The epidemiological evidence of the role of dietary saturated fatty acids (SFA) in the development of coronary heart disease (CHD) is inconsistent. We investigated the associations of dietary fatty acids with the risk of CHD and carotid atherosclerosis in men with high SFA intake and high rates of CHD.
In total, 1981 men from the population-based Kuopio Ischemic Heart Disease Risk Factor Study (KIHD), aged 42 to 60 years and free of CHD at baseline in 1984 to 1989, were investigated. Food consumption was assessed with 4-day food recording. Multivariate nutrient-density models were used to analyze isocaloric replacement of nutrients. CHD events were ascertained from national registries. Carotid atherosclerosis was assessed by ultrasonography of the common carotid artery intima-media thickness in 1015 men. During the average follow-up of 21.4 years, 183 fatal and 382 nonfatal CHD events occurred. SFA or trans fat intakes were not associated with CHD risk. In contrast, monounsaturated fat intake was associated with increased risk and polyunsaturated fat intake with decreased risk of fatal CHD, whether replacing SFA, trans fat, or carbohydrates. The associations with carotid atherosclerosis were broadly similar, whereas the associations with nonfatal CHD were weaker.
Our results suggest that SFA intake is not an independent risk factor for CHD, even in a population with higher ranges of SFA intake. In contrast, polyunsaturated fat intake was associated with lower risk of fatal CHD, whether replacing SFA, trans fat, or carbohydrates. Further investigation on the effect of monounsaturated fat on the CHD risk is warranted.
Patients with coronary artery disease are advised to augment their dietary linoleic acid intakes at the expense of saturated fatty acids. We investigated whether the dietary linoleic acid intake of 57 patients with coronary artery disease (47 males, 10 females; ages 61 +/- 10 years) in Curaçao is higher as compared with 77 controls (51 males, 26 females; ages 56 +/- 7 years). For this, we measured plasma cholesterol ester fatty acids, which reflect the dietary fatty acid composition of the preceding weeks. Patients with coronary artery disease and controls had minor differences in cholesterol ester fatty acids. Their cholesterol ester linoleic acid content suggests that the dietary polyunsaturated/saturated fatty acid ratio is far below 1. Comparison with data reported for The Netherlands, Greenland and Crete showed that the dietary fatty acid composition in Curaçao is typically Western with a high intake of saturated fatty acids, a low intake of monounsaturated fatty acids and the consumption of linoleic acid as the predominant polyunsaturated fatty acid. Intake of long chain polyunsaturated fatty acids from fatty fish is low. Reduction of dietary saturated fatty acids, augmentation of fish consumption, and an increase of the alpha-linolenic/linoleic acid ratio are likely to be of benefit to both primary and secondary prevention from coronary artery disease in Curaçao.
This study assesses the association between dietary transfatty acid (TFA) intake and the risk of selected cancers. Mailed questionnaires were completed between 1994 and 1997 in eight Canadian provinces by 1182 incident, histologically confirmed cases of the stomach, 1727 of the colon, 1447 of the rectum, 628 of the pancreas, 3341 of the lung, 2362 of the breast, 442 of the ovary, 1799 of the prostate, 686 of the testis, 1345 of the kidney, 1029 of the bladder, 1009 of the brain, 1666 non-Hodgkin's lymphomas, 1069 leukemias, and 5039 population controls. Information on dietary habits and nutrition intake was obtained using a food frequency questionnaire, which provided data on eating habits 2 years before the study. Odds ratios (OR) and 95% confidenc530e intervals (CI) were derived by unconditional logistic regression to adjust for total energy intake and other potential confounding factors. Dietary TFA were positively associated with the risk of cancers of the colon (OR: 1.38 for the highest vs. the lowest quartile), breast in premenopause (OR: 1.60), and prostate (OR: 1.42). There were a borderline association for pancreas cancer (OR: 1.38; P=0.06). No significant association was observed for cancers of the stomach, rectum, lung, ovary, testis, kidney, bladder, brain, non-Hodgkin's lymphomas, and leukemia, although the ORs for the highest quartile were above unity for all neoplasms considered, except testis. Our findings add evidence that high TFA is associated with an increased risk of various cancers. Thus, a diet low in transfat may play a role in the prevention of several cancers.
The contribution of dietary trans fatty acids (TFAs) on the risk of ischemic heart disease (IHD) has recently gained further support due to the results from large, prospective, population-based studies. Compared to saturated fat, TFAs are, gram to gram, associated with a considerably (2.5- to >10-fold) higher risk increment for IHD. A negative effect on the human fetus and on newborns and an increase in colon cancer risk in adults are possible but, however, still equivocal. Recent findings justify further studies concerning the effect of TFAs on allergic diseases in children and on the risk of type-2 diabetes in adults. The intake of industrially produced TFAs in European countries is decreasing. However, determination of the TFA content in various popular food items collected in Danish shops showed that it is likely that persons with a frequent intake of, e.g., French fries, microwave oven popcorn, chocolate bars, fast food, etc., consume industrially produced TFAs in amounts far exceeding the average intake, and are thereby exposed to an unnecessary health risk. The Danish government has decided that oils and fats containing more than 2% industrially produced TFAs will not be sold in Denmark after the January 1, 2004.
