Dietary Fat

Dietary Fat and Miscarriage

High butter intake doubles miscarriage odds; Oil increases miscarriage risk by 60%

The major type of seasoning fats have showed a direct association with risk of miscarriage. Comparing "high" versus "low" self reported subjective scores of intake (choices were high, intermediate and low), the odds ratios were 2.0  and 1.6 for butter and oil, respectively. (Adjusted for age, BMI, marital status, education, number of previous miscarriages, coffee and alcohol intake before pregnancy)


Replacing saturated fat with unsaturated fat improves embryonic development

Differences were most evident in the expanded blastocyst stage; at this stage, embryos of cows fed flaxseed (high in alpha-linolenic acid) and sunflower seed (high in linoleic acid) diets had more blastomeres than those of cows fed saturated fat (high in palmitic and stearic acids) (115.4, 132.3, and 89.3 cells, respectively). Although our hypothesis was only partially supported, embryonic development was enhanced in Holstein cows fed unsaturated fatty acids compared to those fed saturated fatty acids.

High intake of olive oil associated with small for gestational age deliveries

Women with high consumption of olive oil had an increased risk of delivering a small for gestational age baby [odds ratio  1.6].

High levels of starch and dietary fat increase miscarriage in underweight but not average weight heifers

High levels of dietary starch, together with dietary fatty acid supplementation, reduced blastocyst yields (embryos successfully advancing to blastocyst stage) in low, but not in moderate, body condition score heifers. (Body condition scoring provides an objective indication of the amount of fat cover on a dairy cow).

Dietary Fat and Fertility

Increasing monounsaturated fat in diet improves fertility

In a study of some 17,000 women conducted by the Harvard School of Public Health, researchers were able to define a group of "fertility foods" able to improve odds. Eating more monounsaturated fats (like olive oil) and less trans fats (like the kind found in many baked goods or fast foods) was one of the keys to increasing fertility.

High polyunsaturated / low saturated fat in diet associated with infertility

Infertile women under 50 years consumed more polyunsaturated fat (odds ratio 1.23), less saturated fat (odds ratio 0.83) and had experienced more hangovers during previous year (odds ratio 1.02) than fertile women.

High intake of ALA improves embryo morphology; High intake of EPA and DHA reduces estrogen response

The association between preconception dietary intake of the polyunsaturated fatty acids omega-6 and omega-3 and the estrogen levels and IVF/intracytoplasmic sperm injection outcome were investigated in women in a prospective study. It revealed that high intakes of omega-3 alpha-linolenic acid increase baseline estrogen, high intakes of eicosapentaenoic acid and docosahexaenoic acid reduce estrogen response and the number of follicles after ovarian stimulation, and total omega-3 intake, in particular alpha-linolenic acid and docosahexaenoic acid, improve embryo morphology.

Diet high in EPA and DHA adversely affects embryonic development in mice

Adult female mice were fed a control diet or a diet relatively high in the long-chain n-3 PUFAs (19% of fat, almost entirely DHA and EPA) for 4 wk, and ovulated oocytes or zygotes were collected after gonadotropin stimulation. This study demonstrated that exposure of the oocyte during maturation in the ovary to an environment high in n-3 PUFA resulted in altered mitochondrial distribution and calcium levels and increased production of reactive oxygen species. Despite normal fertilization and development in vitro following IVF, the exposure of oocytes to an environment high in n-3 PUFA during in vivo fertilization adversely affected the morphological appearance of the embryo and decreased developmental ability to the blastocyst stage. This study suggests that high maternal dietary n-3 PUFA exposure periconception reduces normal embryo development in the mouse and is associated with perturbed mitochondrial metabolism, raising questions regarding supplementation with n-3 PUFAs during this period of time.

Dietary Fat and Hormones

Dietary fat raises estrogen levels

A reduction in fat intake has been associated with decreased estrogen levels in dietary intervention studies.

Dietary fat causes estrogen and DHEAS to increase, even more-so in thin and average women

After controlling for age and other potential breast cancer risk factors, serum estrogen was positively associated with the percentage of energy from total fat. The associations of serum estrogen with monounsaturated fat and polyunsaturated fat were of borderline significance. Serum DHEAS was positively associated with the percentage of energy from total fat, saturated fat, monounsaturated fat, and polyunsaturated fat. Serum estrogen and DHEAS concentrations increased 11.8 and 9.3%, respectively, with a 5% increase in the percentage of energy from total fat. These data suggest that a high intake of fat is associated with higher serum levels of estrogen and DHEAS in postmenopausal women.

