Fruit and vegetable consumption, intake of micronutrients, and benign prostatic hyperplasia in US men

BACKGROUND: Nutrients with antioxidant properties or that influence cell growth and differentiation might reduce the risk of benign prostatic hyperplasia (BPH). OBJECTIVE: The objective was to evaluate the association of fruit, vegetable, and micronutrient intakes with BPH. DESIGN: The participants were members of the Health Professionals Follow-Up Study and were aged 46-81 y in 1992. In 1992 and biennially thereafter, the men reported having surgery for an enlarged prostate, and in 1992 and on 3 subsequent questionnaires they completed the American Urological Association symptom index (AUASI). BPH cases were men who reported having surgery or who had an AUASI score of 15-35 (n = 6092). Control subjects were men who had not had surgery and never had an AUASI score >7 (n = 18 373). Men with a score of 8-14 were excluded (n = 7800). Intakes of fruit, vegetables, and antioxidants were assessed with a food-frequency questionnaire in 1986. We calculated odds ratios (ORs) of BPH and 95% CIs using logistic regression. RESULTS: Vegetable consumption was inversely associated with BPH (fifth compared with first quintile-OR: 0.89; 95% CI: 0.80, 0.99; P for trend = 0.03), whereas fruit intake was not. Consumption of fruit and vegetables rich in beta-carotene (P for trend = 0.004), lutein (P for trend = 0.0004), or vitamin C (P for trend = 0.05) was inversely related to BPH. With increasing vitamin C intake from foods, men were less likely to have BPH (P for trend = 0.0009). Neither alpha- nor gamma-tocopherol intake from foods was associated with BPH (P for trend = 0.05 and 0.84, respectively). CONCLUSION: Our findings are consistent with the hypothesis that a diet rich in vegetables may reduce the occurrence of BPH.     

Dietary intake of n-3 and n-6 fatty acids and the risk of prostate cancer

BACKGROUND: Laboratory studies have shown that n-3 fatty acids inhibit and n-6 fatty acids stimulate prostate tumor growth, but whether the dietary intake of these fatty acids affects prostate cancer risk in humans remains unclear. OBJECTIVE: We prospectively evaluated the association between intakes of alpha-linolenic (ALA; 18:3n-3), eicosapentaenoic (EPA; 20:5n-3), docosahexaenoic (DHA; 22:6n-3), linoleic (LA; 18:2n-6), and arachidonic (AA; 20:4n-6) acids and prostate cancer risk. DESIGN: A cohort of 47 866 US men aged 40-75 y with no cancer history in 1986 was followed for 14 y. RESULTS: During follow-up, 2965 new cases of total prostate cancer were ascertained, 448 of which were advanced prostate cancer. ALA intake was unrelated to the risk of total prostate cancer. In contrast, the multivariate relative risks (RRs) of advanced prostate cancer from comparisons of extreme quintiles of ALA from nonanimal sources and ALA from meat and dairy sources were 2.02 (95% CI: 1.35, 3.03) and 1.53 (0.88, 2.66), respectively. EPA and DHA intakes were related to lower prostate cancer risk. The multivariate RRs of total and advanced prostate cancer from comparisons of extreme quintiles of the combination of EPA and DHA were 0.89 (0.77, 1.04) and 0.74 (0.49, 1.08), respectively. LA and AA intakes were unrelated to the risk of prostate cancer. The multivariate RR of advanced prostate cancer from a comparison of extreme quintiles of the ratio of LA to ALA was 0.62 (0.45, 0.86). CONCLUSIONS: Increased dietary intakes of ALA may increase the risk of advanced prostate cancer. In contrast, EPA and DHA intakes may reduce the risk of total and advanced prostate cancer.     

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.     

Foods and nutrients in relation to bladder cancer risk: a case-control study in Aichi Prefecture, Central Japan

To elucidate the role of diet in the etiology of bladder cancer, we conducted a case-control study from 1996 to 1999 in Aichi Prefecture, Central Japan. Cases were patients newly diagnosed with bladder cancer, and one hospital control was selected for each case, matching gender, age, and hospital. A well-validated food frequency questionnaire was adopted to estimate intakes of nutrients and food groups. Odds ratios (ORs) adjusted for smoking and occupational history were computed using conditional logistic models. The analyses based on 297 cases and 295 controls revealed the following. 1) The more the intake of milk and dairy products, the lower the OR; the ORs across quartiles in all subjects were 1.02, 0.73, and 0.52. Fruit intake was negatively associated with the risk, particularly in men (ORs across quartiles = 0.76, 0.77, and 0.52). Green-yellow vegetables were associated with a decreased risk in the highest quartile of consumption in men (OR = 0.57). 2) Dietary intakes of retinol and saturated fatty acids were related to a reduced risk in all subjects (ORs across quartiles = 0.75, 0.54, and 0.66 and 0.55, 0.54, and 0.60, respectively). Monounsaturated fatty acids had an inverse association with bladder cancer risk in men.     

