which is sometimes too generalized on food frequency questionnaires. Those with the highest levels of urinary polyphenols had a 30 percent mortality risk reduction.
These three recent studies lend a type of scientific credibility to the value of increased flavonoid intake. Over the past few decades other general studies have come to similar conclusions. Furthermore, there are now thousands of studies (cell, animal, and human) with specific flavonoids which help to document their mechanisms of action that contribute to these health benefits.
From a practical point of view a consumer needs to understand how they can get these nutrients from their diet and what dietary supplements may be of help. Part of the issue is that terms like polyphenol and flavonoid are often used interchangeably, making it a bit confusing for the typical lay person to understand which nutrients may be most relevant to them.
To help sort this out I will give a basic overview of the topic of polyphenols and flavonoids I will explain the main types of flavonoids and what they do. And I will offer some common sense suggestions as to how you can incorporate this knowledge into your personal health plan.
Remember, if a drug had produced the results cited in the above three studies it would be worth hundreds of billions of dollars for Big Pharma – the next great “blockbuster” to be pushed down the throats of the baby boomer generation. As always, any Big Pharma drug touting preventive health benefits has many unhealthy side effects, either hidden or downplayed by those pushing the drugs. Mother Nature does not have such a secret agenda – only benefits for you.
Polyphenols and Flavonoids
Flavonoids are the dominant factor that gives fruits their color. In comparison, carotenes give vegetables their color – although smaller amounts of flavonoids are present along with carotenes in many vegetables. There are thousands of types of flavonoids in nature, which scientists break down into general groups. Different flavonoid structures have different functions in your body, which is why a wide variety of flavonoid intake is good for you.
All flavonoids are polyphenols as they contain the common phenol compound as part of their structure. Polyphenols represent a broader group of nutrients, broken down into categories such as phenolic acids, stilbenes, tannins, diferuloylmethanes and flavonoids. Of these various groups, flavonoids are the most abundant type of polyphenol in nature.
The popular nutrient resveratrol is a polyphenol of the stilbene type, and is not a flavonoid. It is found in small amounts in red grapes, which are primarily flavonoids. Blueberries are another fruit high in flavonoids, as well as containing small amounts of another stilbene called pterostilbene. Stilbenes are also being studied for potent metabolic, disease prevention, and anti-aging benefits.
Curcumin is a polyphenol of the diferuloylmethane type, and is not a flavonoid. Thus we see that there is a broad array of health benefits from polyphenols in general, although the focus of this article will be on flavonoids in particular.
Polyphenols and flavonoids have antioxidant capabilities, contributing to your overall antioxidant health reserves. However, the potency of these compounds is poorly understood if you only look at them as antioxidants, as their primary health benefits are in how they help regulate your genes to do the right thing.
This is one reason Big Pharma drugs are an utter failure for preventive health. Modern science is trying to develop gene-regulating drugs, as opposed to their current versions of toxic sledgehammers for which they have no risk profile whatsoever for any aging population taking multiple medications. Unfortunately, we are in the Stone Age when it comes to regulating genes with drugs, as genes turn on and off under a variety of different circumstances. The very same genes signals that are involved with disease processes are involved with health. Drugs have no way to tell the difference and do not know what they are actually doing in human metabolism. A reliance on Western medicine drugs to sustain health as one ages is one of the greatest con jobs in human history.
Nutrition is an entirely different story. Humans have been consuming flavonoids throughout evolution and have learned to use them to regulate the expression of genes that determine health. The human body genome acting in tandem with flavonoid intake produces stunning health benefits. Depending on the health context of gene signaling within cells, flavonoids can rejuvenate stressed-out cells, promote the general well being of any cell, or act to help kill cancer cells. Oftentimes it is changing the regulation of the same gene signal in different ways – but invariably in ways that are good for health. Your body knows how to use flavonoids in many different ways depending on the health context of the cell itself. From Big Pharma’s perspective, such intelligent function is pure magic and something they will spend the next 200 years dreaming about.
Flavonoids have diverse functions within plants. They are part of the defense system against invasive infection, which means they are immune supportive to humans. They help regulate cell functions within plants, and do the same for humans. They are synthesized in higher amounts by plants when plants come under stress. They are needed by humans in higher amounts when we are under stress, helping us to tolerate higher levels of stress without wear and tear that accelerates aging and disease risk.
