Methylmalonic acid, vitamin B12, renal function, and risk of all-cause mortality in the general population: results from the prospective Lifelines-MINUTHE study.

BACKGROUND: Methylmalonic acid (MMA) is best known for its use as a functional marker of vitamin B12 deficiency. However, MMA concentrations not only depend on adequate vitamin B12 status, but also relate to renal function and endogenous production of propionic acid. Hence, we aimed to investigate to what extent variation in MMA levels is explained by vitamin B12 and eGFR and whether MMA levels are associated with mortality if vitamin B12 and eGFR are taken into account. METHODS: A total of 1533 individuals (aged 60-75 years, 50% male) were included from the Lifelines Cohort and Biobank Study. Individuals were included between 2006 and 2013, and the total follow-up time was 8.5 years. RESULTS: Median [IQR] age of the study population was 65 [62-69] years, 50% was male. At baseline, median MMA concentration was 170 [138-216] nmol/L, vitamin B12 290 [224-362] pmol/L, and eGFR 84 [74-91] mL/min/1.73 m2. Log2 vitamin B12, log2 eGFR, age, and sex were significantly associated with log2 MMA in multivariable linear regression analyses (model R2 = 0.22). After a total follow-up time of 8.5 years, 72 individuals had died. Log2 MMA levels were significantly associated with mortality (hazard ratio [HR] 1.67 [95% CI 1.25-2.22], P < 0.001). Moreover, we found a significant interaction between MMA and eGFR with respect to mortality (Pinteraction < 0.001). CONCLUSIONS: Only 22% of variation in MMA levels was explained by vitamin B12, eGFR, age, and sex, indicating that a large part of variation in MMA levels is attributable to other factors (e.g., catabolism, dietary components, or gut microbial production). Higher MMA levels are associated with an increased risk for mortality, independent of vitamin B12, eGFR, and sex. This association was more pronounced in individuals with impaired renal function.

C-reactive protein in traditional melanesians on Kitava.

BACKGROUND: Population-based levels of the chronic low-grade systemic inflammation biomarker, C-reactive protein (CRP), vary widely among traditional populations, despite their apparent absence of chronic conditions associated with chronic low-grade systemic inflammation, such as type 2 diabetes, metabolic syndrome and cardiovascular disease. We have previously reported an apparent absence of aforementioned conditions amongst the traditional Melanesian horticulturalists of Kitava, Trobriand Islands, Papua New Guinea. Our objective in this study was to clarify associations between chronic low-grade systemic inflammation and chronic cardiometabolic conditions by measuring CRP in a Kitava population sample. For comparison purposes, CRP was also measured in Swedish controls matched for age and gender. METHODS: Fasting levels of serum CRP were measured cross-sectionally in ≥ 40-year-old Kitavans (N = 79) and Swedish controls (N = 83). RESULTS: CRP was lower for Kitavans compared to Swedish controls (Mdn 0.5 mg/L range 0.1-48 mg/L and Mdn 1.1 mg/L range 0.1-33 mg/L, respectively, r = .18 p = .02). Among Kitavans, there were small negative associations between lnCRP for CRP values < 10 and total, low-density lipoprotein (LDL) and non-high-density lipoprotein (non-HDL) cholesterol. Among Swedish controls, associations of lnCRP for CRP values < 10 were medium positive with weight, body mass index, waist circumference, hip circumference and waist-hip ratio and low positive with triglyceride, total cholesterol-HDL cholesterol ratio, triglyceride-HDL cholesterol ratio and serum insulin. CONCLUSIONS: Chronic low-grade systemic inflammation, measured as CRP, was lower among Kitavans compared to Swedish controls, indicating a lower and average cardiovascular risk, respectively, for these populations.

Circulating fatty acids as biomarkers of dairy fat intake: data from the lifelines biobank and cohort study.

