Category Archives: health

Aug 08 NO comments
aging, antioxidants, cardiovascular health, chemistry, cholesterol, French Paradox, grape seed extract, health, phenolics, research, resveratrol

Resveratrol Supplements Shown to Decrease Cardiovascular Disease Risk in the First Long-Term Clinical Research Trial


We've all seen evidence time and time again that red wine is good for your health when consumed in moderation.  Scientists have even broken it down to the molecules, and have found that certain compounds are likely most responsible for the increased health benefits of red wine, with the polyphenol resveratrol being the most widely studied.  Resveratrol (and red wine in general) has been shown to benefit many different health issues, including (but certainly not limited to) diabetes, osteoporosis, dementia, and cardiovascular health.  We've seen short-term studied in laboratory settings, rodents, and some humans, however, what we seem to be missing are long term clinical research trials confirming what scientists have already found in the laboratory.


http://supplementsbase.com/wp-content/
uploads/Resveratrol-Supplements-300x199.jpg
The goal of the short study presented today was to examine the effects of a dietary resveratrol-enriched grape supplement on the inflammatory and fibrinolytic status of patients that were at high risk for cardiovascular disease and who were currently undergoing medical treatment for the prevention of those types diseases.

Methods

This study was a randomized, triple-blinded, placebo-controlled clinical trial with three “parallel arms” (a.k.a. treatments).  The three treatments were a grape extract containing 8mg of resveratrol, a grape extract containing similar polyphenolic content but without resveratrol, and a placebo control (maltodextrin).

Patients currently undergoing cardiovascular disease prevention at the Morales Meseguer University Hospital Cardiology Service in Murcia, Spain were recruited for this study.  To be considered for this study, patients had to be between 18 and 80 years old, have diabetes mellitus or hypercholesterolemia in addition to another cardiovascular disease risk factor including arterial hypertension, tobacco smoking (active), or obesity/overweight.  Patients were not allowed to participate in the study if they were pregnant, outside the age requirement, having documented cardiovascular disease or cerebrovascular disease, regularly intaking food supplements (particularly ones containing antioxidants), or if they had an infectious disease, neoplastic disease, or any other known chronic pathological disease.

There were a total of 75 patients in the study, with 34 men and 41 women.  These patients were randomly assigned to one of three treatment groups (as described above). 

The main factor of study was the change in high-sensitivity C-reactive protein (CRP) levels from baseline to the end of the study (12 months).  CRP rises in response to inflammation, thereby is a good indicator any disease that carries with it inflammation (which can be a large variety of diseases, including cardiovascular diseases).

Treatments were contained within a 370mg hard gelatin capsule which contained 350mg of the product (resveratrol, polyphenols, or placebo) plus 20mg of magnesium stearate and silicon dioxide.

The polyphenol content of the resveratrol and polyphenol treatments were: ~40mg procyanidins, ~25mg anthocyanins, ~1mg flavonols, and ~0.8mg hydroxcinamic acids.  For the resveratrol treatment, in addition to the polyphenols listed about, each capsule contained 8.1+/-0.5mg resveratrol and other derivatives in trace amounts (i.e. piceid and viniferins).

Participants were told to maintain their usual medication schedules and other lifestyle and diet choices throughout the duration of the study.  Participants consumed 1 capsule per day (taken in the morning) for the first 6 months and then 2 capsules per day for the following 6 months to determine if there are any dose-dependent effects.  Patients received 10 boxes of 60 capsules for the entire study.  Any unused capsules were sent back to the site by the patients at the end of the study.

Possible negative side effects were monitored throughout the study by questionnaires and telephone interviews.  Participants were asked to make note of any consumption of grape products (especially red wine) other than their treatment capsules, and also detailed records of their diet 3 days before blood draws.  Questionnaires were taken at 6 months and 12 months time.

Blood samples were collected at baseline, 6 months, and 12 months during the study.  Safety of the capsules were monitored by measuring hepatic, thyroid, and renal functions.

The following serum levels of inflammatory-related markers were measured: IL-6, IL-10, TNF-α, IL-18, sICAM-1, hs-GRP, adiponectin, and PAI-1.  (If you’d like more details on these inflammatory markers, just ask.)

Results

  • There were no significant differences in the inclusion characteristics of participants, except minor but insignificant differences were noticed for age, glucose, glycated hemoglobin.
  • Significant correlations were found between: hs-CRP and PAI-1, IL-6 and hs-CRP, TNF-αand hs-CRP, and adiponectin and sICAM-1 in all treatments.
  • The percentages of patients with greater than 3mg/L at baseline for the placebo group was 54%, for the grape extract with polyphenols only group was 32%, and finally for the grape extract with polyphenols plus resveratrol was 48%.
  • Placebo group:

o   The first 6 months showed a slight increase in IL-6 and was a significant increase by the end of the study.
o   IL-10 (anti-inflammatory) decreased after the 12 month study period.
o   The was a marginally significant (not quite statistically significant) increase in the IL-6/IL-10 ratio (pro-inflammatory) after 12 months.
o   Other inflammatory markers were not significantly different.
o   The percentage of patients with greater than 3mg/L hs-CRP values did not change from baseline to the end of the 12 month period.
  • Grape Extract Plus Polyphenols Only Group:

