Habitual dietary intake of n-3 and n-6 fatty acids in relation to inflammatory markers among US men and women

Evaluation of the effect of Neptune Krill Oil on chronic inflammation and arthritic symptoms

OBJECTIVES

a) To evaluate the effect of Neptune Krill Oil (NKO) on C-reactive protein (CRP) on patients with chronic inflammation and b) to evaluate the effectiveness of NKO on arthritic symptoms.

METHODS

Randomized, double blind, placebo controlled study. Ninety patients were recruited with confirmed diagnosis of cardiovascular disease and/or rheumatoid arthritis and/or osteoarthritis and with increased levels of CRP (>1.0 mg/dl) upon three consecutive weekly blood analysis. Group A received NKO (300 mg daily) and Group B received a placebo. CRP and Western Ontario and McMaster Universities (WOMAC) osteoarthritis score were measured at baseline and days 7, 14 and 30.

RESULTS

After 7 days of treatment NKO reduced CRP by 19.3% compared to an increase by 15.7% observed in the placebo group (p = 0.049). After 14 and 30 days of treatment NKO further decreased CRP by 29.7% and 30.9% respectively (p < 0.001). The CRP levels of the placebo group increased to 32.1% after 14 days and then decreased to 25.1% at day 30. The between group difference was statistically significant; p = 0.004 at day 14 and p = 0.008 at day 30. NKO showed a significant reduction in all three WOMAC scores. After 7 days of treatment, NKO reduced pain scores by 28.9% (p = 0.050), reduced stiffness by 20.3% (p = 0.001) and reduced functional impairment by 22.8% (p = 0.008).

CONCLUSION

The results of the present study clearly indicate that NKO at a daily dose of 300 mg significantly inhibits inflammation and reduces arthritic symptoms within a short treatment period of 7 and 14 days.

Depressive symptoms, omega-6:omega-3 fatty acids, and inflammation in older adults

OBJECTIVE

To address how interactions between polyunsaturated fatty acid (PUFA) levels and depressive symptoms were related to proinflammatory cytokine synthesis. Depression and stress promote proinflammatory cytokine production. Dietary intakes of omega-3 (n-3) and omega-6 (n-6) PUFAs also influence inflammation; high n-6:n-3 ratios enhance proinflammatory cytokine production, although n-3 has anti-inflammatory properties.

METHODS

Blood samples from 43 older adults (mean age = 66.67 years, SD = 10.09) provided data on PUFAs and tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, and IL-6 soluble receptor (sIL-6r). Depressive symptoms were assessed by the Center for Epidemiological Studies Depression Scale.

RESULTS

Depressive symptoms and n-6:n-3 ratios worked together to enhance proinflammatory cytokines beyond the contribution provided by either variable alone, with substantial variance explained by their interaction: 13% for IL-6 and 31% for TNF-alpha, whereas full models accounted for 18% and 40%, respectively. Although predicted cytokine levels were consistent across n-6:n-3 ratios with low depressive symptoms, higher n-6:n-3 ratios were associated with progressively elevated TNF-alpha and IL-6 levels as depressive symptoms increased. Higher levels of sIL-6r were associated with higher n-6:n-3 ratios. Six individuals who met the criteria for major depressive disorder had higher n-6:n-3 ratios and TNF-alpha, IL-6, and sIL-6r levels than those who did not meet the criteria; excluding these six individuals reduced the variance explained by the depressive symptoms and n-6:n-3 ratio interaction.

CONCLUSIONS

Diets with high n-6:n-3 PUFA ratios may enhance the risk for both depression and inflammatory diseases.

Soy consumption, markers of inflammation, and endothelial function: a cross-over study in postmenopausal women with the metabolic syndrome

OBJECTIVE

To determine the effects of soy consumption on markers of inflammation and endothelial function in postmenopausal women with the metabolic syndrome.

RESEARCH DESIGN AND METHODS

This randomized cross-over clinical trial included 42 postmenopausal women with the metabolic syndrome. Participants were randomly assigned to consume a control diet (Dietary Approaches to Stop Hypertension [DASH]), soy protein diet, or soy nut diet, each for 8 weeks. Red meat in the DASH diet (one serving/day) was replaced by soy protein in the soy protein diet and by soy nut in the soy nut diet.

RESULTS

For nitric oxide levels, the difference from the control diet was 9.8% (P < 0.01) on the soy nut and -1.7% (P = 0.10) on the soy protein diets. The difference from the control diet for serum E-selectin was -11.4% (P < 0.01) on the soy nut consumption and -4.7% (P = 0.19) on the soy protein diet. Soy nut consumption reduced interleukin-18 compared with the control diet (difference from the control diet: -9.2%, P < 0.01), but soy protein did not (difference from the control diet: -4.6%, P = 0.14). For C-reactive protein, the difference from the control diet was -8.9% (P < 0.01) on the soy nut diet and -1.6% (P < 0.01) on the soy protein diet.

CONCLUSIONS

Short-term soy nut consumption reduced some markers of inflammation and increased plasma nitric oxide levels in postmenopausal women with the metabolic syndrome.

Decreasing linoleic acid with constant alpha-linolenic acid in dietary fats increases (n-3) eicosapentaenoic acid in plasma phospholipids in healthy men

High linoleic acid (LA) intakes have been suggested to reduce alpha-linolenic acid [ALA, 18:3(n-3)] metabolism to eicosapentaenoic acid [EPA, 20:5(n-3)] and docosahexaenoic acid [DHA, 22:6(n-3)], and favor high arachidonic acid [ARA, 20:4(n-6)]. We used a randomized cross-over study with men (n = 22) to compare the effect of replacing vegetable oils high in LA with oils low in LA in foods, while maintaining constant ALA, for 4 wk each, on plasma (n-3) fatty acids. Nonvegetable sources of fat, except fish and seafoods, were unrestricted. We determined plasma phospholipid fatty acids at wk 0, 2, 4, 6, and 8, and triglycerides, cholesterol, serum CRP, and IL-6, and platelet aggregation at wk 0, 4, and 8. LA and ALA intakes were 3.8 +/- 0.12% and 1.0 +/- 0.05%, and 10.5 +/- 0.53% and 1.1 +/- 0.06% energy with LA:ALA ratios of 4:0 and 10:1 during the low and high LA diets, respectively. The plasma phospholipid LA was higher and EPA was lower during the high than during the low LA diet period (P < 0.001), but DHA declined over the 8-wk period (r = -0.425, P < 0.001). The plasma phospholipid ARA:EPA ratios were (mean +/- SEM) 20.7 +/- 1.52 and 12.9 +/- 1.01 after 4 wk consuming the high or low LA diets, respectively (P < 0.001); LA was inversely associated with EPA (r = -0.729, P < 0.001) but positively associated with ARA:EPA (r = 0.432, P < 0.001). LA intake did not influence ALA, ARA, DPA, DHA, or total, LDL or HDL cholesterol, CRP or IL-6, or platelet aggregation. In conclusion, high LA intakes decrease plasma phospholipid EPA and increase the ARA:EPA ratio, but do not favor higher ARA.

