Low-lipid diet reduces frequency and severity of acute migraine attacks.

BACKGROUND AND AIM: There is uncertainty regarding the prevention of migraine crises by changing the lifestyle of patients. The aim of this randomized, crossover intervention trial was to evaluate the effects of a low lipid intake on the incidence and severity of migraine crises, in comparison to a diet with moderate lipid intake. METHODS AND RESULTS: After a 2-month run-in when patients received preventive medication but were left on their habitual diet, a low-lipid or a normal-lipid diet was randomly prescribed for 3 months and thereafter diets were crossed over for the following 3 months. Headache was diagnosed based on the International Classification of Headache Disorders (IHCD) III criteria. The number and severity of attacks were assessed using a self-reported calendar. Adherence to the diet was assessed by a food frequency questionnaire. An analysis was performed on the 83 episodic or chronic migraineurs (63 female and 20 male), in the age range of 18-57 years, who completed both intervention periods. Obese subjects had a significantly higher number of attacks than those overweight or with normal body weight (24.7 ± 8, 16.3 ± 12, and 15.6 ± 11, respectively, p < 0.03) with a significant relationship between the body mass index (BMI) and the number of monthly attacks (r = 0.238, p < 0.03). The number (2.9 ± 3.7 vs. 6.8 ± 7.5, p < 0.001) and severity (1.2 + 0.9 vs. 1.7 ± 0.9, p < 0.01) of attacks significantly decreased during both intervention periods, with a significant difference in favour of the low-lipid diet. CONCLUSIONS: In this group of patients, the low-lipid diet significantly affected the number and severity of migraine attacks in comparison to a normal-lipid diet. ClinicalTrials.gov Identifier: NCT 01917474.

A new analytical approach for humin determination in sediments and soils.

In this work a new analytical approach is proposed for the recovery of humin present in soil and sediments. The procedure is based on microwave oven treatment for humin deashing. In this way both the treatment time and the concentration of the HCl/HF mixture are significantly reduced (minutes rather than hours, 10% rather than concentrated). By means of the proposed scheme organic matter present in sediment and soil samples can be subdivided into the different fractions (hydrophobic and hydrophilic compounds, fulvic and humic acids, humin) making up the balance of organic carbon. Results obtained for samples characterised by different organic carbon content showed a loss of carbon ranging between 20% and 30%, consistent with previous reports about humin deashing.

Self-monitoring of plasma triglyceride levels to evaluate postprandial response to different nutrients.

Self-monitoring of plasma triglycerides (TG) may be a very useful tool to monitor, on a daily basis, the TG responses to different nutrients, particularly carbohydrates (CHO) and fat, whose influence on postprandial TG levels is not very well known. Therefore, the aim of the present study was to evaluate the TG response of hypertriglyceridemic patients to a similar amount of calories deriving from different sources of CHO and fat. Thirty-nine hypertriglyceridemic patients were randomly assigned to 1 of 2 experimental groups. In 1 group (the fat group), patients were given a standard meal plus a fat supplement of 300 kcal derived from different types of fat (butter, sunflower margarine, olive oil) for dinner, once a week for 3 weeks. In the other group (the CHO group), patients consumed the same standard meal plus a supplement of 300 kcal derived from different types of CHO (bread, coke, fruit). In both groups, patients measured their plasma TG before and 3 hours after each meal by Accutrend GCT (ROCHE, Mannheim, Germany). A subgroup of patients (n = 18) also performed TG determinations 2 hours after the test meals. The 3-hour TG increments were not significantly different between the different test meals (f = 0.671; P =.52); instead, the TG increments induced by fat supplements were significantly higher than those induced by the CHO supplements (f = 14.31; P =.0001). Similar results were also obtained 2 hours after the test meals. In conclusion, this study shows that the 2- and 3-hour TG responses to fat are higher compared with that induced by carbohydrate. This point, especially if confirmed by experiments with more frequent after meal measurements and of longer duration, should be taken into account in defining the best dietary approach to lower plasma TG levels throughout the whole day.

Effects of dietary cholesterol on plasma lipoproteins and their subclasses in IDDM patients.