o   There were no significant changes in any inflammatory markers during the 12 month study period.
o   The percentage of patients with greater than 3mg/L hs-CRP values did not change from baseline to the end of the 12 month period.
  • Grape Extract Plus Polyphenols AND Resveratrol Group:

o   There was a decrease in hs-CRP (the main compound of interest).
§  hs-CRP decreased for 20 out of 25 patients.
§  The percentage of patients with greater than 3mg/L hs-CRP values decreased from 48% at baseline to 30% at the end of the 12 month period.
o   TNF-α and PAI-1 decreased by the end of the study in the resveratrol group.
o   The IL-6/IL-10 ratio decreased, primarily due to an increase in IL-10 levels.
o   sICAM-1 decreased only marginally.
o   Adiponectin significantly increased after 6 months and only marginally increased by 12 months.
o   IL-18 decreased over time, though was not significant.
o   IL-6 did not change over time.
o   Correlations:
§  The decrease in hs-CRP was significantly correlated with the decrease in TNF-α.
§  The decrease in sICAM-1 significantly correlated with the decrease in IL-18.
§  The increase in adiponectin was significantly correlated with the decrease in sICAM-1.
  • Contents of the capsules were deemed safe due to no relevant changes occurring in markers for the hepatic, thyroid, or renal systems.
  • There were no adverse effects noted by any patient in the study.


Conclusions

The results of this study are the first of its kind, according to the authors, to demonstrate that a dietary supplementation of grape extract plus 8mg of resveratrol in capsule form significantly improves the inflammatory and fibrinolytic status of patients that are currently undergoing prevention for cardiovascular diseases.  The authors indicate that the most important finding was the decrease in hs-CRP levels by 26% after 1 year, in addition to a decrease in proinflammatory TNF-a and PAI-1.  As a reminder, CRP rises in response to inflammation, thereby is a good indicator any disease that carries with it inflammation (which can be a large variety of diseases, including cardiovascular diseases).  A decrease in this marker means that inflammation in the system is decreased; which is overall positive result in regards to cardiovascular and other systems health.  It does appear that the higher dose of 2 capsules per day is more effective in reducing the levels of these inflammatory markers, particularly of PAI-1.

It is important to note that the patients in this study were not asked to give up any of their other medications for cardiovascular disease prevention.  Therefore, according to the authors, there is a strong possibility that there is a synergistic effect going on between the statins in the cardiovascular medications and the resveratrol or other compounds in the supplement.  Previous studies have shown that pravastatin and resveratrol are more effective than statins alone in protecting against heart attack in hypercholesterolemic rats, so a synergistic effect in humans should not be ruled out.

The main limitation in this study is that the sample sizes were not very large.  Since participants had to be divided into three treatment groups, therefore the sample size per treatment group was very small.  As a result of this, those results that were found to be marginally significant or not significant may change if more patients were enrolled into the study.  The only way around this is to simply repeat the study with more patients per treatment group.

According to the authors, this is the very first long-term clinical trial examining the effects of a resveratrol supplement on the prevention of cardiovascular disease in humans.  I thought it was a very interesting study, however would certainly like to see it performed with more patients enrolled.  Also, I’d like to see the studied carried out for longer, if possible, in attempt to be able to predict future cardiovascular events in patients consuming resveratrol supplements versus placebo. 

Finally, I’d like to see this study performed using a wider range of demographics.  It was not clear the demographic breakdown of the participants, but with such a low number of subjects, it may have been difficult to analyze these factors regardless.  Would we see these same results in other countries that typically have different diets or lifestyles?  How do these results hold up to the typical American diet and lifestyle? 

What do you all think about this study?  Would you change it?  How so?  Please feel free to leave your comments below!

Source: Tomé-Carneiro, J., Gonzálvez, M., Larrosa, M., Yáñez-Gascón, M.J., Gracía-Almagro, F.J., Ruiz-Ros, J.A., García-Conesa, M.T., Tomás-Barberán, F.A., Espín, J.C. 2012. One-Year Consumption of a Grape Nutraceutical Containing Resveratrol Improves the Inflammatory and Fibrinolytic Status of Patients in Primary Prevention of Cardiovascular Disease. American Journal of Cardiology 110(3): 356-363.

DOI: 10.1016/j.amjcard.2012.03.030.



