Antinutrients
Lectins
Some harmful lectins in our food need to be properly prepared
Some harmful lectins in our food need to be properly prepared
What are lectins?
All seeds contain lectins in their seed coats and cotlyledons (part that becomes the first leaves in some plants).
Highest concentrations
are found in grains
and legumes
Which foods have the highest
concentrations of harmful lectins?
Lectins are carbohydrate-binding proteins
that attach to cell membranes. E.g.
Glycoproteins (protein + sugar molecules) are found on the outside of the cell membrane,
with the sugar (oligosaccharides - the strings of blue circles in the diagram) facing
out, making it accessible for lectins to latch onto.
Oligosaccharide side chains attached
to membrane glycolipids and glycoproteins
Lectins have essential functions in all life forms
- In our bodies.
Lectins allow cell-to-cell adherence, inflammation
control and programmed cell death; many types of cell receptors are lectins;
- Part of plants' natural
defense mechanisms. Important
for seed survival, lectins discourage pests from eating them e.g. insects,
bacteria, fungi, man??? :) Their intent is generally to repel (not kill) predators
by stimulating a negative reaction, although
some lectins have proven fatal to various microorganisms.
Only the prolamin and agglutinin lectins
in improperly prepared foods are antinutrients
Prolamins and agglutinins
are currently the only two classes of lectins widely recognized as
antinutrients
in food.
However, it is important to note that the presence of these harmful lectins can
be significantly reduced with appropriate food preparation . Lectins have
the ability to bind to virtually all cell types, but
when they bind to glycoproteins on the epithelial surface
of the small intestine, they can elicit both local and/or systemic reactions involving:
• Damage /inflammation
• Breach of the gut lining
• Immune system modulation
• Dysbiosis (an imbalance in gut flora)
• Nutrient malabsorption;
Prolamins and agglutinins
can cause some serious health problems in those genetically
susceptible to their effects. E.g.
WHOLE wheat contains the prolamin gliadin and several
agglutinins, including wheat germ agglutinin (WGA) (0.5g / kg). Gliadin is
one of the more infamous lectins - being the digestive-troubling half of the gluten
molecule that affects those with gluten-sensitivity. WGA and other food agglutinins,
affect us all to some degree, but in those more prone to its effects, it can wreak
havoc in their gut and body tissues, leaving a wake of inflammatory devastation
that results in any of a long list of common health problems, including rheumatoid
arthritis, chronic candida, allergies, diabetes . . . and many others.
Health Effects of Lectins (Being Updated)
We are eating far more whole grains
than we used to eat. Before the agricultural revolution with
the introduction of big-farming methods, grains were a small part of our diet, now
they are readily available to us in quantity with a quick trip to the grocery store
--- think bread, crackers, pasta, rice and cereals.
Yes of course, whole grains are certainly more nutritious than refined grains, but
eating too many whole grains also introduces an abundance of harmful antinutrients,
such as lectins and phytic acid.
Traditional food preparation methods can remove some
lectins. To wit: soaking, sprouting, fermenting and cooking.
However, agglutinins tend to resist degradation.
How to reduce harmful
dietary lectins
