Alkylresorcinols are phenolic lipids present in high amounts in the bran layer (e.g. pericarp, testa and aleurone layers) of wheat and rye (0.1-0.3 % of dry weight). They are not present in the endosperm (the part of cereal grain that is used to make white flour), which means that alkylresorcinols can be used as 'biomarkers' for people who eat foods containing wholegrain wheat and rye, rather than cereal products based on white flour.
Alkylresorcinols were thought to have anti-nutrative properties (e.g. decreasing growth of pigs and chickens fed rye), but this theory has been discredited, and a number of animal studies have demonstrated that they have no obvious negative effect on animals and humans. In vitro (cell culture) studies have shown that alkylresorcinols may prevent cells turning cancerous, but that they do not have any effect on cells that are already cancerous. Alkylresorcinols also increase gamma-tocopherol levels in rats when fed in high amounts (0.2 % of total diet and above).
Current evidence would suggest that alkylresorcinols in the human diet are benign, but they are currently of interest as biomarkers of wholegrain wheat and rye intake. This may help to gain further knowledge about the links between a diet rich in wholegrains and health benefits.
The average intake of alkylresorcinols in the UK is around 11 mg/person/day, and in Sweden is around 20 mg/person/day. This varies widely depending on whether people normally consume wholegrain/wholemeal/brown bread (high in alkylresorcinols), or white wheat bread (no alkylresorcinols).
Alkylresorcinols are phenolic lipids present at levels of up to 0.15% of whole grain wheat and rye, but little is known about their presence in food, absorption in animals and humans, and their in vivo biological effects.
The absorption of alkylresorcinols in rats, pigs and humans was determined, with values for absorption ranging from 34–79%, depending on the model and the amount of alkylresorcinols consumed.
Alkylresorcinols in the plasma of pigs fed a single meal of rye, peaked at 3-4 hours, and remained elevated compared to the baseline levels after 16 hours.