Background: C14:0, C15:0, C17:0 and trans-C16:1(n-7) are often used as biomarkers for dairy fat intake. Trans-C18:1(n-7) and CLA, two fatty acids which are also present in dairy, have hardly been explored. We investigated whether trans-C18:1(n-7) and CLA can enrich the existing biomarker portfolio. Methods: Data were obtained from Lifelines (n = 769). Dairy fat intake was determined by FFQ. Fatty acids were measured in fasting plasma triglycerides (TG), phospholipids (PL) and cholesterol esters (CE). Results: Median (25th-75th percentile) intakes of dairy and dairy fat were 322(209-447) and 12.3(8.4-17.4) g/d respectively. A pilot study showed that trans-C18:1(n-7) and CLA were only detectable in TG and PL. Of the established markers, TG C15:0 was most strongly associated with dairy fat intake (standardized ß (std.ß) = 0.286, R2 = 0.111). Of the less established markers, TG trans-C18:1(n-7) was most strongly associated with dairy fat intake (Std.ß = 0.292, R2 = 0.115), followed by PL CLA (Std.ß = 0.272, R2 = 0.103) and PL trans-C18:1(n-7) (Std.ß = 0.269, R2 = 0.099). In TG, a combination of C15:0 and trans-C18:1(n-7) performed best (R2 = 0.128). In PL, a combination of C14:0, C15:0, trans-C18:1(n-7) and CLA performed best (R2 = 0.143). Conclusion: Trans-C18:1(n-7) and CLA can be used as biomarkers of dairy fat intake. Additionally, combining established with less established markers allowed even stronger predictions for dairy fat intake.

Influence of daily 10-85 µg vitamin D supplements during pregnancy and lactation on maternal vitamin D status and mature milk antirachitic activity.

Pregnant and lactating women and breastfed infants are at risk of vitamin D deficiency. The supplemental vitamin D dose that optimises maternal vitamin D status and breast milk antirachitic activity (ARA) is unclear. Healthy pregnant women were randomised to 10 (n 10), 35 (n 11), 60 (n 11) and 85 (n 11) µg vitamin D3/d from 20 gestational weeks (GW) to 4 weeks postpartum (PP). The participants also received increasing dosages of fish oil supplements and a multivitamin. Treatment allocation was not blinded. Parent vitamin D and 25-hydroxyvitamin D (25(OH)D) were measured in maternal plasma at 20 GW, 36 GW and 4 weeks PP, and in milk at 4 weeks PP. Median 25(OH)D and parent vitamin D at 20 GW were 85 (range 25-131) nmol/l and 'not detectable (nd)' (range nd-40) nmol/l. Both increased, seemingly dose dependent, from 20 to 36 GW and decreased from 36 GW to 4 weeks PP. In all, 35 µg vitamin D/d was needed to increase 25(OH)D to adequacy (80-249 nmol/l) in >97·5 % of participants at 36 GW, while >85 µg/d was needed to reach this criterion at 4 weeks PP. The 25(OH)D increments from 20 to 36 GW and from 20 GW to 4 weeks PP diminished with supplemental dose and related inversely to 25(OH)D at 20 GW. Milk ARA related to vitamin D3 dose, but the infant adequate intake of 513 IU/l was not reached. Vitamin D3 dosages of 35 and >85 µg/d were needed to reach adequate maternal vitamin D status at 36 GW and 4 weeks PP, respectively.

Milk vitamin D in relation to the 'adequate intake' for 0-6-month-old infants: a study in lactating women with different cultural backgrounds, living at different latitudes.

Breast-fed infants are susceptible to vitamin D deficiency rickets. The current vitamin D 'adequate intake' (AI) for 0-6-month-old infants is 10 µg/d, corresponding with a human milk antirachitic activity (ARA) of 513 IU/l. We were particularly interested to see whether milk ARA of mothers with lifetime abundant sunlight exposure reaches the AI. We measured milk ARA of lactating mothers with different cultural backgrounds, living at different latitudes. Mature milk was derived from 181 lactating women in the Netherlands, Curaçao, Vietnam, Malaysia and Tanzania. Milk ARA and plasma 25-hydroxyvitamin D (25(OH)D) were analysed by liquid-chromatography-MS/MS; milk fatty acids were analysed by GC-flame ionisation detector (FID). None of the mothers reached the milk vitamin D AI. Milk ARA (n; median; range) were as follows: Netherlands (n 9; 46 IU/l; 3-51), Curaçao (n 10; 31 IU/l; 5-113), Vietnam: Halong Bay (n 20; 58 IU/l; 23-110), Phu Tho (n 22; 28 IU/l; 1-62), Tien Giang (n 20; 63 IU/l; 26-247), Ho-Chi-Minh-City (n 18; 49 IU/l; 24-116), Hanoi (n 21; 37 IU/l; 11-118), Malaysia-Kuala Lumpur (n 20; 14 IU/l; 1-46) and Tanzania-Ukerewe (n 21; 77 IU/l; 12-232) and Maasai (n 20; 88 IU/l; 43-189). We collected blood samples of these lactating women in Curaçao, Vietnam and from Tanzania-Ukerewe, and found that 33·3 % had plasma 25(OH)D levels between 80 and 249·9 nmol/l, 47·3 % between 50 and 79·9 nmol/l and 19·4 % between 25 and 49·9 nmol/l. Milk ARA correlated positively with maternal plasma 25(OH)D (range 27-132 nmol/l, r 0·40) and milk EPA+DHA (0·1-3·1 g%, r 0·20), and negatively with latitude (2°S-53°N, r -0·21). Milk ARA of mothers with lifetime abundant sunlight exposure is not even close to the vitamin D AI for 0-6-month-old infants. Our data may point at the importance of adequate fetal vitamin D stores.

