A selection of interesting studies

[Turk]

Olive-oil consumption and health: the possible role of antioxidants.

Owen, R.W., Giacosa, A., Hull, W.E., Haubner, R., Würtele, G., Spiegelhalder, B., & Bartsch, H. (2000)

In the Mediterranean basin, olive oil, along with fruits, vegetables, and fish, is an important constituent of the diet, and is considered a major factor in preserving a healthy and relatively disease-free population. Epidemiological data show that the Mediterranean diet has significant protective effects against cancer and coronary heart disease.

We present evidence that it is the unique profile of the phenolic fraction, along with high intakes of squalene and the monounsaturated fatty acid, oleic acid, which confer its health-promoting properties. The major phenolic compounds identified and quantified in olive oil belong to three different classes: simple phenols (hydroxytyrosol, tyrosol); secoiridoids (oleuropein, the aglycone of ligstroside, and their respective decarboxylated dialdehyde derivatives); and the lignans [(+)-1-acetoxypinoresinol and pinoresinol].

All three classes have potent antioxidant properties. High consumption of extra-virgin olive oils, which are particularly rich in these phenolic antioxidants (as well as squalene and oleic acid), should afford considerable protection against cancer (colon, breast, skin), coronary heart disease, and ageing by inhibiting oxidative stress.

 

[Turk]

Phenolic compounds and squalene in olive oils: the concentration and antioxidant potential of total phenols, simple phenols, secoiridoids, lignansand squalene.

Owen, R.W., Mier, W., Giacosa, A., Hull, W.E., Spiegelhalder, B., & Bartsch, H. (2000)

The aim of this study was to evaluate the phenolic antioxidant and squalene content in a range of olive and seed oils.

A mean of 290 +/- 38 (SEM) mg squalene/100 g was detected. However, while there was a weak significant difference between extra virgin (424 +/- 21 mg/kg) and refined virgin (340 +/- 31 mg/100 g; P<0.05) olive oils, highly significant differences were evident between extra virgin olive oils (P<0.0001) refined virgin olive oils (P<0.0001) and seed oils (24 +/- 5 mg/100 g).

While seed oils were devoid, on average, the olive oils contained 196 +/- 19 mg/kg total phenolics as judged by HPLC analysis, but the value for extra virgin (232 +/- 15 mg/kg) was significantly higher than that of refined virgin olive oil (62 +/- 12 mg/kg; P<0.0001).

Appreciable quantities of simple phenols (hydroxytyrosol and tyrosol) were detected in olive oils, with significant differences between extravirgin (41.87 +/- 6.17) and refined virgin olive oils (4.72 +/- 215; P<0.01). The major linked phenols were secoiridoids and lignans.

Although extra virgin contained higher concentrations of secoiridoids (27.72 +/- 6.84) than refined olive oils (9.30 +/- 3.81) this difference was not significant. On the other hand, the concentration of lignans was significantly higher (P<0.001) in extra virgin (41.53 +/- 3.93) compared to refined virgin olive oils (7.29 +/- 2.56).

All classes of phenolics were shown to be potent antioxidants. In future epidemiologic studies, both the nature and source of olive oil consumed should be differentiated in ascertaining cancer risk.

 

[Turk]

The effects of presleep suggestions on dream affect.

Brunette, R. (2008)

Twenty-four female subjects with a strong dislike for snakes slept in the laboratory for four non-consecutive nights: one adaptation night, one baseline night of REM dream collections and two nights of REM dream collections following presleep suggestion. Subjects were divided into four groups of six, each group receiving a different presleep suggestion. On treatment nights the first group received the suggestion to have pleasant dreams with incorporation of a snake, the second group to have pleasant dreams with the incorporation of a neutral animal, the third group to have unpleasant dreams with the incorporation of a snake and the fourth group to have unpleasant dreams with the incorporation of a neutral animal. In all cases the tape recorded suggestion prescribed a specified context for the dream. It was presented before sleep and after each REM dream collection awakening. On nights two, three and four before sleep and upon awakening in the morning, subjects saw but did not have to touch a live snake. A mood adjective check list (MACL), the Spielberger State Anxiety Test, and a self perception test were administered after each exposure. Dreams were analysed by two judges independently with the Hall and Van de Castle scales and MACL scores were also obtained for each dream.

