Polyphenols and Phytonutrients for Health

Written by Ben Bunting: BA, PGCert. (Sport & Exercise Nutrition) // British Army Physical Training Instructor // S&C Coach.


Phytonutrients and polyphenols are plant-based compounds that provide a number of benefits to the human body. They are not considered essential nutrients, but they are important for overall health.

Phytonutrients and polyphenols can be found in fruits, vegetables, whole grains, beans, seeds, nuts, herbs, and spices. They provide many of the same health benefits as vitamins and minerals.

Polyphenols Explained

A large class of phenolic compounds present in many fruits, vegetables, and beverages. They act as antioxidants and protect the cells of the body against damage from oxidative stress.

Research has shown that dietary intake of these natural plant chemicals may reduce the risk of chronic diseases like cancer, heart disease, and diabetes. In addition, they also help improve your metabolism, aid digestion, and promote healthy brain function.

The chemical structures of polyphenols are similar, with each one containing at least three to five phenol groups. However, different phenols have different chemical properties.

The main classes are phenolic acids, flavonoids, stilbenes, and lignans.

How to get polyphenols into your diet

The best way to boost your intake of these plant-based substances is to eat a wide variety of whole foods. You'll want to include a variety of colorful fruits and vegetables in your meals, as well as whole grains, nuts, and legumes.

Bioavailability of polyphenols

When you eat foods that are high in polyphenols, your body can absorb them better. This is because the polyphenols are metabolized within your digestive tract, rather than in your bloodstream.

This allows them to be absorbed into the cells of your body and have more of an effect on health. Besides being anti-inflammatory, a high intake of flavonoids has also been linked to lowering blood pressure and balancing cholesterol levels, both precursors to heart disease.

It has also been found that high intake of flavonoids can regulate weight, reducing your body mass index and promoting a healthier metabolism.

Types and Sources of Polyphenols

Polyphenols can be found in many plant foods, including fruits, vegetables, herbs, tea, and red wine.

They act as antioxidants, neutralizing free radicals that can damage cells and increase your risk of heart disease, cancer, and other chronic health conditions.

Types of Polyphenols

Flavonoids are the most common type of polyphenol, accounting for 60% of all the dietary polyphenols identified.

The best known flavonoids are quercetin, kaempferol, and catechins. Other flavonoids include hesperetin, cyanidin, and daidzein.

Phenolic acids are another major group of dietary polyphenols, accounting for 30%. These are found in many fruits, vegetables, and whole grains, as well as coffee. The most common phenolic acids are caffeic acid, gallic acid, and ferulic acid.

Stilbenes are a smaller group of polyphenols, accounting for 10% of the total dietary polyphenols.

These compounds can be found in many fruits and vegetables, including berries, peanuts, and red wine.

Lignans are also polyphenols, and these can be found in many fruits, vegetables, and whole grain foods. They are particularly abundant in red grapes, raspberries, and flax seeds.

Despite their positive benefits, it is important to note that some polyphenols can be toxic if consumed in excess. Talk to your doctor about limiting the amount of these compounds in your diet.

Lastly, it is important to remember that polyphenols can have negative interactions with certain medications. For example, if you take statins or anti-anxiety medications, polyphenols from fruit juices can reduce their effectiveness.

Phytonutrients Explained

Many people know that consuming a diet rich in plant-based foods can improve their health, but not everyone understands how phytonutrients work within the body. These bioactive compounds are found in fruits, vegetables, beans, whole grains and herbs.

Phytonutrients are plant-derived chemicals that help plants stay healthy and give them their unique colors, flavors and aromas. These phytochemicals also strengthen a plant's immune system to help it protect itself from threats in its environment.

The best way to eat phytonutrient-rich foods is to consume a wide variety of plants-based foods throughout the day. The most abundant sources of these beneficial compounds are often the fruits and vegetables that have deeper hues or stronger flavors.

Some of the most well-known phytonutrients include lycopene, beta carotene and lutein. These are all antioxidants that fight free radical damage in the body and help prevent cancer and other diseases.

Other plant-derived nutrients that support your overall health are phenols, flavonoids and alpha lipoic acid.

These compounds have been linked with increased longevity, protection against heart disease and other chronic conditions, reduction in inflammation levels, and improved brain function.

These compounds are often difficult to metabolize in the human body, but eating a balanced diet that includes whole plant foods is a good start.

Adding a phytonutrient supplement to your diet can be helpful in boosting your intake of these important vitamins and minerals, but be sure to check with your doctor before starting any new diet or taking supplements.