Intake of n-3 fatty acids and long-term outcome in renal transplant recipients: a post hoc analysis of a prospective cohort study.

Supplementation with n-3 fatty acids may improve long-term outcomes of renal transplant recipients (RTR). Recent evidence suggests that EPA and DHA have different outcomes compared with α-linolenic acid (ALA). We examined the prospective associations of EPA-DHA and ALA intakes with graft failure and all-cause mortality in 637 RTR. During 3·1 years (interquartile range 2·7, 3·8) of follow-up, forty-one developed graft failure and sixty-seven died. In age- and sex-adjusted analyses, EPA-DHA and ALA intakes were not associated with graft failure. EPA-DHA intake was not significantly associated with mortality (hazard ratio (HR) 0·79; 95% CI 0·54, 1·15 per 0·1 energy% difference). ALA intake was significantly associated with mortality (HR 1·17; 95% CI 1·04, 1·31 per 0·1 energy% difference). This association remained following adjustments for BMI, proteinuria and intakes of fat, carbohydrate and protein. RTR in the highest tertile of ALA intake exhibited about 2-fold higher mortality risk (HR 2·21; 95% CI 1·23, 3·97) compared with the lowest tertile. In conclusion, ALA intake may be associated with increased mortality in RTR. Future RCT are needed to confirm these results.

Measurement of plasma vitamin K1 (phylloquinone) and K2 (menaquinones-4 and -7) using HPLC-tandem mass spectrometry.

BACKGROUND: Given the growing interest in the health benefits of vitamin K, there is great need for development of new high-throughput methods for quantitative determination of vitamin K in plasma. We describe a simple and rapid method for measurement of plasma vitamin K1 (phylloquinone [PK]) and K2 (menaquinones [MK]-4 and -7). Furthermore, we investigated the association of fasting plasma vitamin K with functional vitamin K insufficiency in renal transplant recipients (RTR). METHODS: We used HPLC-tandem mass spectrometry with atmospheric pressure chemical ionization for measurement of plasma PK, MK-4, and MK-7. Solid-phase extraction was used for sample clean-up. Mass spectrometric detection was performed in multiple reaction monitoring mode. Functional vitamin K insufficiency was defined as plasma desphospho-uncarboxylated matrix Gla protein (dp-ucMGP) >500 pmol/L. RESULTS: Lower limits of quantitation were 0.14 nmol/L for PK and MK-4 and 4.40 nmol/L for MK-7. Linearity up to 15 nmol/L was excellent. Mean recoveries were >92%. Fasting plasma PK concentration was associated with recent PK intake (ρ=0.41, p=0.002) and with plasma MK-4 (ρ=0.49, p<0.001). Plasma PK (ρ=0.38, p=0.003) and MK-4 (ρ=0.46, p<0.001) were strongly correlated with plasma triglyceride concentrations. Furthermore, we found that MK-4-triglyceride ratio, but not PK-triglyceride ratio, was significantly associated with functional vitamin K insufficiency (OR 0.22 [0.07-0.70], p=0.01) in RTR. CONCLUSIONS: The developed rapid and easy-to-use LC-MS/MS method for quantitative determination of PK, MK-4, and MK-7 in human plasma may be a good alternative for the labor-intensive and time-consuming LC-MS/MS methods and enables a higher sample throughput.

A fish is not a fish: patterns in fatty acid composition of aquatic food may have had implications for hominin evolution.