It is quite fascinating how Mother Nature packages up nutrition for humans. Fruits, which are higher in sugar, are packaged up with flavonoids that help your body metabolize the sugar you are consuming. This is the general reason why they help reduce the risk for type 2 diabetes. And it helps explain why it is so damaging to consume large amounts of sugar without concurrent flavonoids, as is common in our society with its epidemic of obesity and type 2 diabetes.
As these flavonoids travel around your blood they interact with factors in your blood and the structure of your arteries and blood vessels. They have antioxidant, anti-inflammatory, anti-stress, and tissue rejuvenating properties. We now know that in addition to these general mechanisms, they are operating at the gene level to help bolster these direct health benefits to your circulatory system. Once again, it is little wonder that flavonoids are able to show a risk reduction for cardiovascular disease.
Their general net function is anti-stress and anti-wear and tear, helping to preserve the structure of the proteins of genes so that they can function in a healthy way. This reduces the number of damaged and misfolded proteins, which eventually become noticeable in the plaque-tangles of cognitive decline and cardiovascular disease. Their ability to preserve structural components down to the gene level is a main reason for their anti-aging benefit which provided the reduced risk for all-cause morality.
Types of Flavonoids
Some main types of flavonoids with notable health benefits are flavonols, anthocyanins, catechins, and flavones. While this list is not complete, it is sufficient for explaining the benefits of a variety of flavonoids in your diet.
The most abundant flavonoid in nature is quercetin, which is a flavonol. Its highest concentration is in apples and red onions (in the outer, redder rings). A vine ripened apple has about 50 mg of quercetin. Other common foods with higher amounts of quercetin are green tea, capers, watercress, buckwheat, kale, citrus fruit, and sweet potatoes. Plums and many berries contain smaller amounts of quercetin. Quercetin is best known for its ability to stabilize the immune system, reducing excess histamine release, allergy, and asthma. Recent research has extended quercetin’s benefits to weight management, nerve health, cardiovascular health, and anti-aging.
Another important flavonol is fisetin, which is highly concentrated in strawberries. It is best known for its memory and brain-preserving properties, although it also benefits blood sugar metabolism and asthma.
One of the better known flavonols is the proanthocyanidins, often called oligomeric proanthocyanidins or OPCs. They are highly concentrated in grape seeds as well as pine bark, their traditional sources for dietary supplements. Red wine is a major dietary source. They are considered an important factor in the French paradox – meaning how French people eat higher fat diets and have less heart disease. They are actively researched for blood sugar metabolism, Alzheimer’s prevention, and cardiovascular health.
The earlier mentioned study on flavonoids and type 2 diabetes, the researchers specifically found that flavonol intake was the main type of flavonoid with the most benefit at reducing the risk for developing type 2 diabetes. Here are links to a number of the articles I have previously written on quercetin, fisetin, and grape seed extract:
Quercetin for Nerves, Allergies, Immunity, and Metabolism
Quercetin Lowers Blood Pressure and Prevents Cholesterol Damage
Apple Polyphenols (Quercetin) for Extended Lifespan
Quercetin Helps Exercise
Fisetin Lowers Advanced Glycation End Products & Offsets Diabetic Complications
Fisetin Reduces Asthma-Related Inflammation
Fisetin for Neuro-Protection
Fisetin: Mood Boosting and Mind Protecting
Grape Seed Extract Restores Insulin Sensitivity
Grape Seed Extract Lowers Blood Pressure
Grape Seed Extract’s Powerful Cardio Protection
How Grape Seed Extracts Stop Alzheimer’s Plaque
Blue, purple, and dark red fruits signify the presence of anthocyanins, commonly found in blueberries. Other common foods include cherries, raspberries, blackberries, cranberry, and dark grapes. They are in smaller amounts in many foods where their color factor is therefore not a significant issue (banana, asparagus, peas, fennel, pears, and potato).
The U.S. Department of Agriculture has led the world in anthocyanin research, especially regarding brain and metabolic health. The USDA is primarily responsible for blueberries becoming a major food crop. Here are some articles I have written on the topic:
The USDA Touts its Hundred Year Blueberry History for Your Brain Health
Blueberries Help Prevent Type 2 Diabetes
Blueberries Lower Cholesterol & Reverse Memory Decline
Blueberries Lower Blood Pressure & Prevent Damaged LDL Cholesterol in Overweight Individuals
Blueberries and Strawberries Reduce Heart Attack Risk in Middle-Aged Women
Catechins are another type of flavonoid best known for their role in the benefits of green tea. Early green tea research focused on cancer prevention and this research continues. Newer research has emphasized the metabolic benefits of green tea, a pressing issue in an overweight society. The primary catechin in green tea is epigallocatechin gallate.
