Autoimmune Disease

Molecular Mimicry and the Bystander Effect 

Infections are strongly associated with autoimmune disease and seem to initiate them either by the process of molecular mimicry or the bystander effect [1]. 

Molecular mimicry is where the immune system develops antibodies to a particular amino acid sequence expressed by a pathogen, which happens to be structurally similar enough for the antibodies to cross react with self-antigens, our own tissues. 

The bystander effect is where an infection leads to inflammation and tissue damage.  Then this infected and damaged tissue is considered foreign by the immune system, antibodies are made against it, but these antibodies are cross-reactive with nearby undamaged tissue. 

Molecular mimicry and the bystander effect are observed in animal models of autoimmune disease [1].  But these mechanisms are incomplete for two reasons. 

1.      Why does the immune system continue to attack the body after the pathogen has been destroyed? 

2.      Why has the incidence of autoimmune disease increased while infectious disease has decreased? 

Osteoporosis

Bone mineral density is used to diagnose osteoporosis.  Normal bone mineral density is considered less than or equal to 1 standard deviation below the mean bone mineral density of 30 year old men and women.  Osteopenia is diagnosed when between 1 to 2.5 standard deviations below the mean and osteoporosis is diagnosed when greater than or equal to 2.5 standard deviations below the mean.

Discussions about osteoporosis are largely concerned with bone mineral density, but the actual end point we want to avoid are fractures.  Sometimes bone mineral density is unrelated to fractures.  For example, osteopetrosis is a rare inherited disorder and an uncommon side effect of bisphosphonates (a class of drugs used to treat osteoporosis), which leads to extremely dense bones and ironically, increased fracture rates.

Welcome Living La Vida Low Carb Readers

Welcome Living La Vida Low Carb readers.

I recently did a submission to the Dietary Guidelines for all Australians.  You can download the 51 page PDF (with roughly 150 scientific references).  Other things in my blog include:

The posts that make up the submission, which can be found here.  Probably the one of most interest to you is Low Fat or Low Carb

A look into the causes of obesity, which generally supports a low carb, Paleo diet

Research into the role of mitochondrial dysfunction in disease, which again supports a low carb, Paleo diet

A downloadable excel spreadsheet, compiled with data from the USDA nutrient database, which can help you find what nutrients are in what foods/food groups and you can easily input what you eat to see how you’re tracking nutrient wise

A troubleshooting guide for high cholesterol and for weight loss on Paleo and low carb diets

Troubleshooting Weight Loss on Low Carb Diets

Carbohydrate restricted diets work well for weight loss.  Most people are able to achieve their target weight with a carb restricted diet, but some plateau and in some cases even gain weight on carb restricted diet.

I’m of the opinion that the human body isn’t broken by default and almost everyone can attain a healthy body fat percentage.  Once chronic carb restriction stops working, more of the same won’t do any more.  By this point you have netted all the benefits carb restriction can offer and you now need to try something different.  Usually there is an answer to these problems and it’s simply that the overweight/obese person hasn’t found it yet.

I’m going to suggest some potential causes of plateauing on very carbohydrate restricted diets.

Low Carb vs Carb Restriction

Low carb and Paleo are still on the same team.  Where the two communities differ is in how far under the recommended 300 grams of carbs we should go and what is meant by low carb.

Defining ‘Low Carb’

There are so many ways to define low carb.  Jimmy Moore defines it has less than 40g of carbs per day [1], the American Diabetes Association and low carb researchers define it as less than 130g or 26% of total calories [2] and some people simply define it as less than 300g (SAD).

Definitions are often based in grams per day which is irrelevant when you consider people eat varying amounts of calories.  A small 90 year old woman might eat 125g of carbs, but that could represent half the calories she eats.  A highly athletic young man could eat 300g, but that might be a quarter of the calories he eats.  People also confuse that ‘low’ is absolute and lower’ is relative.  So we want definitions in % of total calories, in absolute terms and fair.  I’m going to suggest 20% protein, 40% fat and 40% carb to be moderate.  This is to ensure carbs and fat are equal and because we eat less protein.

	Protein %TC	Fat %TC	Carbohydrate %TC
Very Low	0	0	0
Low	10	20	20
Moderate	20	40	40
High	30	60	60
Very High	40	80	80