What are Phytonutrients?
We’ve all heard of proteins, fats, carbohydrates, vitamins and minerals, but what are phytonutrients?
Food is much more than a vehicle that helps our body to produce energy, food is information and phytochemicals have a profound ability to impact our health. Phytonutrients, also known as phytochemicals are components of plant based foods that have been shown to help reduce the risk of chronic diseases such as heart disease, cancer and diabetes.
Phytonutrients occur naturally in almost all plants while others occur in specific families of plants. The phytochemicals themselves act as protectors of the plant and studies have shown that organic foods tend to have higher levels of these compounds as more is required to protect them from the natural environment, such as the sun, bugs and fungi.
Some of the best sources of phytonutrients include fruits, vegetables, herbs, spices, nuts, seeds, teas, legumes and whole grains.
Phytonutrients help give the plants their colours, thus the best way to think about exposing the body to an array of phytochemicals is to eat a colourful diet. Natural colours in our food are a good indicator of the phytonutrients that plant is rich in.
Simple steps to improving the level and array of phytonutrients that you eat is to promote the intake of lots of different colours in the diet, we like to do this by recommending the following:
- When shopping ensure you have a colourful basket/trolley, actively choosing different coloured foods to eat.
- When cooking try and make your plate colourful. A plate of beige food is unlikely to offer much in the way of phytonutrition.
- When snacking do so again using different coloured foods.
Why Variety is so important
Adding colour to your plate not only makes things look a little presentable it will also help you vary your diet, vary to nutrients and fibers you expose the body to and this helps support a diverse population of gut bugs and a happy digestive and immune system.
The phytochemicals themselves have been linked with changing the structure and function of cells, improving how well we metabolise toxins, optimising memory and cognitive health, reducing inflammation, helping to reduce cancer and/or improve cancer treatments, influencing how our gene’s are expressed, supporting cardiovascular health and reducing the risk of type two diabetes.
How to get more phytonutrients into your diet
As mentioned above the simplest solution in terms of getting more phytonutrients into your diet is to eat a colourful diet and not to overthink the specific individual phytonutrients.
Start by reviewing your plates of food and see how much colour there typically is. An interesting awareness activity is to have a look at other people’s trolleys when shopping. Do you see lots of colours or do you see a lot of packages foods and often time beige foods?
Make sure when you lay your food out at the check out it screams colour & freshness. Be proud of the foods you purchase, shop mindfully and eat mindfully.
How many portions of fruit and veg should you eat per day?
Here’s the million-dollar question. Recommendations are ever changing with this and typically the only way they head is upwards. It is now said that around 9-13servings per day is about adequate to optimise health and to help prevent chronic disease.
A typical serving is around a ½ a cup or about cupped handful. You may not be able to jump straight up to 9-13 servings per day, so have a look at the amount of servings you currently eat and see if you can increase it by 2-3 servings per day.
Is raw food better than cooked?
This is a little dependent on the individual and their circumstances as well as the type of food you intend to eat raw. Of course certain foods like whole grains and legumes should not be eaten raw, however there are also certain vegetables that have high cellulose contents that can also be a little challenging to digest and may cause so digestive upset or at the very least some embarrassing social gases!
If someone struggles a little with their digestion then it is often better to promote more cooked plant foods and just be mindful of the way they are cooked to retain as much nutrient value as possible.
Interestingly there are also certain phytonutrients in foods that can become more absorbable after cooking; this includes foods such as carrots, mushrooms, asparagus, spinach, broccoli, cabbage, peppers, tomatoes and potatoes.
Steaming and waterless cooking tends to retain nutrients better than boiling vegetables in water, thus cooking to the point of making certain vegetables softer and tender is usually recommended.
Beans, lentils etc should be well soaked and cooked before consuming, likewise wholegrains need to be well cooked as well.
Interestingly you can often increase the absorption of the healthy phytochemical compounds in your plant based foods by adding a little fat/oil such as butter or olive oil, so that is worth considering when serving up a salad or a colourful side dish of these healthy phytonutrient rich foods.
Is fresh food better than frozen?
Frozen foods seem to hold onto their nutrient content so utilizing frozen foods as part of your nutrition plan I think can be a good idea.
Keeping some frozen fruits and vegetables in the fridge that you can add to a meal or a smoothies when struggling for fresh ingredients can be a great way of ensuring a phytonutrient rich diet.