I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!
Jul 24 NO comments
allergy, casein, enology, fining agents, health, intolerance, milk, research, wine, wine chemistry, wine label, wine residues

Casein Levels in Commercial Wines Not Enough to Elicit Allergic Reaction in Milk Allergy-Stricken Adults



Food allergies are very common in both children and adults, and some fear that wine can be a potential allergenic threat to certain individuals.  From the alcohol in the wine to the chemicals and reagents used in the winemaking process, determining levels of potential allergens in wine for labeling and warning purposes has become the main concern spearheading several legislative measures in Europe and elsewhere all over the globe.

http://i.istockimg.com/file_thumbview_approve/
13418867/2/stock-illustration-13418867-
cartoon-cow-as-a-milk-man.jpg
Milk allergies, which are different from milk intolerances, occur throughout the globe though are more common in children than in adults.  This allergy, in fact, is quite rare, affecting only 0.062% of Italian adults.  In white winemaking, potassium caseinate is often used as a fining agent and is derived from milk.  Potassium caseinate works as a fining agent by binding to compounds that cause cloudiness in wine and allow those compounds to be removed and the final wine clarified.  During this process, there is a chance that not all of the fining agent is removed, thereby causing a potential health risk to those that suffer from milk allergies.

Alternatives to potassium caseinate (or any casein-based compounds) are available to use during the winemaking process to help avoid possible negative health risks due to milk allergy in certain individuals, however, do wines even possess high enough levels of the compound to elicit an allergic response?  The paper presented today aimed to examine the levels of caseinate in many commercial wines, to determine if residual levels are high enough to potentially cause allergic reactions in adults and if adding a warning label to a wine bottle is a necessary precaution. 

Methods

Both experimental and commercial wines were examined in this study.  Experimental wines were put into treatment groups as follows: untreated controls; samples fined with 20g/h L of commercical caseinate; samples fined with 50g/h L; and samples with both of these caseinate dosages with 0, 30, 60, or 90g/h L of bentonite added.

2 liters of wine were first combined with caseinate (at 0, 20, or 50g/h L) then kept at room temperature for 24 hours.  After this time, bentonite was added (at 0, 30, 60, or 90g/h L) and then kept at room temperature for another 24 hours.  All experimental wines were passed through membranes with a pore size of 3μm.  In total, there were 16 experimental wines and 14 controls (not treated with casein).

Commercial wines were sent to the researchers from all over Italy with the requirement that all wines had be fined with casein.  A total of 59 white wines, 2 rosé wines, and 2 red wines were sent in from around Italy.  All commercial wines were filtered through membranes of pore sizes less than or equal to 1um.  Commercial caseinate used in wines were: alpha caseinate, caseinato di potassio, Caseo Cell, Clarasi DC, Clarito Spray Dry, Clarito SP, Kaseomax, Micron 96, Micron XL, potassium caseinate S, Protoclar, and Vinpur Special.

The following characteristics of the wines were measured: alcohol by volume, total alcoholic strength, sugar content, total acidity, volatile acidity, pH, ash, total dry extract, reduced extract, and total phenolic content.

Casein was measured using several methods, including SDS-page/western blotting and ELISA.  Tests were performed in triplicate.

The entire experiment included 16 experimental wines and 63 commercial wines, all fined with caseinates, with or without bentonite, and microfiltered.  Untreated wines were used as controls.

Results

  • SDS-page/western blotting proved to be an ineffective method for measuring casein in wine, as the binding capabilities of the proteins used in that analysis were nonspecific and bound to many more compounds than casein itself, thereby making it impossible to distinguish what compounds were casein, and what compounds were not.
  •  Results indicated that the antibodies used in the ELISA analysis were very specific to caseins and β-caseins, which indicates that detection of casein in commercial wines is guaranteed (according to the authors) using this method.
  • Control wines (no casein added) were found to be completely free of casein by ELISA analysis.
  • All (experimental and commercial) wines were found to be free from detectable levels of allergenic casein residues (less than 0.28ppm).

o   This result was the same of all wines, regardless of the varietal, dosage of fining agent, and winemaking practices.

Conclusions

According to the results of this study, there was no detectable casein residues remaining (less than 0.28ppm) in all wines studied.  This suggests that those individuals with milk allergies should not be concerned about if a wine is treated with casein during the winemaking process.  According to the authors, clinical trials should not need to be performed, since casein was not present in detectable levels that would have any effect on those very few adults with milk allergies.

The authors put forth a “worst case scenario” situation in order to stress how little casein is actually present in Italian commercial wines which I will describe here.  Clinical evidence has shown that the 0.6mg of milk protein (casein) can cause major problems in some children with milk allergies (children are more sensitive than adults, in general, to milk protein).  If an adult were sensitive to that level of casein/milk protein, they would have to consume 1.2 liters of wine in a short period of time in order to elicit an allergic reaction.  Since the adult threshold for casein/milk protein sensitivity is more along the levels of 10mg (instead of 0.6mg), it is near impossible for commercial wines to elicit allergic reaction in those individuals affected by a milk protein allergy.

I’d be curious to see an analysis of casein levels from all over the world; however, I’m fairly certain that we’d see the same results that we are seeing in this study.  Individuals with a true allergy to milk (NOT a lactose intolerance, which is a different medical problem) should not be concerned if a wine was treated with casein during the winemaking process, nor there a need to require labeling a wine as having undergone casein treatment.

I’d love to hear what you all think about this topic!  Please feel free to leave your comments!

Source: Restani, P., Uberti, F., Danzi, R., Ballabio, C., Pavanello, F., and Tarantino, C. 2012. Absence of allergenic residues in experimental and commercial wines fined with caseinates. Food Chemistry 134: 1438-1445.

