We’re all familiar with the recommendation to eat 5 portions of fruit and vegetables each day, to help strengthen our immune systems and improve overall wellbeing. This may be common knowledge, but recent studies have shown that the number of us who are eating this small portion of fruit and veg is at an all time low .
It’s not just a case of eating too few, but also the concern that we have very little variety in the types of fruits and vegetables we are consuming each day, with the healthiest fruits – brightly coloured berries, and the healthiest vegetables – dark green cruciferous vegetables, being left out of our diet almost completely.
Fruits and vegetables are very nutrient dense with vitamins and minerals that we know are essential for proper health and keeping our bodies functioning. However, an often overlooked aspect of these food groups are phytonutrients.
What Are Phytonutrients?
Phytonutrients are plant-based compounds that have specific health benefits.
These compounds include plant pigments and hormones. Some of the better-known classifications of phytonutrients include carotenoids, flavonoids and isoflavones, but there are phytonutrients that we don’t even know about yet!
These compounds play a similar role in the body as anti-oxidant nutrients in processes such as:
- Fighting cancer – detoxifying carcinogens
- Combating the effects of free radicals and oxidative stress
- Reducing the risk of heart disease
- Supporting and strengthening our immune system
- Improving gut health and function
- Protecting the body against harmful toxins, diseases and viruses
They have even been shown to work pro-actively to prevent disease occurring by causing minor metabolic stress to our bodies, and therefore strengthening it against any potential future threats .
There has been increasing research around the impact phytonutrients have on our bodily systems. We can live without them so they are not considered essential nutrients, and unlike vitamins and minerals there are no RDAs for them. However, this does not mean that their intake is not beneficial, and phytonutrients are being recognised in worldwide research as being helpful in preventing disease and promoting longevity.
Studies have shown the benefits of phytonutrients in treating diseases such as:
- delaying the onset of Alzheimer’s 
- reducing the mortality of cancer [4, 5]
- delaying cognitive ageing associated with neurological diseases such as dementia [2, 6, 7].
Oxidative Stress and Genetics
As it is becoming more and more apparent that oxidative stress is one of the underlying mechanisms behind chronic disease, it becomes vitally important for those of us who are more inclined to high levels of oxidative stress to be wary of the inherent risks.
At FitnessGenes we look at multiple gene variations that have a particular association with high levels of cellular oxidation. Genetics, diet and exercise all have an effect on the overall level of oxidation occurring in your body. If you have favourable genetics and you exercise, then you may not need to consume as many antioxidants in your diet.
However, for some genetic variations and combinations of the PGC1A and UCP2 gene, they have been shown to have a higher risk of being susceptible to oxidation.
Only 1-2% of people globally have the UCP2 VV and the PGC1A SS combination of genetic variants, with this group of people having the highest susceptibility to oxidative damage.
The increased risk of oxidative stress can lead to overtraining syndrome, muscular fatigue and an impaired adaptation to exercise [9, 10].
Anything you do that raises your metabolic rate, including exercise, accelerates the production of free radicals and it becomes very important for those who are susceptible to high levels of oxidative stress to become aware of the potential negative effects and to make sure they have a good supply of antioxidants.
Too much oxidative stress can alter the normal metabolic functioning of your cells, causing the production of too many free radicals.
Free radicals are essentially damaged oxygen molecules missing one electron, that are constantly searching for another electron in your body in order to stabilise. Although by doing this, they can cause a chain reaction that can lead to damaging effects on your cells and DNA as they have an extremely unstable atomic structure.
Our bodies are constantly under the threat of free radicals during our lifetime as they are by-products of our metabolic system. We can usually deal with these free radical attacks using our anti-oxidant protection matrix of vitamins, minerals, enzymes and phytonutrients, which will help neutralise the free radicals.
Nonetheless, even though our bodies are capable of tolerating and even benefiting from a few free radical attacks and stresses, it cannot tolerate overwhelming and frequent assaults. This is when “cell ageing” occurs and disease risk heightens to new levels.
As our modern diets are lacking the defence system of phytonutrients with an unvaried consumption of fruits and vegetables, the balance between oxidative attacks and antioxidant protection worsens, increasing the risk of cellular damage and disease.
So how do I increase the number of phytonutrients in my diet?
Simple answer: Eat a variety of fruits and vegetables regularly, eating as many different colours as possible (excluding if they are unripe, or passed their sell-by date!).
To ensure you are getting a good supply of phytonutrients, it is essential to eat at least the recommended five portions of fruit and vegetables per day.
As many of the phytonutrients are found in the plant pigments, it is important to consume a wide variety of brightly coloured fruits and vegetable, as each colour will provide a different unique combination and amount of phytonutrients.
As the different phytochemicals bind to proteins and specific receptors in our body, it shouldn’t be considered that all phytonutrients are equal as they all have different health giving properties .
Try to eat a variety of whole fruits and vegetables, grains, legumes, soya products, herbs and spices. When possible opt for local, organically sourced foods - the fresher the better!
“Variety is the spice of life” - with a range of colours in your fruit and vegetable choices, you will obtain a beneficial level of phytonutrients to support your training and health.
- Adults meeting fruit and vegetable intake recommendations - United States, 2013, Latetia V. Moore and Frances E. Thompson, Morbidity and Mortality Weekly Report, CDC, published online 10 July 2015.
- Rahman K. Studies on free radicals, antioxidants, and co-factors. Clinical Interventions in Aging. 2007;2(2):219-236.
- N Hishikawa, Y Takahashi, Y Amakusa, Y Tanno, Y Tuji, H Niwa, N Murakami, U K Krishna. Effects of turmeric on alzheimer’s disease with behavioral and psychological symptoms of dementia. Ayu. 2012 Oct-Dec; 33(4): 499–504.
- Adams LS, Chen S. Phytochemicals for breast cancer prevention by targeting aromatase. Front Biosci. 2009 Jan 1;14:3846-63.
- F L Buchner, H B Bueno-de-Mesquita, M M Ros, K Overvad, C C Dahm, L Hansen, A Tjonneland, and more. Variety in fruit and vegetable consumption and the risk of lung cancer in the European prospective investigation into cancer and nutrition. Cancer Epidemiol Biomarkers Prev. 2010 Sep;19(9):2278-86.
- Ortiz D, Shea TB. Apple juice prevents oxidative stress induced by amyloid-beta in culture. J Alzheimers Dis. 2004 Feb;6(1):27-30.
- Youdim KA, Joseph JA. A possible emerging role of phytochemicals in improving age-related neurological dysfunctions: a multiplicity of effects. Free Rad Biol Med. 2001;30:583–94.
- W. Craig and L. Beck, “Phytochemicals: Health Protective Effects,” Canadian Journal of Dietetic Practice and Research, Vol. 60, No. 2, 1999, pp. 78-84.
- Tanskanen, M., Atalay, M. and Uusitalo, A., 2010. Altered oxidative stress in overtrained athletes. Journal of sports sciences, 28(3), pp.309-317.
- Ji, L., 1995. Oxidative stress during exercise: implication of antioxidant nutrients. Free Radical Biology and Medicine, 18(6), pp.1079-1086.
- J. Dias, "Nutritional Quality and Health Benefits of Vegetables: A Review," Food and Nutrition Sciences, Vol. 3 No. 10, 2012, pp. 1354-1374. doi: 10.4236/fns.2012.310179.
- Chen, L., Vigneault, C., Vijaya Raghavan, G.S. and Kubow, S., 2007. Importance of the phytochemical content of fruits and vegetables to human health. Stewart Postharvest Review, 3(3), pp.1-5.