Luis García-Diz

Analysis of resistant starch : a method for foods and food products

Abstract A method for resistant starch (RS) determination in food and food products is proposed. The main features are: removal of protein; removal of digestible starch; solubilization and enzymatic hydrolysis of RS; and quantification of RS as glucose released. Stomach and intestine physiological conditions (pH, transit time) were approximately simulated. All operations were performed in a 50ml centrifuge tube. Reference materials and food products were analysed by three laboratories. Statistical analysis included repeatability and reproducibility. This procedure is quite satisfactory for starchy foods containing appreciable quantities of RS and it may be useful for nutritional labelling of foodstuffs. For samples containing ⩽ 1% RS, differences are not significant and they can be considered as foods with a negligible RS content.

Effects of grape antioxidant dietary fiber in cardiovascular disease risk factors

OBJECTIVE The objective of the study was to evaluate the effects of a grape product rich in dietary fiber and natural antioxidants on cardiovascular disease risk factors. METHODS A randomized, controlled parallel-group trial was carried out. Thirty-four non-smoking (21 normocholesterolemic and 13 hypercholesterolemic) adults were supplemented for 16 wk with 7.5 g/d of grape antioxidant dietary fiber, a natural product containing 5.25 g of dietary fiber and 1400 mg of polyphenols. Nine non-supplemented non-smokers were followed as a control group. Fasting blood samples, blood pressure, and anthropometric readings were obtained at baseline and at week 16. Subjects were allowed to consume their regular diet, which was monitored weekly. RESULTS Grape antioxidant dietary fiber (7.5 g/d) reduced significantly (P < 0.05) total cholesterol (9%), low-density lipoprotein cholesterol (9%), and systolic and diastolic blood pressures (6% and 5% respectively). Greater reductions in total cholesterol (14.2%) and low-density lipoprotein cholesterol (11.6%, P < 0.05) were observed in hypercholesterolemic subjects. No changes were observed in the control group. There was a reduction of 2.5 points in the Framingham Global Risk Score in the supplemented group. A significant reduction in triacylglycerol concentration took place in the supplemented hypercholesterolemic subjects (18.6%, P < 0.05). CONCLUSION Grape antioxidant dietary fiber showed significant reducing effects in lipid profile and blood pressure. The effects appear to be higher than the ones caused by other dietary fibers, such as oat fiber or psyllium, probably due to the combined effect of dietary fiber and antioxidants.

Regular consumption of a cocoa product improves the cardiometabolic profile in healthy and moderately hypercholesterolaemic adults

Cocoa products present great health potential due to their high content of polyphenols, mainly of flavanols. However, the antioxidant, anti-inflammatory and other health effects of regularly consuming cocoa products seem to depend on the intake and health status of the consumer, etc. and need to be further clarified. A randomised, controlled, cross-over, free-living study was carried out in healthy (n 24) and moderately hypercholesterolaemic (>2000 mg/l, n 20) subjects to assess the influence of regularly consuming (4 weeks) two servings (15 g each) of a cocoa product rich in fibre (containing 33·9 % of total dietary fibre (TDF) and 13·9 mg/g of soluble polyphenols) in milk v. consuming only milk (control) on (1) serum lipid and lipoprotein profile, (2) serum malondialdehyde levels, carbonyl groups, ferric reducing/antioxidant power, oxygen radical absorbance capacity and free radical-scavenging capacity, (3) IL-1β, IL-6, TNF-α, IL-10, IL-8, monocyte chemoattractant protein-1, and vascular and intracellular cell adhesion molecule levels, and (4) systolic and diastolic blood pressure and heart rate. Throughout the study, the diet and physical activity of the volunteers, as well as any possible changes in weight or other anthropometric parameters, were also evaluated. The intake of TDF increased (P< 0·001) to the recommended levels. Serum HDL-cholesterol (HDL-C) levels were increased (P< 0·001), whereas glucose (P= 0·029), IL-1β (P= 0·001) and IL-10 (P= 0·001) levels were decreased. The rest of the studied cardiovascular parameters, as well as the anthropometric ones, remained similar. In conclusion, regularly consuming a cocoa product with milk improves cardiovascular health by increasing HDL-C levels and inducing hypoglycaemic and anti-inflammatory effects in healthy and hypercholesterolaemic individuals without causing weight gain.

Effects of bioactive constituents in functional cocoa products on cardiovascular health in humans

Cocoa manufacturers are producing novel products increasing polyphenols, methylxanthines or dietary fibre to improve purported health benefits. We attempt to explain the contribution of cocoa bioactive compounds to cardiovascular effects observed in previous studies, placing particular emphasis on methylxanthines. We focused on a soluble cocoa product rich in dietary fibre (DFCP) and a product rich in polyphenols (PPCP). Effects of regularly consuming DFCP (providing daily 10.17 g, 43.8 mg and 168.6 mg of total-dietary-fibre, flavanols and methylxanthines, respectively) as well as PPCP (providing daily 3.74 g, 45.3 mg and 109.8 mg of total-dietary-fibre, flavanols and methylxanthines, respectively) on cardiovascular health were assessed in two controlled, cross-over studies in free-living normocholesterolemic and moderately hypercholesterolemic subjects. Both products increased HDL-cholesterol concentrations, whereas only DFCP decreased glucose and IL-1β levels in all subjects. Flavanols appeared to be responsible for the increase in HDL-cholesterol, whereas insoluble-dietary-fibre and theobromine in DFCP were associated with the hypoglycemic and anti-inflammatory effects observed.

