The Impulsin story

The first studies on PEA (brandname Impulsin) have been focusing on respiratory tract infection. In a paper 2 double blind controlled trials were described with in total 1345 healthy subjects, from which 41 subjects failed to complete the trial.^[1]The goal of these trials was to evaluate the prophylacticefficacy of Impulsin in upper respiratorytract infections. The persons had to take 600 mg PEA 3 times a day or placebo during 12 days. In the first trial 468 employees of the Skoda car fabrik were randomised.

The employees had to register the following symptoms: temperature of 37.5 °C or higher, headache, sore throat, myalgia, nasalstuffiness or discharge, productive or dry cough,malaise and fatigue, the impression to feel sick or healthy. In the second trial 918 voluteers from 16 to 18 years old living in one army unit were included. In this trial medical personel was registering the complaints. In a period of 8 weeks, the complaints in both groups were evaluated. Another analysis was done in the period of 6 weeks in which the first week and the last week was omitted.

The results from the first trial showed that the group of PEA had less numbers of episodes of fever, headache and sore throat, compared with placebo (18 versus 33). PEA had much less effect on symptoms such as nasal stuffiness, discharge and cough. The episodes of fever and pain were significantly reduced by 45.5% in the PEA group compared with the placebo group (p<0.05).

The beneficial effect of PEA was apparent from the second week of the trial. The total number of days was significantly reduced in the PEA group measured in the 6 and 8 week period. Comparable results were obtained in the second trial. In total 901 soldiers completed the trial. The incidence of disease in the PEA group was 40% lower in the 6 week period and 32% lower in the 8 week period (p<0.0005). The incidence rate of influenza A 2 England was 15.4% in the PEA group and 44.9% in the placebo group (p< 0.0002)^[2].

Double blind study of palmitoylethanolamide in school children

Another placebo controlled study with PEA examining the incidence of acute respiratory tract infections was preformed in January 1976.^[3] In total 457 childern were divided into 2 groups: PEA 600 mg 2 times 2 tablets a day with an interval of 6 hours and placebo with the same regime. In the PEA 169 children and placebo 224 children were included. The included children had the age between 11 and 15 years. They received 10 days their tablets at school, so that means that in the weekend they didn't receive the study medication. Childern were excluded when they became ill in the first 5 days, or did not take their medication. In total 64 children were excluded. Blood samples were taken before the study and 8 weeks later in 65% of the children. Also bacteriological examination was preformed form the nose samples.

The results were that in the 8 weeks from the start of the study, the children from the PEA group had 15.7% less acute respiratory tract infections than the control group. Younger children (from 11 to 13 years) this difference was even more pronounced: 25.5%. Though these differences were not statistically significant. The reason could be the short duration of the intake and/or not preforming the study in the epidemic flue period  The duration of the illness was not influenced by PEA.

Even earlier, in 1960, Coburn and Rich conducted a small clinical study evaluating the ability of PEA to prevent rheumatic occurrences in children with rheumatic fever. The results were difficult to interpreted, due to the low incidence of rheumatic occurrences in all the children possibly as a result of a better general diet (not the due to consumption of eggs) during the test period.  (ref not in pubmed: Coburn, A.F., Rich, H. Arch. Interam. Rheumatol. 1960, 4, 498-515)

Working mechanism of palmitoylethanolamide according to old studies

It was not clear how PEA works. Therefore other studies evaluated the effect of PEA on several proteins and the phagocytic activitly of leucocytes, (white blood cells). A group of 50 children, 4 years old, received 30mg per kg PEA a day during 19 days.^[4] The following molecules were measured before and after PEA in the blood: albumin, orosomucoid, ceruloplasmin, transferin, C3 and C4 complements, and G, A, M and D immunoglobulins. Phagocytic activity was measured with the photometric tetrazolium test. Significance (p<0.05) was obtainted for the fall of C3 complement (80.9 ± 13.3 versus 76.4 ± 12.2) and an increase in IgG (75.1 ± 16.1 versus 79.0 ± 16.6)The "spontaeous" metabolic activity of unstimulated neutrophilic granulocytes showed a significant increase after PEA.

Another group of 18 children between 5 and 7 years old was given PEA 30mg/kg/day during 12 days.^[5] The T and B lymphocytes were counted in the blood before and after the treatment of PEA. PEA did not affect significantly the absolute numbers of the lymphocytes, but did change the percentual proportion of the lymphocytes. The percetual proportion of the T lymphocytes was significantly reduced (56.84 ± 6.12 versus 50.64 ± 9.24 p<0.05), while the proportion of the B lymphocytes was increased (3.73 ± 1.55 versus 4.62 ± 1.87 p<0.075).

Also animal studies on the effect of PEA have been done. For example the study of PEA in rats with leukemia next to chemotherapy.^[6] This animal study revealed that PEA reduced side effects of the chemotherapy which anabled to give higher dosages. PEA did not have direct effect on cancer.^[7]

Historical sources of PEA as medical active food:

Kuehl, F.A.; Jacob, T.A.; Ganley, O.H.; Ormond, R.E.; Meisinger, M.A.P. J.Am.Chem. Soc. 1957, 79, 5577-5578.  

Coburn, A.F., Graham, C.E., Haninger, J. J. Exp. Med. 1954, 100, 425-435.  

January 2011, Jan M. Keppel Hesselink MD, PhD and David J Kopsky, MD 

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