Differences between Japan and Taiwan in the treatment of pregnant women with depressive symptoms by omega-3 fatty acids: An open-label pilot study.

OBJECTIVES: Although safe approaches for improving depression in pregnancy are required and the efficacy of omega-3 polyunsaturated fatty acids (PUFAs) has been suggested, the amount of supplemental omega-3 PUFAs has varied among previous studies and adequate amount might be different among countries. The aim of this pilot study is to explore the feasibility of using 1800 mg of omega-3 PUFAs supplementation for our future double-blind, placebo-control trial, and to clarify the clinical difference and the similarity between two sites of Japan and Taiwan. METHODS: Pregnant women between 12 and 24 weeks' gestation with depressive symptoms were recruited. Participants were supplemented daily with omega-3 PUFAs capsules containing 1206 mg eicosapentaenoic acid and 609 mg docosahexaenoic acid for 12 weeks. The primary outcome was change in total score on the 17-item Hamilton Rating Scale for Depression (HAMD) at 12 weeks after supplementation. RESULTS: Eight pregnant women in Japan and five in Taiwan participated in the study. A substantial proportion of pregnant women reported high consumption of omega-3 supplements and dietary fish were excluded in Taiwan rather than in Japan sites. The decrease in HAMD score from baseline to 12 weeks after the start of the intervention was significantly larger in Japanese participants than in Taiwanese participants (Wilcoxon rank sum test; P = 0.045). DISCUSSION: The improvement of depressive symptoms was smaller at the Taiwan site than at the Japan site. Differences in psychopathology of recruited participants identified by self-rating scales might affect the degree of population heterogeneity and the treatment efficacy. A randomized-controlled trial is needed to confirm these findings. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01948596.

A Critical Review of the Consensus Statement from the European Atherosclerosis Society Consensus Panel 2017.

BACKGROUND: The Consensus Statement from the European Atherosclerosis Society (EAS) Consensus Panel 2017 concludes on the basis of 3 different types of clinical studies that low-density lipoprotein (LDL) causes atherosclerotic cardiovascular disease (ASCVD). In Mendelian randomization studies, rare genetic mutations affecting LDL receptor function were found to cause higher or lower LDL-C levels, which are associated with correspondingly altered ASCVD risk. In prospective cohort studies and randomized controlled trials (RCTs) of statins, a remarkably consistent log-linear association was demonstrated between the absolute magnitude of LDL-C exposure and ASCVD risk. The EAS Statement proposes that any mechanism of lowering plasma LDL concentration should reduce the risk of ASCVD events proportional to the absolute reduction in LDL-C and the cumulative duration of exposure to lower LDL-C. However, as we explain, we do not find this conclusion acceptable. SUMMARY: Our review points out that different interpretations are possible for the results of Mendelian randomization studies. As for prospective cohort studies, many inconsistent reports on the association of LDL-C and ASCVD were disregarded when drafting the Statement, reports with and without genetic factors related to LDL receptor function should be analyzed separately, and the term ASCVD in the Statement is used inappropriately because myocardial infarction and cerebral infarction differ in their association with LDL-C. As for RCTs, clinical reports on statins published before and after the implementation of new regulations affecting clinical trials (2004/2005) should not both be included in meta-analyses because the evaluated efficacy of statins changed markedly, and the irreversible adverse effects of statins need to be evaluated more rigorously now that their mechanisms have been elucidated. Key Messages: Apart from the EAS hypothesis that LDL causes ASCVD, recent pharmacological/biochemical studies, as summarized in this review and elsewhere, have revealed that atherosclerosis is caused by statins taken to lower LDL-C, as well as by warfarin and some types of vegetable fats and oils, in the absence of significantly elevated LDL-C levels. Thus, the promotion of statin treatment by the Statement is rather risky and we do not feel that the conclusions are justified for the prevention of ASCVD.

The synchronized trial on expectant mothers with depressive symptoms by omega-3 PUFAs (SYNCHRO): Study protocol for a randomized controlled trial.

