Hi there, Helen from Hedley Nutrition here again.
After my last piece on health eating for immunity I thought it might be helpful to go back to basics and explain some of the terms I might talk about in future blogs. It’s all very well me banging on about how you need to eat more vegetables to up your phytonutrient intake for example but just what is a Phytonutrient? And, more importantly, why do you need them?
If you don’t already know; Phytonutrient basically means “plant nutrients”. It refers to all the chemical compounds found in plants that are not classed as macronutrients (carbohydrate, protein and fat) or micronutrients (vitamins and minerals) but still have an effect in our bodies.
Plants make these chemicals in reaction to their environments. It may be that they are medicines for the plant itself, protection from animal predators, communication molecules or chemicals produced as part of the growth cycle.
Research into these chemicals and their effects on us is often done on the isolated chemical whereas, when we eat them as part of our diets, they can act together with other compounds contained in the same stalk of broccoli for example and so have a greater effect (take home message – always “food first”!!!)
They can work in lots of different ways, often acting on our individual body cells. They might act as an antioxidant; preventing damage to our cells. Some may act on the cycle of what our cells actually do and protect DNA within cells. They may help to remove unhealthy compounds or interact with hormones. Dietitian Annemarie Aburrow explains for The British Heart Foundation that diets rich in food with phytonutrients are associated with lower levels of cardiovascular disease (CVD). As you can see, they can play a very big role so it helps to know a little more about them.
Just as an aside, not all phytochemicals are good though; some can be dangerous or toxic to the body. They are also very powerful, some are the basis of modern medical drugs. Many are helpful in small amounts but bad for us if we have too much; caffeine is a great example of this!
Many things in the plants lifecycle can effect the levels of phytonutrients they contain. Organic plants can often have higher levels of certain phytonutrients as the plants have had to naturally work harder and produce more to protect themselves from pest or disease. It may also depend on the type of plant, its growing conditions (is seasonal or grown in a greenhouse?), other plants grown near it, climate conditions and much more. Nicky Kyle tells us the most important thing you need to know about maximising nutrients when growing vegetables.
Phytonutrients are not classed as essential for your health but deficiency in them can contribute to chronic disease and they are responsible in some way for the many benefits and positive effects that fruit and vegetables have on your health and why we should be eating more of them.
Did you know the UK now eats the highest level of processed foods in the whole of Europe? In the last 50 years our diets have altered so much to massively decrease the amount of phytonutrients we eat and this may be contributing to chronic disease. If that’s not a good reason to add an extra box of vegetables to your order I don’t know what is?
So you know about the background of phytonutrients but this is just an umbrella term. They come under many different names and classifications. Which ones should you be looking out for and what kinds of things will they do for your health?
Phenols and Polyphenols
These are the largest family of Phytonutrients so there’s a long list. Here’s some of the more common ones you may of heard of:
Flavonoids (quercetin, rutin, catechins, isoflavones)
Phenolic Acids (salicyclic acid)
Terpenes (beta-carotene, lycopene, astaxanthin, lutein)
Flavonoids, are found in most plants. They have been shown to have lots of benefits to your health such as supporting against allergies, anti-inflammatory and anti-viral activities. Green tea owes much of its health benefits to its high flavonoid content but black tea contains flavonoids too so you can still enjoy a cup of “Builders Brew” (just leave the sugars).
Lignans, are transformed by our gut bacteria into phytoestrogens which means they have a mild effect of the hormone oestrogen. They are found in flax and sesame seeds, legumes, beans & pulses. They have lots of other benefits too including a high fiber content which helps feed and increase our gut bacteria meaning there’s more to make more phytoestrogens – clever huh?
Similar in structure and function to our own cholesterol meaning they may reduce how much actual cholesterol we absorb hence lowering your levels – just by simply eating more fruit and vegetables!
(beta-carotene/lycopene). Beta-carotene is probably the most well known of the 3 types of carotenoids which are precursors to vitamin A and can be converted by the body when needed. They are abundant in orange fruits and vegetables. Some studies have suggested that they may protect the eyes against age related macular degeneration (though this has not been proven by other studies) but, along with lutein and zeaxanthin, its where carrots have gained their reputation for helping you see in the dark! Lycopene has made tomatoes famous for their health benefits. From helping to protect skin against UV damage, contributing to heart health and reduced stroke risk and studies show they may also be protective against some cancers. Lycopene content is increased if tomatoes are stored at room temperature and is even higher in cooked tomatoes so pass the pasta sauce!
From the Anthocyanin family which are responsible for the red blue and violet colours in foods. Resveratrol is well studied, it is found in high amounts in blueberries and red grapes for example. Studies have shown it to be beneficial as an antioxidant, to heart health and have anti inflammatory action. However this obviously is not a green light for a large glass of Rioja;… purified resveratrol, not red wine, and it shouldn’t serve as an excuse for a cheeky glass or two writes Emma Smith for Cancer Research UK.
These are just a handful of the more common and well studied phytonutrients, there’s many more contained within our fruits and vegetables and science is only just beginning to understand what they do and how they do it. One thing we do know is that they have some pretty amazing effects and so I always recommend that you eat a wide variety of fruits and vegetables to maximise your intake of these wonderful compounds. You’ll be hearing much more about them in weeks to come!