More recently dark chocolate and cocoa have been recognized for the high content of epicatechin, which is slightly different than green tea. Unfortunately, chocolate products must be minimally processed or their epicatechin content is damaged (milk chocolate has little). Consumers will see more and more high-epicatechin chocolate coming to the market, which will no doubt have a legion of consumers ready and willing to boost their flavonoid intake.
Catechins are in small amounts in the skins of many of the fruits that primarily contain flavones or anthocyanins. Peaches are especially high in catechins. Here are some articles on catechins:
The Effects of Green Tea on Weight Management
Green Tea Extract Lowers Blood Pressure, Cholesterol, Blood Sugar & Inflammation
Green Tea and Quercetin Prevent Telomere Loss from Cardio Stress
Chocolate Reduces Cardiovascular Disease and Stroke
Chocolate Raises HDL Cholesterol
Dark Chocolate Protects Against Stroke-Induced Brain Injury
Flavones are yet another type of flavonoid which is high in citrus fruit which also contain other flavonoid types. One of the hottest areas of research is on a type of flavone called polymethoxyflavonoids which are very high in tangerines. Extracts of these flavones from the skins of tangerines and oranges, called tangeretin and nobiletin, are being actively researched for cholesterol and blood sugar metabolism, as well as cancer prevention and brain health. Here are several articles I’ve written on the topic:
Tangeretin and Nobiletin Lower Cholesterol by Inhibiting ApoB Production
Tocotrienols and Citrus Flavonoids Lower Cholesterol by 20-30 Percent
Nobiletin and Tangeretin Prevent Insulin Resistance by Improving Fat Fitness
Nobiletin Helps Prevent Fatty Liver, High Cholesterol, Weight Gain, and Insulin Resistance
As you can see there is a diverse range of dietary options for flavonoid intake. Unfortunately, many farming methods and seasonal availability reduce the flavonoid quality in these foods. Everyone knows the wonderful flavor of eating fresh fruit during the natural growing season. Vine-ripened fruit is highly superior in flavonoid content.
While fruit may be available in the off-season, it is typically picked early and does not develop its proper flavonoid potential.
Another huge problem is the chemicals sprayed on fruit to kill germs and pests. These accumulate in the skins, giving a person a dose of toxins along with the flavonoids. Berries are one of the heaviest sprayed crops, making them a poor choice. Organic is a must for almost all fruits, especially berries. It is interesting that organically grown crops typically have higher flavonoid content. This is because these crops must bolster their own defense systems to protect themselves, which means they need to synthesize more flavonoids for natural defense purposes – meaning you get more when you eat them. When fruit is spayed with chemicals it becomes “lazy,” as the defense work is done by something else. This means less flavonoids in the food and less health benefit for you.
Dietary supplements offer a wonderful way to supplement your diet throughout the year with extremely high quality concentrates of flavonoids. You can get concentrations of the active flavonoid components in a single capsule that are often more than a serving of fresh fruit. While I am not suggesting that you use supplements to replace high quality fruit intake, I am suggesting that the modern world of dietary supplements places a wide variety of superfruit components at your fingertips – a great way to fortify your diet.
A healthy person with a good diet can still benefit from moderate intake of such supplements for general health and anti-aging purposes. As your stress level goes up, as the internal feeling of wear and tear mounts, if your metabolism is not functioning up to par, and especially if health is declining in some way, then increased intake of supplemental flavonoids can be of great value.
While it is certainly possible to get many of these nutrients from a good diet, it is only easy during certain times of the year when the good farmers in the world are still growing healthy food for the people. Please go out of your way to support such farmers.
I personally like a variety of flavonoid nutrients to help get a good response to exercise and for general stress-busting and anti-aging benefits. The science is clear, the higher the concentration of flavonoids in your diet, the healthier you are likely to be. The modern science of epigenetics is proving that flavonoids are an invaluable component of the diet, highly associated with a healthier life – especially as one grows older.