BACKGROUND: Maternal depression can be harmful to both mothers and their children. Omega-3 polyunsaturated fatty acid (PUFA) supplementation has been investigated as an alternative intervention for pregnant women with depressive symptoms because of the supporting evidence from clinical trials in major depression, the safety advantage, and its anti-inflammatory and neuroplasticity effects. This study examines the efficacy of omega-3 PUFA supplementation for pregnant women with depressive symptoms in Taiwan and Japan, to provide evidence available for Asia. The rationale and protocol of this trial are reported here. METHODS: The Synchronized Trial on Expectant Mothers with Depressive Symptoms by Omega-3 PUFAs (SYNCHRO) is a multicenter, double-blind, parallel group, randomized controlled trial. Participants will be randomized to either the omega-3 PUFAs arm (1,200 mg eicosapentaenoic acid and 600 mg docosahexaenoic acid daily) or placebo arm. Primary outcome is total score on the Hamilton Rating Scale for Depression (HAMD) at 12 weeks after the start of the intervention. We will randomize 56 participants to have 90 % power to detect a 4.7-point difference in mean HAMD scores with omega-3 PUFAs compared with placebo. Because seafood consumption varies across countries and this may have a major effect on the efficacy of omega-3 PUFA supplementation, 56 participants will be recruited at each site in Taiwan and Japan, for a total number of 112 participants. Secondary outcomes include depressive symptoms at 1 month after childbirth, diagnosis of major depressive disorder, changes in omega-3 PUFAs concentrations and levels of biomarkers at baseline and at 12 weeks' follow-up, and standard obstetric outcomes. Data analyses will be by intention to treat. The trial was started in June 2014 and is scheduled to end in February 2018. DISCUSSION: The trial is expected to provide evidence that can contribute to promoting mental health among mothers and children in Asian populations. TRIAL REGISTRATION: Clinicaltrials.gov: NCT02166424 . Registered 15 June 2014; University Hospital Medical Information Network (UMIN) Center: UMIN000017979. Registered 20 May 2015.

Medicines and Vegetable Oils as Hidden Causes of Cardiovascular Disease and Diabetes.

BACKGROUND: Positive associations have been observed between cardiovascular disease (CVD) and type 2 diabetes mellitus (DM), but their causal relationship has not been clarified. Nevertheless, guidelines from relevant medical societies recommend using cholesterol lowering medication (statin) for both types of patients. Medicines with several different action mechanisms have been developed, and the effectiveness of different lifestyle modifications has been studied extensively for the prevention of DM, which was successful in improving clinical marker status in relatively short-term treatments, but none have been shown to be effective in improving long-term outcomes (mortality from CVD and all causes). SUMMARY: Statin-induced suppression of prenyl intermediates in the cholesterol biosynthetic pathway has been linked to stimulated atherosclerosis and heart failure. On the other hand, certain types of vegetable oil and hydrogenated oil shortened the survival of stroke-prone spontaneously hypertensive rats by decreasing platelet number, increasing hemorrhagic tendency and damaging kidney functions, which could not be accounted for by their fatty acid and phytosterol compositions. These vegetable oils and medicines such as statin and warfarin share, in part, a common mechanism to inhibit vitamin K2-dependent processes, which was interpreted to lead to increased onset of CVD, DM, chronic kidney disease, bone fracture and even mental disorder. Impaired vitamin K2-dependent processes by some types of vegetable oils and medicines, but not plasma high low density lipoprotein cholesterol, were proposed as the cause of CVD, DM and other lifestyle-related diseases. High n-6/n-3 fatty acid ratio of ingested foods, but not animal fats, was emphasized to be another risk factor for many of the diseases described above. KEY MESSAGES: To date, no randomized controlled trials (RCTs) have been performed to prove the above interpretation. However, the opposite types of RCT trials have been performed by increasing the intake of high-linoleic vegetable oils and reducing that of animal fats, which resulted in increased CVD and all-cause mortality. The amounts of these vegetable oils to exhibit adverse effects in animal studies are not huge (<6 energy %), which should not be overlooked nor disregarded.

Tachikawa project for prevention of posttraumatic stress disorder with polyunsaturated fatty acid (TPOP): study protocol for a randomized controlled trial.