From c. 2 Ma (millions of years ago) onwards, hominin brain size and cognition increased in an unprecedented fashion. The exploitation of high-quality food resources, notably from aquatic ecosystems, may have been a facilitator or driver of this phenomenon. The aim of this study is to contribute to the ongoing debate on the possible role of aquatic resources in hominin evolution by providing a more detailed nutritional context. So far, the debate has focused on the relative importance of terrestrial versus aquatic resources while no distinction has been made between different types of aquatic resources. Here we show that Indian Ocean reef fish and eastern African lake fish yield on average similarly high amounts of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA). Hence a shift from exploiting tropical marine to freshwater ecosystems (or vice versa) would entail no material difference in dietary long-chain polyunsaturated fatty acid (LC-PUFA) availability. However, a shift to marine ecosystems would likely mean a major increase in access to brain-selective micronutrients such as iodine. Fatty fish from marine temperate/cold waters yield twice as much DHA and four times as much EPA as tropical fish, demonstrating that a latitudinal shift in exploitation of African coastal ecosystems could constitute a significant difference in LC-PUFA availability with possible implications for brain development and functioning. We conclude that exploitation of aquatic food resources could have facilitated the initial moderate hominin brain increase as observed in fossils dated to c. 2 Ma, but not the exceptional brain increase in later stages of hominin evolution. We propose that the significant expansion in hominin brain size and cognition later on may have been aided by strong directional selecting forces such as runaway sexual selection of intelligence, and nutritionally supported by exploitation of high-quality food resources in stable and productive aquatic ecosystems.

Interrelationships between maternal DHA in erythrocytes, milk and adipose tissue. Is 1 wt% DHA the optimal human milk content? Data from four Tanzanian tribes differing in lifetime stable intakes of fish.

Little is known about the interrelationships between maternal and infant erythrocyte-DHA, milk-DHA and maternal adipose tissue (AT)-DHA contents. We studied these relationships in four tribes in Tanzania (Maasai, Pare, Sengerema and Ukerewe) differing in their lifetime intakes of fish. Cross-sectional samples were collected at delivery and after 3 d and 3 months of exclusive breast-feeding. We found that intra-uterine biomagnification is a sign of low maternal DHA status, that genuine biomagnification occurs during lactation, that lactating mothers with low DHA status cannot augment their infants' DHA status, and that lactating mothers lose DHA independent of their DHA status. A maternal erythrocyte-DHA content of 8 wt% was found to correspond with a mature milk-DHA content of 1·0 wt% and with subcutaneous and abdominal (omentum) AT-DHA contents of about 0·39 and 0·52 wt%, respectively. Consequently, 1 wt% DHA might be a target for Western human milk and infant formula that has milk arachidonic acid, EPA and linoleic acid contents of 0·55, 0·22 and 9·32 wt%, respectively. With increasing DHA status, the erythrocyte-DHA content reaches a plateau of about 9 wt%, and it plateaus more readily than milk-DHA and AT-DHA contents. Compared with the average Tanzanian-Ukerewe woman, the average US woman has four times lower AT-DHA content (0·4 v. 0·1 wt%) and five times lower mature milk-DHA output (301 v. 60 mg/d), which contrasts with her estimated 1·8-2·6 times lower mobilisable AT-DHA content (19 v. 35-50 g).

DHA status is positively related to motor development in breastfed African and Dutch infants.

OBJECTIVES: Docosahexaenoic (DHA) and arachidonic (AA) acids are important for neurodevelopment. We investigated the relation between erythrocyte (RBC) DHA and AA contents and neurological development, by assessment of General Movements (GMs), in populations with substantial differences in fish intakes. METHODS: We included 3-month-old breastfed infants of three Tanzanian tribes: Maasai (low fish, n = 5), Pare (intermediate fish, n = 32), and Sengerema (high fish, n = 60); and a Dutch population (low-intermediate, fish, n = 15). GMs were assessed by motor optimality score (MOS) and the number of observed movement patterns (OMP; an MOS sub-score). RBC-DHA and AA contents were determined by capillary gas chromatography. RESULTS: We found no between-population differences in MOS. OMP of Sengerema infants (high fish) was higher than OMP of Dutch infants (low-intermediate fish). MOS related to age. OMP related positively to infant age (P < 0.001) and RBC-DHA (P = 0.015), and was unrelated to ethnicity and RBC-AA. DISCUSSION: The positive relation between RBC-DHA and the number of observed movement patterns of 3-month old infants might reflect the connection of DHA with motor development.

Vitamin D status indicators in indigenous populations in East Africa.