Dietary intake of fatty acids and serum C-reactive protein in Japanese

BACKGROUND: Inflammation has been established as a risk factor for cardiovascular diseases. The relationships of polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids to inflammation are still controversial in Western populations. The relationships are not clear in Japanese whose intake of seafood-based long-chain n-3 PUFAs is high. METHODS: We conducted a cross-sectional epidemiologic study in the Japanese population (1,556 men and 1,461 women aged 35-60). Serum high sensitivity C-reactive protein (CRP) was measured, and intakes of 7 specific fatty acids (% of energy) were evaluated by a validated self-administered dietary history questionnaire. RESULTS: CRP was significantly and inversely related to the intakes of oleic acid (p=0.008) and alpha-linolenic acid (p=0.026) in women after adjustment for confounding factors. A multiple regression analysis showed that, especially in the middle tertile of long-chain n-3 PUFAs (eicosapentaenoic acid and docosahexaenoic acid) intake, CRP was inversely related to the intake of oleic acid and linoleic acid in both sexes and to the intake of alpha-linolenic acid in women. CONCLUSION: Intakes of oleic acid, linoleic acid, and alpha-linolenic acid would reduce serum CRP, especially when the intake of long-chain n-3 PUFAs is at a moderate level in Japanese.     

Contribution of specific foods to fat, fatty acids, and cholesterol in the development of a food frequency questionnaire in Koreans

The present study identified dietary sources of fat, fatty acids, and cholesterol in Koreans residing in and near Seoul. The study also identified foods to be included in a food frequency questionnaire (FFQ) by both contribution analysis (CA) and multiple regression analysis (MRA). Three-day dietary records were collected from 224 subjects (107 men and 117 women) aged 30 to 85 years. Pork was the main source of total fat and the largest contributor to saturated fatty acids (SFA) was beef. MRA identified animal food as the primary source of between-person variance for SFA. Arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid originated primarily from marine products. About a fourth of the total cholesterol intake was derived from chickens' eggs by CA, while chickens' eggs accounted for 46% of the cholesterol intake for between-person variance by MRA. With 10 food items, the FFQ could explain more than half of total intakes except for total fat and n-3 polyunsaturated fatty acids (PUFA), and at least 65% of between-person variances. The percentage coverage in the FFQ ranged from 61% for n-6 PUFA and linoleic acid and to 90% for arachidonic acid. The value of this FFQ is that it can estimate usual dietary food patterns and nutrient intake in Koreans for epidemiological studies. It can also potentially be used to study the relationship between specific diseases and nutrient intakes of interest.     

Dietary intakes of arachidonic acid and alpha-linolenic acid are associated with reduced risk of hip fracture in older adults

PUFA are hypothesized to influence bone health, but longitudinal studies on hip fracture risk are lacking. We examined associations between intakes of PUFA and fish, and hip fracture risk among older adults (n = 904) in the Framingham Osteoporosis Study. Participants (mean age ~75 y at baseline) were followed for incident hip fracture from the time they completed the baseline exam (1988-1989) until December 31, 2005. HR and 95% CI were estimated for energy-adjusted dietary fatty acid exposure variables [(n-3) fatty acids: α-linolenic acid (ALA), EPA, DHA, EPA+DHA; (n-6) fatty acids: linoleic acid, arachidonic acid (AA); and the (n-6):(n-3) ratio] and fish intake categories, adjusting for potential confounders and covariates. Protective associations were observed between intakes of ALA (P-trend = 0.02) and hip fracture risk in a combined sample of women and men and between intakes of AA (P-trend = 0.05) and hip fracture risk in men only. Participants in the highest quartile of ALA intake had a 54% lower risk of hip fracture than those in the lowest quartile (Q4 vs. Q1: HR = 0.46; 95% CI = 0.26-0.83). Men in the highest quartile of AA intake had an 80% lower risk of hip fracture than those in the lowest quartile (Q4 vs. Q1: HR = 0.20; 95% CI = 0.04-0.96). No significant associations were observed among intakes of EPA, DHA, EPA+DHA, or fish. These findings suggest dietary ALA may reduce hip fracture risk in women and men and dietary AA may reduce hip fracture risk in men.     

