Primer on Protein
Protein is the Answer
Protein Makes a Comeback
Protein Comes First
Athletes and Elderly May be Protein Deficient
High Protein Diets Applauded
High Protein Diets Criticized
High Protein Diets Dangerous
-- and the list goes on.
These are actual recent headlines in the popular press. Even the talk show hosts are on the band wagon with interviews about the pros and cons over more protein or less protein in the diet.
I thought it appropriate to offer a primer on protein to help the consumer sort out fact from fiction or science from innuendo.
The word Protein comes from the Greek word Protos or Proteose depending on who you read and it means "to come first". It has been recognized from early times to be absolutely essential for life.
Protein (made from combinations of 22 known amino acids) makes up our DNA, hormones, enzymes, muscles - including skeletal, heart, smooth muscle which surrounds our arteries, immune cells, liver, kidneys, glands etc. etc. etc. Some of the amino acids 8 or 9 (depending on who you read again) are considered essential which means we must consume them so we can make the other 13 or 14 amino acids and thus create proteins.
Even primitive man understood the importance of protein foods by following their protein sources. When the fish, fowl or animals became scarce, they moved on.
We plan our meals around the protein dish (pasta may be an exception but that doesn't make it right). Restaurant menus are categorized according to protein source and protein usually commands a significant portion of the grocery budget.
The primacy of protein persists. It is preferred because most protein rich foods are tasty, satisfy hunger and are rich in other nutrients.
Protein critics have often stated that North Americans eat too much protein. That protein will contribute to osteoporosis by leaching calcium from the bones.
They also refer to potential kidney damage and the dangers of Ketosis which refers to incompletely metabolized fats which occur in some high protein - low carbohydrate diets. Like the Atkins Diet, The Protein Power Diet and The Type II Diabetes Diet.
Here are some things you need to know
According to a symposium published in the Journal of Nutrition in December of 1998, there is no evidence of an increase in calcium excretion when one "self selects" a high protein diet from high protein foods. "This is likely due to the high calcium content of such foods".
On the other hand there is evidence that low protein intakes are associated with negative calcium balance and likely reductions in bone density. Studies which have reported higher calcium excretion during high protein consumption have assumed bone loss but not measured it.
In fact it may simply be a case of less calcium absorption of the calcium present in the high protein food. Adequate protein is necessary for optimum bone health.
The only studies which have demonstrated kidney problems with high protein diets have used extremely high protein intakes. Levels like 600 grams per day which represents 2400 Calories or 85% of the diet.
Nobody would naturally eat this kind of diet because protein controls appetite and it would be very distasteful.
When it come to Ketosis, Dr. Calvin Ezerin, author of the Type II Diabetes Diet and a professor of endocrinology at UCLA, has stated that there is no danger to "dietary induced ketosis". Of course, there may a downside and that is bad breath and body odor from the ketones but they are not dangerous.
There are, on the other hand, reports of low protein diets that weaken the immune system, increase the chances of yeast infection, and slow the ability to recover from injury.
Dr. William Evans of Penn State University has written that any person who eats only the minimum protein, could find themselves protein deficient after a bout of moderate exercise or during a physically demanding job.
Dr. Vernon Young of MIT University has published research that supports the position that we should be eating two to three times more protein than current recommendations.
The American Journal of Clinical Nutrition recently reported that women who ate 24% or more of their calories from protein experienced significantly fewer heart and cardiovascular problems.
In another report from the journal Cancer, it was shown that women on high protein diets experienced better breast cancer survival rates. In the same study, contrary to many previous reports, fat intake (including saturated fat) had no bearing on the results.
According to Dr. Boyd Eaton, a specialist in Paleolithic diets, 30% of the primitive diet was protein. This level would be consistent with the recommendations of MIT professor Young - mentioned above.
My take on this is as follows:
- because protein comes first, we need between 0.75 gm and 1.0 gm per pound of desirable weight.
- eat protein in every meal and every snack and make it 30% of your calories.
- never eat more than 35 grams of protein in a single sitting, that's all you can absorb.
- as physical activity or stress increase our protein requirements increase.
- remember that protein controls appetite and
- eat some of your protein selection first in every case to control the rate of rise in blood sugar. This will avoid hypo-glycemic reactions and spikes of insulin production.
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