Results demonstrated that the suggestions were successful in manipulating dream emotionality both positively and negatively. Subjects receiving pleasant suggestions had significantly more positive affect in their dreams than subjects receiving unpleasant suggestions. Conversely, subjects receiving unpleasant suggestions experienced significantly more negative affect in their dreams than subjects receiving the pleasant suggestions. Although the adaptation notion could not be tested, the finding that dream affect can be controlled encourages further experimental studies of the functions of dreams.

 

[Turk]

Sleep deprivation and energy metabolism: to sleep, perchance to eat?

Penev, P.D. (2007)

PURPOSE OF REVIEW: Many people currently sleep only 5-6 h per night. Epidemiological studies have demonstrated that self-reported short sleep is associated with an increased incidence of obesity and diabetes, highlighting the importance of this trend for public health. This finding has triggered renewed research into the mechanisms that link the regulation of mammalian sleep and metabolism.

RECENT FINDINGS: In rodents, periods of starvation are accompanied by increased vigilance and sleep loss, presumably to help maximize food finding and energetic survival, whereas sleep deprivation results in increased energy expenditure and weight loss, consistent with a role of sleep in energy conservation and tissue maintenance. Information about the corresponding processes in humans is limited. Available data indicate that despite the presence of qualitative and quantitative differences, human sleep and metabolism also share reciprocal connections.

SUMMARY: Evolution in an environment with limited resources has established bidirectional links between sleep and energy homeostasis, the molecular mechanisms of which are emerging rapidly. Epidemiological data suggest that the unique ability of humans to restrict their sleep voluntarily in an environment that promotes physical inactivity and overeating may have a negative impact on metabolic health. Randomized intervention trials are needed to confirm the validity of this hypothesis.

 

[Turk]

Do sleep deprivation and alcohol have the same effects on psychomotor performance?

Yegneswaran, B., & Shapiro, C. (2007)

The most recent National Highway Traffic Safety Administration report suggests that drowsiness should be the next public health awareness frontier beyond driving and seatbelt use. Sleep is as important to the human body as food and water are, but most people in the Western society do not get enough sleep. Insufficient sleep or disruptions to the sleep-wake cycle (e.g., those that occur with shift work or traveling to a different time zone) cause the pathophysiological state known as sleep deprivation.

A sleep-deprived individual is accident prone, has impaired judgment, and is more likely to make mistakes. Studies have documented that staying awake for 24 h leads to reduced hand-to-eye coordination, which is similar to having a blood alcohol concentration (BAC) of 0.08%. As a result, sleep deprivation contributes to road accidents and work injuries. Lack of sleep is known to affect psychomotor performance and has been linked to increased risk for emotional problems such as depression. Efforts should be invested into developing a roadside testing device equivalent to the breathalyzer to measure current sleepiness.

 

[Turk]

Elimination of delayed-onset muscle soreness by pre-resistance cardioacceleration before each set.

Davis, W.J., Wood, D.T., Andrews, R.G., Elkind, L.M., & Davis, W.B. (2008)

We compared delayed-onset muscle soreness (DOMS) induced by anaerobic resistance exercises with and without aerobic cardioacceleration before each set, under the rationale that elevated heart rate (HR) may increase blood perfusion in muscles to limit eccentric contraction damage and/or speed muscle recovery.

In two identical experiments (20 men, 28 women), well-conditioned athletes paired by similar physical condition were assigned randomly to experimental or control groups. HR (independent variable) was recorded with HR monitors. DOMS (dependent variable) was self-reported using Borg's Rating of Perceived Pain scale. After identical pre-training strength testing, mean DOMS in the experimental and control groups was indistinguishable (P > or = 0.19) for musculature employed in eight resistance exercises in both genders, validating the dependent variable. Subjects then trained three times per week for 9 (men) to 11 (women) weeks in a progressive, whole-body, concurrent training protocol. Before each set of resistance exercises, experimental subjects cardioaccelerated briefly (mean HR during resistance training, 63.7% HR reserve), whereas control subjects rested briefly (mean HR, 33.5% HR reserve).