Trans fatty acids constitute 0-30% of the fat in Danish margarines, most in industry and bakery margarines and usually less in table margarine. The trans fatty acids make margarines more solid at room temperature and therefore provide an economical storage advantage. In British and U.S. reports from 1984-1989, the trans fatty acids were more or less acquitted of unhealthy effects. During the last 5-6 years, however, a series of new studies has been published regarding both the connection between the consumption of trans fatty acids and the occurrence of coronary heart disease and the impact on the lipoprotein level in plasma. Studies suggest that the consumption of trans fatty acids from margarine is equally, or perhaps more, responsible for the development of arteriosclerosis than saturated fatty acids. In addition, it is now clear that both the fetus and the breast-fed baby are exposed to trans fatty acids in relation to the mother's consumption. A couple of recent studies suggest a possible restrictive influence of the trans fatty acids on the weight of the fetus. The average consumption of trans fatty acids from margarine in Denmark in 1991 was approximately 2.5 g/day per person. For about 150,000 adult Danes, the consumption is assumed to be more than 5 g/day per person. On this basis, the Danish Nutrition Council recommend that the consumption of trans fatty acids is reduced as much as possible. This can be done by reducing the fat content in food and by reducing the trans fatty acid content in all Danish margarine products to 5% or less. Thereafter, the group of adult Danes, including pregnant and breast-feeding women, with a large consumption of margarine and margarine-containing products, will on average only consume 2 g of vegetable trans fatty acids/day. This corresponds to the consumption in the low-risk groups in the above-mentioned epidemiological studies. In addition, the Danish Nutrition Council encourage the producers of margarines to make products that can be marketed as 'free of trans fatty acids'.
Follow-up studies have suggested that total intake of trans fatty acids (TFA) is a risk factor for gain in body weight and waist circumference (WC). However, in a cross-sectional study individual TFA isomers in adipose tissue had divergent associations with anthropometry. Our objective was to investigate the association between intake of TFA from ruminant dairy and meat products and subsequent changes in weight and WC. Furthermore, potential effect modification by sex, age, body mass index and WC at baseline was investigated.
Data on weight, WC, habitual diet and lifestyle were collected at baseline in a Danish cohort of 30,851 men and women aged 50-64 years. Follow-up information on weight and WC was collected 5 years after enrolment. The associations between intake of ruminant TFA (R-TFA) and changes in weight and WC were analysed using multiple linear regression with cubic spline modelling.
Intake of R-TFA, both absolute and energy-adjusted intake, was significantly associated with weight change. Inverse associations were observed at lower intakes with a levelling-off at intakes >1.2?g/day and 0.4 energy percentage (E %). Absolute, but not energy-adjusted, intake of R-TFA was significantly associated with WC change. An inverse association was observed at lower intakes with a plateau above an intake of 1.2?g/day.
The present study suggests that intake of R-TFA is weakly inversely associated with changes in weight, whereas no substantial association with changes in WC was found.
Although carbohydrate reduction of varying degrees is a popular and controversial dietary trend, potential long-term effects for health, and cancer in specific, are largely unknown.
We studied a previously established low-carbohydrate, high-protein (LCHP) score in relation to the incidence of cancer and specific cancer types in a population-based cohort in northern Sweden. Participants were 62,582 men and women with up to 17.8 years of follow-up (median 9.7), including 3,059 prospective cancer cases. Cox regression analyses were performed for a LCHP score based on the sum of energy-adjusted deciles of carbohydrate (descending) and protein (ascending) intake labeled 1 to 10, with higher scores representing a diet lower in carbohydrates and higher in protein. Important potential confounders were accounted for, and the role of metabolic risk profile, macronutrient quality including saturated fat intake, and adequacy of energy intake reporting was explored.
For the lowest to highest LCHP scores, 2 to 20, carbohydrate intakes ranged from median 60.9 to 38.9% of total energy intake. Both protein (primarily animal sources) and particularly fat (both saturated and unsaturated) intakes increased with increasing LCHP scores. LCHP score was not related to cancer risk, except for a non-dose-dependent, positive association for respiratory tract cancer that was statistically significant in men. The multivariate hazard ratio for medium (9-13) versus low (2-8) LCHP scores was 1.84 (95% confidence interval: 1.05-3.23; p-trend?=?0.38). Other analyses were largely consistent with the main results, although LCHP score was associated with colorectal cancer risk inversely in women with high saturated fat intakes, and positively in men with higher LCHP scores based on vegetable protein.
These largely null results provide important information concerning the long-term safety of moderate carbohydrate reduction and consequent increases in protein and, in this cohort, especially fat intakes. In order to determine the effects of stricter carbohydrate restriction, further studies encompassing a wider range of macronutrient intakes are warranted.