Last week we discussed wheat history and started scrutinising some nonsensical and scientifically baseless assertions about wheat. This week in part II we'll discuss some more unsubstantiated claims made in the book 'Wheat Belly'. We'll also (briefly) put the Paleo diet through its paces.
3) “The starch in wheat is different from that found in other carbohydrate-rich foods such as bananas, potatoes and vegetables. The amylopectin structure allows it to be very efficiently converted to raise blood sugar” (undesirably).
- There are two kinds of starch polymers found in plant tissues (including grains, some vegetables and fruit): Amylose and amylopectin (Fig 1)
- With few exception, the ratio of these polymers varies little: 20-25% amylose to 70-75% amylopectin
- Factors that effect blood sugar include: Prior meals eaten, fat/protein content of a meal, and food matrix (eg: untoasted vs toasted bread). The ratio of polymers isn't the decisive factor
- Research shows the blood glucose response after eating bread was actually lower compared to eating the same amount of white rice or potato... Gotta love science
|Fig 1: Amylopectin (left) is branched and thus digested more rapidly. Amylose (right) is linear and digested slower relative to amylopectin|
4) “Wheat opioids are so addictive that they cause people to be unable to control their eating, and removal of wheat from the diet causes withdrawal”.
- First off: This is a terribly worded (and wordy) statement
- Secondly: There is no data to support this suggestion
- Here's a little more detail: Gluten (the storage protein in wheat) is divided into two fractions, gliadins (monomers) and glutenins (polymers)
- It gets kinda complex, but I'll do my best to keep it short and simple: Incomplete digestion of gliadin (called gliadorphin) had opiate-like effects in rats who were infused with gliadorphin (note infused: Gliadorphin was injected directly into the blood, this is quite different to eating and digesting because...)
- Gliadorphin cannot be absorbed by the human intestine, meaning it cannot get into the circulatory system to have any neural effect. So, unless you're a politician and your brain is in your colon... Don't sweat it
- Summation: There's no evidence that gliadin stimulates appetite or induces addiction-like withdrawals
Before we wrap it up (in a tasty, glutinous flour tortilla), let's talk a little about grains and Paleo. But let me preface this segment with a few disclaimers:
- People have begged me to write about Paleo since I started Pie Hole... Congratulations, you win
- I really don't dig writing about specific fad diets like Paleo
- See point 2
Paleo says 'no' to:
- Cereal grains
- Refined sugar
- Processed foods
- Certain oils
- Legumes (including peanuts... but other nuts and seeds are ok... am I the only one having a wtf moment?)
- Potatoes (which are vegetables... another wtf moment brought to you by the 'experts' at ThePaleoDiet.com)
Rather than speculate too closely about how unsustainable (and quite frankly silly) this is, let's look at some facts:
- There is a large collection of evidence showing whole grain consumption is associated with lower BMI, lower body weight and lower risk of developing various fabulous first world conditions like heart disease, type 2 diabetes and cancer (1, 2, 3)
- Legumes have many beneficial health effects including the ability to prevent and manage obesity and obesity-related diseases like heart disease and diabetes (shocker)
- Whole grains and legumes are a great source of fiber
- And what is something Americans (and a large number of people worldwide) don't eat enough of? You guessed it: Fiber, the stuff that helps you Fast Track Your Faeces
- It's really (like, I mean really) difficult to get enough fiber when you cut out legumes and whole grains
- We're talking ~1.1kg (2.4lbs) of fruit and vegetables per day to get 25g of fiber (the lower end of what's recommended)
|But I'm pretty sure your average caveman didn't spend 6 hours a day 'lifting'|
This is by no means a comprehensive review of the Paleo diet (because... See above point 2). We haven't even mentioned the unhealthy notion of cutting out another whole food group (dairy) in addition to the grains group. But see the links below for some additional reading.
Take home points and tips:
- Think critically people!
- Where are you getting your advice?
- What qualifications back up their expertise?
- What peer reviewed studies support their recommendations?
- Cavemen didn't live in houses with air conditioning/heating, they didn't brush their teeth, go to the doctor, lift at the gym for 6 hours a day, drive cars, use condoms, wax their chests, take multivitamins or shop at supermarkets. They also died (toothless) at age 40. Does it still 'just make sense'?
I'd like to dedicate the Quit Your Wheat Belly Aching series to some friends who've been pestering, I mean encouraging me to write about this topic for quite a while (cough: Mark, Allannah and co).