All about fruitarianism with a long-term fruitarian, Lena

With the exception of calcium deficiency rickets in Nigeria, no satisfactory explanation has been found for the apparently low prevalence of osteoporosis in countries on low calcium intakes. On international comparisons on a larger scale, it is very difficult to separate genetic from environmental factors. Osteoporosis was largely a disease of affluent industrialized cultures. Hip fracture prevalence (and by implication osteoporosis) is consequently related to animal protein intake, but also, paradoxically, to calcium intake because of the strong correlation between calcium and protein intakes within and between societies. This could be explained if protein actually increased calcium requirement. 

Fracture risk has recently been shown to be a function of protein intake in North American women. There is also suggestive evidence that hip fracture rates depend on protein intake, national income, and latitude. Vitamin D deficiency in hip fracture patients in the developed world was established. Such fractures can be successfully prevented with small doses of vitamin D and calcium. It is therefore possible that hip fracture rates may be related to protein intake, vitamin D status, or both.

Mahatma Gandhi

The greatness of a nation and its moral progress can be judged by the way its animals are treated.

Protein Digestibility-Corrected Amino Acid Score

The protein digestibility-corrected amino acid score (PDCAAS) has been adopted by FAO/WHO as the preferred method for the measurement of the protein value in human nutrition. 

PDCAAS = Amino Acid Score x Digestibility

The method is based on comparison of the concentration of the first limiting essential amino acid in the test protein with the concentration of that amino acid in a reference (scoring) pattern. This scoring pattern is derived from the essential amino acid requirements of the preschool-age child.

Although the principle of the PDCAAS method has been widely accepted, critical questions have been raised in the scientific community:

  1. the validity of the preschool-age child amino acid requirement values (more than 4 times greater than the EAA requirement for an adult),
  2. the validity of correction for fecal instead of ileal digestibility,
  3. the truncation of PDCAAS values to 100%.

The reference scoring pattern was based on studies performed more than 25 years ago on a limited number of 2-year-old children recovering from malnutrition.

According to the current official recommendations, a 2-year old child needs ~ 3x higher essential-to-non-essential amino acid ratio, and needs essential amino acids in different proportions than adult. Methionine/cysteine is the limiting essential amino acids for adults, and for children it is lysine or tryptophan.

The use of fecal digestibility overestimates the nutritional value of a protein because amino acid nitrogen entering the colon is lost for protein synthesis in the body and is, at least in part, excreted in urine as ammonia. Apple