Is fresh fruit better than dried?
As a general rule fresh is better than dried. Dried fruit especially can have a very high sugar content and often results in us eating much more than we would if we were to eat those foods nice and fresh.
Freeze drying does seem to retain a good level of nutrient content so freeze dried powdered forms or fruits and vegetables can be a good addition to a diet if looking to get that extra boost of phytonutrients.
The relationship between colour and Phytonutrients
Below I am going to discuss groups of phytonutrients as they relate to the colour of the food, picking out some of the most abundant and researched phytonutrients. You can skip to the relevant section using the following links:
- Blue / Purple / Black Foods
- Green Foods
- Red Foods
- White / Tan / Brown Foods
- Yellow Foods
- Orange Foods
Blue / Purple / Black foods
Darker foods are typically richest in phytonutrients, however there are typically less of these foods available so we often have to make a bit more of an effort to consume these foods.
Consuming these foods is well worth it though as they have been linked with having anti-cancer, anti-inflammatory properties as well as protecting the brain, heart and general vascular system.
Here are two interesting phytochemicals in this colour group:
This compound became most famous probably because of its link to red wine. Found in high levels of the skin of grapes it is most well known for its potential to increase lifespan or at least adding life to years rather than adding years to life.
It has been strongly linked with protecting humans from insulin resistance, which is the primary cause of type 2 diabetes and contributes strongly to cardiovascular disease. From a cardiovascular point of view it has also been linked with reducing blood pressure and helping to improve LDL cholesterol levels.
It also appears to reduce the occurrence of osteoporosis, beneficially effecting blood pressure and possibly even contributing to long-term fat loss.
Similar to resveratrol, pterostilbene appears to have more potent anti-cancer and antioxidant capabilities.
Even at low dosages pterostilbene seems to have benefits on cognition and this phytonutrient alongside another phytonutrient called anthocyanin is thought to be the main factors in the research linking blueberries with improved cognitive function and potential reduced risk of brain related decline.
- Purple cabbage, cauliflower, carrots, kale
- Black/purple rice
Tips for eating more of these foods
- Add frozen berries to a smoothie.
- Try our famous cherry ice-cream on a warm day.
- Substitute in some purple carrot, kale, cabbage instead of the more common choices.
- Occasionally add black or purple rice as a substitute for white or brown rice.
- Add some chopped figs to your salad.
From a young age we have always been told to eat our greens and there is good reason for this. Many green foods and the chemical compounds naturally found in these foods have been linked with reducing the risk of cancer, having an anti-inflammatory benefit, balancing hormones and protecting the brain, heart, liver and skin.
Unlike the deeper colour foods, green foods are typically very abundant through most seasons, and that is great news because there is a long list of phytochemicals available in green foods. Three of the most famous ones are:
This group of phytonutrients which make up the cruciferous vegetable family (broccoli, cauliflower, cabbage, kale etc) are strongly linked with the anti-cancer properties, particularly of hormone related cancers such as breast and uterine cancer as well as cancer of the lungs and the digestive system.
Typically these are best eaten lightly cooked, but it should be remembered that they can also cause some bloating and uncomfortableness in some individuals, thus further cooking may be required. If they are well tolerated then adding raw into smoothies or salads may be a good idea as chopping and chewing raw cruciferous vegetables results in the release of specific metabolites further linked with the health promoting properties of cruciferous vegetables.
There are many different types of phytosterols, however they are probably most famous for their ability to block the absorption of cholesterol from the gut, helping to reduce the levels of LDL cholesterol, hence they have been added to foods or dietary supplements, although the known benefit against cardiovascular risk is not known.
Phytosterols are much more than just a compound to help with cholesterol. Phytosterols may inhibit the growth of breast and prostate cancer or benign prostatic hyperplasia (BPH).
Catechins are found in green tea, with the most famous catechin in green tea known as (EGCG).
It has been implicated in benefiting almost all systems in the body, helping to protect us against cardiometabolic issues like heart disease and diabetes, neurological issues, liver problems and even supporting fat loss.
Benefits are not just seen in supplemental form, they are seen in dosages as small as a cup of green tea. Just one cup per day has been shown to reduce the risk of breast cancer by 50% in one study.