DOI: 10.1016/j.foodchem.2012.03050



I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!
Jul 19 NO comments
antioxidants, chemistry, enology, grapes, health, melatonin, research, wine, wine chemistry

Identifying Melatonin in Wine: A "New" Antioxidant with Potential Positive Health Benefits Found



Almost a year ago, The Academic Wino presented an article that examined the role of melatonin in grapes.  Results of that study found that melatonin fluctuates in the grape vine and grapes during the day, and that in order to create a wine with higher levels of melatonin, one must harvest the grapes at an optimum time.  One thing this article did not examine was the levels of melatonin in wine itself, and whether or not these levels would be detectable in the finished wine after going through the winemaking process.

http://upload.wikimedia.org/wikipedia/commons
/thumb/1/14/Melatonin2.svg/
220px-Melatonin2.svg.png
Melatonin is a compound found in many life forms that is synthesized from L-tryptophan metabolism via serotonin (think “turkey coma”) and is considered both an antioxidant and a compound that aides in regulating circadian rhythms.  In humans (and other vertebrate species), melatonin is synthesized by the pineal gland and secreted into the blood stream.  Melatonin tends to be highest in younger humans/vertebrates, and decreases with age.  Melatonin is also found in the leaves, fruits, and seeds of plants, the purpose of which is not entirely understood, but some have speculated is a defensive mechanism against UV light exposure.

Up until recently, melatonin has been found in about 8 grape varieties, though only one study so far has identified melatonin in wine.  The short study presented today aimed to determine whether or not melatonin was present in wine from different grape varieties and to test a few different analytical methods for efficiency and accuracy.

Methods

Wines used in this study were made at the Instituto de Investigación y Formación Agraria y Pesquera in Jerez de la Frontera, Spain.  Grapes were harvested in 2007 at maturity and underwent controlled winemaking procedures at 25oC.  Grape varieties harvested were: Cabernet Sauvignon, Jaen Tinto, Merlot, Palomino Negro, Petit Verdot, Prieto Picudo, Syrah, and Tempranillo.  All wines made were single varietal.

Methods used for analyzing melatonin levels were: ELISA, LC-fluorescence, and LC-ESI-MS/MS.

Eight single varietal wines were analyzed in duplicate by ELISA, and triplicate by all other methods.

Results

  • ELISA analysis indicated that Palomino Negro possessed the highest levels of melatonin out of all wines analyzed.
  • Cabernet Sauvignon, Jaen Tinto, Merlot, Petit Verdot, Prieto Picudo, and Syrah all showed similar levels of melatonin, which ranged from 162pg/mL to 230pg/mL.
  • Due to the complexity of the wines, which contain many primary and secondary metabolites, these compounds can interfere with ELISA results, creating false positives or false negatives when there may or may not be present the compound of interest.

o   Results indicated a 25% false positive rate and a 28.6% false negative rate.
o   These results suggest that ELISA is a poor method for analyzing melatonin in wine, since results were unclear and inaccurate.
  • Unlike ELISA, the LC-Fluorescence method was reliable for analyzing melatonin levels in wine.

o   For Trebbiano wines, the melatonin level determined by LC-Fluorescence was 0.04ng/mL.
  • LC-MS/MS analysis showed that Tempranillo wines contained the highest levels of melatonin.

o   Cabernet Sauvignon, Petit Verdot, Prieto Picudo, and Syrah all had markedly variable levels of melatonin.
o   Melatonin was not found to be present in Jaen Tinto, Merlot, and Palomino Negro wines.
  • LC-MS/MS analysis showed that isomers of melatonin (same molecular formula, but different structure) were found in highest levels in Jaen Tinto wines (32.6ng/mL).

o   ¼ of the melatonin found in Tempranillo wines was in its isomeric form.
o   Small amounts of melatonin isomer were found in Cabernet Sauvignon, Merlot, Palomino Negro, Prieto Picudo, and Tempranillo.
o   There were no melatonin isomers found in Petit Verdot or Syrah.
  • The presence of melatonin in wines was quantitatively and qualitatively extremely diverse.
  • Melatonin in wines was present in its functional form and also in its isomeric form in wines, the levels of which varied greatly depending upon varietal of wine.
  • Melatonin and melatonin isomer levels may be a function of grape variety and winemaking techniques.


Concluding Thoughts

The results of this study were simple in that melatonin is present in wines, though is specific to varietal and potentially winemaking technique.  Levels of melatonin in wines are also highly variable, again due to varietal, winemaking technique, and the method used to collect the data.  According to the results of this study, LC-MS/MS was the best method for determining levels of melatonin in wines, though further analysis would need to be done to ensure repeatability.

So what does it mean if there is melatonin present in wine?  Well, I (and science!) am not 100% sure, but since it often functions as an antioxidant, it would likely join the ranks of the other polyphenols, flavanols, and resveratrol that have all been shown to have incredibly positive health benefits.  Melatonin has been so little studied in wine that it is difficult to determine what other, if any, health benefits it may have in wine.  Are the levels of melatonin present in wine enough to even elicit these health benefits?  There have been no clinical trials focusing on this compound as a function of its health benefits when in wine, so it is hard to say.