To compare the effects of dietary cholesterol supplementation in insulin-dependent diabetic (IDDM) patients and normal subjects, 10 male IDDM patients in good glycaemic control (HbA1c 7.3+/-0.9%) (mean+/-SD) and normal plasma lipid levels, and 11 control male subjects of similar age, body mass index and lipid plasma levels underwent a double blind, cross-over, sequential study. Cholesterol supplementation of 800 mg/day or placebo were given for consecutive periods of 3 weeks. The concentration of plasma total cholesterol increased significantly with the dietary cholesterol supplementation compared to placebo in IDDM patients by 6% (p < 0.05) and in control subjects by 9% (p < 0.05). No changes were observed in the concentration of plasma triglycerides in either group. The LDL cholesterol level increased by 12% (p < 0.01) in patients and by 7% (p < 0.05) in control subjects. In patients plasma HDL cholesterol concentration remained the same, while in control subjects it tended to increase after cholesterol supplementation (from 1.14+/-0.26 to 1.23+/-0.27 mmol/l, p = 0.06). During the cholesterol intake period the mean concentration of LDL1, LDL2 and LDL3 subclasses in patients showed a significant increase by 21.0 (p < 0.05), 20.4 (p < 0.001) and 11.1% (p < 0.05), respectively, resulting in an 18.0% increase in mean total LDL mass (p < 0.001) without major changes in LDL composition. In the control subjects the changes in the concentrations of LDL subclasses during cholesterol intake were less and not significant. In the IDDM patients the cholesterol intake did not affect the concentration or composition of HDL subclasses or total HDL mass. In contrast, in control subjects cholesterol intake increased the mean concentration of HDL2a by 12.2.% (p < 0.05) and this increase was significantly different if compared to changes obtained in the patients. In conclusion, compared to normal subjects, in IDDM patients, dietary cholesterol intake increased the LDL particle mass significantly and had no positive effect on HDL.

Increasing the dietary potassium intake reduces the need for antihypertensive medication.

OBJECTIVE: To determine whether an increase in dietary potassium intake from natural foods reduces the need for antihypertensive medication in patients with essential hypertension. DESIGN: Randomized, controlled trial with 1-year follow-up. SETTING: Hypertension outpatient clinic of a university hospital. PATIENTS: Fifty-four patients with well-controlled hypertension, 47 of whom completed 1 year of follow-up. INTERVENTION: Patients were randomly assigned to one of two groups and were given dietary advice aimed at selectively increasing potassium intake (group 1) or at keeping their customary diet unchanged (group 2). During a 1-year follow-up period, drug therapy was reduced in stepwise fashion, according to a fixed protocol, provided that blood pressure remained below 160/95 mm Hg. MAIN RESULTS: Potassium intake was checked monthly by referring to 3-day food records and by measuring 24-hour urinary potassium excretion. Potassium intake increased in group 1 but did not change in group 2 (P less than 0.001). No change was observed in either urinary sodium excretion or in body weight. After 1 year, the average drug consumption (number of pills per day) relative to that at baseline was 24% in group 1 (95% Cl, 15% to 32%) and 60% in group 2 (Cl, 44% to 76%) (P less than 0.001). By the end of the study, blood pressure could be controlled using less than 50% of the initial therapy in 81% of the patients in group 1 (Cl, 66% to 96%) compared with 29% of the patients in group 2 (Cl, 10% to 48%) (P = 0.001). Patients in group 1 ended the study with a lower number of reported symptoms compared with patients in the control group (P less than 0.001). CONCLUSION: Increasing the dietary potassium intake from natural foods is a feasible and effective measure to reduce antihypertensive drug treatment.

Evaluation of new computerized method for recording 7-day food intake in IDDM patients.

OBJECTIVE: To evaluate a new computerized method for recording 7-day food intake. RESEARCH DESIGN AND METHODS: Randomized crossover trial was conducted with patients recording the amount and type of every food and drink consumed during a week by either a computerized device (Food-meter) or recording the data in a diary. Each method was applied twice. Twenty-one insulin-dependent diabetic patients (mean +/- SD age 25 +/- 9 yr) were studied. RESULTS: The two methods showed very good agreement in the evaluation of the patients' diets (1792 +/- 408 vs. 1764 +/- 436 kcal/day, 84 +/- 19 vs. 82 +/- 21 g/day protein, 68 +/- 22 vs. 67 +/- 23 g/day fat, 210 +/- 60 vs. 207 +/- 58 g/day carbohydrate with the conventional and computerized methods, respectively). The variability between the methods and the variability within each method were of similar magnitude. CONCLUSIONS: The Food-meter represents a useful tool for computerizing the 7-day food record. The method is easy, reliable, and time saving. Moreover, it minimizes the risk of transcriptional errors.

Effects of changing amount of carbohydrate in diet on plasma lipoproteins and apolipoproteins in type II diabetic patients.