Dietary patterns and markers of systemic inflammation among Iranian women

Few studies have examined the contribution of major dietary patterns to markers of systemic inflammation. This study was conducted to evaluate the association of major dietary patterns with markers of systemic inflammation among Iranian women. In a cross-sectional study of 486 healthy women aged 40-60 y, we assessed usual dietary intakes by means of an FFQ. Dietary patterns were identified by factor analysis. Anthropometric measurements were made and blood samples from fasting were taken for measuring inflammatory markers. The healthy pattern (high in fruits, vegetables, tomato, poultry, legumes, tea, fruit juices, and whole grains) was inversely related to plasma concentrations of C-reactive protein (CRP) (beta = -0.09, P < 0.001), E-selectin (beta = -0.07, P < 0.05), and soluble vascular cell adhesion molecule-1 (sVCAM-1) (beta = -0.08, P < 0.001) after control for potential confounders; with further adjustment for BMI and waist circumference (WC), the associations remained significant for CRP (beta = -0.05, P < 0.05) and sVCAM-1 (beta = -0.04, P < 0.05). In contrast, the western pattern score (high in refined grains, red meat, butter, processed meat, high-fat dairy, sweets and desserts, pizza, potato, eggs, hydrogenated fats, and soft drinks) was positively related to CRP (beta = 0.08, P < 0.001), serum amyloid A (SAA) (beta = 0.11, P < 0.05), IL-6 (beta = 0.09, P < 0.001), soluble intercellular adhesion molecule-1 (beta = 0.05, P < 0.05), and sVCAM-1 concentrations (beta = 0.07, P < 0.05). However, after additional control for BMI and WC, the associations remained significant only for SAA (beta = 0.06, P < 0.05) and IL-6 (beta = 0.07, P < 0.001). The traditional dietary pattern (high in refined grains, potato, tea, whole grains, hydrogenated fats, legumes, and casserole) was positively associated with the plasma IL-6 concentration (beta = 0.04, P < 0.05) when we controlled for confounders including BMI and WC. The findings suggest an independent association between major dietary patterns and plasma concentrations of markers of inflammation.

Komplexe diätetische und Pharmakotherapie beim metabolischen Syndrom

Metabolic syndrome is characterized by a group of risk factors (obesity, glucose metabolism disorders, dyslipidemia and hypertension) which appear to be caused by obesity related mechanisms of cellular metabolism and the systemic energy balance. A fibre poor diet rich in fat combined with lack of physical activity are important causative factors. A suitable change in diet combined with regular physical exercise and a moderate weight loss of about 5% leads to a massive reduction in the consequential disease diabetes type 2 by 60% in pre-diabetics and reduces the risk factors for metabolic syndrome. Pharmacological therapies using metformin or acarbose were about half as effective in reducing new cases of diabetes, while thiazolidinedione also led to a 60% reduction in new diabetes cases in pre-diabetics in spite of a weight increase. A sensible and realizable change in lifestyle provides a highly efficient therapy of metabolic syndrome, in addition to effective pharmacological options.

The effects of eicosapentaenoic acid-fortified food on inflammatory markers in healthy subjects--A randomized, placebo-controlled, double-blind study

Epidemiological studies showed that habitual fish intakes were associated with lower blood inflammatory markers. In the present study the effects of a fish oil-containing food on inflammatory markers were investigated in healthy, mostly middle-aged subjects (59 men and 82 women) with normal to mildly elevated triglyceride levels. Study subjects were randomly allocated to two groups in a double-blind manner; one group ingested an eicosapentaenoic acid (EPA)-rich fish oil-fortified drink (0.60 g EPA+0.26 g docosahexaenoic acid/d. EPA group, n=68) for 12 wk. The rest of the subjects took a placebo (control group, n=73). Plasma levels of high sensitivity C-reactive protein (hs-CRP) and soluble tumor necrosis factor-receptors 1 and 2 (sTNF-Rs 1 and 2) were measured at the start and end of intervention. EPA concentrations in the total RBC phospholipid fraction significantly increased by 79% in the EPA group at the end of the study, and they changed very little in the control group (+0.68%). The inflammatory markers did not change in either group. It is likely that fish oil does not change hs-CRP or sTNF-Rs 1 or 2 in subjects without active inflammation.

Dietary alpha-linolenic acid inhibits proinflammatory cytokine production by peripheral blood mononuclear cells in hypercholesterolemic subjects

BACKGROUND

Atherosclerosis is a chronic inflammatory disease. We previously reported that a diet high in alpha-linolenic acid (ALA) reduces lipid and inflammatory cardiovascular disease risk factors in hypercholesterolemic subjects.

OBJECTIVE

The objective was to evaluate the effects of a diet high in ALA on serum proinflammatory cytokine concentrations and cytokine production by cultured peripheral blood mononuclear cells (PBMCs) from subjects fed the experimental diets.

DESIGN

A randomized, controlled, 3-diet, 3-period crossover study design was used. Hypercholesterolemic subjects (n = 23) were assigned to 3 experimental diets: a diet high in ALA (ALA diet; 6.5% of energy), a diet high in linoleic acid (LA diet; 12.6% of energy), and an average American diet (AAD) for 6 wk. Serum interleukin (IL)-6, IL-1beta, and tumor necrosis factor-alpha (TNF-alpha) concentrations and the production of IL-6, IL-1beta, and TNF-alpha by PBMCs were measured.

RESULTS

IL-6, IL-1beta, and TNF-alpha production by PBMCs and serum TNF-alpha concentrations were lower (P < 0.05 and P < 0.08, respectively) with the ALA diet than with the LA diet or AAD. PBMC production of TNF-alpha was inversely correlated with ALA (r = -0.402, P = 0.07) and with eicosapentaenoic acid (r = -0.476, P = 0.03) concentrations in PBMC lipids with the ALA diet. Changes in serum ALA were inversely correlated with changes in TNF-alpha produced by PBMCs (r = -0.423, P < 0.05).

CONCLUSIONS

Increased intakes of dietary ALA elicit antiinflammatory effects by inhibiting IL-6, IL-1beta, and TNF-alpha production in cultured PBMCs. Changes in PBMC ALA and eicosapentaenoic acid (derived from dietary ALA) are associated with beneficial changes in TNF-alpha release. Thus, the cardioprotective effects of ALA are mediated in part by a reduction in the production of inflammatory cytokines.

Omega-3 fatty acids and antioxidants in neurological and psychiatric diseases: an overview

RATIONALE

Omega-3 fatty acids are known to play a role in nervous system activity, cognitive development, memory-related learning, neuroplasticity of nerve membranes, synaptogenesis and synaptic transmission. The brain is considered abnormally sensitive to oxidative damage, and aging is considered one of the most significant risk factors for degenerative neurological disorders. Recently, clinical trials of several neurodegenerative diseases have increasingly targeted the evaluation of the effectiveness of various antioxidants.

OBJECTIVES

The effects of omega-3 fatty acids and antioxidants on the anatomic and functional central nervous system development and their possible therapeutical use in some neurological and psychiatric pathologies are evaluated.

RESULTS

A number of critical trials have confirmed the benefits of dietary supplementation with omega-3 fatty acids not only in several psychiatric conditions, but also in inflammatory and autoimmune and neurodegenerative diseases. Many evidences indicate that antioxidants are also essential in maintaining a correct neurophysiology.

CONCLUSIONS

Omega-3 fatty acids could be useful in the prevention of different pathologies, such as cardiovascular, psychiatric, neurological, dermatological and rheumatological disorders. A number of studies suggest that antioxidants can prevent the oxidation of various macromolecules such as DNA, proteins, and lipids. The ideal use of antioxidants should be a prophylactic and continue treatment before aging.