Platelet phospholipid fatty acid composition and function in vegans compared with age- and sex-matched omnivore controls.

Platelet function and phospholipid composition, plasma lipids and dietary intakes were assessed in 20 vegan subjects and 20 age- and sex-matched omnivore controls. The intakes of saturated fat were lower in the vegans and those of linoleic and linolenic acids were greater. Eicosapentaenoic and docosahexaenoic acids were absent from the diets of the vegans. Plasma total cholesterol and low-density lipoprotein concentrations were lower in the male vegan subjects and those of carotene were greater compared with their controls. The platelet phospholipids of the vegans contained higher proportions of linoleic (18:2n-6) and adrenic (22:4n-6) acids and lower proportions of arachidonic (20:4n-6), eicosapentaenoic (20:5n-3), docosapentaenoic (22:5n-3) and docosahexaenoic (22:6n-3) acids. Template bleeding times, platelet aggregation induced by adenosine diphosphate, compound U44619 and collagen were similar in both groups.     

Dietary fatty acid intake and prostate cancer survival in Örebro County, Sweden

Although dietary fat has been associated with prostate cancer risk, the association between specific fatty acids and prostate cancer survival remains unclear. Dietary intake of 14 fatty acids was analyzed in a population-based cohort of 525 Swedish men with prostate cancer in ?rebro County (1989-1994). Multivariable hazard ratios and 95% confidence intervals for time to prostate cancer death by quartile and per standard deviation increase in intake were estimated by Cox proportional hazards regression. Additional models examined the association by stage at diagnosis (localized: T0-T2/M0; advanced: T0-T4/M1, T3-T4/M0). Among all men, those with the highest omega-3 docosahexaenoic acid and total marine fatty acid intakes were 40% less likely to die from prostate cancer (P(trend) = 0.05 and 0.04, respectively). Among men with localized prostate cancer, hazard ratios of 2.07 (95% confidence interval: 0.93, 4.59; P(trend) = 0.03) for elevated total fat, 2.39 (95% confidence interval: 1.06, 5.38) for saturated myristic acid, and 2.88 (95% confidence interval: 1.24, 6.67) for shorter chain (C4-C10) fatty acid intakes demonstrated increased risk for disease-specific mortality for the highest quartile compared with the lowest quartile. This study suggests that high intake of total fat and certain saturated fatty acids may worsen prostate cancer survival, particularly among men with localized disease. In contrast, high marine omega-3 fatty acid intake may improve disease-specific survival for all men.     

Intake of specific carotenoids and essential fatty acids and breast cancer risk in Montreal, Canada

BACKGROUND: Evidence from previous investigations into the possible role of dietary and serum carotenoid concentrations in the etiology of breast cancer is inconsistent. No study has examined the combined effect of carotenoids and essential fatty acids on the risk of breast cancer. OBJECTIVE: The objective was to assess the possible association between specific and total carotenoids and breast cancer risk and to evaluate the effect modification by diet-related fatty acids and lifestyle factors in the development of breast cancer. DESIGN: A population-based case-control study involving 414 incident cases and 429 controls was conducted in French Canadians in Montreal. Dietary intake was estimated with the use of a validated food-frequency questionnaire in face-to-face interviews. RESULTS: No significant association was apparent between any of the individual or total carotenoids and the risk of breast cancer after adjustment for major underlying determinants of breast cancer. In premenopausal women who ever smoked, an increased risk was related to alpha-carotene [odds ratio (OR) for the upper relative to the lowest quartiles of intake: 2.40; 95% CI: 0.90, 6.41; P for trend = 0.046]. Conversely, a reduced risk was related to beta-carotene (OR: 0.57; 95% CI: 0.26, 1.24; P for trend = 0.05) in women who never used hormone replacement therapy. In postmenopausal women, total carotenoids were positively associated with breast cancer risk in those with a high arachidonic acid intake (OR: 1.92; 95% CI: 0.93, 3.94; P = 0.028 for trend) and inversely associated in those with a high docosahexaenoic acid intake (OR: 0.52; 95% CI: 0.25, 1.07; P for trend = 0.054). CONCLUSION: These findings suggest that the combined high intake of total carotenoids and docosahexaenoic acid may reduce the risk of breast cancer.     