PURPOSE: Sufficient vitamin D status may be defined as the evolutionary established circulating 25-hydroxyvitamin D [25(OH)D] matching our Paleolithic genome. METHODS: We studied serum 25(OH)D [defined as 25(OH)D2 + 25(OH)D3] and its determinants in 5 East African ethnical groups across the life cycle: Maasai (MA) and Hadzabe (HA) with traditional life styles and low fish intakes, and people from Same (SA; intermediate fish), Sengerema (SE; high fish), and Ukerewe (UK; high fish). Samples derived from non-pregnant adults (MA, HA, SE), pregnant women (MA, SA, SE), mother-infant couples at delivery (UK), infants at delivery and their lactating mothers at 3 days (MA, SA, SE), and lactating mothers at 3 months postpartum (SA, SE). Erythrocyte docosahexaenoic acid (RBC-DHA) was determined as a proxy for fish intake. RESULTS: The mean ± SD 25(OH)D of non-pregnant adults and cord serum were 106.8 ± 28.4 and 79.9 ± 26.4 nmol/L, respectively. Pregnancy, delivery, ethnicity (which we used as a proxy for sunlight exposure), RBC-DHA, and age were the determinants of 25(OH)D. 25(OH)D increased slightly with age. RBC-DHA was positively related to 25(OH)D, notably 25(OH)D2. Pregnant MA (147.7 vs. 118.3) and SE (141.9 vs. 89.0) had higher 25(OH)D than non-pregnant counterparts (MA, SE). Infant 25(OH)D at delivery in Ukerewe was about 65 % of maternal 25(OH)D. CONCLUSIONS: Our ancient 25(OH)D amounted to about 115 nmol/L and sunlight exposure, rather than fish intake, was the principal determinant. The fetoplacental unit was exposed to high 25(OH)D, possibly by maternal vitamin D mobilization from adipose tissue, reduced insulin sensitivity, trapping by vitamin D-binding protein, diminished deactivation, or some combination.

Autoantibodies to selenoprotein P in chronic fatigue syndrome suggest selenium transport impairment and acquired resistance to thyroid hormone.

Chronic Fatigue Syndrome (CFS) presents with symptoms of hypothyroidism, including mental and physical fatigue, poor sleep, depression, and anxiety. However, thyroid hormone (TH) profiles of elevated thyrotropin and low thyroxine (T4) are not consistently observed. Recently, autoantibodies to the Se transporter SELENOP (SELENOP-aAb) have been identified in Hashimoto's thyroiditis and shown to impair selenoprotein expression. We hypothesized that SELENOP-aAb are prevalent in CFS, and associate with reduced selenoprotein expression and impaired TH deiodination. Se status and SELENOP-aAb prevalence was compared by combining European CFS patients (n = 167) and healthy controls (n = 545) from different sources. The biomarkers total Se, glutathione peroxidase (GPx3) and SELENOP showed linear correlations across the samples without reaching saturation, indicative of Se deficiency. SELENOP-aAb prevalence was 9.6-15.6% in CFS versus 0.9-2.0% in controls, depending on cut-off for positivity. The linear correlation between Se and GPx3 activity was absent in SELENOP-aAb positive patients, suggesting impaired Se supply of kidney. A subgroup of paired control (n = 119) and CSF (n = 111) patients had been characterized for TH and biochemical parameters before. Within this subgroup, SELENOP-aAb positive patients displayed particularly low deiodinase activity (SPINA-GD index), free T3 levels, total T3 to total T4 (TT3/TT4) and free T3 to free T4 (FT3/FT4) ratios. In 24 h urine, iodine concentrations were significantly lower in SELENOP-aAb positive than in SELENOP-aAb negative patients or controls (median (IQR); 43.2 (16.0) vs. 58.9 (45.2) vs. 89.0 (54.9) µg/L). The data indicate that SELENOP-aAb associate with low deiodination rate and reduced activation of TH to active T3. We conclude that a subset of CFS patients express SELENOP-aAb that disturb Se transport and reduce selenoprotein expression in target tissues. Hereby, TH activation decreases as an acquired condition not reflected by thyrotropin and T4 in blood. This hypothesis opens new diagnostic and therapeutic options for SELENOP-aAb positive CFS, but requires clinical evidence from intervention trials.

Mothers' Breast Milk Composition and Their Respective Infant's Gut Microbiota Differ between Five Distinct Rural and Urban Regions in Vietnam.

