In this blog series, we ask Dr. Fogarty, a nutrition and exercise expert from the UK, to weigh in on how eating vegetables affect our health and athletic performance.
Mark Fogarty earned a PhD in Exercise Physiology and Biochemistry at the University of Ulster in the United Kingdom where he has been researching, publishing and lecturing on natural nutritional intervention in the context of exercise stress for over a decade.
Spinaca Farms: In one of your published research papers, you write “..there is a need to ascertain an antioxidant vitamin-rich vegetable that has the potential to counteract exercise-induced oxidative stress…causing severe perturbations to cell structure and function.” Let’s start there. What are some of the most noticeable and worrisome symptoms of oxidative stress that athletes ought to be wary of?
Dr. Fogarty: Good question!
Most athletes will experience oxidative stress pretty much all the time. In fact, we all do, it’s basically what makes us age. It is the body’s response to this stress that probably makes us “fitter” as a result of training. We have this amazing capacity to not just simply repair our bodies back to its normal level, but for a period we can overcompensate to ensure we’re better protected from the next dose of stress.
Where the stress might become more noticeable is if the athlete becomes ‘overtrained’ (not allowing enough recovery time between training sessions). If this happens, the athlete becomes more prone to muscle injury, or they might start picking up viruses as the immune system becomes dampened over time.
So to answer your question, I don’t think an athlete would actually notice oxidative stress directly. But, if he or she has a well-balanced diet and allows ample recovery time between workouts then the stress should have less negative effects and more positive effects.
SF: You talk a lot about how antioxidant-rich vegetables could potentially counteract exercise-induced oxidative stress and damage at the molecular level caused by free-radicals. How does that work? What criteria do these vegetables need to fill to qualify as an oxidative stress fixer?
Dr. Fogarty: An oxidative stress fixer—I like that!
Most fruit and vegetables will contain a range of oxidative stress fixers—antioxidants, or more commonly known as vitamins. The body has two lines of defense against oxidative stress: The first is built-in and made up of enzymes that stop the stress chain reaction by neutralising the radicals that are causing the damage. The second line of defense comes from the foods we eat.
Vitamins C & E are perhaps the most well-known antioxidants and work in difference cellular areas. Vitamin C is water-based so it acts in the liquid within the cell and between cells while Vitamin E lives in the cell membrane itself because its fat-based.
So, if we consider these two simple macromolecules as both being extremely important we have to recognise they will come from the different food sources we eat. Vitamin C is largely found in citrus fruits while food like nuts and avocados are high in Vitamin E.
SF: What advice to have for us to be sure our diets are antioxidant-rich?
Dr. Fogarty: First, it’s important to realise that our vitamins don’t work by themselves—they all work together. For example, Vitamin C’s main role is actually to recycle Vitamin E after it has interacted with a free radical. So, popping pills with 500 or 1000mg of a specific vitamin isn’t the best ideas unless you are specifically deficient in that molecule.
Likewise, multivitamins aren’t the best idea either. Our bodies have not yet evolved to digest pills—we take all the nutrients in the capsule/tablet into our blood very quickly to which the body responds to by saying “WOW we don’t need all that in here” and pee it all down the toilet within a few hours.
Consider real food. It’s full of fibre—especially vegetables like broccoli—so they may have fewer vitamins in them compared to a pill, but we break vegetables down over time and slowly release the nutrients into our bodies to give us wider protection.
There are lots of different vitamins and, like these two examples, work in different places in the body. So, in order to ensure we get a good balance of antioxidants we need to eat a wide range of fruit and vegetables. The colour is often a reflection of its content, for example, orange foods tend to be high in beta-carotene (Vitamin A) and green veggies like watercress, spinach, kale, etc. are good for Vitamin C and iron while nuts and grains will give you Vitamin E and other fat-based vitamins. I call it a rainbow diet—the more colour you can add the better.