Monday, April 12, 2010

Paleo Diet Special Report: Chia Seeds

Dear Readers,

The following is an excerpt from a special report authored by Dr. Cordain on Chia seeds. The full report is available in our newsletter, The Paleo Diet Update, Volume 6 Issue 7.

Q: Are there any negative effects associated with chia seeds which would make them inappropriate in The Paleo Diet?

Thank you.

A: Good question. I would imagine that many of our readers have never even heard of chia seeds much less eaten them. Chia seeds (Salvia hispanica L.) are a member of the Labiatae plant family and are native to southern Mexico and northern Guatemala. The seeds are small, oval shaped; either black or white colored and resemble sesame seeds. These seeds were cultivated as a food crop for thousands of years in this region by the Aztecs and other native cultures. Chia seeds can be consumed in a variety of ways including roasting and grinding the seeds into a flour known as Chianpinolli which can then become incorporated into tortillas, tamales, and various beverages. The roasted ground seeds were traditionally consumed as a semi-fluid mucilaginous gruel (Pinole) when water is added to the flour. In post-Columbian times the most popular use of chia flour was to make a refreshing beverage in which the ratio of seeds to water is decreased, thereby resulting in a less gelatinous consistency to which lemon, sugar or fruit juice are added. The sticky consistency of chia seed Pinole or chia beverages comes from a clear mucilaginous, polysaccharide gel that remains tightly bound to the seeds. This sticky gel forms a physical barrier which may impair digestion and absorption of fat from the seed4 while also causing a low protein digestibility.

In the past 20 years a revival of interest in chia seeds has occurred primarily because of their high fat content of about 25-39% by weight, of which 50-57% is the therapeutic omega 3 fatty acid and alpha linolenic acid (ALA). In the past 10 years chia seeds have been used as a foodstuff for animals to enrich their eggs and meat with omega 3 fatty acids. So I wholeheartedly approve of feeding chia seeds to animals and then eating the omega 3 fatty acid enriched meat or eggs of these animals.

How about feeding chia seeds to humans – should we consume chia seeds because of their high omega 3 fatty acid (ALA) content? The Table below shows the entire nutrient profile of chia seeds. At least on paper, it would appear that chia seeds are a nutritious food that is not only high in ALA, but also is a good source of protein, fiber, certain B vitamins, calcium, iron and manganese.

Unfortunately, the devil is always in the details...