Sources of Phytonutrients

The body uses phytochemicals to fight off harmful bacteria, viruses, and fungi. Phytochemicals are also used to give plants their color, like the red of a pomegranate or the orange of a carrot.

Phytonutrients are essential for a healthy diet and can help prevent disease. Eating a variety of plant-based foods including vegetables and fruit, whole grains, nuts and seeds, legumes, and tea is one of the best ways to consume enough phytonutrients for your body.

There are over 1,000 different types of phytonutrients and they occur in many different plants.

Some occur naturally in almost all plants, while others are found in specific families of plants, such as the cruciferous family of vegetables (broccoli, cabbage, cauliflower and Brussels sprouts).

Some phytonutrients are found in most fruits, vegetables, legumes, nuts and seeds, tea and other plants that can be eaten raw or cooked.

For example, lycopene, which gives tomatoes and watermelon their red color, is one of the best sources of phytonutrients because it has strong anti-inflammatory properties.

Another phytonutrient that is great for promoting health is curcumin. It is a powerful antioxidant that scavenges free radicals and reduces oxidative stress.

Studies have shown that a diet rich in phytonutrients can protect against cancer, heart disease, high blood pressure and arthritis.

Phytonutrients can also improve immune function and enhance communication between cells, repair DNA damage from toxin exposure, detoxify carcinogens and alter estrogen metabolism.

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Antioxidants Explained

Antioxidants are substances that help the body protect itself against free radicals, which cause damage to cells and may lead to many health problems.

These molecules are natural byproducts of metabolism or are created in response to stressors, such as pollution and cigarette smoke.

But an overload of these 'free radicals' can result in oxidative stress, which can increase your risk of disease, including cancer and heart disease.

They are a key part of maintaining a healthy immune system and keeping the skin and hair looking young.

While antioxidants have a variety of effects, they're particularly important for boosting the immune system and fighting off harmful viruses and bacteria.

These compounds also play a crucial role in the aging process. They can slow the onset of wrinkles, reduce the appearance of fine lines and improve the skin's ability to retain moisture.

In general, the best way to get a good supply of antioxidants is to eat lots of fresh fruit and vegetables. These include berries, carrots, green tea, red grapes, onions, avocados, radishes and kale.

There are many different types of antioxidants, some are more effective than others and can help with different parts of the body. The most common are vitamin C, vitamin E, beta-carotene and selenium.

The best way to get antioxidants is by eating a varied diet that includes a lot of fresh, colourful fruit and vegetables.

The amount of antioxidants in each food is measured by its Oxygen Radical Absorbance Capacity (ORAC) score, which can be found on the label.

Boosting your intake of antioxidants can benefit the brain and mental health. Several studies have linked oxidative stress to anxiety and depression.

While the research is not yet conclusive, it suggests that a regular intake of antioxidants could be beneficial to those with these conditions.

One of the most important dietary antioxidants is Vitamin C, which plays a role in blood vessel and immune health. It can also reduce inflammation and protect against diseases like Alzheimer's.

Another antioxidant is beta-carotene, which is a precursor to the Vitamin A and is found in orange fruits and vegetables, such as carrots, apricots, sweet potatoes and pumpkin.

It is thought to play a role in vision, immunity and bone health.

The third most important dietary antioxidant is Vitamin E, which is also a precursor to the Vitamin A and is contained in green, leafy vegetables. It is also found in avocados, seeds and nuts.

Lastly, there are the minerals selenium, zinc and copper.

These minerals are also a form of antioxidant and act as co-factors for the synthesis of enzymes that aid in protecting the body from oxidative stress.

There are a lot of different sources of antioxidants, and the best way to ensure you are getting enough is by eating a balanced, nutritious diet that contains a variety of fruits, vegetables, whole grains, lean protein and healthy fats.

If you are unable to eat enough of these foods, then supplements can be an effective source of antioxidants.


Carotenoids are a group of yellow, orange and red pigments that are produced by photosynthesizing plants (such as carrots and squash) as well as by some bacteria and fungi.

These pigments help to protect the cells of plants from the sun’s damaging rays. They are also known to be antioxidants that fight free radicals.

These antioxidants have many health benefits, including reducing inflammation, improving eye health, boosting immunity, and protecting the skin from UV damage. They also aid in the prevention of cancer and heart disease.

The most common types of carotenoids include beta-carotene, lutein, zeaxanthin and lycopene. These are the main ones that are found in a variety of different fruits and vegetables, such as carrots, spinach, pumpkins and cantaloupes.