Microbiota colonization and development in early life is impacted by various host intrinsic (genetic) factors, but also diet, lifestyle, as well as environmental and residential factors upon and after birth. To characterize the impact of maternal nutrition and environmental factors on vaginally born infant gut microbiota composition, we performed an observational study in five distinct geographical areas in Vietnam. Fecal samples of infants (around 39 days old) and fecal and breast milk samples of their mothers (around 28 years) were collected. The microbiota composition of all samples was analyzed by 16S rRNA gene Illumina sequencing and a bioinformatics workflow based on QIIME. In addition, various breast milk components were determined. Strong associations between the geographically determined maternal diet and breast milk composition as well as infant fecal microbiota were revealed. Most notable was the association of urban Ha Noi with relatively high abundances of taxa considered pathobionts, such as Klebsiella and Citrobacter, at the expense of Bifidobacterium. Breast milk composition was most distinct in rural Ha Long Bay, characterized by higher concentrations of, e.g., docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), selenium, and vitamin B12, while it was characterized by, e.g., iron, zinc, and α-linolenic acid (ALA) in Ha Noi. Breast milk iron levels were positively associated with infant fecal Klebsiella and negatively with Bifidobacterium, while the EPA and DHA levels were positively associated with Bifidobacterium. In conclusion, differences between five regions in Vietnam with respect to both maternal breast milk and infant gut microbiota composition were revealed, most likely in part due to maternal nutrition. Thus, there could be opportunities to beneficially steer infant microbiota development in a more desired (rural instead of urban) direction through the mother's diet.

Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l.

Cutaneous synthesis of vitamin D by exposure to UVB is the principal source of vitamin D in the human body. Our current clothing habits and reduced time spent outdoors put us at risk of many insufficiency-related diseases that are associated with calcaemic and non-calcaemic functions of vitamin D. Populations with traditional lifestyles having lifelong, year-round exposure to tropical sunlight might provide us with information on optimal vitamin D status from an evolutionary perspective. We measured the sum of serum 25-hydroxyvitamin D2 and D3 (25(OH)D) concentrations of thirty-five pastoral Maasai (34 (SD 10) years, 43 % male) and twenty-five Hadzabe hunter-gatherers (35 (SD 12) years, 84 % male) living in Tanzania. They have skin type VI, have a moderate degree of clothing, spend the major part of the day outdoors, but avoid direct exposure to sunlight when possible. Their 25(OH)D concentrations were measured by liquid chromatography-MS/MS. The mean serum 25(OH)D concentrations of Maasai and Hadzabe were 119 (range 58-167) and 109 (range 71-171) nmol/l, respectively. These concentrations were not related to age, sex or BMI. People with traditional lifestyles, living in the cradle of mankind, have a mean circulating 25(OH)D concentration of 115 nmol/l. Whether this concentration is optimal under the conditions of the current Western lifestyle is uncertain, and should as a possible target be investigated with concomitant appreciation of other important factors in Ca homeostasis that we have changed since the agricultural revolution.

A maternal erythrocyte DHA content of approximately 6 g% is the DHA status at which intrauterine DHA biomagnifications turns into bioattenuation and postnatal infant DHA equilibrium is reached.

PURPOSE: Higher long-chain polyunsaturated fatty acids (LCP) in infant compared with maternal lipids at delivery is named biomagnification. The decline of infant and maternal docosahexaenoic acid (DHA) status during lactation in Western countries suggests maternal depletion. We investigated whether biomagnification persists at lifelong high fish intakes and whether the latter prevents a postpartum decline of infant and/or maternal DHA status. METHODS: We studied 3 Tanzanian tribes with low (Maasai: 0/week), intermediate (Pare: 2-3/week), and high (Sengerema: 4-5/week) fish intakes. DHA and arachidonic acid (AA) were determined in maternal (m) and infant (i) erythrocytes (RBC) during pregnancy (1st trimester n = 14, 2nd = 103, 3rd = 88), and in mother-infant pairs at delivery (n = 63) and at 3 months postpartum (n = 104). RESULTS: At delivery, infants of all tribes had similar iRBC-AA which was higher than, and unrelated to, mRBC-AA. Transplacental DHA biomagnification occurred up to 5.6 g% mRBC-DHA; higher mRBC-DHA was associated with "bioattenuation" (i.e., iRBC-DHA < mRBC-DHA). Compared to delivery, mRBC-AA after 3 months was higher, while iRBC-AA was lower. mRBC-DHA after 3 months was lower, while iRBC-DHA was lower (low fish intake), equal (intermediate fish intake), and higher (high fish intake) compared to delivery. We estimated that postpartum iRBC-DHA equilibrium is reached at 5.9 g%, which corresponds to a mRBC-DHA of 6.1 g% throughout pregnancy. CONCLUSION: Uniform high iRBC-AA at delivery might indicate the importance of intrauterine infant AA status. Biomagnification reflects low maternal DHA status, and bioattenuation may prevent intrauterine competition of DHA with AA. A mRBC-DHA of about 6 g% during pregnancy predicts maternal-fetal equilibrium at delivery, postnatal iRBC-DHA equilibrium, but is unable to prevent a postnatal mRBC-DHA decline.