BACKGROUND: Preclinical and clinical studies suggest that supplementation with omega-3 fatty acids after trauma might reduce subsequent posttraumatic stress disorder (PTSD). To date, we have shown in an open trial that PTSD symptoms in critically injured patients can be reduced by taking omega-3 fatty acids, hypothesized to stimulate hippocampal neurogenesis. The primary aim of the present randomized controlled trial is to examine the efficacy of omega-3 fatty acid supplementation in the secondary prevention of PTSD following accidental injury, as compared with placebo. This paper describes the rationale and protocol of this trial. METHODS/DESIGN: The Tachikawa Project for Prevention of Posttraumatic Stress Disorder with Polyunsaturated Fatty Acid (TPOP) is a double-blinded, parallel group, randomized controlled trial to assess whether omega-3 fatty acid supplementation can prevent PTSD symptoms among accident-injured patients consecutively admitted to an intensive care unit. We plan to recruit accident-injured patients and follow them prospectively for 12 weeks. Enrolled patients will be randomized to either the omega-3 fatty acid supplement group (1,470 mg docosahexaenoic acid and 147 mg eicosapentaenoic acid daily) or placebo group. Primary outcome is score on the Clinician-Administered PTSD Scale (CAPS). We will need to randomize 140 injured patients to have 90% power to detect a 10-point difference in mean CAPS scores with omega-3 fatty acid supplementation compared with placebo. Secondary measures are diagnosis of PTSD and major depressive disorder, depressive symptoms, physiologic response in the experiment using script-driven imagery and acoustic stimulation, serum brain-derived neurotrophic factor, health-related quality of life, resilience, and aggression. Analyses will be by intent to treat. The trial was initiated on December 13 2008, with 104 subjects randomized by November 30 2012. DISCUSSION: This study promises to be the first trial to provide a novel prevention strategy for PTSD among traumatized people. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00671099.

Concern over radiation exposure and psychological distress among rescue workers following the Great East Japan Earthquake.

BACKGROUND: On March 11, 2011, the Great East Japan Earthquake and tsunami that followed caused severe damage along Japans northeastern coastline and to the Fukushima Daiichi nuclear power plant. To date, there are few reports specifically examining psychological distress in rescue workers in Japan. Moreover, it is unclear to what extent concern over radiation exposure has caused psychological distress to such workers deployed in the disaster area. METHODS: One month after the disaster, 424 of 1816 (24%) disaster medical assistance team workers deployed to the disaster area were assessed. Concern over radiation exposure was evaluated by a single self-reported question. General psychological distress was assessed with the Kessler 6 scale (K6), depressive symptoms with the Center for Epidemiologic Studies Depression Scale (CES-D), fear and sense of helplessness with the Peritraumatic Distress Inventory (PDI), and posttraumatic stress symptoms with the Impact of Event Scale-Revised (IES-R). RESULTS: Radiation exposure was a concern for 39 (9.2%) respondents. Concern over radiation exposure was significantly associated with higher scores on the K6, CES-D, PDI, and IES-R. After controlling for age, occupation, disaster operation experience, duration of time spent watching earthquake news, and past history of psychiatric illness, these associations remained significant in men, but did not remain significant in women for the CES-D and PDI scores. CONCLUSION: The findings suggest that concern over radiation exposure was strongly associated with psychological distress. Reliable, accurate information on radiation exposure might reduce deployment-related distress in disaster rescue workers.

Relationships among skin conditions, mood, and polyunsaturated fatty acids of RBCs in healthy women.

Little is known about nonpathological facial skin problems at present. The aim of the present study was to investigate the relationships among facial skin conditions, mood, and the fatty acid composition of red blood cells (RBCs) in women. One hundred and thirty-two apparently healthy Japanese women aged between 20 and 60 years were recruited. Facial skin conditions were analyzed using a Robo Skin Analyzer, and the RBC fatty acid composition was also determined. Questionnaires concerning mood were administered. Forehead pigmentation was more mood-dependent (in 20s group) and less arachidonic acid (AA)-dependent (in all participants) than that in other areas of the face. Actually there was no correlation in pigmentation between the forehead and other areas of the face when adjusted for age, smoking, and drinking. Skin conditions were adversely correlated with a negative mood. α-Linolenic acid concentrations were negatively correlated with negative mood scores. Pigmentation characteristics in the forehead were independent from other areas of the face. Negative mood and AA were adversely correlated with skin conditions.

Docosahexaenoic acid is an independent predictor of all-cause mortality in hemodialysis patients.