The omega-6/omega-3 ratio and cardiovascular disease risk: uses and abuses

The cardioprotective effects of omega-3 fatty acids (n-3 FAs) are well known, but the role that the n-6 FAs play in coronary heart disease is unclear. These two classes of essential FAs compete for a number of enzyme systems, and their metabolites can powerfully influence (often in different directions) inflammatory responses, vascular reactivity, and platelet aggregation. Accordingly, the n-6/n-3 FA ratio may be of value in interpreting biomarker data and in making nutritional recommendations. Although initially appealing, there are few human experimental and clinical trial data to support this view. This paper reviews a variety of studies that, in the aggregate, suggest that the ratio is, both on theoretical and evidential grounds, of little value. Metrics that include the n-3 FAs alone, especially eicosapentaenoic and docosahexaenoic acids, appear to hold the greatest promise.

Effect of fish or soybean oil-rich diets on bradykinin, kallikrein, nitric oxide, leptin, corticosterone and macrophages in carrageenan stimulated rats

We have previously demonstrated that both n-3 and n-6 polyunsaturated fatty acids (PUFA)-rich diets decrease the acute inflammatory response partially explained by the high corticosterone basal levels. The present study aimed to determine the effect of hyperlipidic diets (PUFA n-3 or n-6) on phagocytosis, hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) release by macrophages, bradykinin (BK) and NO release in the paw inflammatory perfusate and Kallikrein (KK), corticosterone and leptin blood levels. Hyperlipidic diets decreased H(2)O(2) release from macrophages stimulated by carrageenan or phorbol-miristate-acetate (PMA), NO release from macrophage stimulated by carrageenan, BK and NO release in the edema perfusate, KK plasma levels and the increase of serum leptin after carrageenan stimulus. These data show that both fish and soybean oil-rich diets promote similar alterations on inflammatory mediators of carrageenan edema and a causal association with the anti-inflammatory effect of these diets.

Dietary fatty acid intakes and the risk of ovulatory infertility

BACKGROUND

Pharmacologic activation of the peroxisome proliferator-activated receptor gamma (PPAR-gamma) improves ovulatory function in women with polycystic ovary syndrome, and specific dietary fatty acids can affect PPAR-gamma activity.

OBJECTIVE

The objective of the study was to assess whether the intakes of total fat, cholesterol, and major types of fatty acids affect the risk of ovulatory infertility.

DESIGN

We conducted a prospective cohort study of 18 555 married, premenopausal women without a history of infertility who attempted a pregnancy or became pregnant between 1991 and 1999. Diet was assessed twice during follow-up by using a food-frequency questionnaire.

RESULTS

During follow-up, 438 incidents of ovulatory infertility were reported. In logistic regression analyses, intakes of total fat, cholesterol, and most types of fatty acids were not related to ovulatory infertility. Each 2% increase in the intake of energy from trans unsaturated fats, as opposed to that from carbohydrates, was associated with a 73% greater risk of ovulatory infertility after adjustment for known and suspected risk factors for this condition [relative risk (RR) = 1.73; 95% CI: 1.09, 2.73]. Obtaining 2% of energy intake from trans fats rather than from n-6 polyunsaturated fats was associated with a similar increase in the risk of ovulatory infertility (RR = 1.79; 95% CI: 1.11, 2.89). In addition, obtaining 2% of energy from trans fats rather than from monounsaturated fats was associated with a more than doubled risk of ovulatory infertility (RR = 2.31; 95% CI: 1.09, 4.87).

CONCLUSION

trans Unsaturated fats may increase the risk of ovulatory infertility when consumed instead of carbohydrates or unsaturated fats commonly found in nonhydrogenated vegetable oils.

Effects of N-3 PUFAs supplementation on insulin resistance and inflammatory biomarkers in hemodialysis patients

AIMS/HYPOTHESIS

It was suggested that polyunsaturated n-3 fatty acids (n-3 PUFAs) could improve insulin sensitivity and have an anti-inflammatory effects in overall population. This study investigates a possible effect of n-3 PUFAs supplementation on the insulin sensitivity and some inflammatory markers; hence, patients with chronic renal failure (CRF) on maintenance hemodialysis (MHD) are presented with insulin resistance.

METHODS

This study explored the ratio between red blood cells (RBC) phospholipid long chain fatty acids (LC FAs) and components of metabolic syndrome (MeS) in 35 patients (mean age 54.50 +/- 11.99 years) with CRF on MHD. Furthermore, the effects of omega-3 FA eight-week's supplementation (EPA+DHA, 2.4 g/d) on the MeS features and inflammatory markers TNF-alpha, IL 6, and hsCRP were examined.

RESULTS

Supplementation increased EPA and DHA levels in RBCs (p = 0.009 for EPA and p = 0.002 for DHA). Total n-6 PUFAs: n-3 PUFAs ratio tended to be lower after supplementation (p = 0.31), but not significantly. Data revealed a significant decrease of saturated FAs (SFA) (p = 0.01) as well as total SFA: n-3 PUFAs ratio during the treatment (p = 0.04). The values of serum insulin and calculated IR index-IR HOMA were reduced after supplementation (p = 0.001 for both). There was a significant decrease in the levels of all inflammatory markers (p = 0.01 for TNF alpha, p = 0.001 for IL 6, p = 0.001 for hsCRP, and p = 0.01 for ferritin). In multivariate regression analysis, only the changes in n-6 PUFAs: n-3 PUFAs ratio independently contributed to 40% of the variance in IR HOMA. The impact of changes in PUFAs level in RBCs membrane phospholipid fatty acids on inflammation markers was also registered. The changes in n-6: n-3 PUFAs ratio independently contributed to 18% of the variance in TNF alpha.

CONCLUSION

It was concluded that the EPA and DHA moderate dose administration in the patients with CRF on MHD had a beneficial effect on insulin resistance decrease. The anti-inflammatory effects of the supplemented PUFAs were also presented.

Nutrition and Inflammatory Load

Chronic inflammation has been suggested to play an important role in metabolic diseases, such as atherothrombosis and type 2 diabetes. A lot of research has focused on the immunomodulatory effects of several nutrients, such as fatty acids, antioxidants, carbohydrates, specific amino acids, micronutrients, and alcohol, which play a crucial role in the maintenance of an "optimal" immune response. In addition, specific dietary patterns, such as the Mediterranean diet, are evolving as protective against cardiovascular disease, because of their anti-inflammatory properties. In this article, the existing data concerning the nutrients' pro- and anti-inflammatory properties are presented, as well as dietary patterns that could protect from chronic inflammation and its metabolic and atherothrombotic complications.

Effects of omega-3 fatty acids on serum markers of cardiovascular disease risk: A systematic review

Greater fish oil consumption has been associated with reduced CVD risk, although the mechanisms are unclear. Plant-source oil omega-3 fatty acids (ALA) have also been studied regarding their cardiovascular effect. We conducted a systematic review of randomized controlled trials that evaluated the effect of consumption of fish oil and ALA on commonly measured serum CVD risk factors, performing meta-analyses when appropriate. Combining 21 trials evaluating lipid outcomes, fish oil consumption resulted in a summary net change in triglycerides of -27 (95% CI -33, -20)mg/dL, in HDL cholesterol of +1.6 (95% CI +0.8, +2.3)mg/dL, and in LDL cholesterol of +6 (95% CI +3, +8)mg/dL. There was no effect of fish oil on total cholesterol. Across studies, higher fish oil dose and higher baseline levels were associated with greater reductions in serum triglycerides. Overall, the 27 fish oil trials evaluating Hgb A(1c) or FBS found small non-significant net increases compared to control oils. Five studies of ALA were inconsistent in their effects on lipids, Hgb A(1c) or FBS. Four studies investigating the effects of omega-3 fatty acids on hs-CRP were also inconsistent and non-significant. The evidence supports a dose-dependent beneficial effect of fish oil on serum triglycerides, particularly among people with more elevated levels. Fish oil consumption also modestly improves HDL cholesterol, increases LDL cholesterol levels, but does not appear to adversely affect glucose homeostasis. The evidence regarding the effects of omega-3 fatty acids on hs-CRP is inconclusive, as are data on ALA.