Eight type II (non-insulin-dependent) normolipidemic diabetic patients (aged 45 +/- 15 yr, body mass index 22 +/- 2 kg/m2, means +/- SD) treated with diet alone or diet plus oral hypoglycemic agents were given, in random order for periods of 15 days, two diets with different carbohydrate (CHO) (40 vs. 60% of total calories) and fat (20 vs. 40%) levels. Simple CHO, fiber, saturated fat, cholesterol, and polyunsaturated-saturated fat ratio were similar in the two diets. Total plasma cholesterol was not significantly affected by dietary changes; conversely, plasma triglyceride (1.38 +/- 0.59 vs. 1.11 +/- 0.39 mM, P less than 0.05) and apolipoprotein CII (3.8 +/- 1.4 vs. 3.3 +/- 0.8 mg/dl) increased significantly after the high-CHO low-fat diet. Among the various lipoproteins, very-low-density lipoprotein (VLDL) was the most affected by diet: VLDL cholesterol concentrations increased from 0.30 +/- 0.19 to 0.43 +/- 0.28 mM (P less than 0.05), and triglyceride concentrations increased from 0.62 +/- 0.33 to 0.88 +/- 0.53 mM (P less than 0.05). In conclusion, increasing the amount of complex CHO in the diet induces an elevation of VLDL in normolipidemic, nonobese, mildly type II diabetic patients.

Metabolic consequences of feeding a high-carbohydrate, high-fiber diet to diabetic patients with chronic kidney failure.

The aim of this study was to compare the metabolic effects of a high-carbohydrate (CHO), high-fiber diet with only moderate protein restriction with those of a low-CHO, low-fiber diet with a low protein content in six diabetic patients with moderate chronic renal failure. The high-CHO, high-fiber diet induced a significant improvement in blood glucose control, a significant decrease in serum cholesterol, and a significant increase in fecal nitrogen losses. Other variables evaluated were not significantly different between the two diets, except for a significant increase in serum phosphorus during the high-CHO, high-fiber diet. N balance was not significantly different from 0 at the end of either dietary period and was very similar for both diets. The high-CHO, high-fiber diet presents many beneficial metabolic effects in diabetic patients with chronic renal failure.

Controlled trial of low calcium versus high calcium intake in mild hypertension.

A controlled trial of the effect of low versus high calcium intake on blood pressure was performed in 15 patients with mild essential hypertension (supine blood pressure after a 1-month run-in period: 145.7 +/- 2.6/97.8 +/- 0.9 mmHg, mean +/- s.e.m.). After a 1-week baseline period on a standard calcium intake (900 mg/day, obtained by giving a 500-mg calcium tablet daily, in addition to a 400-mg calcium diet), the patients were randomly entered into a double-blind crossover study of 4-week low calcium intake (400 mg calcium diet plus two placebo tablets/day) and 4-week high calcium intake (1400 mg/day: 400-mg calcium diet plus two 500-mg calcium tablets/day). Compliance with the diets appeared to be satisfactory, based on the results of food record analysis. No significant blood pressure change was observed at the end of the low-compared to the high-calcium regimen. Serum ionized calcium was slightly, but not significantly lower, while 24-h urinary calcium excretion was significantly reduced during the low-calcium diet. No difference was found in urinary sodium and potassium excretion between the two study periods. We conclude that moderate modifications of oral calcium intake are not associated with changes in blood pressure within the time span of this study.

Different glycaemic responses to pasta, bread, and potatoes in diabetic patients.

To evaluate whether the same amount of carbohydrate (CHO) in different foods gives different glycaemic responses when consumed in the context of a real meal, seven diabetic patients were given in a random order and on alternate days three test meals of identical composition. Each meal consisted of a fixed part to which a 50 g CHO portion of either bread (90 g) or spaghetti (65 g) or potatoes (285 g) was added. The glycaemic response was significantly higher after ingestion of bread than after the spaghetti meal both at 2 (5.9 +/- 0.8 vs 4.3 +/- 0.7 mmol/l X hour, p less than 0.05) and at 5 hours (16.5 +/- 3.6 vs 9.8 +/- 2.3 mmol/l X hour, p less than 0.05). The glycaemic response to the potato meal was similar to that for bread at 2 hours (6.2 +/- 1.2 mmol/l X hour, p less than 0.05 vs spaghetti) and intermediate between the two other test meals at 5 hours (14.6 +/- 4.3 mmol/l X hour). Meal planning for diabetic patients should be based not only on the biochemical properties but also on the glycaemic response to the food.

