All about fruitarianism with a long-term fruitarian, Lena

In India, most people adhere to a vegetarian diet, which may lead to cobalamin deficiency. About 75% of the subjects had metabolic signs of cobalamin deficiency, which was only partly explained by the vegetarian diet.

The study population included 204 men and women aged 27–55 y from Pune, Maharashtra, India, categorized into 4 groups:

  • patients with cardiovascular disease (CVD) and diabetes,
  • patients with CVD but no diabetes,
  • patients with diabetes but no CVD,
  • healthy subjects.

Data on medical history, lifestyle, and diet were obtained by interviews and questionnaires. Blood samples were collected for measurement of serum or plasma total cobalamin, holotranscobalamin (holoTC), methylmalonic acid (MMA), and total homocysteine (tHcy) and hemetologic indexes.

  1. Methylmalonic acid, total homocysteine, total cobalamin, and holotranscobalamin did not differ significantly among the 4 groups.
  2. Total cobalamin showed a strong inverse correlation with total homocysteine (r = −0.59) and methylmalonic acid (r = −0.54). 
  3. 47% of the subjects had cobalamin deficiency (total cobalamin <150 pmol/L),
  4. 73% had low holotranscobalamin (<35 pmol/L),
  5. 77% had hyperhomocysteinemia (total homocysteine >15 μmol/L),
  6. 73% had elevated serum methylmalonic acid (>0.26 μmol/L).

These indicators of impaired cobalamin status were observed in both vegetarians and nonvegetarians.

Folate deficiency was rare and only 2.5% of the subjects were homozygous for the MTHFR 677C→T polymorphism. 

Marked ethnic differences in cobalamin metabolism have been reported (40); therefore, the possibility that Indians have adapted to a chronic low cobalamin concentrations through genetic mechanisms should be considered.

This finding agrees with our observation that even subjects with relatively high cobalamin concentrations can have high tHcy and MMA concentrations. Notably, in the study by Lindenbaum et al, the high MMA concentration was related to anaerobic gut flora and the high tHcy concentration was explained by a low cobalamin concentration. Some studies suggest that overgrowth of intestinal bacteria may lead to formation and absorption of inactive cobalamin analogues.

George Bernard Shaw

The thought of two thousand people crunching celery at the same time horrified me.

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