They also occur in some algae and certain fungi, such as yeast. The lycopene in tomatoes is the strongest carotene that can be found in nature and has been shown to help lower your risk of cardiovascular disease and age-related eye diseases, such as macular degeneration.

Aside from their beneficial effects on the body, some studies have shown that certain carotenoids can help prevent liver damage by lowering your risk of nonalcoholic fatty liver disease (NAFLD).

This disease is characterized by the accumulation of fat in your liver, which results in oxidative stress and inflammation. NAFLD can be prevented by a diet high in fruits and vegetables and by taking supplements.

Another study shows that b-cryptoxanthin can reduce the risk of bone loss in postmenopausal women.

However, whether or not this effect is due to a specific carotenoid or the other nutrients in the supplement remains unclear.

Despite these findings, researchers are still not sure how much of these compounds you need to get the most health benefits.

The key is to eat a wide variety of colorful foods, such as carrots, pumpkins, sweet potatoes and leafy greens.

These health benefits may be more pronounced when they are obtained from whole foods, rather than consuming them as supplements.

This is because many of the interactions between different carotenoids and other chemicals within a food make them more effective in providing health benefits.


Resveratrol is a polyphenol found in grapes, berries and other fruits and nuts. It's one of the many flavonoids that have been found to have beneficial effects on health, including reducing blood pressure and protecting against heart disease.

It is also a powerful antioxidant, and research suggests that it can reduce the risk of Alzheimer's disease. It may also help fight plaque buildup that can lead to cardiovascular disease.

It might also reduce the oxidation of "bad" LDL cholesterol, which can contribute to the development of heart disease and strokes.

The benefits of resveratrol aren't limited to the inside of your body, though; it's also a topical antioxidant that helps combat skin-aging molecules called free radicals.

It's also believed to have anti-tumor properties, so it might be able to slow the progression of certain types of cancer.

If you're interested in using resveratrol to improve your health, be sure to consult with a doctor or nutritionist before taking any supplements. You can also look for resveratrol-rich foods, such as red wine, peanuts, pistachios, grapes, and blueberries.

Phytonutrients are compounds from plants that have specific therapeutic effects on your health, and there are four main groups of phytonutrients: polyphenols, lignans, carotenoids and flavonoids.

Phenolic acids are the most common type of phytonutrients and are found in a variety of fruits, vegetables and nuts. They're also found in some beverages, such as coffee and tea.

They are known to have an anti-inflammatory effect and can reduce pain. They also boost your energy and increase your alertness.

It's worth noting that resveratrol is an estrogen-like compound, so it can be dangerous for women who already have hormone-related cancers, such as ovary and breast cancer.

It might have negative interactions with some medications, so it's best to speak with your doctor before taking resveratrol if you take any prescription drugs or supplements.

While some people find that resveratrol supplements are effective, others experience side effects, such as gastrointestinal upset. This is why it's important to talk to a qualified medical professional before trying any supplement.


Turmeric and its component curcumin have a wide range of biological activities that can benefit the health of people in many ways. Among these are antioxidant activity, anti-inflammatory effects and anticancer properties (35).

A few studies have shown that curcumin may be useful for preventing cancer in the first place as well as treating it once it has developed.

For instance, it may help prevent and treat gastrointestinal cancers such as colorectal cancer. It also has a calming effect on the immune system and can reduce inflammation in autoimmune conditions such as arthritis.

Some studies have also found that it can help improve heart health, especially in patients undergoing coronary artery bypass surgery. This is because it can help regulate blood pressure and blood clotting, which are often associated with heart disease.

The curcumin found in turmeric has anti-inflammatory properties that can improve the symptoms of arthritis and other inflammatory disorders. It can also prevent joint damage and is more effective than some anti-inflammatory drugs.

One study found that it can also reduce the levels of a protein that forms b-amyloid plaques in the brain, which are linked to Alzheimer's disease. It also appears to improve cognitive function and impede brain aging in animal models of Alzheimer's.

Researchers are currently investigating curcumin's ability to cross the blood-brain barrier and potentially prevent dementia in humans. This research is still early, but it has the potential to make a significant difference in the treatment of this condition.

Taking curcumin as an oral supplement has been shown to reduce muscle soreness after exercise, attenuating oxidative stress in the muscles and inhibiting the synthesis of proinflammatory compounds.

In addition, curcumin has been found to decrease hepatic gluconeogenic gene expression and to activate the canonical Wnt signaling pathway in white adipose tissue to repress adipogenesis.

While the research into the effects of curcumin on cancer is promising, it is important to be cautious about using products containing this substance.