BACKGROUND: Dietary n-3 polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid have been shown to reduce cardiovascular mortality. Patients on hemodialysis (HD) have a very high mortality from cardiovascular disease. Fish consumption reduces all-cause mortality in patients on HD. Moreover, n-3 PUFAs, especially DHA levels in red blood cells (RBCs), are associated with arteriosclerosis in patients on HD. The aim of this study was to determine whether DHA levels in RBCs predict the mortality of patients on HD in a prospective cohort study. METHODS: A cohort of 176 patients (64.1 ± 12.0 (mean ± SD) years of age, 96 men and 80 women) under HD treatment was studied. The fatty acid composition of their RBCs was analyzed by gas chromatography. RESULTS: During the study period of 5 years, 54 deaths occurred. After adjustment for 10 confounding factors, the Cox hazard ratio of all-cause mortality of the patients on HD in the highest DHA tertile (>8.1%, 15 deaths) was 0.43 (95% CI 0.21-0.88) compared with those patients in the lowest DHA tertile (<7.2%, 21 deaths). CONCLUSION: The findings suggest that the level of DHA in RBCs could be an independent predictor of all-cause mortality in patients on HD.

Serum brain-derived neurotrophic factor and antidepressant-naive major depression after lung cancer diagnosis.

Previous studies have reported the existence of an association between brain-derived neurotrophic factor and major depression. However, the possible role of brain-derived neurotrophic factor in the pathophysiology of major depression after cancer diagnosis has not yet been investigated. Subjects were collected using the Lung Cancer Database project. Using the cut-off scores on the depression subscale of the Hospital Anxiety and Depression Scale (HADS-D), 81 subjects with depression (HADS-D > 10) and 81 subjects without depression (HADS-D < 5) were selected. The two groups were matched for age, sex, clinical stage and performance status. The serum brain-derived neurotrophic factor levels were measured using an enzyme-linked immunosorbent assay method. The serum brain-derived neurotrophic factor levels were not statistically different between the subjects in the depression group [29.1 (13.6) ng/ml; mean (SD)] and the non-depression group [31.4 (10.6) ng/ml] (P = 0.22). In a stratified analysis by gender, however, the mean serum brain-derived neurotrophic factor level in the depression group tended to be lower than that in the non-depression group among women (n = 24 pairs, P = 0.06). Major depression after cancer diagnosis is not associated with serum brain-derived neurotrophic factor levels.

Attenuating posttraumatic distress with omega-3 polyunsaturated fatty acids among disaster medical assistance team members after the Great East Japan Earthquake: the APOP randomized controlled trial.

BACKGROUND: On March 11, 2011, a magnitude 9.0 earthquake, the most powerful ever recorded in Japan, and a massive tsunami struck off the coast of the Sanriku region. A Disaster Medical Assistance Team, a mobile medical team with specialized training that is deployed during the acute phase of a disaster, was dispatched to areas with large-scale destruction and multiple injured and sick casualties. Previous studies have reported critical incident stress (i.e. posttraumatic stress disorder symptoms and depressive symptoms) among rescue workers as well as the need for screening and prevention for posttraumatic stress disorder. So far we have shown in an open trial that posttraumatic stress disorder symptoms in critically injured patients can be reduced by taking omega-3 fatty acids intended to stimulate hippocampal neurogenesis. METHOD/DESIGN: This study is designed to determine the effectiveness of attenuating posttraumatic distress with omega-3 polyunsaturated fatty acids among Disaster Medical Assistance Team members after the Great East Japan Earthquake, and is named the APOP randomized controlled trial which is currently ongoing. First, we will provide psycho-education on posttraumatic distress, which is common in responders to the Disaster Medical Assistance Team members deployed to the disaster area. Second, observational research will be conducted to evaluate critical incident stress following the completion of medical activities. Third, team members who provide consent to participate in the intervention research will be randomly divided into a group given an omega-3 fatty acid supplement and a group not given the supplements. Outcome will be evaluated at 12 weeks after the supplements are shipped to the team members. DISCUSSION: Measures that address critical incident stress in disaster responders are important, but there is no substantial evidence that links such measures with prevention of posttraumatic stress disorder. Thus, any confirmation through this study that the intake of omega-3 fatty acid supplements serves as a simple preventative measure for critical incident stress will be of great significance. TRIAL REGISTRATION: UMIN Clinical Trials Registry, UMIN000005367.

Hostility of drug-free patients with schizophrenia and n-3 polyunsaturated fatty acid levels in red blood cells.

