Category Archives: Life and Health

Free Radicals, Antioxidants, and Oxidative Stress – Good or Evil?

 

Let’s face it.  All this hype and attention on the secrets of aging, what exactly is it and how does it affect everyday people like us?

FreeRadicalSuperHero

Put it simply, free radicals are highly reactive molecules produced as part of a normally functioning human being.  We use energy every day to think, eat, work, sleep and do what we do, and while forming and burning that energy our body also makes waste, with free radicals being one of them.  Left alone, free radicals can destroy cells very quickly by reacting with nearby molecules, causing cells to lose their function and die.  Thankfully our body has clever mechanisms to destroy them before they do the same to us.  Antioxidants are one of those mechanisms.

When we produce more free radicals than we can destroy, scientists call that “oxidative stress”.  Exercise, for example, drives the body into oxidative stress, as well as being overworked, tired, or sick.  It is popular belief that taking antioxidants can help us reduce oxidative stress.  So the theory goes: Oxidative stress causes aging because free radicals kill nearby cells prematurely.  Wait, did I hear you question, does that mean exercise is bad for you?

cell-process

That’s exactly what the scientists thought.  They did some more experiments and found that, in fact, free radicals are good for you!  The worms in the labs are able to survive and reproduce with better conditions if they were exposed to artificial free radicals than if they didn’t (this particular type of worm does not produce its own free radicals).  So now the scientists say, let the free radicals reign!

Still there are others critical of this conclusion.  Maybe the better lives that these worms lived was not directly from the exposure to free radicals, but as a result of their system adapting to being more efficient at removing them.  Those supporting this view think that it is more important to improve the free-radical-destroying mechanisms than it is to be under oxidative stress.

What does all this mean for us?  To be honest, nothing really.  Just keep exercising like you should and relax when needed.  Let science do the work.  For now, keep calm and read our posts!

 

– Freak

 

Sources:

Yee, C., Yang, W., Hekimi, S. (2014). The intrinsic apoptosis pathway mediates the pro-longevity response to mitochondrial ROS in c. elegans. Cell, 157(4), 897-909. doi:10.1016/j.cell.2014.02.055

Hancock, J.T. (2010). Cell Signalling, 3rd Ed. NY: Oxford University Press.

Liochev, S.I. (2013). Reactive oxygen species and the free radical theory of aging. Free Radical Biology and Medicine, 60, 1-4.

Lobo, Patil, Phatak & Chandra (2010). Free radicals, antioxidants and functional foods: Impact on human health. Pharmacognition Review. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3249911/

Nutrition for special populations: Children and Adolescence

What you see on TV or on the internet talking about what we are supposed to eat, how much of each blablablablablabla, is not always right, as it is mostly directed towards your average bloke down the street (if you live in a regular street of course. If you live in a mansion or luxury villa without neighbors, feel free to switch spots with me). For example the nutrient needs of an adult average bloke is different than that of a child and teenager/adolescent that is still growing, which is the topic of this post.

Defining children and adolescent

It is safe to say that the little troublemakers (children aged 0-12ish ) do not usually know a lot about what  they consume, but are experts on whether they like it or not. This means that it is also safe to say that parental influence is probably the key factor of what a kid eats, for example packing them full of lollies to make them shut the **** up. This influence of course diminishes with age but remains a key factor, as it is the parent that can choose what to stock the fridge with, as well as most of the time choose what a meal will contain.

Once adolescence (13-18/20ish) is reached the  individual starts developing a closer relationship to the food consumed (food literacy), and the connection between diet, exercise and body image starts to form. Hormones fluctuate, stuff just gets crazy.

The importance of developing food literacy

During the growing years as biological maturity is pursued, there is a higher chance of suffering bone fractures. Growth spurts weaken the bones as the bone density will not often have time to catch up. Nutrition can play a key role preventing this. Imagine a newborn kid, the skeleton only holds about 30g of calcium, and by the age of 20, it will hold about 1500 grams. Peak bone mass and density is not achieved until the end of puberty, this is why calcium is extremely important, especially during puberty as calcium plays a superduper major role in bone growth.