Dietary intakes of fat and risk of Parkinson's disease

Previous epidemiologic studies have generated inconsistent results regarding the associations between fat intakes and risk of Parkinson's disease. The authors investigated these associations in two large, prospective US cohorts. They documented 191 incident cases of Parkinson's disease in men (1986-1998) and 168 in women (1980-1998) during the follow-up. Overall, intakes of total fat or major types of fat were not significantly associated with the risk. The relative risks comparing the highest quintile of animal fat intake with the lowest were 1.42 for men (95% confidence interval (CI): 0.91, 2.20; p for trend = 0.1) and 0.65 for women (95% CI: 0.36, 1.16; p for trend = 0.3). For men, but not women, replacement of polyunsaturated fat with saturated fat was associated with a significantly increased risk (5% of energy intake, relative risk (RR) = 1.83, 95% CI: 1.10, 3.03). Of the individual polyunsaturated fatty acids, arachidonic acid tended to be inversely associated with the risk (pooled RR between extreme quintiles = 0.65, 95% CI: 0.46, 0.91; p for trend = 0.05). Results do not support an important role of overall fat intake in the pathogenesis of Parkinson's disease, but a possible adverse effect of saturated fat for men could not be excluded.     

Nutrient intake of women with and without gestational diabetes with a specific focus on fatty acids

OBJECTIVE: Diet therapy is the cornerstone for the management of gestational diabetes mellitus (GDM). Women with GDM are commonly given dietary advice that broadly focuses on a reduction of total energy and fat consumption. We compared nutrient intake and specifically fatty acids of women with GDM who had received individualized nutritional counseling with those of non-diabetic women who did not. METHOD: Women with GDM (n=44) and healthy pregnant women (n=44) with uncomplicated singleton pregnancies were recruited during the third trimester. Women with GDM were given consultation on diet, health, and macronutrient content of foods commonly consumed by the individual. The non-diabetic group did not receive any dietary advice. Both groups were asked to keep a detailed record of all of foods and fluid consumed over a 4-d period. RESULTS: After dietary counseling, the GDM group had lower intakes of energy (P<0.05), refined sugar (P<0.0001), total and saturated fats (P<0.0001), and monounsaturated (P<0.01) and trans (P<0.0001) fatty acids and higher levels of docosahexaenoic acid and fiber (P<0.05) compared with the non-diabetic group. CONCLUSIONS: Individualized dietary advice was associated with a lower consumption of the target nutrients in women with GDM. Another benefit of the advice was a slight increase in intake of eicosapentaenoic and docosahexaenoic acids, although consumption of omega-3 fatty acids by both groups was well below the recommendations for pregnancy. There is evidence that docosahexaenoic acid modulates insulin resistance and that it is vital for neurovisual development. We suggest that dietary management for women with GDM should foster the current recommendations for essential fatty acids in pregnancy.     

Association between Protein Intake and the Risk of Hypertension among Chinese Men and Women: A Longitudinal Study

This study aimed to examine the relationship between hypertension risk and protein intake in Chinese individuals. Our analysis included 7007 men and 7752 women from 9 China Health and Nutrition Survey waves (1991–2015). The main outcome was incident hypertension. Dietary intake was recorded using a combination of 3 consecutive 24-h recalls and a household food inventory survey. Energy-adjusted cumulative average intakes were analyzed, and Cox proportional hazards regression models were built. After 143,035 person-years of follow-up, 2586 and 2376 new male and female hypertension cases were identified, respectively. In multivariate-adjusted models with dietary protein intakes included as categorical variables, higher animal protein intake was associated with lower hypertension risk in women (p-trend = 0.01), whereas non-significant in men. Plant protein intake showed a significant positive correlation with hypertension risk, while non-significant for total protein. On a continuous scale, restricted cubic spline curves visually revealed L-, J-, and U-shaped associations between hypertension risk and animal-, plant-, and total-protein intakes, respectively, in both sexes (all p-nonlinearity < 0.0001). Our results suggest a beneficial association between intakes of animal, plant, and total proteins and hypertension risk at lower intake levels, and excessive intake of plant or total protein may increase the hypertension risk in the Chinese population.     