I’d love to hear what you all think about this topic.  This study leaves much to be determined, so I’d love to hear how you all interpret these data and how you extrapolate this to real world functionality.

Please feel free to comment below!

Source:  Rodriguez-Naranjo, M.I., Gil-Izquierdo, A., Troncoso, A.M., Cantos, E., Garcia-Parrilla, M.C. 2011. Melatonin: A new bioactive compound in wine. Journal of Food Composition and Analysis 24: 603-608.

DOI: 10.1016/j.jfca.2010.12.009






I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!
Jul 18 NO comments
adults, alcohol, allergy, egg protein, enology, food, health, intolerance, research, wine chemistry, wine preference

How Common Are Wine Allergies?: The First Study Results



This post comes as a suggestion from a reader (@dswaddle) who contacted me with an idea for a peer reviewed article to present.  Great find! If any of you have papers/ideas in mind, don’t hesitate to contact me with your suggestions!

http://www.drinkingdiaries.com/wp-content/
uploads/2010/12/wine_allergy_080908_mn.jpg
We’ve all read countless articles that show positive benefits of wine on various aspects of human health.  However, what is not as often studied are the more negative effects felt by certain individuals.  Specifically, many people claim to have a wine allergy or intolerance, which may range from very mild to severe in rare cases.  When I was working 5 days per week in the tasting room, I would hear at least once a day a story of how someone possessed symptoms of wine intolerance/allergy, or how a friend of theirs could not drink red wine without suffering some consequences.  All that we know about wine intolerance, however, is anecdotal or conjecture, since to date there have been no studies examining the frequency of wine intolerance in humans. 

The short exploratory study presented today aimed to evaluate how common wine intolerance actually is in a wine region, the results of which may serve as a baseline or launching point for many epidemiological studies on wine intolerance in the future.

Methods

4000 people were randomly selected from the residential population of Mainz, Germany.  A short questionnaire was sent out to all 4000 individuals in 2010, and 1114 of them (27.9%) were returned to the researchers.  Out of those 1114 questionnaires, only those that were completely filled out were analyzed, therefore a total of 948 individuals’ questionnaires were subjected to analysis.

The short questionnaire asked questions regarding sex, age, as well as the average weekly consumption of wine, beer, and liquor.  In addition, questions regarding allergy-like symptoms after wine consumption were also included (for red, white, and rosé wines), with a list of symptoms being supplied by the researchers.  Questions regarding frequency of symptoms were also included in the questionnaire.  Questions regarding allergies or intolerances to other items such as pollen, house dust, latex, medications, seafood, nuts, milk, apples, cherries, oranges, peaches, plums, kiwis, strawberries, grapes, bananas, carrots, peppers, alcohol, or beer were also included.  In addition to self-reporting, participants were asked to note if any of these allergies had been medically diagnosed.  All reported symptoms were considered as a symptom of wine intolerance except for headache, which is an extremely general symptom and could be a result of other ailments or problems.

Participants were labeled as being “wine intolerant” if their symptoms scores summed greater than 10 (see Table 1 for individual symptom scores), or if they self-reported to be wine intolerant.

Table 1 from Wigand et al, 2012.


Results

  • Mean age of participants was 43.7 years.
  • 429 of the participants were men (45.3%), and 519 were women (54.7%).
  • The distribution for age and sex of the study group was comparable to the entire Mainz, Germany population, with only the younger generation not as represented.
  • 84.3% of participants said they consumed alcohol during the past year.
  • 76.6% of participants said they consumed wine, with an average of 3.66 glasses per week.
  • Participants reported consuming slightly more white wines than red, and almost no rosé wines.
  • 49.3% of participants reported consuming beer.
  • 18.1% of participants reported consuming liquor.
  • Men drank more wine then women; however, after only taking into account those that consume alcohol, there was no difference in wine consumption between men and women.
  • 3.2% of participants claimed they have an intolerance to wine (9 men and 21 women).
  • Only one man and one woman had a wine allergy that was verified by a doctor.
  • 24% of participants reported allergy-like symptoms after consuming wine.

o   223 of the 225 reporting symptoms also reported headache, however, this symptom was not included in analysis due to the very non-specific nature of the symptom.
  • More people reported symptoms after consuming red wine than white wine.
  • Wine intolerance scores over 10 were observed for 23% of those that reported symptoms.

o   Only 14 of these individuals (14 out of 52) actually claimed they had a wine intolerance.
  • The following were the most common symptoms reported for wine intolerance in participants:

o   Flushed skin (57.4%)
o   Itching (35.3%)
o   Rhinorrhea (32.4%)
o   Diarrhea (27.9%)
o   Tachycardia (25.0%)
o   Stomach or Intestinal Cramps (25.0%)
  • Of those reporting wine intolerance (68 people), 57.5% of them reported experiencing flushed skin.