The percentages of increase in serum estrogen were 12.3%, 25.0% , 29.9%, and 33.9% with a 5% increase in energy from total fat, saturated fat, monounsaturated fat, and polyunsaturated fat, respectively. The corresponding figures for DHEAS were 10.6%, 31.1%, 27.1%, and 20.3%, respectively.

The associations were somewhat stronger after limiting the study subjects to those with lower BMI. For example, estrogen and DHEAS levels were 19.9% and 12.4% higher, respectively, with a 5% increase in the percentage of energy from total fat in women with a BMI ≤ 23 kg/m2 after controlling for the covariates.

High fat diet leads to insulin resistance

Mice were maintained on a high fat diet for 4 weeks. Mice maintained on a low fat diet served as controls. The high fat diet did not alter dopamine release. However, the high fat diet did hamper insulin action as evidenced by diminished glucose disposal during hyperinsulinemia. We show here that short term high fat feeding does not affect dopaminergic neurotransmission in the hypothalamus, whereas it does impair insulin action.

Consuming more polyunsaturated fat and less saturated fat leads to lower estrogen in the luteal phase

After energy intake was adjusted for, the ratio of polyunsaturated to saturated fat (P:S) in the diet was significantly inversely associated with plasma estradiol and estrone (estrogen) during the luteal phase of the menstrual cycle. For each 0.1 increment in the P:S, there was a 7.6% (95% CI: -14.3%, -0.5%) decrease in estradiol and a 6.8% (95% CI: -12.7%, -0.6%) decrease in estrone.

FSH higher in women on a low fat diet

Follicle-stimulating hormone (FSH) was 29% higher in postmenopausal members of the intervention group who adopted a low fat diet than in controls, but there was no difference in levels of estrogen. The intake of all types of fat (saturated fat, linoleic acid, and oleic acid) and dietary cholesterol was lower in the in the intervention group; however, the polyunsaturated/saturated fat ratio did not differ between the groups.

Prolactin lower during times of stress when on low fat or saturated fat diet

Prolactin levels were lower during proestrus-estrus in rats fed a low-fat diet than in animals fed a high-fat diet, statistically independent of the type of dietary fat, but only during [times of stress]. This effect of amount of dietary fat on prolactin in proestrus-estrus animals anesthetized with ether was predominantly present in animals fed polyunsaturated fat and was statistically not significant in rats fed saturated fat diets. During metestrus-diestrus, prolactin levels were significantly lower in animals fed a high-saturated fat diet than in those fed low-saturated fat, low-unsaturated fat, or high-unsaturated fat diets, independent of the blood sampling conditions. No consistent effects on estrogen levels were found in type or amount of dietary fat. This study confirms the hypothesis that effects of dietary fat, particularly polyunsaturated fat, on circulating prolactin occur only during stress. Because stress is a frequent and normal phenomenon, this observation implies that the mammary glands of animals with a high dietary intake of polyunsaturated fat are frequently exposed to higher circulating prolactin concentrations than rats fed a low-fat diet, which may be a major mechanism by which dietary fat enhances rat mammary carcinogenesis.

Low fat diet leads to lower luteal phase estrogen

Fifteen normal premenopausal women followed a low-fat diet for a period of 2 months. Daily fat intake was reduced from 81 g on their customary diet to 36 g on the low-fat diet. A significant reduction in total energy intake and an increase in the dietary polyunsaturated fat: saturated fat ratio was also observed. There was a significant decline in body-weight, percentage body fat and total serum cholesterol, but no significant change in high-density-lipoprotein-cholesterol. 3. Luteal-phase prolactin concentrations were not altered, but there was a significant decline in estrogen concentrations on the low-fat diet

One month increase in dietary fat, with same saturated/unsaturated ratio, does not effect hormone levels

To compare the influence of low- and high-fat diets on hormone metabolism, we studied six premenopausal women over two complete menstrual cycles. After the adjustment period and on the first day of their menses, three subjects were randomly chosen to begin the lowfat diet and three to begin the high-fat diet. The diets were isocaloric and similar in proportions of protein, polyunsaturated:saturated fatty acid ratio, fiber, and cholesterol. These diets were consumed for the duration of the menstrual cycle and then the subjects were switched to the other diet, which they maintained until the end of their second cycle. Fasting blood and 24-h urine samples were collected every other day. No significant differences in plasma luteinizing hormone (LH), progesterone, prolactin, estrone (E1), and estradiol-17 beta (E2) or in urinary E1, E2, and estriol (estrogens) were observed. Prolactin secretion in response to thyrotropin-releasing hormone stimulation was also unchanged. Dietary fat may influence breast-cancer incidence by modulating the hormonal environment; however, an increase in short-term fat intake from 28 to 51 g/1000 kcal did not lead to substantial differences in the hormonal milieu.