Mean DOMS among all muscle groups and workouts was discernibly less in experimental than control groups in men (P = 0.0000019) and women (P = 0.0007); less for each muscle group used in nine resistance exercises in both genders, discernible (P < 0.025) in 15 of 18 comparisons; and less in every workout, discernible (P < 0.05) in 32% (men) and 55% (women) of workouts. Most effect sizes were moderate.

In both genders, mean DOMS per workout disappeared by the fourth week of training in experimental but not control groups. Aerobic cardioacceleration immediately before each set of resistance exercises therefore rapidly eliminates DOMS during vigorous progressive resistance training in athletes.

 

[Turk]

Dietary zinc intake and sex differences in taste acuity in healthy young adults.

McDaid, O., Stewart-Knox, B., Parr, H., & Simpson, E. (2007)

Background: Previous research suggests that adequate dietary zinc intake may be important in determining the sensory experience of food, appetite and consequently, dietary quality. The aim of this pilot study was to explore relationships between taste sensitivity and dietary zinc intake in healthy young adults (age 20-40 years: 24 male, mean age SD = 27 4.86 years; 26 female, mean age SD = 23 2.10).

Method: A signal detection method was used to assess taste acuity for the four basic tastes: sweet (glucose), sour (citric acid), salt (sodium chloride) and bitter (quinine). A 4-day food diary was used to determine dietary intakes of zinc (mg day-super(-1) and salt.

Results: Males reported a higher zinc intake than females (P = 0.001). Higher dietary zinc intake was associated with better taste acuity for salt in females (P = 0.017) but not in males. Acuity for bitter taste appeared to be related to zinc intake in males (P = 0.007) but not females. Among those whose average daily zinc intake was below the RNI, males were less sensitive than females to sour (P = 0.02) and bitter (P = 0.014) taste.

Conclusion: These findings suggest that zinc is more important for taste acuity in males than females and indicate the importance of taking sex differences into account when studying taste acuity.

 

[meanjoebean]

Excellent! Keep them coming!

 

[Smiler51]

Very interesting studies. Please post as many as you have. Highly appreciated!

 

[Turk]

The antimicrobial spectrum of honey and its clinical significance.

Efem, S.E., Udoh, K.T., Iwara, C.I. (1992)

The antimicrobial spectrum of honey was investigated by placing two drops into each of the wells made on culture media on which pure cultures of various organisms obtained from surgical specimens were grown. The organisms were grown under both aerobic and anaerobic environments. Fungal cultures of common fungi causing surgical infections or wound contaminations were mixed with 100%, 50% and 20% unprocessed honey. Growth inhibition was complete in the media containing 100%, partial in media containing 50% and no inhibition was produced by 20% honey.

Unprocessed honey inhibited most of the fungi and bacteria causing wound infection and surgical infection except Pseudomonas aeruginosa and Clostridium oedematiens. Apart from Streptococcus pyogenes which is only moderately inhibited, golden syrup, a sugar syrup with similar physical properties as honey, did not inhibit any of the bacteria or fungi tested, demonstrating that honey is superior to any hypertonic sugar solution in antimicrobial activity. Honey is thus an ideal topical wound dressing agent in surgical infections, burns and wound infections.

 

[Turk]

Color and shopping intentions: The intervening effect of price fairness and perceived affect

Babin, B.J., Hardesty, D.M., & Suter, T.A. (2003)

How do consumers react to various color, lighting, and price point combinations? The results described in this article depict varying consumer reactions with the three-way congruence between a store's environmental cues, consumers' cognitive categories representing known store types, and salient situational shopping motivations.

For fashion-oriented stores, blue interiors are associated with more favorable evaluations, marginally greater excitement, higher store patronage intentions, and higher purchase intentions than are orange interiors. However, the results change substantially when the effect of lighting in combination with color is considered. The use of soft lights with an orange interior generally nullifies the ill effects of orange and produces the highest level of perceived price fairness while controlling for price. Additionally, the results suggest that the effects of environmental and price cues are mediated by consumers' cognitive and affective associations.