Coronary heart disease and depression: a review of recent mechanistic research

OBJECTIVE

Both behavioural and physiological factors have been proposed as mechanisms that may explain the negative effect of depression on coronary heart disease (CHD). Our aim is to review some of the most important findings since our prior review.

METHOD

We searched MEDLINE, PsycINFO, and other sources for recent studies of candidate mechanisms, with an emphasis on publications since 2002.

RESULTS

Physiological pathways have received far greater attention than behavioural ones in the emerging literature. Recent studies have identified shared genetic determinants, inflammation, blood clotting, and vascular mechanisms as plausible explanatory mechanisms.

CONCLUSIONS

Future research should focus on relations between behavioural and physiological mechanisms and on the effects of pharmacologic and psychotherapeutic treatments for depression on candidate mechanisms.

Homograft valved right ventricle to pulmonary artery conduit as a modification of the Norwood procedure

BACKGROUND

The use of a right ventricle to pulmonary artery (RV-PA) conduit in the Norwood procedure has been proposed to increase postoperative hemodynamic stability. A valve within the conduit should further decrease RV volume load. We report our clinical experience with this modification.

METHODS AND RESULTS

From February 2002 through August 2005, we performed 88 consecutive Norwood procedures using RV-PA conduits. We used composite valved conduits made from cryopreserved homograft and polytetrafluoroethylene (PTFE) in 66 cases (54 pulmonary, 12 aortic homografts), other valved conduits in 14, and unvalved PTFE in 8 cases. Hospital survival was 88.6% overall and increased to 93.1% after the initial year. Early interventions were required in 18 patients (16 for cyanosis). Prestage II cardiac catheterization was performed at a mean age of 126 days. Mean Qp/Qs was 1, with mean aortic saturation 71%, mean O2 extraction 24%, and mean right ventricular end-diastolic pressure 9 mm Hg. Patient weight, use of an aortic homograft valve in the conduit, stage I palliation within the first year of our experience, and low O2 extraction and high transpulmonary gradient prestage II were risk factors for overall death. Early interventions were more frequent in aortic valve conduits compared with all other conduits.

CONCLUSIONS

The valved RV-PA conduit was associated with low early mortality after the Norwood procedure. The majority of these patients had normal cardiac output and well-maintained RV function. There may be a higher risk for early conduit interventions and death when aortic valve homografts are used in the RV-PA conduit.

The effects of diet on inflammation: emphasis on the metabolic syndrome

Reducing the incidence of coronary heart disease with diet is possible. The main dietary strategies include adequate omega-3 fatty acids intake, reduction of saturated and trans-fats, and consumption of a diet high in fruits, vegetables, nuts, and whole grains and low in refined grains. Each of these strategies may be associated with lower generation of inflammation. This review examines the epidemiologic and clinical evidence concerning diet and inflammation. Dietary patterns high in refined starches, sugar, and saturated and trans-fatty acids, poor in natural antioxidants and fiber from fruits, vegetables, and whole grains, and poor in omega-3 fatty acids may cause an activation of the innate immune system, most likely by an excessive production of proinflammatory cytokines associated with a reduced production of anti-inflammatory cytokines. The whole diet approach seems particularly promising to reduce the inflammation associated with the metabolic syndrome. The choice of healthy sources of carbohydrate, fat, and protein, associated with regular physical activity and avoidance of smoking, is critical to fighting the war against chronic disease. Western dietary patterns warm up inflammation, while prudent dietary patterns cool it down.

Dietary long-chain n-3 fatty acids of marine origin and serum C-reactive protein concentrations are associated in a population with a diet rich in marine products

BACKGROUND

Several studies have reported that the intake of n-3 polyunsaturated fatty acids (PUFAs) or fish is inversely associated with serum C-reactive protein (CRP) concentrations, but few studies have evaluated the relations between serum CRP concentrations and consumption of n-3 PUFAs derived from marine products in populations with a diet rich in marine products. Therefore, it is still unclear whether a greater consumption of n-3 PUFAs is associated with lower serum CRP concentrations.

OBJECTIVE

The aim of this study was to investigate the relations between n-3 PUFA intake and serum CRP concentration in the Japanese, who have a diet rich in marine products.

DESIGN

We designed a cross-sectional survey of 401 men and 570 women aged > or =70 y who were living in Japan. CRP concentrations were measured, and subjects whose serum CRP concentrations were > or =10.0 mg/L were excluded. Dietary intake was assessed with a self-administered diet-history questionnaire.

RESULTS

After adjustment for several predictors of inflammation, the odds ratio of high CRP (> or =1.0 mg/L) for increasing quartiles of total n-3 PUFA and eicosapentaenoic acid + docosahexaenoic acid were 1.0, 0.72, 0.57, and 0.44 (P for trend = 0.01) and 1.0, 0.91, 0.76, and 0.54 (P for trend = 0.03), respectively.

CONCLUSIONS

Greater intake of n-3 PUFAs derived from marine products, as measured with a self-administered questionnaire, was independently related to a lower prevalence of high CRP concentrations in this older Japanese population with a diet rich in marine products. Our findings suggest that even very high intakes of n-3 PUFAs may lower serum CRP concentrations.

Baseline plasma C-reactive protein concentrations influence lipid and lipoprotein responses to low-fat and high monounsaturated fatty acid diets in healthy men

To date, no studies have compared the effects of consuming a low-fat diet and a high monounsaturated fatty acid (MUFA) diet, under unrestricted energy intake conditions, on plasma C-reactive protein (CRP) concentrations. Men [n = 61; 37.5 +/- 11.5 y old (mean +/- SD), mean BMI 29.0 +/- 5.0 kg/m2] were randomly assigned to consume ad libitum a moderately low-fat diet (25.8% of energy intake from fat) or a high-fat diet rich in MUFA (40.1% of energy intake from fat, 22.5% from MUFA) for 6-7 wk. Plasma CRP concentrations were measured using a highly sensitive assay. Neither diet affected the plasma CRP concentration. However, baseline CRP concentrations predicted lipoprotein/lipid responsiveness to the experimental diets. After intake of the low-fat diet, plasma total and VLDL-triglyceride (TG) concentrations were increased in the subgroup with high CRP concentrations (P < 0.05 and P < 0.01, respectively) whereas they were reduced in the subgroup with low CRP concentrations at baseline (P < 0.01 for both). The high-MUFA diet reduced plasma TG, VLDL-TG, and VLDL cholesterol only in the subgroup with low CRP at baseline (P < 0.0001). In conclusion, the low-fat diet and the high-MUFA diet did not affect plasma CRP concentrations. However, baseline plasma CRP concentrations may modulate the diet-induced changes in plasma lipid and lipoprotein concentrations.

Effects of combined dietary supplementation on oxidative and inflammatory status in dyslipidemic subjects

BACKGROUND AND AIM

Dyslipidemia is one of the main risk factors for atherosclerosis, usually the underlying cause of cardiovascular diseases which are the major cause of morbidity and mortality in developed countries. The aim of this study was to assess the effects and the advantages of a combined dietary supplementation with PUFA n-3, vitamin E, niacin and gamma-oryzanol on lipid profile, inflammatory status and oxidative balance.

