PQQ in Food *
* In addition to the values taken from published papers, some of the values are from conference reports or abstracts presented at meetings. As noted in the main text, there is a lot of variability. Kamazama et al. in their 1995 Biochemistry Journal paper report ~0.06 micrograms as the PQQ concentration in dried skim milk per 100 grams of milk solids. However, later in an abstract of a paper presented at the Biochemical Society Transactions in 2000 in England, they report detection and quantization of IPQ in human breast milk at 0.14 to 5.5 microgram/100 mL of fresh milk or 1.4 to 55 micrograms per 100 grams of milk solids. Given the variability, this is inline with the data reported in Characterization of Pyrroloquinoline Quinone Amino Acid Derivatives by Electrospray Ionization Mass Spectrometry and Detection in Human Milk, i.e. ~140-180 micrograms (PQQ +IPQ) per 100 g of milk solids. Moreover, Fluckinger et al. reported that the PQQ concentration of milk is 15-150 micrograms/100 mL or 150 to 500 micrograms/100 grams of bovine milk solids. For the Fluckinger assays PQQ was separated and then measured using a 16-channel electrochemical detector, a highly precise and sensitive procedure. All other assay involved sophisticated separation and mass spectrometer for detection, also highly precise and sensitive.The information above is taken mostly from the work of Kumazawa et al. (Levels of pyrroloquinoline quinone in various foods). Some of the values are higher than corresponding values for foods analyzed by Noji et al. (Simple and Sensitive Method for Pyrroloquinoline Quinone (PQQ) Analysis in Various Foods Using Liquid Chromatography/Electrospray-Ionization Tandem Mass Spectrometry). Although the number of foods analyzed is small, an important finding is that PQQ has been observed in all tissues analyzed to date in both plants and animals. In the above table, Column A indicates some of the currently available sources for pyrroloquinoline quinone (for which compositional values have been obtained). Column B are amounts taken mostly from the Kumazawa et al. paper, but are expressed as micrograms of PQQ per 100 grams of food (~1/4 lb) and not as nanograms per grams of food (as they were originally reported). Next, in column C, the amounts in column B are multiplied by 5-10 to obtain an estimate of micrograms of PQQ per 100 grams of dried foods or so-called food solids (e.g., given that most of the food items mentioned contain at least 75% water or more). Column D requires making some guesses. As noted, some researchers have reported that IPQ is 5 to 8 times greater than the amount of PQQ in tissues. While others have reported a low ratio of 2 to 3 for IPQ to PQQ. Thus, the apparent IPQ + PQQ values given in Column D range from the lowest to highest amounts obtained by multiplying arbitrarily the values in Column C by 2 or 8. Column E is even trickier. It represents the estimated amounts consumed per day for an “ideal” person consuming a maintenance diet of 2000 calories per day. Regarding the diet consumed, the values for the major food categories are based on the estimated amounts consumed per day (on a dry weight basis) derived from values given in the USDA publication, Profiling Food Consumption in America. The question is whether a typical selection of foods can yield the minimum amount that corresponds to optimizing growth in animal models, i.e. about 100-200 microgram per day. If you’re curious about pyrroloquinoline quinone intake please visit PQQ Dosage, What size pyrroloquinoline quinone pills should I take?. Regarding various conclusions, the first is that much better data are needed. However, setting aside that concern and assuming the actual values for PQQ in foods may be at the median (middle) of the estimates provided, one can guess that a typical intake in humans is indeed about 0.3 mg or 300 micrograms of pyrroloquinoline quinone per day or more. That amount is very much is line with the amount of pyrroloquinoline quinone or PQQ + IPQ needed to stimulate growth in animals. It is also an amount that is found in human milk, which is always a good starting point in assessing a need related to growth or maintenance. So what can we conclude? In the paper by Kumazawa et al. Levels of pyrroloquinoline quinone in various foods it is stated that probably the PQQ in animal tissues are derived at least in part from the diet given and that the levels of pyrroloquinoline quinone in plant tissues are in the aggregate about 10 times those in animal tissues. In a review by Rucker et al. Potential physiological importance of pyrroloquinoline quinone, the same conclusion was reached, particularly given that stomach microflora does not make an abundance of PQQ . The data also beg the question do we need supplements and if so how much? Many of the PQQ products sold are in the 10-20 mg range. As indicated in the section — PQQ Dosage, What size pyrroloquinoline quinone pills should I take? — we discuss that the reasonable pyrroloquinoline quinone dosage, like many supplements, for an active adult is probably the result of an arbitrary decision, but the levels we’ve reported are safe and effective. From the inferences developed in this section, however, a 3-5 mg supplement per day may be sufficient and just as effective for an average health adult. Such dietary levels are more than sufficient to sustain optimal mitochondriogenesis in animal models. As a final point, unlike many dietary factors and biofactors, PQQ and its derivatives are sustained in tissues and seem to play a fundamental role related to energy metabolism. In this regard, the dosage might vary depending on your desired outcome.