o   Flushed skin occurred often or always for 36.8% of those reporting experiencing the symptom.
  • Two people reported circulatory collapse after drinking wine, though this reaction was rare.
  • 22% of participants (209 individuals) reported having food intolerance, with more women reporting food intolerance than men.

o   The most common food allergies reported were nuts, apples, and milk.
  • Other common intolerances/allergies reported were pollen, house dust, and medication.

o   Many of these intolerances were confirmed by a doctor, however, most wine/beer/alcohol intolerances went unconfirmed.
  • Those participants with a wine intolerance more frequently reported that they had other intolerances in addition to wine.

o   15 of the 68 reporting wine intolerance also reported beer intolerance, and 19 reported intolerance to alcohol in general.
  • Of the 68 individuals reporting wine intolerance, 18 did not drink wine, and 10 did not drink alcohol at all.
  • Those in the wine intolerance group self-reported drinking on average 2.66 glasses of wine per week (when only those that consumed alcohol were considered) compared to 3.66 glasses per week reported by the self-proclaimed wine drinkers in the study.
  • There was no difference between the 68 individuals with self-reported wine intolerance and the 880 who did not claim wine intolerance in respect to average wine consumption levels.


Limitations

This study has several limitations that were presented by the authors, which make extrapolating the results to a larger population more difficult.

First, there was a low return rate on the questionnaires.  According to the authors, a low return rate such as this one could lead to selection bias and therefore either an over- or underestimation of the frequency of wine intolerance.  However, if one were to assume all of the wine intolerant individuals sent in their completed questionnaires, then that would result in a wine intolerance prevalence of 1.7% (or 68 out of 4000 people), which would therefore be the lower limit of wine intolerance.  This result suggests wine intolerance is higher and more prevalent in adult humans than first thought.

Second, adding up the individual symptoms to result in a “threshold 10 points” may not be an accurate representation of which individuals are wine intolerant and which are not.  A single symptom could, in fact, be the result of wine intolerance, however, if that symptom were not worth “10 points”, it would not be counted as wine intolerance in this study. 

Third, the results of this study were based 100% off self-reported data, which may not be completely accurate.  Clinical trials would be necessary to corroborate or refute these self-reported figures.

Next, sociodemographics were also not considered for this study, which could potentially have an effect on the results if taken into consideration.

Finally, this study focused only on a group of individuals from one particular wine region in the world.  The results, therefore, may not be generalizable to the entire general public, and more studies incorporating many different groups of individuals may be required to get a greater sense of the wine intolerance in the general population.

Conclusions

According to the authors, this study is the first of its kind to present data on the frequency of wine intolerance in a general population.  About one quarter of those individuals claiming wine intolerance also claimed general alcohol intolerance, which could be one of the underlying causes of the wine intolerance:  it’s not that they are allergic to the wine, but in fact allergic to the alcohol within the wine.  It is unlikely the intolerance is a result of an allergic reaction to grapes themselves, since results showed that only 6 out of 68 wine-intolerant individuals claimed intolerance to grapes.

Also according to the authors, others may also have intolerance related to the presence of lipid transfer protein (LTP) in the wine, which is known to cause allergic reactions in some individuals.  Since LTP is located on the skins of grapes, it is possible that those individuals citing intolerance to red wine but not white wine have an intolerance to the LTP protein, which gets deposited in the wine after the maceration (skin contact) process of red wine production.

The results of this study, though rich in methodological limitations, suggest that wine intolerance is a relatively common occurrence in the general population, comparable to intolerance of other foods and allergenic sources.  Clinical research trials are required to further understand this phenomena, as simple questionnaires alone will not tease out the intricate mechanistic details of what is likely multiple reasons and mechanisms for wine intolerance.

I’d love to hear what you all this of this topic!  Please feel free to leave your comments below!

Source: Wigand, P., Blettner, M., Saloga, J., and Decker, H. 2012. Prevalence of wine intolerance: results of a survey from Mainz, Germany. Deutsches Ärzteblatt International 109 (25): 437-444.

DOI: 10.3238/arztebl.2012.0437






I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!
Jun 22 NO comments
antioxidants, cardiovascular health, chemistry, cholesterol, exercise, health, phenolics, rats, research, resveratrol

Resveratrol Consumption During Endurance Training Significantly Improves Physical Performance and Cardiac Function in the Rat Model



Improvement in physical performance is an ever-present ongoing goal for both clinical and nonclinical purposes.  It is well known that endurance training can improve physical performance by increasing energy metabolism in skeletal muscles, as well as improved cardiac function, particularly when undergoing more intense exercise sessions.  It is also well known that resveratrol, a polyphenolic compound found in many edibles including grapes and red wine; possess a wide range of cardiovascular benefits in humans. 

http://vesanianutrition.com/wp-content/
uploads/2012/04/resveratrol-vs-acai.gif
In mice, resveratrol has been found to increase skeletal muscle mitochondrial biogenesis, fatty acid oxidation, and also improved exercise performance in a way that is similar to exercising alone without supplementation of the compound.  Specifically, one study found that resveratrol supplementation in the diet of aged mice (fed a “Western diet”) increased physical performance, suggesting that resveratrol may stimulate the same physiological pathways as exercise alone.  What is unknown, however, is whether the health beneficial effects of resveratrol can improve exercise performance greater than the act of exercising alone. Does supplementation with resveratrol further improve the benefits of exercise?