Dietary fatty acids and colorectal cancer: a case-control study

Fatty acid effects on colorectal cancer risk were examined in a national prospective case-control study in Scotland (1999-2006), including 1,455 incident cases and 1,455 matched controls. Three conditional logistic regression models adjusted for energy (residual method) and for other risk factors were applied in the whole sample and were stratified by sex, cancer site, age, and tumor staging. Total and trans-monounsaturated fatty acids and palmitic, stearic, and oleic acids were dose-dependently associated with colorectal cancer risk, but these effects did not persist after further energy adjustment. Significant dose-dependent reductions in risk were associated with increased consumption of omega-3 polyunsaturated fatty acids (highest vs. lowest quartile of intake: odds ratio = 0.63, 95% confidence interval: 0.50, 0.80; p < 0.0005 for trend) and of eicosapentaenoic (odds ratio = 0.59, 95% confidence interval: 0.47, 0.75; p < 0.0005 for trend) and docosahexaenoic (odds ratio = 0.63, 95% confidence interval: 0.50, 0.80; p < 0.0005 for trend) acids. These associations persisted after including energy with the nutrient-energy-adjusted term or total fatty acid intake (energy adjusted). The observed different effects of different types of fatty acids underline the importance of type of fat in the etiology and prevention of colorectal cancer.     

Phylloquinone intake as a marker for coronary heart disease risk but not stroke in women

OBJECTIVE: To examine the feasibility of using phylloquinone intake as a marker for coronary heart disease (CHD) and stroke risk in women. DESIGN AND SETTING: Nurses' Health Study, a prospective cohort study during 1984-2000. Dietary data were collected in 1984, 1986, 1990, and 1994 using a validated semiquantitative food frequency questionnaire. SUBJECTS: A total of 72 874 female nurses, aged 38-65 y, without previously diagnosed angina, myocardial infarction (MI), stroke, or cancer at baseline. MAIN OUTCOME MEASURES: Incidence of nonfatal MI, CHD deaths, total CHD events, ischemic, and total strokes. RESULTS: There were 1679 CHD events (1201 nonfatal) and 1009 strokes (567 ischemic). After adjustment for age and lifestyle factors associated with cardiovascular disease risk, the multivariate relative risks (RR) (95% CI) of total CHD from the lowest to the highest quintile category of phylloquinone intake were 1 (reference), 0.80 (0.69-0.94), 0.86 (0.74-1.00), 0.77 (0.66-0.99), and 0.79 (0.68-0.92), P for trend=0.01. Further adjustment for dietary intakes of saturated fat, polyunsaturated fat, trans fatty acids, eicosapentaenoic, and docosahexaenoic acids, cereal fiber, and folate attenuated the association (RR comparing extreme quintiles 0.84 [0.71-1.00], P for trend=0.12). Incidence rates of total or ischemic strokes were not associated with phylloquinone intake. CONCLUSION: The data suggest that high phylloquinone intake may be a marker for low CHD risk. Dietary and lifestyle patterns associated with phylloquinone intakes, rather than intake of the nutrient itself, might account for all or part of the weak association. .     

Intakes of essential n-6 and n-3 polyunsaturated fatty acids among pregnant Canadian women

BACKGROUND: Fetal growth requires n-3 docosahexaenoic acid (DHA), which is derived from the essential n-3 fatty acids in the maternal diet. DHA is accumulated in the developing brain and is critical for normal neural and visual function. Available estimates suggest that 67 mg DHA/d is accumulated by the fetus during the third trimester of gestation. Little is known about n-3 fatty acid intakes in pregnant women, although human milk concentrations of DHA have decreased in recent years. OBJECTIVE: We prospectively determined the n-3 and n-6 fatty acid intakes of 55 pregnant Canadian women. DESIGN: A food-frequency questionnaire was completed at 28 and 35 wk, and plasma n-3 and n-6 fatty acids were measured at 35 wk gestation. The fatty acid composition of approximately 500 foods was analyzed to allow analysis of dietary intakes from specific foods. RESULTS: Intakes, as a percentage of energy, were (macro x +/- SEM) total fat, 28.0 +/- 3.6%; saturated fat, 9.8 +/- 0.3%; monounsaturated fat, 11.2 +/- 0.4%; polyunsaturated fat, 4.7 +/- 0.2%; linoleic acid, 3.9 +/- 0.2%; and alpha-linolenic acid, 0.54 +/- 0.05%. The daily intakes (range) were 160 +/- 20 (24-524) mg DHA/d, 121 +/- 8 (15-301) mg arachidonic acid/d, and 78 +/- 2 (4-125) mg eicosapentaenoic acid/d. The plasma phospholipids had (mg/100 g fatty acid) 5.0 +/- 0.18 DHA, 8.7 +/- 0.18 arachidonic acid, and 0.52 +/- 0.32 eicosapentaenoic acid. CONCLUSION: The low intake of DHA among some pregnant women highlights the need for studies to address the functional significance of maternal fat intakes during pregnancy on fetal development.     