A multidisciplinary reconstruction of Palaeolithic nutrition that holds promise for the prevention and treatment of diseases of civilisation.

Evolutionary medicine acknowledges that many chronic degenerative diseases result from conflicts between our rapidly changing environment, our dietary habits included, and our genome, which has remained virtually unchanged since the Palaeolithic era. Reconstruction of the diet before the Agricultural and Industrial Revolutions is therefore indicated, but hampered by the ongoing debate on our ancestors' ecological niche. Arguments and their counterarguments regarding evolutionary medicine are updated and the evidence for the long-reigning hypothesis of human evolution on the arid savanna is weighed against the hypothesis that man evolved in the proximity of water. Evidence from various disciplines is discussed, including the study of palaeo-environments, comparative anatomy, biogeochemistry, archaeology, anthropology, (patho)physiology and epidemiology. Although our ancestors had much lower life expectancies, the current evidence does neither support the misconception that during the Palaeolithic there were no elderly nor that they had poor health. Rather than rejecting the possibility of 'healthy ageing', the default assumption should be that healthy ageing posed an evolutionary advantage for human survival. There is ample evidence that our ancestors lived in a land-water ecosystem and extracted a substantial part of their diets from both terrestrial and aquatic resources. Rather than rejecting this possibility by lack of evidence, the default assumption should be that hominins, living in coastal ecosystems with catchable aquatic resources, consumed these resources. Finally, the composition and merits of so-called 'Palaeolithic diets', based on different hominin niche-reconstructions, are evaluated. The benefits of these diets illustrate that it is time to incorporate this knowledge into dietary recommendations.

Obesity and Leptin Resistance in the Regulation of the Type I Interferon Early Response and the Increased Risk for Severe COVID-19.

Obesity, and obesity-associated conditions such as hypertension, chronic kidney disease, type 2 diabetes, and cardiovascular disease, are important risk factors for severe Coronavirus disease-2019 (COVID-19). The common denominator is metaflammation, a portmanteau of metabolism and inflammation, which is characterized by chronically elevated levels of leptin and pro-inflammatory cytokines. These induce the "Suppressor Of Cytokine Signaling 1 and 3" (SOCS1/3), which deactivates the leptin receptor and also other SOCS1/3 sensitive cytokine receptors in immune cells, impairing the type I and III interferon early responses. By also upregulating SOCS1/3, Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 adds a significant boost to this. The ensuing consequence is a delayed but over-reactive immune response, characterized by high-grade inflammation (e.g., cytokine storm), endothelial damage, and hypercoagulation, thus leading to severe COVID-19. Superimposing an acute disturbance, such as a SARS-CoV-2 infection, on metaflammation severely tests resilience. In the long run, metaflammation causes the "typical western" conditions associated with metabolic syndrome. Severe COVID-19 and other serious infectious diseases can be added to the list of its short-term consequences. Therefore, preventive measures should include not only vaccination and the well-established actions intended to avoid infection, but also dietary and lifestyle interventions aimed at improving body composition and preventing or reversing metaflammation.

Thyroidal and Extrathyroidal Requirements for Iodine and Selenium: A Combined Evolutionary and (Patho)Physiological Approach.