METHODS AND RESULTS

Fifty-seven dyslipidemic volunteers were randomly assigned to receive: placebo (group A, 19 subjects); PUFA n-3 and vitamin E (group B, 18 subjects); the same as B plus gamma-oryzanol and niacin (group C, 20 subjects). Lipid profile, reactive oxygen species (ROS), total antioxidant capacity (TAC), vitamin E, interleukin 1-beta (IL1-beta), tumor necrosis factor (TNF-alpha) and thromboxane B2 (TXB2) were determined at baseline (T0) and after four months (T1). All dyslipidemic subjects showed, at baseline, oxidative stress and, after four months, all biochemical markers improved significantly in groups treated with dietary supplementation. Particularly in group C all lipid patterns improved significantly.

CONCLUSIONS

Our findings demonstrate that the strategy of combining different compounds, which protect each other and act together at different levels of the lipid chain production, improves lipid profile, inflammatory and oxidative status, allowing us to reduce the dose of each compound under the threshold of its side effects.

Understanding omega-3's

Omega-3 fatty acids are a subset of polyunsaturated fatty acids found in marine sources as eicosapentaenoic acid and docosahexaenoic acid and in some leafy vegetables, nuts, and oils as alpha-linolenic acid (ALA). The metabolism of omega-3's may explain the cardioprotective effects observed in epidemiologic and experimental studies. Although most data for cardioprotective effects come from studies of marine sources, vegetable sources of omega-3 fatty acids (alpha-linolenic acid) may have similar effects through in vivo conversion to eicosapentaenoic acid and docosahexaenoic acid. This document will provide an overview of omega-3 fatty acids with a focus on specific sources, metabolism, safety issues, and their potential indication for cardiovascular prevention.

Mediterranean-inspired diet lowers the ratio of serum phospholipid n-6 to n-3 fatty acids, the number of leukocytes and platelets, and vascular endothelial growth factor in healthy subjects

BACKGROUND

Reduced cardiovascular mortality and morbidity have been shown in persons adhering to Mediterranean-inspired diets (MIDs). Although the underlying mechanisms of this association are poorly understood, the importance of increasing dietary amounts of polyunsaturated fatty acids of the n-3 series has been emphasized.

OBJECTIVE

We investigated whether a MID provided to healthy subjects would affect 1) the inflammatory process and endothelial indexes such as vasoregulation and vascular endothelial growth factor (VEGF) and 2) serum phospholipid fatty acid composition.

DESIGN

A total of 22 subjects (10 women) received a MID or an ordinary Swedish diet (OSD) for 4 wk in a crossover fashion. Concentrations of lipids and fatty acids, high-sensitivity C-reactive protein, and interleukin 6, both before and after lipopolysaccharide stimulation; the number of leukocytes and platelets; and VEGF and monocyte chemoattractant protein 1 were analyzed.

RESULTS

The plasma ratio of n-6 to n-3 fatty acids was substantially lower after the MID than after the OSD (x +/- SEM: 4.72 +/- 0.19 and 2.60 +/- 0.17, respectively; P < 0.0001). Neither C-reactive protein nor interleukin 6 concentrations changed significantly after the MID compared with the OSD. The total number of leukocytes and platelets was 10% (P < 0.05) and 15% (P < 0.001) lower, respectively, after the MID than after the OSD. Serum VEGF concentrations were lower after the MID than after the OSD (237 +/- 30 and 206 +/- 25 pg/mL, respectively; P = 0.0014).

CONCLUSIONS

A MID reduces the number of platelets and leukocytes and VEGF concentrations in healthy subjects. This may be linked to higher serum concentrations of n-3 fatty acids, which promote a favorable composition of phospholipids.

Nut and seed consumption and inflammatory markers in the multi-ethnic study of atherosclerosis

Nuts and seeds are rich in unsaturated fat and other nutrients that may reduce inflammation. Frequent nut consumption is associated with lower risk of cardiovascular disease and type 2 diabetes. The authors examined associations between nut and seed consumption and C-reactive protein, interleukin-6, and fibrinogen in the Multi-Ethnic Study of Atherosclerosis. This 2000 cross-sectional analysis included 6,080 US participants aged 45-84 years with adequate information on diet and biomarkers. Nut and seed consumption was categorized as never/rare, less than once/week, 1-4 times/week, and five or more times/week. After adjustment for age, gender, race/ethnicity, site, education, income, smoking, physical activity, use of fish oil supplements, and other dietary factors, mean biomarker levels in categories of increasing consumption were as follows: C-reactive protein-1.98, 1.97, 1.80, and 1.72 mg/liter; interleukin-6-1.25, 1.24, 1.21, and 1.15 pg/ml; and fibrinogen-343, 338, 338, and 331 mg/dl (all p's for trend < 0.01). Further adjustment for hypertension, diabetes, medication use, and lipid levels yielded similar results. Additional adjustment for body mass index moderately attenuated the magnitude of the associations, yielding borderline statistical significance. Associations of nut and seed consumption with these biomarkers were not modified by body mass index, waist:hip ratio, or race/ethnicity. Frequent nut and seed consumption was associated with lower levels of inflammatory markers, which may partially explain the inverse association of nut consumption with cardiovascular disease and diabetes risk.

Putting the 'Ome' in lipid metabolism

The recognition that altered lipid metabolism underlies many metabolic disorders challenging Western society highlights the importance of this metabolomic subset, herein referred to as the lipidome. Although comprehensive lipid analyses are not a recent concept, the novelty of a lipidomic approach lies with the application of robust statistical algorithms to highlight subtle, yet significant, changes in a population of lipid molecules. First-generation lipidomic studies have demonstrated the sensitivity of interpreting quantitative datasets with computational software; however, the innate power of comprehensive lipid profiling is often not exploited, as robust statistical models are not routinely utilized. Therefore, the current review aims to briefly describe the current technologies suitable for comprehensive lipid analysis, outline innovative mathematical models that have the ability to reveal subtle changes in metabolism, which will ameliorate our understanding of lipid biochemistry, and demonstrate the biological revelations found through lipidomic approaches and their potential implications for health management.

Mediterranean diet has no effect on markers of inflammation and metabolic risk factors in patients with coronary artery disease

OBJECTIVE

Mediterranean diet is associated with decreased levels of inflammatory markers and metabolic risk factors in epidemiologic studies and recent trials on patients with metabolic syndrome. Given the recent improvements in medical treatments, it is unclear if such beneficial effects are also present in patients with coronary artery disease (CAD). We therefore investigated the effect of Mediterranean diet on markers of inflammation and metabolic risk factors in patients with treated CAD.

DESIGN

Randomized, controlled trial.

SUBJECTS

A total of 101 patients (59.4+/-8.6 years, 23% female) with established and treated CAD (80% statins).

INTERVENTIONS

Participants were assigned to a Mediterranean diet group (MG; n=48) with a 1-year program of 100 h of education, or to a written advice-only group (AG; n=53). Before and after intervention, we measured serum high-sensitivity C-reactive protein (hs-CRP), fibrinogen, fasting insulin, homocysteine, serum lipids and plasma fatty acids.

RESULTS

The Mediterranean diet program increased the intakes of fish, fruits/vegetables and moderately of canola/olive oil and increased plasma concentrations of long-chain n-3 polyunsaturated fatty acids in the MG. Median hs-CRP and mean fibrinogen, homocysteine, fasting insulin, triglycerides and serum cholesterols remained unchanged in both groups.

CONCLUSIONS

Adoption of a Mediterranean diet by patients with medically treated CAD has no effect on markers of inflammation and metabolic risk factors.