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.     

Assessment of risk associated with specific fatty acids and colorectal cancer among French-Canadians in Montreal: a case-control study

BACKGROUND: Discrepancies in findings on the association between dietary fats and colorectal cancer (CRC) persist, and it is hypothesized that fatty acids (FA) may modulate CRC risk because of their physiological functions. METHODS: Between 1989 and 1993, a case-control study involving 402 cases and 668 population-based controls was conducted among French-Canadians. Dietary intake was assessed by a food frequency questionnaire. RESULTS: Oleic acid was the major FA consumed by the study population. A significant inverse association was found among females between CRC and butyrate (OR = 0.57; 95% CI: 0.34-0.96; P = 0.006), alpha-linoleic acid (ALA) (OR = 0.78; 95% CI: 0.46-1.32; P = 0.016), and w-3 FA (OR = 0.84; 95% CI: 0.50-1.41; P = 0.028), comparing the upper to the lower quartiles of intake. An increased risk was associated with arachidonic acid (AA) (OR = 2.03; 95% CI: 1.16-3.54; P = 0.001) among males, and with the w6/w3 ratio (OR = 1.47; 95% CI: 0.86-2.50; P = 0.001) among females. Arachidonic acid was linked with up to fivefold increased risk (OR = 5.33; 95% CI: 2.04-13.95; P = 0.0004 for trend) among men with high vitamin C intake. Females with low carotenoids intake were at elevated risk associated with AA (OR = 4.07; 95% CI: 1.84-8.99; P = 0.003); eicosapentaenoic acid (OR = 3.50; 95% CI: 1.59-7.71; P = 0.015), and docosahexaenoic acid (OR = 5.77; 95% CI: 2.50-13.33; P = 0.002), comparing the upper with the lower quartiles of intake. CONCLUSION: The results of this study suggest that independently of total energy intake, substituting AA by butyrate, ALA, or omega-3 FA may reduce CRC risk. The role of interactions between vitamin C, total carotenoids, and polyunsaturated FA requires further investigation.     

The independent effects of eicosapentaenoic acid and docosahexaenoic acid on cardiovascular risk factors in humans

PURPOSE OF REVIEW: This review details the independent effects of purified eicosapentaenoic acid and docosahexaenoic acid on cardiovascular risk factors in humans. We report data from the recent literature and our own controlled clinical trials which compared the independent effects of these fatty acids in individuals at increased risk of cardiovascular disease, namely overweight hyperlipidaemic men and treated-hypertensive, type 2 diabetic men and women. We discuss the biological effects of these fatty acids and the potential mechanisms through which they may affect cardiovascular disease risk factors. RECENT FINDINGS: A cardioprotective effect for omega3 fatty acids is supported by prospective studies demonstrating an inverse association between fish intake and coronary heart disease mortality. Data from secondary prevention trials support a reduction in ventricular fibrillation as a primary mechanism for the decreased incidence of myocardial infarction. Clinical trials and experimental studies have shown that omega3 fatty acids have many other potentially important antiatherogenic and antithrombotic effects. Omega-3 fatty acids lower blood pressure and heart rate, improve dyslipidaemia, reduce inflammation, and improve vascular and platelet function. These favourable effects have until recently been primarily attributed to the omega3 fatty acid eicosapentaenoic acid, which is present in large amounts in fish oil. Controlled studies in humans now demonstrate that docosahexaenoic acid, although often present in lower quantities, has equally important anti-arrhythmic, anti-thrombotic and anti-atherogenic effects. SUMMARY: Available evidence strongly suggests that eicosapentaenoic acid and docosahexaenoic acid have differing haemodynamic and anti-atherogenic properties. The effects of the two fatty acids may also differ depending on the target population.