 

[Turk]

What's in a steak? A cross-cultural study on the quality perception of beef

Grunert, K.G. (1997)

With the Total Food Quality Model as point of departure, a study is described which analyses how consumers evaluate the quality of beef in a purchase situation in four European countries: France, Germany, Spain and the UK. The study consisted of a series of focus groups and of an extended form of conjoint analysis which allows an estimation of meansend structures. Tradition and security, variation, atmosphere and social life, health, acceptance from family/children/ guests, nutrition, demonstration of cooking abilities, and status are the most important purchasing motives in all four countries. The most important quality aspects of beef are that it tastes good, is tender, juicy, fresh, lean, healthy and nutritious. Purchasing motives as well as quality aspects are uni-dimensional in Germany, Spain, and the UK, while they are multi-dimensional in France. Place of purchase and quality perception are related in all four countries, i.e. the butcher is regarded as a sort of guarantor of high quality. This applies less in the UK than in the other countries, however.

The most important concrete product characteristics which consumers base their quality evaluation on are fat content and colour. Fat is generally negative, and this applies to all aspects of fat. The positive effects of fat on taste and tenderness are not perceived. German consumers prefer dark meat, whereas Spanish consumers tend to prefer light meat. Information about country of origin and breeding and feeding has no effect on quality perception. The results suggest that producers of superior beef have a problem in communicating this quality to consumers, and that a quality grading system developed in co-operation between producer and retailer may be the best way to overcome consumer uncertainty in evaluating the quality of beef.

 

[Turk]

Chefs' opinions of restaurant portion sizes.

Condrasky, M., Ledikwe, J.H., Flood, J.E., & Rolls, B.J. (2007)

OBJECTIVES: The objectives were to determine who establishes restaurant portion sizes and factors that influence these decisions, and to examine chefs' opinions regarding portion size, nutrition information, and weight management.

RESEARCH METHODS AND PROCEDURES: A survey was distributed to chefs to obtain information about who is responsible for determining restaurant portion sizes, factors influencing restaurant portion sizes, what food portion sizes are being served in restaurants, and chefs' opinions regarding nutrition information, health, and body weight. The final sample consisted of 300 chefs attending various culinary meetings.

RESULTS: Executive chefs were identified as being primarily responsible for establishing portion sizes served in restaurants. Factors reported to have a strong influence on restaurant portion sizes included presentation of foods, food cost, and customer expectations. While 76% of chefs thought that they served "regular" portions, the actual portions of steak and pasta they reported serving were 2 to 4 times larger than serving sizes recommended by the U.S government. Chefs indicated that they believe that the amount of food served influences how much patrons consume and that large portions are a problem for weight control, but their opinions were mixed regarding whether it is the customer's responsibility to eat an appropriate amount when served a large portion of food.

DISCUSSION: Portion size is a key determinant of energy intake, and the results from this study suggest that cultural norms and economic value strongly influence the determination of restaurant portion sizes. Strategies are needed to encourage chefs to provide and promote portions that are appropriate for customers' energy requirements.

 

[Turk]

Exploring comfort food preferences across age and gender.

Wansink, B., Cheney, M.M, & Chan, N. (2003)

Building on findings related to physiological and psychological motivations of food preference, this research develops a framework to examine preferences toward comfort foods. Study 1 used a North American survey of 411 people to determine favored comfort foods, and Study 2 quantified the preferences for these foods across gender and across age groups using a stratified sample of 1005 additional people.

Consistent with hypotheses, the findings showed different comfort food preferences across gender and across age. Males preferred warm, hearty, meal-related comfort foods (such as steak, casseroles, and soup), while females instead preferred comfort foods that were more snack related (such as chocolate and ice cream). In addition, younger people preferred more snack-related comfort foods compared to those over 55 years of age. Associations with guilty feelings underscored how these different preferences between males and females may extend to areas of application.

 

[Turk]

Daily consumption of a dark chocolate containing flavanols and added sterol esters affects cardiovascular risk factors in a normotensive population with elevated cholesterol.

Allen, R.R., Carson, L., Kwik-Uribe, C., Evans, E.M., & Erdman, J.W. Jr. (2008)

Previous studies with plant sterols (PS) and cocoa flavanols (CF) provide support for their dietary use in maintaining cardiovascular health. This double-blind, placebo-controlled, cross-over study evaluated the efficacy of daily consumption of a cocoa flavanol-containing dark chocolate bar with added PS on serum lipids, blood pressure, and other circulating cardiovascular health markers in a population with elevated serum cholesterol.