In some people, green tea can cause a bit of nausea, especially if taken on an empty stomach either as a tea or a supplement form, if that is the case then try not to have first thing in the morning before eating.
- Bamboo Shoots
- Bean Sprouts
- Bell peppers
- Bitter melon
- Bok Choy
- Brussels Sprouts
- Green Beans
- Green Peas
- Green Tea
- General green leafy veg
- Snow Peas
Tips for eating more of these foods
- Add a cup of green tea to your routine each day.
- Utilise lots of green herbs within your cooking or as a garnish to meals.
- Add some avocado to your salad.
- Snack on some tasty olives.
- Squeeze some fresh lime into your water.
- Add some green veggies or powdered greens into a smoothie.
The phytonutrients associated with red foods have been associated with helping to reduce the risk of certain types of cancer as well as their heart, brain, liver and immune system benefits. Here is one of the most popular phytonutrients associated with the colour red:
This phytonutrient has had a lot of press in the past, particularly in its association with tomatoes. Lycopene like so many phytonutrients is part of a family of plant pigments known as carotenoids.
Interestingly the processing of tomato-based foods can increase the lycopene concentration. So utilising tomato base sauces/juices can be a way of adding in this phytonutrient. Like many carotenoids the absorption/bioavailability is greatly improved in the presence of fats, so adding a little fat to your meal or snack that contains these lycopene rich foods is a good idea. Think about the Mediterranean approach of tomato based sauces and plenty of olive oil.
Salads consumed without fats have shown that no measurable uptake of lycopene occurred. Likewise when adding higher fat dressings compared to low fat dressings this also improved absorption. I’d recommend sticking to good old olive oil, sprinkling some nuts or adding some avocado to your salad to help with the absorption.
Interestingly with some lycopene containing foods, cooking them appears to improve the bioavailability as well, thus absorbing more of the lycopene from the food you eat.
Lycopene has been associated with reducing cancer risk, in particular prostate, lung and stomach. It has also been associated with reduced cardiovascular risk and reduced inflammation as well.
You are certainly not short of red foods in the diet, here are some red foods to try and include in your diet:
- Sweet red peppers
- Red bell peppers
- Red onions
- Blood oranges
- Pink grapefruit
Tips for eating more of these foods
- Sprinkle some pomegranate into your favourite salad.
- Chop up some watermelon on a hot summers add and eat as a refreshing and rehydrating snack.
- Use tomatoes in a cooked breakfast, as a base for a soup, stew, curry or bolognaise.
- Snack on some tasty strawberries.
- Grate fresh beetroot into a salad.
White / Tan / Brown foods
Phytonutrients are less associated with the white, tan or brown foods, however some of the best phytonutrients are present in the foods that are naturally these colours.
Healthy real food, non-processed white, tan and brown foods have been linked with their anti-cancer effects, cardiovascular health, anti-inflammatory and anti bacterial, yeast and parasitic activity.
Here is one of the most significant phytonutrients in this group.
This is a compound found in high levels in garlic. There is a strong association with cardiovascular health through reduced blood pressure and improved blood lipid levels, it has also been associated with improved cognition and reduced cancer risk in particular prostate, colon and stomach cancer. It is also a strong anti-bacterial, anti-fungal and anti-parasitic compound making it useful when addressing underlying infections, particularly of the digestive system, although the smell can be a bit pungent and off-putting.
When garlic is crushed, chewed or sliced this releases allicin. Cooking does not seem to impact the allicin levels, although microwave cooking destroys allicin. Whilst nutrient content such as vitamins and minerals are not largely effected by microwave cooking, phytonutrients are often impacted, one of the reasons I’m not so keen on microwave cooking.
Typically people think about flour based foods when we consider these colours. However the types of foods we really want to focus are:
- Whole grains
- Spices such as cinnamon, clove etc
- Legumes like chickpeas, beans, peas, cashews etc
Tips for eating more of these foods
- Make use of garlic and onion as a base to soups, stews, stir fry and curry dishes.
- Treat yourself to a small amount of 70%+ dark chocolate or a nut and date bar/ball every now and again.
- Whip up some of your own hummus made with chickpeas or a bean and chickpea mix.
- Add mushrooms to a cooked breakfast or omelet.
- Why not try some cooked apples with cinnamon as a healthy dessert.