In addition to physiological improvements based on exercise-related activity, resveratrol is very well known for cardiovascular benefits in humans.  However, to date, nearly all of the studies focusing on resveratrol and cardiovascular health in humans have been related to the prevention of pathological conditions of the heart, and very little on the effect of resveratrol on skeletal muscle and cardiac function in those undergoing some form of exercise.  The study presented today, which I first discovered a few days ago from a new internet news sources, focused on these very questions.

Methods

For this study, 50 male Wistar rats were obtained at age 8 weeks of age.  Throughout the study, rats had free access to drinking water and were fed ad libitum.  Rats were either fed a standard chow diet, or a standard chow diet plus 4g of resveratrol per kg bodyweight (dosage equivalent to 146mg resveratrol per kg bodyweight per day).

http://extremelongevity.net/
wp-content/uploads/rat_treadmill.jpg
Rats were exercised on a calibrated motor driven rodent treadmill with an electrical simulation for foot shock.  When rats were 9 weeks of age, they were acclimated to the treadmill.  The exercise treatment began when the rats were 10 weeks of age and was performed by having the rats run daily progressions for a total of 60 minutes that started off at 10m/min with a 0% incline, and eventually increased to 20m/min at a 0% incline.

Endurance training occurred 5 days per week for 12 weeks.  To encourage the rats to run on the treadmill, a combination of electrical stimulation and puffs of air were used.  After the 12 weeks of endurance training, exercise performance was assessed in the then-22 week old rats.  Exercise performance was evaluated by a graded exercise test to exhaustion (at a 0% incline).  The test began with 10m/min for 1 minute, 11m/min for 1 minute, 12m/min for 1 minute, 13m/min for 2 minutes, 15m/min for 5 minutes, 17m/min for 5 minutes, and 20m/min until exhaustion. A rat was determined to be exhausted when the animal could no longer run on the treadmill as determined by the rat spending less than half the time or more than 30 seconds on the electrical stimulus and resistant to the puffs of air.  Control rats were sedentary (did not undergo endurance training), were acclimated to the treadmill and handled 5 days per week.

Exercise treatments were as follows: 1) sedentary rats fed a standard diet; 2) sedentary rats fed a standard diet plus resveratrol (see dosage above); 3) rats undergoing endurance training while on a standard diet; and 4) rats undergoing endurance training while on a standard diet plus resveratrol (see dosage above).

Muscle force measurements were taken on the soleus muscles (back part of the calf).  Also in this muscle, maximum twitch and tetanic forces were sequentially recorded in both left and right sides.  Also measured was fatigue index, which is calculated to be the ratio of initial to final force, measured during stimulation. 

In regards to cardiovascular and other physiological measurements, the following were taken: transthoracic echocardiography, non-invasive blood pressure, glucose and palmitate oxidation rates, glucose tolerance (after a 5 hour fast), and insulin tolerance.

After 10 weeks of diets and/or exercise treatments, food intake and whole body energy metabolism were measured in the rats.  Oxygen consumption, CO2 production, heat production, respiratory exchange ratio, lipid and glucose oxidation, and physical activity were also measured. Finally, lipids (triacylglycerol and free fatty acids) and gene expression were measured.

Results

  • Endurance training significantly reduced the weight of rats fed either the standard diet or the diet with resveratrol added compared with sedentary rats.
  • Supplementing diets of sedentary rats with resveratrol significantly improved exercise performance (25% improvement).
  • 12 weeks of endurance training alone increased the endurance of rats compared to sedentary rats.

o   Comparing endurance training alone with endurance training plus resveratrol supplementation further increased exercise performance by 20%.
  • Endurance training plus resveratrol significantly increased the twitch force in the tibialis anterior muscle (front portion of shin) by 18% when compared to endurance training alone.
  • There did not appear to be any differences between endurance training alone and endurance training plus resveratrol in regards to the tetanic muscle force in the tibialis anterior muscle.

o   In the soleus muscle, twitch and tetanic forces were both significantly increased (58% and 22%, respectively) in endurance training plus resveratrol rats compared to endurance training alone.
o   These results suggest that resveratrol supplementation in the diet during endurance training increases the isometric force production by skeletal muscles.
  • Fatigue index was not different between endurance training rats and endurance training plus resveratrol rats.

o   Resveratrol does not increase endurance capacity of isolated skeletal muscles.
o   The increased endurance seen in rats with a resveratrol-supplemented diet is not directly attributed to resistance to muscle fatigue, which is consistent with human findings that running performance is more closely correlated with cardiovascular performance than muscle-fiber type distribution.
  • Increased exercise performance in rats undergoing endurance training and resveratrol-enriched diets was associated with significantly improved LV ejection fraction and fractional shortening (i.e. improved cardiac function).