Hypotensive, hypoglycaemic and antioxidant effects of consuming a cocoa product in moderately hypercholesterolemic humans

OBJECTIVE The health benefits of dietary fiber and polyphenols in reducing cardiovascular risk have been evidenced. Cocoa husks are a good source of both components and a considerable by-product. A cocoa product rich in cocoa fiber (CP) has been produced from cocoa husks and this study assessed whether its regular consumption may be a strategy to improve lipid profile, serum glucose and antioxidant activity as well as blood pressure in moderately hypercholesterolemic subjects. METHODS In this free-living, non-controlled, non-randomized, two-month-long, open intervention trial. 21 volunteers consumed daily two servings of CP, which provided 12 g of dietary fiber and 283 mg of soluble polyphenols. Subjects were moderately hypercholesterolemic (>200 mg dl(-1)), non-vegetarian, non-smoker, women and men between 18 and 45 years old, with a body mass index under 30 kg m(-2), not suffering from any other chronic pathology. Blood samples were drawn and anthropometric measurements, systolic (SBP) and diastolic (DBP) blood pressures were evaluated at the baseline, and at weeks 2, 4, and 8. Serum lipids, creatinine, uric acid, glucose, C-reactive protein, ferric reducing/antioxidant power and malondialdehyde (MDA) levels were analyzed. RESULTS Glucose (p = 0.019), SBP (p = 0.001), DBP (p = 0.001) and MDA (p = 0.036) decreased, HDL-cholesterol slightly increased, whereas the rest of the parameters remained similar. CONCLUSIONS This preliminary study suggests that CP might be considered part of a dietary approach or a functional food or ingredient for the food industry to achieve hypotensive and hypoglycemic effects in moderately hypercholesterolemic subjects without inducing changes in body weight and waist circumference, although results should be confirmed in a longer, controlled human study.

Food habits and nutritional status of elderly people living in a Spanish Mediterranean city

AIMS The aim of this study was to assess the food habits and nutritional status of free-living, non-institutionalised, elderly people of Torrevieja, a Spanish city located in the Mediterranean coast. METHODS Anthropometric and dietary survey (two 24 hour recalls) were assessed in 200 (83 men and 117 women) free-living elderly people (average age 72.3±6.6 years). RESULTS Just married women accomplished the recommended energy intake. The contribution of macronutrients to the total energy intake was different from the Recommended Intake for the elderly, since it was too derived from proteins, fats, SFA and sugars, but in only small amounts was derived from complex carbohydrates. High percentages of elderly persons showed inadequate intake of calcium, zinc, magnesium, potassium, copper, iodine, folic acid, vitamin A, vitamin D, vitamin E, and riboflavin. Men showed lower micronutrient intake than women. CONCLUSIONS An increase in dietary complex carbohydrate, and a decrease in protein and fats, especially SFA, is recommended. It would be desirable to increase the consumption of fruits, vegetables, whole cereals, fish and skimmed dairy products.

Assessing nutritional status of acute intermittent porphyria patients.

Eur J Clin Invest 2012; 42 (9): 943–952

Haem Biosynthesis and Antioxidant Enzymes in Circulating Cells of Acute Intermittent Porphyria Patients.

The aims of the present study were to explore the expression pattern of haem biosynthesis enzymes in circulating cells of patients affected by two types of porphyria (acute intermittent, AIP, and variegate porphyria, VP), together with the antioxidant enzyme pattern in AIP in order to identify a possible situation of oxidative stress. Sixteen and twelve patients affected by AIP and VP, respectively, were analysed with the same numbers of healthy matched controls. Erythrocytes, neutrophils and peripheral blood mononuclear cells (PBMCs) were purified from blood, and RNA and proteins were extracted for quantitative real time PCR (qRT-PCR) and Western-blot analysis, respectively. Porhobilinogen deaminase (PBGD) and protoporphyrinogen oxidase (PPOX) gene and protein expression was analysed. Antioxidant enzyme activity and gene expression were additionally determined in blood cells, together with protein carbonyl content in plasma. PBMCs isolated from AIP patients presented low mRNA levels of PBGD when compared to controls, while PBMCs isolated from VP patients presented a decrease in PPOX mRNA. PPOX protein content was higher in AIP patients and lower in VP patients, compared to healthy controls. Regarding antioxidant enzymes, PBMCs and erythrocyte superoxide dismutase (SOD) presented statistically significant higher activity in AIP patients compared to controls, while catalase activity tended to be lower in these patients. No differences were observed regarding antioxidant gene expression in white blood cells. Circulating cells in AIP and VP patients present altered expression of haem biosynthetic enzymes, which could be useful for the differential diagnosis of these two types of porphyria in certain difficult cases. AIP patients present a condition of potential oxidative stress similar to VP patients, evidenced by the post-transcriptional activation of SOD and possible catalase impairment.