Yellow foods have been strongly associated with their anti-inflammatory and anti-cancer effects. Studies have also associated the compounds found in yellow foods with brain, heart, eye and skin health. Below are some of the most common phytonutrients found in yellow foods.
Zeaxanthin & Lutein
Although also found in dark green foods and orange foods as well, yellow foods are also a great source of zeaxanthin and lutein. One of the best sources of these is actually eggs because they tend to have a higher absorption potential than that found in plant based foods. One way to increase the absorption through plant based sources is actually increasing the fats in the meal, without dietary fats the absorption is significantly effected, hence adding a little butter or olive oil to your veggies is a great way of supporting absorption.
Zeaxanthin and Lutein are naturally occurring compounds that appear to have more significance in the retina of the eye, hence its association with eye health in particular helping to prevent macular degeneration.
There is also evidence linking zeaxanthin and lutein with improvements in memory, learning, cognitive performance and reducing dementia severity.
Rutin is a compound found predominately as part of another natural food compound known as quercetin which is well known for its antioxidant properties, meaning it can help protect our cells from damage. There is good evidence linking quercetin and thus rutin with reducing general oxidation and stress induced by exercise.
There are many great food sources of the above phytonutrients, these include:
- Yellow Bell Peppers
- Corn on the cob
- Ginger root
- Butternut squash
- Asian Pears
Tips for eating more of these foods
- Adding a little frozen banana to any smoothie makes it taste amazing. We also add frozen banana to a little coconut milk and blend together to make an easy and great tasting banana ice-cream.
- Slice up some apple and consume with a few nuts as part of a day time snack.
- Add some ginger and yellow bell peppers to a stir fry meal.
- Make a ginger and lemon tea or ice-tea drink.
Orange foods and the phytonutrients associated have been linked with supporting the immune system, skin health, eye health, reducing inflammation, reducing the risk of heart disease and cancer prevention and support.
Below are a couple of the most famous orange phytonutrients:
One of the most famous and well researched is the polyphenol-phytonutrient of curcumin, something found in high levels in the spice turmeric and to a lesser extent ginger. Although a strong yellow pigment it is found naturally in orange foods such as turmeric root.
Curcumin is somewhat of a gem compound; it has been associated with the following:
- Strong anti-inflammatory and anti-oxidant.
- Cancer prevention and also supporting cancer treatment.
- Reducing cognitive decline.
- Supporting healthy blood lipids and reducing plaque in the arteries.
- Reducing the risk of diabetes.
- Reducing symptoms of depression.
- General pain reduction and reducing symptoms of osteoarthritis.
- General improvement in the functionality of the elderly or injured.
One worthy note is that curcumin is poorly absorbed, however adding black pepper is a sure way of increasing absorption allowing for the above systemic effects.
Another really famous phytonutrient and often one that people may have heard of is beta carotene. You might have heard the saying if you eat your carrots it can help you see in the dark, whilst technically not true beta-carotene is a compound that has the ability to be converted into vitamin A.
Whilst animal sources of vitamin A in the form of retinol are more absorbable we have the capability to convert cartinoids to vitamin A, although for some people genetic, digestive, toxicity issues and certain over the counter medications will impact this process. Thus vegans should be aware that it is not possible in all individuals to get adequate amounts of the active form of vitamin A from plant based sources alone.
Cartinoids such as beta-carotene are fat soluble, meaning they absorb better in the presence of fats. Adding a little fat to meals rich in these compounds like adding a little olive oil, butter or a handful of healthy nuts might be a good idea.
There are many orange foods you can add to your diet. Some of the best include:
- Sweet potato
- Orange bell peppers
- Cantaloupe melon
- Butternut squash
Tips for eating more of these foods
- Add a carrot to a morning and snack smoothie.
- Make some turmeric milk tea and use turmeric liberally in curry dishes. Don’t forget to add a little black pepper to support absorption.
- Mix up some carrot, butternut squash and sweet potato in a mash to serve with your dinner. Add a knob of butter or some olive oil to improve the absorption of the beta-carotene.
- Make a little fruit salad of fresh apricot, mango, cantaloupe melon and some freshly squeezed orange juice.
Blue / Purple / Black Foods
White / Tan / Brown Foods
- Institute For Functional Medicine Phytonutrient Spectrum Comprehensive Guide (2015)