o   There were significant improvements in LV diastolic function in exercise + resveratrol rats compared to exercise rats alone.
  • Resveratrol in the diets of rats during endurance training improved both glucose and insulin performance more than rats undergoing endurance training alone.
  • The respiratory exchange ratio in exercise + resveratrol rats was significantly lower compared to exercise-alone rats.
  • Fatty acid oxidation was significantly higher in exercise + resveratrol rats than in exercise-alone rats.

o   Results indicate resveratrol in the diet enhances cardiac muscle fatty acid oxidative capacity which contributes to increased cardiac function in the rat.
  • For both exercise-alone rats and exercise + resveratrol rats, high levels of activity increased both heart rate and peak systolic pressure (therefore overall cardiac function), though in exercise + resveratrol rats, LV developed pressure, coronary flow, and cardiac work were even more increased then in exercise-alone rats.

o   Results suggest resveratrol in the diet of rats increases the hearts’ ability to adapt to increased workloads that are induced by exercise.
  • Resveratrol reduced the expression of several pro-inflammatory genes.
  • Resveratrol reduced inflammatory mediators and increased expression of cardiac adiponectin.

o   Results suggest resveratrol supplementation during endurance training exercise alters cardiac energy metabolism and reduces cardiac inflammation.
  • Exercise + resveratrol elevated AMP-activated protein kinase phosphorylation when compared with exercise-alone.
  • Exercise + resveratrol increased the expression of PGC1-α (a transcriptional regulator of mitochondrial biogenesis and function).

o   Results suggest resveratrol supplementation during endurance training exercise enhances performance through increased cardiac fatty acid metabolism.

Conclusions

According to the results of this study, rats that consumed resveratrol as part of their daily diets during 12 weeks of endurance training were able to run longer and further than rats that underwent endurance training alone.  Resveratrol supplementation was associated with improved strength in soleus and tibialis anterior leg muscles which likely played a big role in the improved exercise performance.

This study showed that resveratrol supplementation significantly improves physical performance and cardiac function in rats.  What about humans?  Would we see the same results? Or is this just a special occurrence for rodents?  Recent studies have shown that resveratrol supplementation improved mitochondrial efficiency in overweight middle aged men, which indicates that the results we’ve seen here in rats may not be limited to that particular species.

The results of this study also found that resveratrol supplementation in the diets of rats undergoing endurance training increased whole body oxygen consumption, as well as whole body fat oxidation and ultimately improved aerobic exercise capacity.  Based on these results, resveratrol and exercise (specifically, endurance training) act together to improve skeletal muscle oxidative capacity and metabolism, which overall aids in the significantly improved endurance capacity of the skeletal muscles.

The authors also claimed that the increased oxidation of fat seen in rats consuming resveratrol and undergoing exercise training are not only improving exercise performance, but also helping to prevent insulin resistance in pre-diabetic persons undergoing moderate exercise.  Also, since humans are notorious for not being able to maintain vigorous exercise programs (for the most part), resveratrol supplementation in the diet coupled with more moderate exercise may be equally as beneficial as just performing a very vigorous exercise regime alone.

These results suggest that resveratrol supplemented in the diet contributes to improved endurance capacity in rats undergoing endurance training significantly improves exercise performance greater than exercise alone, which could potentially have significant clinical and nonclinical applications where improved physical performance needs to be “helped along” due to a persons’ inability to perform vigorous exercise (due to injury, illness, laziness…).  We can’t be certain these results will carry over into humans from the rat model, however, the few studies within humans that are in existence gives hope that we may see similar mechanisms at work.

As an aside, I’m really curious about these results.  As a distance runner myself (I’ll be training for marathon #4 shortly), I’m interested in trying a little self-experimenting and perhaps supplementing my marathon training with some form of resveratrol.  Anyone want to sponsor me?  ;-)  Also, I’m wondering how one should pace oneself at “water stops” of the Marathon du Medoc to effectively increase their endurance without becoming unpleasantly sloshed (what is Marathon du Medoc? Read about it here.).  This last wonderment is said jokingly, as I’m sure the alcohol involved would negate any benefits of the resveratrol at the rate most people consume it during the race.

What do you all think about this topic?  Would you try supplementing your diet with resveratrol to help increase exercise/endurance performance?  Are you waiting until more research with humans comes out to even try?  Please feel free to leave your comments below (reminder: any unapproved/unsolicited HTML tags will be promptly removed).

Source: Dolinsky, V.W., Jones, K.E., Sidhu, R.S., Haykowsky, M., Czubryt, M.P., Gordon, T., and Dyck, J.R.B. 2012. Improvements in skeletal muscle strength and cardiac function induced by resveratrol during exercise training contribute to enhanced exercise performance in rats. Journal of Physiology 590(11): 2783-2799.

DOI: 10.1113/jphysiol.2012.230490



I am not a health professional, nor do I pretend to be. Please consult your doctor before altering your alcohol consumption habits. Do not consume alcohol if you are under the age of 21. Do not drink and drive. Enjoy responsibly!