We recruited 49 adults (32 women, 17 men) with serum total cholesterol concentrations of 5.20-7.28 mmol/L and blood pressure of < or = 159/99 mm Hg. Following a 2-wk lead-in utilizing the AHA style diet, participants were randomized into 2 groups and instructed to consume 2 cocoa flavanol-containing dark chocolate bars per day with (1.1 g sterol esters per bar) or without PS. Each 419-kJ bar was nutrient-matched and contained approximately 180 mg CF. Participants consumed 1 bar 2 times per day for 4 wk then switched to the other bar for an additional 4 wk. Serum lipids and other cardiovascular markers were measured at baseline and after 4 and 8 wk. Blood pressure was measured every 2 wk. Regular consumption of the PS-containing chocolate bar resulted in reductions of 2.0 and 5.3% in serum total and LDL cholesterol (P < 0.05), respectively. Consumption of CF also reduced systolic blood pressure at 8 wk (-5.8 mm Hg; P < 0.05).

Results indicate that regular consumption of chocolate bars containing PS and CF as part of a low-fat diet may support cardiovascular health by lowering cholesterol and improving blood pressure.

 

[Turk]

Probiotics as drugs against human gastrointestinal infections.

Sanz, Y., Nadal, I., & Sánchez, E. (2007)

The commensal gut microbiota confer health benefits to their host by helping dietary digestion, regulating gut immunity, maintaining the microbial balance, and preventing pathogen colonization. A number of probiotic strains have been introduced in the market in dietary and pharmaceutical forms. Lactic acid bacteria (e.g. Lactobacillus) and Bifidobacterium constitute the main group of probiotics commercialized for human consumption. The treatment of gastrointestinal infections continues to be complicated due to the expansion of antibiotic resistances. Of the benefits of probiotics, those related to their preventive and therapeutic uses against gastrointestinal infections have an outstanding position, as reflected in a large number of patents. The mechanisms of action of probiotics against gastrointestinal pathogens addressed in diverse patent applications include: (i) modification of the environmental conditions, (ii) competition for nutrients and adhesion sites, (iii) production of antimicrobial metabolites and (iv) modulation of the immune and non-immune defense mechanisms of the host.

The bioactive components of probiotics include cell-wall fractions, surface proteins, nucleic acids, organic and short-chain fatty acids, antimicrobial proteins and other less-well identified soluble factors. The effectiveness of probiotics is supported by solid clinical studies mainly on treatment of acute diarrhea in children and prevention of antibiotic associated disorders.

Currently, probiotics and their bioactive compounds constitute attractive alternative drugs that can help to reduce the use of antibiotics as well as to improve conventional pharmacological therapies. The advances on the knowledge of the intricate host-microbe dialogues within the intestine and extraintestinal sites will result in the future development of a new generation probiotic-based products targeting broader range of pathologies and their etiologic agents.

 

[Turk]

The physiological relevance of the intestinal microbiota--contributions to human health.

Tappenden, K.A., & Deutsch, A.S. (2007)

The intestinal commensal microbiota is a dynamic mixture of essential microbes that develops under key influences of genetics, environment, diet and disease. Population profiles differ along the gastrointestinal tract, from the lumen to the mucosa, and among individuals.The total microbiota population outnumbers the cells in the human body and accounts for 35-50% of the volume of the colonic content.

Key physiological functions of the commensal microbiota include protective effects exerted directly by specific bacterial species, control of epithelial cell proliferation and differentiation, production of essential mucosal nutrients, such as short-chain fatty acids and amino acids, prevention of overgrowth of pathogenic organisms, and stimulation of intestinal immunity. Oral probiotics are living microorganisms that upon ingestion in specific numbers exert health benefits beyond those of inherent basic nutrition. Emerging evidence indicates prophylactic and therapeutic utility for probiotic consumption in gastrointestinal health and disease.

 

[Turk]

Gut microflora as a target for energy and metabolic homeostasis.