Separate influence of dietary carbohydrate and fibre on the metabolic control in diabetes.

To clarify the separate influences of digestible carbohydrate and of dietary fibre on blood glucose control and serum lipoproteins, 14 diabetic patients (six Type 1 and eight Type 2) were submitted to three weight-maintaining diets for 10 days each: (1) low carbohydrate/low fibre diet with 42% carbohydrate and 20 g fibre; (2) high carbohydrate/low fibre diet (carbohydrate 53%, fibre 16 g); (3) high carbohydrate/ high fibre diet (carbohydrate 53%, fibre 54 g). In comparison with the low carbohydrate/low fibre diet, the 2-h post-prandial blood glucose and the daily blood glucose profile decreased significantly on the high carbohydrate/high fibre diet, without significant changes during the high carbohydrate/low fibre diet. The diet-induced modifications of blood glucose control were similar in both types of diabetic patients (two-way analysis of variance: F = 5.86, p less than 0.02 for dietary treatment and F = 2.09, NS for type of diabetes). Total and low-density lipoprotein cholesterol were also decreased after the high carbohydrate/high fibre diet in comparison with the low carbohydrate/low fibre diet (p less than 0.001 for both), while they were not significantly modified after the high carbohydrate/low fibre diet. Again the modifications of low density lipoprotein cholesterol induced by diet were similar in both types of diabetic patients (F = 10.02, p less than 0.005 for dietary treatment and F = 0.14 for type of diabetes, NS). High-density lipoprotein cholesterol was lower after the two test diets than after the low carbohydrate/low fibre diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the hypocholesterolemic effect of vegetable proteins.

The hypocholesterolemic effect of dietary vegetable proteins was studied by comparing egg-white protein and fava bean protein concentrate in one normal and seven hypercholesterolemic (six type II A, one II B) persons; five completed the crossover design. To maintain stable body weight, subjects were kept on an isocaloric diet (20% protein, 48% carbohydrate (CH), 32% fat, P/S = 2) for 1 month and then hospitalized for two consecutive 18-day periods while receiving an isocaloric diet of different composition (15% protein, 50% CH, 26% fat, P/S = 2). Women were provided 50 g and men 70 g daily of egg-white or fava bean protein concentrate during the two crossover periods. Hematocrit and fasting plasma or serum were analyzed every 3 days for glucose, insulin, uric acid, creatinine, total and low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and high-density lipoprotein (HDL) cholesterols, and for total and VLDL triglyceride. Dietary adequacy of both proteins was evaluated by measuring plasma concentration of prealbumin, transferrin, and retinol-binding globulin. Insulin and hematocrit did not show any change, nor did any other biochemical variables show significant differences when results were compared at the end of each crossover period. Compared with baseline, fasting plasma glucose significantly decreased on the fava bean diet. Serum total and LDL cholesterol decreased during both diets but were statistically significant only on the egg-white diet. Serum HDL cholesterol significantly decreased only on the fava bean diet. Serum total and VLDL triglyceride did not show any significant change. Labile plasma protein concentration was significantly reduced only on the fava bean diet. In conclusion, the fava bean diet did not show a significant effect on lowering serum total and LDL cholesterol. Such an effect was mild but significant on the egg-white diet, compared with baseline.

Effect of dietary fibre on glucose control and serum lipoproteins in diabetic patients.

To evaluate the effects of a fibre-rich diet on blood glucose and serum lipoproteins, eight diabetic patients, four on insulin and four on oral hypoglycaemic drugs, were put on three different diets, a different one for each consecutive 10-day period: diet A (carbohydrate 53%, fibre 16 g), diet B (carbohydrate 53%, fibre 54 g), and diet C (carbohydrate 42%, fibre 20 g). All diets had identical polyunsaturated/saturated fat ratios. Both 2 h post-prandial glucose and mean daily glucose levels were significantly lower after diet B than after either of the two other diets, as were total and LDL cholesterol levels. Total and VLDL triglyceride levels after diet B were significantly lower than those after diet A but almost identical to those after diet C. HDL cholesterol concentration was not affected by dietary fibre but was significantly increased by the low-carbohydrate diet. A high-fibre, normal-carbohydrate diet (the fibre coming exclusively from foodstuffs with a naturally high content of fibre) improves blood glucose control and decreases the concentration of atherogenic lipoproteins in diabetic patients. This effect is independent of the amount of available carbohydrates in the diet.