Nonhuman Molecules Lining Our Arteries

I did a little “non-scholarly” reading– general Wikipedia and Google searches, but not Google scholar– on this Neu5Gc molecule; here’s a very brief summary of what i found: We very likely had this molecule long ago, as other primates still make it. Neu5Gc is an integral part of the outer cell membrane (lipid layer) of red cells, and is a member of a broad class of similar-functioning molecules called “sialic acids” or “sialoglycoproteins.” (We still produce Neu5Ac, which is very similar to Neu5Gc, differing by an oxygen atom). We probably lost the ability to produce Neu5Gc because of some kind of parasitic epidemic– probably some kind of malaria variant, which was using the Neu5Ac molecule to recognize & enter human red cells. Some scientists believe this to be the case, because the modern malarial variant, Plasmodium falciprum, uses Neu5Ac to bind with red blood cells. Although malaria infection is still an epidemic today, the loss of Neu5Ac probably helped us evade a parasite that was decimating our (at that time) small populations of humans and putting selective pressure on humans to remove Neu5Gc from our red cells. It didn’t stop parasitic/malarial infection of our red cells, as we still get malaria infection– the malaria parasite has evolved with us, however it may have helped us evade a major parasite way back in the early mists of time.

Seems that our cells don’t recognize Neu5Gc as being foreign, and happily use and incorporate it into our different tissues. The problem is that our immune systems still view it as being foreign and that’s where inflammation enters the story.

We are indeed omnivores based on our ability to digest and use meat but this doesn’t necessarily make meat healthy for us. Here is the Okinawan diet, the population with the most centenarians per capita.

Caloric Restriction, the Traditional
Okinawan Diet, and Healthy Aging

The Diet of the World’s Longest-Lived People and Its Potential Impact on Morbidity and Life Span
Ann. N.Y. Acad. Sci. 1114: 434–455 (2007).

TABLE 1. Traditional dietary intake of Okinawans and other Japanese circa 1950

Total calories 1785
Total weight (grams) 1262
Caloric density (calories/gram) 1.4
Total protein in grams (% total calories) 39 (9)
Total carbohydrate in grams (% total calories) 382 (85)
Total fat in grams (% total calories) 12 (6)
Saturated fatty acid 3.7
Monounsaturated fatty acid 3.6
Polyunsaturated fatty acid 4.8
Total fiber (grams) 23

Food group Weight in grams (% total calories)

Grains

Rice 154 (12)
Wheat, barley, and other grains 38 (7)
Nuts, seeds Less than 1 (less than 1)
Sugars 3 (less than 11)
Oils 3 (2)
Legumes (e.g., soy and other beans) 71 (6)

Fish 15 (1)
Meat (including poultry) 3 (less than 1)
Eggs 1 (less than 1)
Dairy less than 1 (less than 1)

Vegetables

Sweet potatoes 849 (69)
Other potatoes 2 (less than1)
Other vegetables 114 (3)
Fruit less than 1 (less than 1)
Seaweed 1 (less than 1)
Pickled vegetables 0 (0)
Foods: flavors & alcohol 7 (less than 1)

Data derived from analysis of U.S. National Archives, archived food records, 1949 and based on survey of 2279 persons.

Some points

Their diet was 85% carb, and 6% fat. Sweet potatoes (a Japanese sweet potato) made up almost 70% of their calories. Nuts were less than 1% of calories (the equivalent of 1/10 of an ounce a day) Oil was less than 2% of calories (which is about 1 tsp a day) and sugars were less than 1% of calories (less than a tsp a day)

The total animal products including fish was less than 4% of calories which is less then 70 calories a day. That is the equivalent of around 2 oz of animal products or less a day