Iodide is an antioxidant, oxidant and thyroid hormone constituent. Selenoproteins are needed for triiodothyronine synthesis, its deactivation and iodine release. They also protect thyroidal and extrathyroidal tissues from hydrogen peroxide used in the 'peroxidase partner system'. This system produces thyroid hormone and reactive iodine in exocrine glands to kill microbes. Exocrine glands recycle iodine and with high urinary clearance require constant dietary supply, unlike the thyroid. Disbalanced iodine-selenium explains relations between thyroid autoimmune disease (TAD) and cancer of thyroid and exocrine organs, notably stomach, breast, and prostate. Seafood is iodine unconstrained, but selenium constrained. Terrestrial food contains little iodine while selenium ranges from highly deficient to highly toxic. Iodine vs. TAD is U-shaped, but only low selenium relates to TAD. Oxidative stress from low selenium, and infection from disbalanced iodine-selenium, may generate cancer of thyroid and exocrine glands. Traditional Japanese diet resembles our ancient seashore-based diet and relates to aforementioned diseases. Adequate iodine might be in the milligram range but is toxic at low selenium. Optimal selenoprotein-P at 105 µg selenium/day agrees with Japanese intakes. Selenium upper limit may remain at 300-400 µg/day. Seafood combines iodine, selenium and other critical nutrients. It brings us back to the seashore diet that made us what we currently still are.

Pregnant Dutch Women Have Inadequate Iodine Status and Selenium Intake.

Iodine and selenium are essential for thyroid hormone synthesis. Iodine and selenium interact. Pregnancy increases the maternal iodine requirement. We previously reported inadequate iodine status in pregnant Dutch women. Since little is known about their selenium intake, we investigated the iodine status and selenium intake in relation to iodine and selenium supplement use during pregnancy. Iodine status was established in 201 apparently healthy pregnant women as 24 h iodine excretion (24H-UIE; sufficient if median ≥225 µg), iodine concentration (24H-UIC; ≥150 µg/L) and iodine/creatinine ratio (24H-UICR; ≥150 µg/g). Selenium intake was calculated from 24 h selenium excretion. Iodine status in pregnancy proved insufficient (medians: 24H-UIE 185 µg; 24H-UIC 95 µg/L; 24H-UICR 141 µg/g). Only women taking 150 µg iodine/day were sufficient (median 24H-UIE 244 µg). Selenium intake was below the Estimated Average Requirement (EAR; 49 µg/day) in 53.8%, below the Recommended Dietary Allowance (RDA; 60 µg/day) in 77.4% and below the Adequate Intake (AI; 70 µg/day) in 88.7%. Combined inadequate iodine status and selenium intake

Maternal DHA equilibrium during pregnancy and lactation is reached at an erythrocyte DHA content of 8 g/100 g fatty acids.

Low long-chain PUFA (LC-PUFA, or LCP) consumption relates to suboptimal neurodevelopment, coronary artery disease, and [postpartum (PP)] depression. Maternal-to-infant LCP transport during pregnancy and lactation is at the expense of maternal status, a process known as biomagnification. Despite biomagnification, maternal and infant LCP status generally declines during lactation. To assess the 1) turning point of biomagnification [level from which maternal (m)LCP status exceeds infant (i)LCP status]; 2) LCP equilibrium (steady-state-level from which mRBC-LCP stop declining during lactation); 3) corresponding iLCP-status; and 4) the relationship between RBC-DHA and RBC-arachidonic acid (AA), we measured RBC-fatty acids in 193 Tanzanian mother-infant pairs with no, intermediate (2-3 times/wk), and high (4-5 times/wk) freshwater fish consumption at delivery and after 3 mo of exclusive breast-feeding. At 3 mo, mRBC-DHA was lower than the corresponding iRBC-DHA up to a mRBC-DHA of 7.9 g%. mRBC-DHA equilibrium, with equivalent mRBC-DHA at both delivery and at 3 mo PP, occurred at 8.1 g%. This mRBC-DHA equilibrium of 8.1 g% corresponded with an iRBC-DHA of 7.1-7.2 g% at delivery that increased to 8.0 g% at 3 mo. We found between-group differences in mRBC-AA; however, no differences in iRBC-AA were observed at delivery or 3 mo. Relations between RBC-DHA and RBC-AA were bell-shaped. We conclude that, at steady-state LCP intakes during lactation: 1) biomagnification occurs up to 8 g% mRBC-DHA; 2) mRBC-DHA equilibrium is reached at 8 g%; 3) mRBC-DHA equilibrium corresponds with an iRBC-DHA of 7 g% at delivery and 8 g% after 3 mo; 4) unlike RBC-DHA, mRBC-AA and iRBC-AA are independently regulated in these populations; and 5) bell-shaped RBC-DHA vs. RBC-AA-relations might support uniform iRBC-AA. A (maternal) RBC-DHA of 8 g% might be optimal for infant neurodevelopment and adult cardiovascular disease incidence.