SPONSORSHIP

Alfried Krupp Foundation, Essen, Germany.

Is atrial fibrillation an inflammatory disorder?

There is mounting evidence to support the influence of inflammation in the pathogenesis of atrial fibrillation (AF). Indeed, AF is associated with increased levels of known inflammatory markers, even after adjustment for confounding factors. The renin-angiotensin-aldosterone system (RAAS) appears to play a key role in this process. Atrial biopsies from patients with AF have also confirmed the presence of inflammation. Furthermore, there is preliminary evidence to support a number of drug therapies that have the potential to reduce the clinical burden of AF. In this review, we present an overview of the evidence supporting a link between inflammation and AF, and some of the drug therapies, such as the angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, steroids, fish oils, and vitamin C, that might be efficacious in the prevention of AF by modulating inflammatory pathways.

Effects of dietary fats versus carbohydrates on coronary heart disease: A review of the evidence

Recommendations arising from the traditional diet-coronary heart disease (CHD) paradigm, which focuses on effects of total and saturated fat on serum total and low-density lipoprotein cholesterol, may have failed to reduce CHD risk and inadvertently exacerbated dyslipidemia, insulin resistance, and weight gain, particularly among individuals who are older, female, sedentary, or obese. A suitable dietary paradigm must consider types and qualities of fats and carbohydrates consumed, their effects on a range of intermediary risk factors, and characteristics that may modify individual susceptibility. Based on current evidence, replacement of total, unsaturated, and even possibly saturated fats with refined, high-glycemic index carbohydrates is unlikely to reduce CHD risk and may increase risk in persons predisposed to insulin resistance. In contrast, a diet that is 1) rich in whole grains and other minimally processed carbohydrates; 2) includes moderate amounts of fats (approximately 30%-40% of total energy), particularly unsaturated fats and omega-3 polyunsaturated fats from seafood and plant sources; 3) is lower in refined grains and carbohydrates; and 4) eliminates packaged foods, baked goods, and fast foods containing trans fatty acids, will likely reduce the risk of CHD.

Diet and inflammation: a link to metabolic and cardiovascular diseases

Both epidemiological studies and intervention trials support an important role of diet in reducing the risk of a variety of chronic diseases, including cardiovascular disease, and overall mortality. We discuss available evidence indicating that the generation of a pro-inflammatory milieu might be one mechanism through which unhealthy diets are linked to metabolic and cardiovascular diseases. In practical terms, fully understanding the link between diet and inflammation holds the premise to elucidate the mechanisms by which dietary patterns improve cardiovascular health.

Dietary Fat Intake and Proinflammatory Cytokine Levels in Patients With Heart Failure

BACKGROUND

Dietary fat intake affects proinflammatory cytokine levels of healthy adults. Whether dietary fats have similar effects in patients with heart failure (HF) is unknown. The purposes of this study were to determine (1) effect of dietary fat on interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, and soluble receptors sTNF-R1 and sTNF-R2 levels in patients with HF and (2) subsequent impact of these levels on event-free survival.

METHODS AND RESULTS

Forty-two patients provided 4-day food diaries and blood for cytokines. Event-free survival curves were calculated by Kaplan-Meier method and groups compared using log-rank test. IL-6 was not related to fat intake. TNF-alpha levels were elevated in patients with diets higher versus lower in saturated (6.9 +/- 5 versus 4.2 +/- 2 pg/mL) and trans fats (6.8 +/- 4.5 versus 4.5 +/- 2.8 pg/mL). Patients consuming diets higher in polyunsaturated fats had lower sTNF-R1 (2391 +/- 1010 versus 3373 +/- 2098 pg/mL) and sTNF-R2 (3803 +/- 1187 versus 5974 +/- 3275 pg/mL) levels. Higher omega-3 intake produced similar results: sTNF-R1 (2323 +/- 1304 versus 3307 +/- 1973) and sTNF-R2 (4117 +/- 2646 versus 5409 +/- 2801). Event-free survival was decreased in patients with higher TNF-alpha and sTNF-R1 levels.

CONCLUSION

Dietary fat intake may affect proinflammatory cytokine levels in patients with HF. Research to determine whether changing composition of dietary fat can alter proinflammatory cytokine activity of HF patients is warranted.

Biomarkers of inflammation and progression of chronic kidney disease

BACKGROUND

Chronic kidney disease is associated with higher levels of inflammatory biomarkers. Statins have anti-inflammatory properties and may attenuate loss of kidney function. Although inflammation may mediate progressive renal injury, the relation between statin use, markers of inflammation, and the rate of kidney function loss has not been elucidated. We examined the association between pravastatin use, levels of C-reactive protein (CRP), soluble tumor necrosis factor receptor II (sTNFrii), and the rate of kidney function loss.

METHODS

We performed a post hoc analysis of data from a randomized placebo controlled trial of pravastatin 40 mg daily in people with previous myocardial infarction. Glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease Study (MDRD) GFR equation. We studied 687 subjects with chronic kidney disease (GFR < 60 mL/min/1.73 m(2)) who did not experience a cardiovascular event during follow-up. Multivariate linear regression was used to study the relation between baseline CRP and sTNFrii and the rate of kidney function loss in mL/min/1.73 m(2)/year. Cross-product interaction terms were used to determine if these relations varied with pravastatin use.

RESULTS

Median baseline GFR was 54.5 mL/min/1.73 m(2) (interquartile range 49.7, 57.8) and median duration of follow-up was 58 months. Higher baseline CRP level was independently associated with more rapid kidney function loss (highest tertile 0.6 mL/min/1.73 m(2) per year faster than lowest tertile) (P= 0.001). A similar independent relation was observed between tertile of sTNFrii and rate of kidney function loss (highest tertile 0.5 mL/min/1.73 m(2) per year faster than lowest tertile) (P= 0.006). Subjects with both CRP and sTNFrii in the highest tertile ("inflamed" status) appeared to derive more renal benefit from pravastatin than those without (P for interaction 0.047). In these 108 subjects, renal function loss in pravastatin recipients was 0.8 mL/min/1.73 m(2)/year slower than placebo (95% CI 0 to 1.5 mL/min/1.73 m(2)/year slower) (P= 0.039).

CONCLUSION

Higher CRP and sTNFrii are independently associated with faster rates of kidney function loss in chronic kidney disease. Pravastatin appears to prevent loss of kidney function to a greater extent in individuals with greater evidence of inflammation, although this was of borderline significance. These data suggest that inflammation may mediate the loss of kidney function among subjects with chronic kidney disease and concomitant coronary disease.

Effects of omega-3 polyunsaturated fatty acids on plasma indices of thrombogenesis and inflammation in patients post-myocardial infarction

OBJECTIVE

To determine the effects of n-3 PUFAs supplementation on plasma indices of coagulation (fibrinogen), fibrin D-Dimer (an index of thrombogenesis and fibrin turnover), endothelial damage/dysfunction (von Willebrand factor (vWf)), platelet activation (soluble P-selectin (sP-sel)) and inflammation (interleukin-6, IL-6) in patients following acute myocardial infarction.

METHODS

Open-labelled randomised controlled trial. Seventy-seven post-myocardial infarction (MI) patients stabilized on standard secondary prevention therapy were randomised either to 3 months' treatment with Omacor 1 g/day (n=37) or 'usual care' control (n=40). Plasma levels of fibrinogen, D-Dimer, vWf, sP-sel, IL-6 and plasma viscosity at baseline and after 3 months were determined.