Higher dietary fat linked to higher estrogen levels

Analysis of dietary components and plasma estrogens in premenopausal women showed a positive correlation between daily intake of total fat and saturated fat and plasma estrone and estradiol concentrations.

Specific types of energy may be associated with hormone levels, rather than overall intake

Vegetarian estradiol-17 beta and estriol levels were positively correlated with linoleic acid and protein intake, while non-vegetarian prolactin levels were significantly correlated with intakes of oleic and linoleic acids and total fat. The data suggest that specific dietary nutrients were related to the hormonal milieu of these vegetarian and non-vegetarian subjects.

Replacing fat with starch increases LH and progesterone

Results indicate that feeding Starch-rich diets to sows compared with Fat-rich diets, on an isocaloric basis, increases LH pulsatility during early lactation, the preovulatory LH surge, and progesterone production after the LH surge.

High fat diet does not effect prolactin, progesterone or estrogen in mice

We have found no difference in plasma prolactin during the proestrus surge or at the other stages of the estrous cycle in rats fed a diet high (24%) in corn oil that augments DMBA-induced tumorigenesis or a control diet containing 5% corn oil. There was no effect of the same dietary treatment on plasma progesterone or serum estrogenin the same experiments.

Dietary Fat and Thrombosis

High fat diet increases, while Omega 3's lower, blood viscosity and coagulability

Compared with control group, rats injected with a single dose of vitamin D(3) (600,000 U/kg) and fed with a high-fat diet had higher total cholesterol, low density cholesterol, plasma viscosity, whole blood viscosity, fibrinogen and malonaldehyde concentrations, and lower activated partial thromboplastin time, prothrombin time, thrombin time, erythrocyte deformation index, plasma nitric oxide, and total antioxidant capacity. After a 6-week high-fat diet, the rats in treatment group were treated with omega 3 polyunsaturated fatty acids at 250 mg×kg(-1)×d(-1). Compared with the high-fat diet group, omega 3 polyunsaturated fatty acids could reduce blood lipid levels, inhibit atherosclerotic plaque formation, decrease plasma viscosity (1.58 vs 1.81 mPa·s), whole blood viscosity [(4.76 vs 5.47 mPa·s),(4.24 vs 4.91  mPa·s), (4.04 vs 4.58 mPa·s)] and fibrinogen (2.45 vs 2.65 g/L), lower malonaldehyde content (10.1  vs 11.2 µmol/ml), prolong activated partial thromboplastin time, prothrombin time and thrombin time (29.04 vs 26.46 s), (13.86 vs 10.71 s), (23.05 vs 20.90 s), increase erythrocyte deformation index (0.35 vs 0.31), plasma nitric oxide (3.9 vs 2.8 nmol/ml) and total antioxidant capacity levels (8.0 vs 6.7 U/ml).

Replacing dietary fat with canola oil reduces coagulation and inflammation

An increase in the fibrinogen level of the blood is largely caused by the lack of omega-3-alpha-linolenic acid in the diet. A high level of fibrinogen promotes the creation of thrombosis and maintains inflammation within the body. When the omega-3-alpha-linolenic acid level is too low, the body starts to manufacture more harmful omega-6-arachidonic acid out of the omega-6-linoleic acid, creating hormone-like compounds that cause thrombosis and inflammation. The study subjects replaced one-fourth of the food fat (margarine, cheese, butter) they used with rapeseed oil (canola oil). They took about a tablespoon of oil a day, for example, mixed with a salad. The rapeseed oil dose doubled the intake of omega-3-alpha-linolenic acid during the experiment period of six weeks. Due to the regime, all higher-than-average fibrinogen levels decreased by approximately 30 per cent.

Other topics covered under Diet and Miscarriage:

Alcohol, Chocolate, Dairy, Eggs, Fiber, Fruit, L-Arginine, Meat, Methionine, Soy, Vegetables