For instance, a turmeric-based supplement called Fortodol and Miradin are available in the UK and online as food supplements but the Medicines and Healthcare products Regulatory Agency has warned against them as they can cause liver damage.

Grape Seed Extract

Grape seed extract is a natural source of polyphenols and phytonutrients, which have been shown to support health in several ways.

They are antioxidants that can help prevent cell damage and protect cells from disease. They also have antimicrobial and anti-inflammatory properties.

They may help lower blood pressure, especially in people with high cholesterol or metabolic syndrome.

Some studies have found that they can also improve blood sugar levels in people with diabetes. They might also help reduce edema, swelling that occurs after surgery or an injury.

One study found that people with breast cancer who took 600 mg of grape seed extract daily for 6 months had less edema than those who took a placebo.

Another study found that people who experienced a sports injury had less swelling when they took grape seed extract.

These nutrients can also help to protect liver cells from damage caused by chemotherapy medications. T

alk to your doctor or pharmacist about whether grape seed extract is safe to take with chemotherapy medicines.

The anti-inflammatory effects of grape seed extract are thought to come from its antioxidant properties, which can neutralize free radicals and other oxidants in the body that cause damage. They may also help to protect the liver from harmful bacteria and viruses.

In addition, some studies have found that grape seed extract can help prevent the growth of certain types of cancer in test tubes. These include breast, stomach, colon, prostate, and lung cancers.

Some studies have found that grape seed extract may help control high blood pressure and high cholesterol in people with a history of diabetes or obesity.

It can help to decrease triglycerides and raise LDL (good) cholesterol. It may also help to lower C-reactive protein, a marker of inflammation in the body.

It can also help to increase urination and reduce urinary toxins in people with kidney stones. It can also help to protect against some infections in the urinary tract, including yeast infections and bladder infections.

The best way to get the most benefits from grape seed extract is to use it as directed on the label, or as recommended by your doctor or pharmacist.

This includes taking it at the same time as other medications, vitamins, and herbal supplements you may be taking.

Polyphenols and Phytonutrients IncreaseTestosterone

Phytonutrients are naturally occurring compounds found in plants. They are antioxidants, helping to prevent free radicals (molecules with unpaired electrons) from causing cell damage and ultimately leading to disease.

Phytonutrients can also promote healthy testosterone levels through a variety of mechanisms.

Increasing Testosterone

Androgen production is essential to maintain appropriate Sertoli cells function, which contributes to normal spermatogenesis and is a key factor in male fertility. Appropriate

Sertoli cell function is mainly achieved through androgen secretion by the testicular Leydig cells.

This is especially important during aging, when testicular androgen production decreases by 1% per year in adults.

Flavonoids have been shown to increase steroidogenic enzymes in Leydig cells and this can lead to increased testosterone production from these cells.

Among the most active flavonoids are quercetin, genistein, daidzein, and resveratrol.

These molecules act on the expression of StAR gene, a key protein in androgen biosynthesis. Moreover, flavonoids such as chrysin, apigenin, luteolin, and quercetin may help in delaying the onset of late-onset hypogonadism associated with aging in men.

Multiple polyphenols have been reported to enhance testosterone production by regulating steroidogenic enzymes, such as CYP11A1 and HSD3B2 in testis Leydig cells, although their mechanism of action remains unclear.

Nevertheless, numerous studies have provided evidence that flavonoids and isoflavonoids increase testosterone production in a dose-dependent manner.

Similarly, pomegranate fruit contains punicalagin, which has been shown to block the conversion of testosterone to estrogen and DHT in a way that raises testosterone levels in men.

It also increases nitric oxide, which improves erections and sexual performance. Pomegranate juice is recommended for individuals wanting to boost their testosterone levels.


Phytonutrients are naturally occurring chemicals found in foods that have positive impacts on human health and nutrition. They are categorized into different groups depending on their chemical structure.

These groups include flavonoids, phenolic acids, stilbenes and lignans (flavonoid polyphenols). Non-flavonoid polyphenols include curcuminoids, tannins, resveratrol and cinnamic acid.

How They Work

Almost all phytonutrients are antioxidants, which means they help prevent cellular damage from free radicals that occur from smoking, pollution, and eating rancid foods. They also help maintain a healthy immune system, protect your eyes, and facilitate cell signaling.

They may also help reduce inflammation, lower your risk for cancer, and support cardiovascular health.

Phytonutrients may be consumed in different forms including foods, beverages, and supplements. It is important to consult your doctor or pharmacist before using a supplement.

Despite the significant benefits of these molecules, the knowledge about their mechanisms of action is limited. Nevertheless, they are emerging as an additional therapeutic option. 


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