The inclusion of nuts in the diet is associated with a decreased risk of coronary artery disease, hypertension, gallstones, diabetes, cancer, metabolic syndrome, and visceral obesity.
Frequent consumption of berries seems to be associated with improved cardiovascular and cancer outcomes, improved immune function, and decreased recurrence of urinary tract infections.
The consumption of nuts and berries is associated with reduction in oxidative damage, inflammation, vascular reactivity, and platelet aggregation, and improvement in immune functions. However, only recently have the effects of nut and berry consumption on the brain, different neural systems, and cognition been studied. There is growing evidence that the synergy and interaction of all of the nutrients and other bioactive components in nuts and berries can have a beneficial effect on the brain and cognition. Regular nut consumption, berry consumption, or both could possibly be used as an adjunctive therapeutic strategy in the treatment and prevention of several neurodegenerative diseases and age-related brain dysfunction.
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:
- the validity of the preschool-age child amino acid requirement values (more than 4 times greater than the EAA requirement for an adult),
- the validity of correction for fecal instead of ileal digestibility,
- 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.