Many reports suggest that n-3 polyunsaturated fatty acids (PUFAs) influence the symptoms of psychiatric disorders. Moreover, it has also been reported that n-3 PUFAs control aggression and hostility. Acute symptoms of schizophrenia such as aggression can be a formidable clinical problem resulting in hospitalization. However, few investigations have determined the relationships between acute symptoms of drug-free schizophrenia and n-3 PUFAs. We recruited 75 inpatients with acute drug-free schizophrenia admitted to Chiba Psychiatric Medical Center, an emergency psychiatric hospital. Blood was sampled immediately after admission. The red blood cell (RBC) fatty acid composition and hostility score of Positive and Negative Syndrome Scale (PANSS) scores were measured. Multiple regression analysis showed that the concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the ratio of EPA/arachidonic acid (AA) in RBC showed significant negative correlations with the hostility score of PANSS scores after adjustment for age and sex. AA, on the other hand, showed significant positive correlations. The tissue n-3 PUFA and n-6 PUFA levels were negatively and positively associated with the hostility score of PANSS scores, respectively, suggesting possible effects of PUFA levels on hostile behavior in patients with schizophrenia.

Fish oils and aggression or hostility.

Fish oils have long been known to protect the heart from ischemic heart disease and fatal arrhythmia. Recently they have also been suggested to protect the heart in a literal sense! Although not all reports on fish oils and psychiatric disorder support the latter notion, many of them claim that fish oils were effective. The point is that, different from currently prescribed psychiatric medicines, fish oils do not do harm to any part of the body. We have been working on the effects of fish oils on aggressive behavior and hostility. Unfortunately this area of research is not mature yet. The number of related papers is rather limited, so we will take aggression and/or hostility in a broader sense including oppositional behavior, violence etc. in this review. We found fourteen intervention studies checking the effects of fish oils on aggressive behavior. Eleven of them showed the aggression/hostility-controlling effects of fish oils one way or another. We did not try to summarize those effects by meta-analysis, because we thought that the methods of research were too heterogeneous. The mechanisms as to how fish oils affect aggression/hostility is not clear yet, but several possible mechanisms have been postulated. Among them, activation of the serotonergic neuron system is the most promising. The research area of fish oils and aggression/hostility is clearly important from the medical and social points of view.

Short-term pregnancy hormone treatment of N-methyl-N-nitrosourea-induced mammary carcinogenesis in relation to fatty acid composition of serum phospholipids in female Lewis rats.

AIM: Short-term oestrogen and progesterone treatment (STEPT) mimics the pregnancy hormone milieu. This study compared the development of N-methyl-N-nitrosourea (MNU)-induced mammary cancer in female Lewis rats that received STEPT in early or later life. MATERIALS AND METHODS: Rats in Groups 1 and 2 received a single intraperitoneal injection of 50 mg/kg MNU at 4 weeks old. Pellets containing 0.5 mg 17beta-estradiol and 32.5 mg progesterone (EP) were subcutaneously implanted in rats in Group 1 during 6-9 weeks old. Rats in Groups 3 and 4 received 50 mg/kg MNU at 22 weeks old and again at 23 weeks old. EP pellets were implanted in rats in Group 3 during 24-27 weeks old. At the time of EP removal and 8 weeks afterward, 4 randomly selected rats in each group were sacrificed for blood sampling. The fatty acid composition of serum phospholipids was measured by capillary gas chromatography. The remaining rats were sacrificed when they developed mammary tumours >or=1 cm in diameter or at the termination of the experiment, which was at 18 weeks old for Groups 1 and 2 and at 64 weeks old for Groups 3 and 4. Mammary cancer was histologically confirmed. RESULTS: Group 1 had a significantly suppressed incidence of mammary cancer compared to Group 2 (7% vs. 90%), whereas the cancer incidence in Group 3 was similar to that of Group 4 (50% vs. 56%). Rats in Group 1 had significantly smaller n-6/n-3 polyunsaturated fatty acid (PUFA) ratios and higher levels of docosahexaenoic acid (DHA) than those in Group 2 at the time of EP removal but not 8 weeks after EP removal. Neither the PUFA ratios nor the DHA levels differed between Groups 3 and 4 at any time. These data suggest that the age at which STEPT is administered is important, since its mammary cancer-suppressing potential was lost in aged animals. CONCLUSION: DHA and the n-6/n-3 PUFA ratio may play a crucial role in mammary cancer suppression by STEPT.

Effects of eicosapentaenoic acid on biochemical failure after radical prostatectomy for prostate cancer.