RESULTS

At baseline, there were no significant differences between the groups in all research indices, except vWf levels were higher in patients allocated to Omacor supplementation. After 3 months, there were no significant changes in the levels of any research indices in either the Omacor supplemented or the 'usual care' control patients when compared to baseline. Patients who received Omacor experienced a fall in total cholesterol (p=0.019), total/HDL-cholesterol ratio (p=0.009) and LDL-cholesterol (p=0.023). However, the relative changes in plasma lipids and lipoproteins did not differ between the two groups.

CONCLUSIONS

Three-month supplementation of Omacor at 1 g per day in post-MI patients is not associated with an improvement in the levels of peripheral indices of coagulation potential, endothelial function, platelet reactivity and inflammation.

Omega-3 fatty acid supplementation in patients with chronic epilepsy: a randomized trial

Animal studies and a preliminary clinical observation suggest that nutritional supplementation with long chain omega-3 fatty acids (omega-3 FAs) may be useful in the nonpharmacological treatment of patients with epilepsy. Omega-3 FAs increase seizure thresholds, and lower inflammatory mediators, which are increased in patients with epilepsy. In this first randomized, placebo-controlled parallel group trial of omega-3 FA supplementation with 1 g eicosapentaenoic acid (EPA) and 0.7 g docosahexaenoic acid (DHA) daily, 57 patients completed a 12-week double-blind phase. Seizure frequency was reduced over the first 6 weeks of treatment in the supplement group, but this effect was not sustained. The supplementation produced a significant increase in EPA and DHA concentrations and a reciprocal fall in arachidonic and linoleic acid concentrations. No change in serum AED concentrations was detected. Further studies are required to examine different omega-3 FA preparations, different doses, longer treatment duration, and larger sample sizes.

Intake of n-6 and n-3 fatty acids and fish and risk of community-acquired pneumonia in US men

BACKGROUND

Essential fatty acids modulate inflammation and glucose metabolism and may alter infection risk.

OBJECTIVE

We examined the association between intakes of n-6 and n-3 fatty acids and fish and the risk of community-acquired pneumonia.

DESIGN

We prospectively evaluated 38,378 male US health professionals aged 44-79 y at the outset. We updated medical and lifestyle information biennially through questionnaires and diet every 4 y with the use of a validated food-frequency questionnaire. We excluded men who reported pneumonia, myocardial infarction, stroke, other heart disease, arterial surgery, cancer, or asthma before 1990 or those with incomplete dietary data. Community-acquired pneumonia was determined by blinded medical record review of chest radiographs.

RESULTS

During 10 y of follow-up, there were 441 new cases of nonfatal community-acquired pneumonia. Pneumonia risk was lower in men in the highest energy-adjusted quintiles of intake than in men in the lowest quintiles of intake of linoleic acid [multivariate relative risk (RR): 0.70; 95% CI: 0.51, 0.96; P for trend = 0.01] and alpha-linolenic acid (multivariate RR: 0.68; 95% CI: 0.50, 0.93; P for trend = 0.01). Pneumonia risk decreased 4% for every 1-g/d increase in linoleic acid intake (multivariate RR: 0.96; 95% CI: 0.93, 0.99). Pneumonia risk was reduced by 31% for every 1-g/d increase in alpha-linolenic acid intake (multivariate RR: 0.69; 95% CI: 0.51, 0.93). Intakes of eicosapentaenoic acid and docosahexaenoic acid were not significantly related to pneumonia risk.

CONCLUSION

Higher intakes of alpha-linolenic and linoleic acids and possibly of fish may reduce the risk of pneumonia.

Association between nutrient intake and peripheral artery disease: results from the InCHIANTI study

BACKGROUND

Little is known about the relationship between dietary patterns and peripheral arterial disease (PAD). Our aim was to estimate the association between nutrient intake and diagnosis of PAD.

METHODS AND RESULTS

We assessed the nutrient intake of 1251 home-dwelling subjects enrolled in the InCHIANTI study, mean age 68 years (S.D.: 15). We explored the relationship between nutrient intake, obtained through the European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire, and PAD, defined as an ankle-brachial index (ABI)<0.90. After adjustment for potential confounders, we found a reduction of the risk of having an ABI<0.90 associated with vegetable lipid intake>or=34.4 g/day (OR: 0.39; 95% CI: 0.16-0.97), Vitamin E intake>or=7.726 mg/day (OR: 0.37; 95% CI 0.16-0.84) and higher serum HDL cholesterol concentration (OR: 0.76; 95% CI: 0.63-0.92 for 10mg/dl increase). Age (OR: 1.11; 95% CI 1.07-1.14 for 1 year increase), smoking (OR: 1.03; 95% CI: 1.01-1.04 for 10 packs/year increase) and pulse pressure (OR: 1.11; 95% CI: 1.03-1.19 for 5 mmHg increase) were associated with an increased risk of PAD.

CONCLUSIONS

A higher intake of vegetable lipids, Vitamin E and higher concentrations of serum HDL cholesterol characterize subjects free from PAD. Prospective studies are needed to verify whether this dietary pattern and/or interventions aimed at increasing HDL cholesterol exert some protective effect against PAD.

Moderate alcohol consumption and lower levels of inflammatory markers in US men and women

OBJECTIVE

Moderate alcohol consumption is associated with substantially lower risk of cardiovascular disease (CVD). We assessed the relationship between alcohol intake and inflammatory markers to partially explain this beneficial effect.

METHODS AND RESULTS

From two large prospective studies, we sampled 959 healthy male and 473 healthy female health professionals with reported alcohol intake. Markers of inflammation were soluble tumor necrosis factor-alpha receptors 1 and 2 (sTNF-R1 and sTNF-R2), C-reactive protein (CRP), and interleukin-6 (IL-6). We found significant inverse linear trends for sTNF-R1 (p-trend<0.001 men; 0.03 women) and sTNF-R2 (p-trend=0.002 men; 0.08 women) with increasing alcohol intake. Compared to non-drinkers, men who consumed on average 1-2 drinks/day had 26% lower CRP (-0.66 mg/L, p=0.13), and 36% lower IL-6 (-1.12 pg/ml, p=0.02) levels. Among women, a similar though stronger association was observed at half drink per day. Compared to non-drinkers, both men and women who consumed 1-2 drinks/drinking day had significantly lower sTNF-R1 (-9% in men, -6% in women) and sTNF-R2 (-7% in men, -6% in women) levels as well as lower CRP (-10% in men, -32% in women) and IL-6 (-45% in men, -27% in women) levels.

CONCLUSIONS

Alcohol in moderation is associated with lower levels of inflammatory markers and may lower risk of CVD through these mechanisms.

Direct comparison of dietary portfolio vs statin on C-reactive protein

BACKGROUND

3-Hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) markedly reduce serum cholesterol and have anti-inflammatory effects. The effect of cholesterol-lowering diets on inflammatory biomarkers is less well known.

OBJECTIVE

To compare the efficacy of a dietary combination (portfolio) of cholesterol-lowering foods vs a statin in reducing C-reactive protein (CRP) as a biomarker of inflammation linked to increased cardiovascular disease risk.

METHODS

In all, 34 hyperlipidemic subjects completed three 1-month treatments as outpatients in random order: a very low-saturated fat diet (control); the same diet with 20 mg lovastatin (statin); and a diet high in plant sterols (1.0 g/1000 kcal), soy protein (21.4 g/1000 kcal), viscous fibers (9.8 g/1000 kcal), and almonds (14 g/1000 kcal) (portfolio). Fasting blood samples were obtained at weeks 0, 2, and 4.