Cani, P.D., & Delzenne, N.M. (2007)

PURPOSE OF REVIEW: Gut microbiota plays an important role in health and disease, but this ecosystem remains incompletely characterized and shows a wide diversity. This review discusses new findings that may explain how gut microbiota can be involved in the control of energy and metabolic homeostasis.

RECENT FINDINGS: Over the past 5 years studies have highlighted some key aspects of the mammalian host-gut microbial relationship. Gut microbiota could now be considered a 'microbial organ' placed within a host organ. Recent data suggest that the modulation of gut microbiota affects host metabolism and has an impact on energy storage. Several mechanisms are proposed that link events occurring in the colon and the regulation of energy metabolism.

SUMMARY: Gut microflora may play an even more important role in maintaining human health than previously thought. The literature provides new evidence that the increased prevalence of obesity and type 2 diabetes cannot be attributed solely to changes in the human genome, nutritional habits, or reduction of physical activity in our daily lives. One must also consider this important new environmental factor, namely gut microbiota. Scientists may take into consideration a key question: could we manipulate the microbiotic environment to treat or prevent obesity and type 2 diabetes? This opens up a new area in nutrition research.

 

[Turk]

Probiotic and prebiotic influence beyond the intestinal tract.

Lenoir-Wijnkoop, I., Sanders, M.E., Cabana, M.D. Caglar, E., Corthier, G., Rayes, N., Sherman, P.M., Timmerman, H.M., Vaneechoutte, M., Van Loo, J., & Wolvers, D.A. (2007)

Probiotics and prebiotics have long been appreciated for their positive influences on gut health. Research on the mechanisms and effects of these agents shows that their impact reaches beyond the intestine. Effects on the microecology and pathology of the oral cavity, stomach, and vaginal tract have been observed. Likely mediated through immune influences, systemic effects such as reduced severity of colds or other respiratory conditions, impact on allergy incidence and symptoms, and reduced absences from work or daycare have also been noted. These observations, among others, suggest a broader spectrum of influence than commonly considered for these unique substances.

 

[Turk]

A comparison of bone mineral density and muscle strength in young male adults with different exercise level.

Pettersson, U., Nordström, P., & Lorentzon, R. (1999)

The aim of this study was to investigate any differences in bone mass at different sites between young adults subjected to a high physical activity and a group of young adults with a low level of physical activity. In addition, we compared the relationship among bone mass, muscle strength, and body constitution in these two groups. The reference group consisted of 20 men, age 24.6 +/- 2.3 years, not training for more than 3 hours per week. The ice hockey players consisted of 20 players, age 23.4 +/- 4.9 years, from an ice hockey team in the second highest national Swedish league, training for about 10 hours per week. The groups were matched according to age, height, and weight. Areal bone mineral density (BMD) was measured in total body, head, humerus, spine, pelvis, femur, femoral neck, Ward's triangle, trochanter, femur diaphysis, proximal tibia, and tibia diaphysis using dual energy X-ray absorptiometry.

BMD was significantly higher in the total body (8.1%), humerus (11.4%), spine (12.7%), pelvis (12.4%), femoral neck (10.3%), femur (7.4%), proximal tibia (9.8%), and tibia diaphysis (7.5%) in the high activity group. Fat mass was significantly lower in the high activity group (18.7%). The high activity group also had a significantly higher lean body mass (5.4%) and a significantly higher isokinetic muscle strength of the quadriceps muscle compared with the reference group.

In the reference group, there was a general strong independent relationship between muscle strength of the thigh and all BMD sites, except for the head, tibia diaphysis, and proximal tibia. Furthermore, in the same group, body mass index (BMI) independently predicted pelvis BMD. On the contrary, in the high activity group, muscle strength did not predict any BMD site at all. In the same group, body constitutional parameters (weight, height, and fat mass) independently predicted pelvis BMD, and BMI was shown to be an independent predictor of humerus BMD. The differences in BMD between the groups seem to be site-specific and may be associated with the type and magnitude of loading during off season training and preferentially during ice hockey. High physical activity seems to weaken the relationship between BMD and muscle strength. Hence, impact forces may be of greater importance in regulating bone mass than muscle strength in itself in highly trained athletes.