AIM: To study the effects of eicosapentaenoic acid (EPA) on prostate-specific antigen (PSA) failure in prostate cancer patients who underwent prostatectomy. PATIENTS AND METHODS: Sixty-two prostate cancer patients whose PSA levels were less than 0.2 ng/ml 3 months after surgery were randomized to either an EPA group (n=32) or a control group (n=30). EPA (2.4 g/day) was administered in the EPA group for 2 years. PSA was measured every two months. RESULTS: The EPA concentration increased but the docosahexaenoic acid concentration decreased significantly (P<0.001) in erythrocytes. The PSA recurrence rates during a mean follow-up of 53.8 months were not different between the two groups (p=0.16). CONCLUSION: A longer and/or larger intervention or docosahexaenoic acid supplementation might be necessary to identify significant preventive effects of mega-3 polyunsaturated fatty acids on PSA recurrence.

[Cholesterol controversy: cutoff point of low-density lipoprotein cholesterol level in Guidelines by Japan Atherosclerosis Society].

In 2007, the Japan Atherosclerosis Society published the Guidelines for prevention of atherosclerotic cardiovascular diseases. However, the guidelines have several flaws with regard to the cutoff level of serum low-density lipoprotein cholesterol (LDL-C). First, LDL-C level is used instead of serum total cholesterol (TC) level in the guidelines. In this case, they must show at least some basic data on the relationship between LDL-C level and mortality or morbidity from coronary heart disease (CHD). Second, it was recommended that the LDL-C level be below 140 mg/dL or 3.6 mmol/L (corresponding to a TC level of 220 mg/dL or 5.7 mmol/L, respectively). These levels are unreasonable considering that the TC levels of 240-260 mg/dL are optimal in terms of all-cause mortality for the Japanese population. Third, although there are big differences in mortality and morbidity from CHD between sexes, they discussed the matter without considering these differences. Last but not least, the conflict of interest of the editors of the guidelines has never been disclosed. The Japanese population has a lower CHD mortality and incidence than populations from other industrialized countries despite an increase in serum TC level in the former. In populations with a markedly lower coronary mortality or morbidity such as the Japanese population, it is still important to determine the optimal cutoff level of LDL-C to prevent the development of CHD and other atherosclerotic diseases.

The new European guidelines for prevention of cardiovascular disease are misleading.

Introduction: The European Society of Cardiology and European Atherosclerosis Society (ESC/EAS) have recently published three major revisions of their guidelines for the management of chronic heart disease, blood lipids, and diabetes. Areas covered: We have scrutinized these guidelines in detail and found that the authors have ignored many studies that are in conflict with their conclusions and recommendations. Expert commentary: The authors of the guidelines have ignored that LDL-cholesterol (LDL-C) of patients with acute myocardial infarction is lower than normal; that high cholesterol is not a risk factor for diabetics; that the degree of coronary artery calcification is not associated with LDL-C; and that 27 follow-up studies have shown that people with high total cholesterol or LDL-C live just as long or longer than people with low cholesterol. They have also ignored the lack of exposure-response in the statin trials; that several of these trials have been unable to lower CVD or total mortality; that no statin trial has succeeded with lowering mortality in women, elderly people, or diabetics; and that cholesterol-lowering with statins has been associated with many serious side effects.

The depressive effects of 5,8,11-eicosatrienoic Acid (20:3n-9) on osteoblasts.

In cases of essential fatty acid deficiency, 5,8,11-eicosatrienoic acid (Mead acid, 20:3n-9) is synthesized from oleic acid as a 20-carbon analog of arachidonic acid. It was reported that 20:3n-9 levels were markedly higher in human fetal cartilage than in the muscle, liver and spleen. We, therefore, hypothesized that 20:3n-9 decreased osteoblastic activity. Goldfish scales were incubated either with 20:3n-9 or with oleic acid at 15 degrees C for 6 and 18 h. Both osteoblastic and osteoclastic activities in the scale were assessed by measuring alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase, respectively. MC3T3-E1 cells (an osteoblast cell line derived from the mouse) were incubated with 20:3n-9 or oleic acid at 37 degrees C for 6 and 18 h. ALP activity in cell lysate was measured. In the case of experiments with scales, 20:3n-9 (1-100 muM) significantly suppressed osteoblastic activity after 6 and 18 h of incubation, whereas oleic acid did not change this activity. Osteoclastic activity was not affected either by 20:3n-9 or by oleic acid. In the case with the cell line, osteoblastic activity was again significantly decreased with 20:3n-9 (10-30 muM) after 6-h incubation but not after 18 h incubation. The presence of 20:3n-9 in fetal cartilage may be important for the prevention of calcification in the cartilage. 20:3n-9 could be applied to some clinical situations where bone formation should be inhibited.