Children are not little adults

Starting Paediatrics today, its important to realize that the medical approach to children can be incredibly different than that to adults. Children differ from adults physiologically and in their exposure to the environment, here is a list of some important points to consider when dealing with a paediatric patient: 
(this post is based on the WHO document linked here, reference are included within that document)

• Minute ventilation per Kg bodyweight a day is higher in children. It is around 600l in <1year old  which is 3 times the value of an adult, 200l. Therefore environmental toxicants will be delivered to the airways of a child at a higher level than adults. for example: ozone, lead, particulates, nitrogen oxides, mercury, moulds, volatile organic compunds etc. 

• Calorie and water needs are higher in children. Cal/kg/day and ml/kg/day have higher values in younger children, its pretty obvious considering their anabolic state and growth demands. Therefore oral exposures are likely to be higher in children, think of pesticides or mycotoxins that are common in food. I could mention here that a vegan diet may be harmful to children since their calorie demand is so much higher (even though I'm an avid supporter of plant based diets). 

• Gastrointestinal absorption is higher in children and dynamic. For example a child may absorb 70% of ingested lead while an adult around 5-20%. There are microbiome changes throughout childhood, contributing to digestion and absorption. important considering pharmacokinetics, always prescribe drugs in mg/kg not by single doses. 

• Renal function: GFR (glomerular filtration rate) is low at birth (around 10-15ml/min/m2 for a normal full term newborn) and doubles in the first week of life (cirtical period). GFR reaches adult values by around 6-12 months, the general rule is 8 months. tubular function is impaired (secretion) at birth and is normal by 1 year of life. 

• Hepatic function: The activity of phase 1 enzymes are reduced and mature at different rates as child grows. in fact activity of these enzymes can then exceed adult rates between 6-12 years age. phase two enzymes are ready at birth for processes such as conjugation and acetylation. Therefore metabolites of xenobiotics may differ between adults and children, even if rates of metabolism are the same. 

• Transplacental exposures: Many chemicals and drugs cross the placenta, including mercury, lead, substances of abuse, alcohol etc. We all know the story of thalidomide. Also physical factors can affect the baby such as heat and ionizing radiation. important thing to point out here is that maternal exposures do matter!

• Breastfeeding: Breast milk is the safest and most complete nutrition for infants, so mothers should avoid toxic exposures. We use breast milk to spot environmental contaminants, its very likely that you reading this have DDT in your fat because your mother was exposed to it as a child. Lipophilic chemicals are especially good at transferring in breast milk, hence why we don't prescribe quinolones for breastfeeding mothers. 

• Size and surface area: The ratio between skin/surface area to body volume/mass is much higher in children, about 3x for a newborn compared to an adult and 2 times with an infant. therefore dermal exposures may be much higher in children, children also tend to have more skin abrasions/cuts and rashes which make it easier for germs/contaminants to cross the skin barrier. Very important to consider the surface area in children when dealing with burns.

• Organ and system development: the organs in a childs bodie grow and mature throughout childhood. Neuron growth and maturation (myelination and synpatogenesis) continues right the way through puberty, The respiratory system continues linear growth after birth so any exposures to toxic compunds (tobacco smoke! ozone etc.) can have very adverse consequences. The immune system is also actively maturing throughout childhood.

In summary, children have unique and differing-to-adults exposures and a highly dynamic developmental physiology. Combining this with a longer life expectancy and the insidious effects of environmental toxins, it is very important to consider the world/environment we leave behind for children to inherit. 
Children have a completely different pharmacokinetic profile and can be exposed in a variety of ways, so its also important for physicians to be vigiliant in paediatrics pharmo-prescribing. 


Bonus point: Introducing a food early to children does not increase their risk of allergies, NEJM editorial.

Why a super low calorie or crash diet isn't good for you

Many of the most popular diets at the moment make use of the process of 'Ketosis' or as it known in my textbooks 'beta oxidation'. You have probably heard of it, and lets not be mistaken ketosis will burn fat and you can potentially lose a lot of weight.

Beta oxidation is the process the body uses when its running out of sugar, a kind of rescue system for energy. The process converts your body's fat stores into 'ketones', a potent fuel source for the body and brain. These fat stores are incredibly precious to the body and the body would much rather lower your basal metabolic rate (BMR) and shut off 'non-essential' bodily functions before resorting to this ketosis phase. Your skin, hair, brain, hormones and energy levels are all effected, it can thwart your ability to heal wounds and even give you diarrhea.  

Restricting your calorie intake to lower than your BMR will leave you feeling tired, hungry and unable to concentrate. (Lets not get into the effects of lack of fibre these diets will entail either). 

don't do it. 

So what should you do?... well firstly keep your calorie intake above your BMR

See next nutrition post....

Nutrition 101: Dr Gregers annual nutrition summaries, How Not To Die

Dr Greger is an internationally recognized expert in the field of nutrition. He created the website and youtube channel Nutritionfacts.org and he wrote the New York Times bestseller 'How not to die'. Every year he gives a presentation summarizing the latest in nutrition research and current understanding of the effects of nutrition on medical diseases.
His talks are absolutely brilliant and eye-opening,  The common theme circles around the benefits of a plant-based diet and how it can reverse and be used in the prevention of many diseases. (heart disease and diabetes just to name a couple.)
I think physicians and future doctors everywhere should watch his videos.
Here are the videos for the annual talks below:

2012:

2013:

2014:

2015:

The perfect diet

"The perfect diet does not exist because you wont be happy on the perfect diet"

Said my flatmate this evening after a long discussion on diet.

I was trying to tell him about the benefits of a plant based diet, Having watched all Dr Gregers talks I posted previously. The problem is, having been a regular meat eater all my life and probably iced donuts number one fan in the world (so tasty), suddenly converting to near veganism is downright miserable. Nothing against my culinary skills, I'm becoming quite the stirfry and cauliflower rice expert actually. I just really miss bacon sandwiches and poached egg breakfasts. 

The benefits of a plant based diet are incredibly clear, almost to the point of a miracle cure. Reversing diabetes and reducing athersclerotic plaques to name a couple. Patients all over the western world would benefit hugely from this incredibly non-invasive and 'simple' change (its really not that simple though is it).

How can i expect my future patients to adopt the diet if i continue to munch on burgers and kebabs. Doctors are meant to role models, much like the smoking doctors of the 60's and 70's, how can you expect patients to stop smoking if you are puffing on one in front of them or posing for cigarette ads (see picture below). 

So anyway to the point, I'm all torn up about plant based diets and their medical applications. Huge numbers of patients could benefit, millions of pounds could be saved and the environment would benefit a huge amount as well. Shouldnt every patient have a plant based diet subscribed? 

Doctors own reluctance to try them themselves and lack of exposure to the evidence may be some of the reasons.