RESULTS

Using the complete data, no treatment reduced serum CRP. However, when subjects with CRP levels above the 75th percentile for previously reported studies (> 3.5 mg/l) were excluded, CRP was reduced similarly on both statin, -16.3 +/- 6.7% (n = 23, P = 0.013) and dietary portfolio, -23.8 +/- 6.9% (n = 25, P = 0.001) but not the control, 15.3 +/- 13.6% (n = 28, P = 0.907). The percentage CRP change from baseline on the portfolio treatment (n = 25) was greater than the control (n = 28, P = 0.004) but similar to statin treatment (n = 23, P = 0.349). Both statin and portfolio treatments were similar in reducing CRP and numerically more effective than control but only the change in portfolio was significant after the Bonferroni adjustment.

CONCLUSIONS

A combination of cholesterol-lowering foods reduced C-reactive protein to a similar extent as the starting dose of a first-generation statin.

Fish Consumption Among Healthy Adults Is Associated With Decreased Levels of Inflammatory Markers Related to Cardiovascular Disease

OBJECTIVES

The aim of this work was to investigate the association between fish consumption and levels of various inflammatory markers among adults without any evidence of cardiovascular disease.

BACKGROUND

Fish consumption has been associated with reduced risk of coronary heart disease, but the mechanisms have not been well understood or appreciated.

METHODS

The ATTICA study is a cross-sectional survey that enrolled 1,514 men (age 18 to 87 years) and 1,528 women (age 18 to 89 years) from the Attica region, Greece. Of them, 5% of men and 3% of women were excluded due to a history of cardiovascular disease. Among others, C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, serum amyloid A (SAA), and white blood cells (WBC) were measured, and dietary habits (including fish consumption) were evaluated using a validated food frequency questionnaire.

RESULTS

A total of 88% of men and 91% of women reported fish consumption at least once a month. Compared to non-fish consumers, those who consumed >300 g of fish per week had on average 33% lower CRP, 33% lower IL-6, 21% lower TNF-alpha, 28% lower SAA levels, and 4% lower WBC counts (all p < 0.05). Significant results were also observed when lower quantities (150 to 300 g/week) of fish were consumed. All associations remained significant after various adjustments were made.

CONCLUSIONS

Fish consumption was independently associated with lower inflammatory markers levels, among healthy adults. The strength and consistency of this finding has implications for public health and should be explored further.

Pathophysiology of metabolic syndrome X and its links to the perinatal period

It is proposed that metabolic syndrome X is initiated in the perinatal period as a low-grade systemic inflammatory condition. Increased consumption of energy-dense diets by pregnant women and lactating mothers suppresses the activities of Delta-6 and Delta-5 desaturases not only in maternal tissues but also in fetal liver and the placenta, resulting in decreased plasma and tissue concentrations of long-chain polyunsaturated fatty acids omega-6 arachidonic acid (AA), omega-3 eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). EPA, DHA, and AA have negative feedback control on tumor necrosis factor-alpha and IL-6 synthesis. Hence, EPA, DHA, and AA deficiencies induced by an energy-dense diet increase generation of tumor necrosis factor-alpha and interleukin-6, markers of inflammation that in turn decrease production of endothelial nitric oxide and adiponectin to induce insulin resistance in maternal and fetal tissues. Increased concentrations of tumor necrosis factor-alpha and interleukin-6 enhance expression and activity of 11beta-hydroxysteroid dehydrogenase type 1 enzyme, which produces abdominal obesity, insulin resistance, hyperlipidemia, hyperphagia, and hyperleptinemia, characteristic features of metabolic syndrome X. Continued consumption of an energy-dense diet in childhood aggravates these molecular events. This implies that supplementation of long-chain polyunsaturated fatty acids (especially AA, EPA, and DHA in appropriate ratios) from the perinatal period through adulthood could prevent, arrest, or postpone development of metabolic syndrome X.

Dietary linolenic acid is inversely associated with calcified atherosclerotic plaque in the coronary arteries: the National Heart, Lung, and Blood Institute Family Heart Study

BACKGROUND

High dietary intake of linolenic acid is associated with a lower risk of cardiovascular disease mortality. However, little is known about the association between linolenic acid and subclinical atherosclerosis.

METHODS AND RESULTS

To examine the association between dietary linolenic acid measured by food frequency questionnaire and calcified atherosclerotic plaque in the coronary arteries (CAC) measured by cardiac CT, we studied 2004 white participants of the National Heart, Lung, and Blood Institute (NHLBI) Family Heart Study aged 32 to 93 years. The presence of CAC was defined on the basis of total CAC score of > or =100. We used generalized estimating equations to estimate odds ratios for the presence of CAC across quintiles of linolenic acid. The average consumption of dietary linolenic acid was 0.82+/-0.36 g/d for men and 0.69+/-0.29 g/d for women. From the lowest to the highest quintile of linolenic acid, adjusted odds ratios (95% CI) for the presence of CAC were 1.0 (reference), 0.61 (0.42 to 0.88), 0.55 (0.35 to 0.84), 0.57 (0.37 to 0.88), and 0.35 (0.22 to 0.55), respectively (P for trend <0.0001), after we controlled for age, gender, education, family risk group, smoking, fruit and vegetable intake, history of coronary artery disease, hypertension, diabetes mellitus, and statin use. When linolenic acid was used as a continuous variable, the multivariate adjusted odds ratio was 0.38 (95% CI, 0.24 to 0.46) per gram of linolenic acid intake. Use of different cut points for CAC score yielded similar results.

CONCLUSIONS

Consumption of dietary linolenic acid is associated with a lower prevalence of CAC in a dose-response fashion in white men and women.

Dietary Marine n-3 Fatty Acids in Relation to Risk of Distal Colorectal Adenoma in Women

Epidemiologic studies of dietary marine n-3 fatty acids and risk of colorectal cancer have been inconsistent, and their relation to risk of colorectal adenoma has not been evaluated in detail. We examined dietary marine n-3 fatty acids and the ratio of marine n-3 to total n-6 fatty acids (n-3/n-6 ratio) in relation to risk of adenoma of the distal colon or rectum among 34,451 U.S. women who were initially free of colorectal cancer or polyps, who completed a semiquantitative food frequency questionnaire in 1980, and who underwent endoscopy from 1980 to 1998. We documented 1,719 distal colorectal adenoma cases (705 large adenomas, 897 small adenomas, 1,280 distal colon adenomas, and 505 rectal adenomas) during 18 years of follow-up. Neither dietary marine n-3 fatty acids nor n-3/n-6 ratio were associated with risk of total distal colorectal adenoma after adjustment for age and established risk factors [multivariable relative risk (RR) for extreme quintiles of dietary marine n-3 fatty acids = 1.04; 95% confidence interval (95% CI), 0.84-1.27, P(trend) = 0.66; RR for extreme quintiles of n-3/n-6 ratio = 1.02; 95% CI, 0.83-1.25; P(trend) = 0.86]. Similarly, no significant associations were observed separately for distal colon or rectal adenoma. However, higher intake of dietary marine n-3 fatty acids was nonsignificantly but suggestively inversely associated with large adenoma (RR, 0.74; 95% CI, 0.54-1.01; P(trend) = 0.16) but directly associated with small adenoma (RR, 1.36; 95% CI, 1.02-1.81; P(trend) = 0.09). Our findings do not support the hypothesis that a higher intake of marine n-3 fatty acids or a higher n-3/n-6 ratio reduces the risk of distal colorectal adenoma but are suggestive that higher intake may reduce the progression of small adenomas to large adenomas.