Managing energy imbalance issues in young folks is complex. Constant negative energy balance can result in the following: short stature, puberty and menstrual irregularities, and poor bone health. Did you know that the mechanically inefficient movement of children causes them to expend more energy doing it? So yes kids spend a higher percentage of their energy just walking than adults do. This is one of the reasons negative energy imbalance in some children occurs – as some may logically think children will need less food as they are not fully grown yet, but that is of course not true, as ATP is also used in the growth process.

Nutrient Requirements

Now there is not a lot of evidence on the timing recommendations of the different nutrients for young folks so this post will be limited to the RDIs, and a short paragraph for young elite athletes will be included at the end.

Protein (first, cause you know, protein)
The grams per bodyweight (note bodyweight of the kid, not the parent) of protein required for a youngster is actually higher than the average bloke.  Now these requirements are usually reached by just eating healthy, but here is a table for you anyways with RDIs (athletes would of course have a higher need).

Age 1-3 4-8 9-13 14-18
All 1.08g/kg 0.91g/kg
Boys 0.94g/kg 0.99g/kg
Girls 0.87g/kg 0.77g/kg

Carbohydrates
Your average young folk (yes I said young folk mate) will not be competing in events that will deplete muscle glycogen, and this is little evidence that adolescent requirements should differ from adults. It is simply recommended to be adjusted to daily energy demands. Only things that are to worry about is pretty much dental caries, so stay away from the acidic candy kids!

Fats
One interesting thing about fats is that young athletes tend to utilize fats as the major fuel source during exercise, but there are still no RDIs about how much they should consume. However it is likely that that enough is consumed through a normal diet and typically it would not differ that of an adult.

Fluids

Did you know children and adolescence have less effective thermoregulation and lower exercise tolerance? This is because developed sweat glands are not instantly given to you at birth, but you might have noticed them when they started firing during puberty. Two other reasons are the increased energy expenditure from motor movements as previously mentioned, and because higher surface area-to-body mass ratio they will tend to get hotter faster on warm days and lose heat faster on cold ones. So yes water is extremely important, always have water present and keep sipping (not excessive amount of course) across the day. Recent studies have actually shown that given matched fitness levels and hydration status, the capacity to deal with thermal loads and exercise tolerance in the heat are similar in children and adults (Instead of sweating for cooling, peripheral blood redistribution are relied upon to maintain thermal equilibrium). And in the case of the athlete, it is common knowledge that just a slight decrease in hydration will cause significant performance drops.

The key is to drink water before, during and immediately after. The guidelines (assuming that the exercise lasts about 30-70minutes) are: 150-200ml for children, 300-400ml for adolescent 45minutes before exercise. 75-100ml for children and 150-200ml for adolescent during. A liberal good amount as soon as possible after exercise for both.

Vitamins and Minerals

Now this is the most important part of the diet of young folks. There are high requirements for a good amount of specifically calcium, iron and zinc in these individuals diets. Here is why: Calcium – bone growth. Iron – mostly a problem in females (menses, loss of iron in blood), but training may also increase the loss of the mineral. Zinc – a deficiency of zinc may lead to  a delay of sexual maturity and slower bone growth.

Ergogenic aids (for athletes)
The thing about the use of sports supplements in young athletes is that it is mostly not tested and therefore simply not recommended. The athlete however may be vulnerable to the use of supplements because of: Performance pressure, pursuit of physical ideals or body image and impulsive behaviors caused by commercials and the availability of it (caffeinated energy drinks is a big one)

In the case of young elite athletes

Elite performance during a young age will not always coexist with optimal health, something that is more normal in some sports than others, as the athlete sometimes would wish to achieve a low bodyweight and compliment that with lean body mass. The want to achieve this often comes along with inadequate energy intake and building poor eating practices and habits. This often causes a delay in the maturation process. A good example of this is gymnasts and sports requiring a high level muscular endurance, which may end up having growth spurts after they have finished their career (however it unsure if their “if-not” height is reached) . An opposite example might a basketball player, as explosive short bursts and the constant striving for height may in fact support bone growth, but of course it also sets them at a higher risk for bone fractures.

– Bear