NEWS: Herald-Sun 10 Sep 03: Coffee diet myths brew

Coffee diet myths brew
By JANE METLIKOVEC
10sep03

MYTHS about coffee are brewing faster than your average espresso.

While coffee may not cause high blood pressure or increase cancer risk, it is not a fat-free, weight-loss supplement.
After brewing, espresso coffee contains 2.5 per cent fat. Filtered coffee contains 0.6 per cent.

A recent Australian study found coffee could increase stamina and aid weight loss.

But Dietitians Association of Australia spokesman Trent Watson said weight loss would be minimal.

"Coffee increases fat oxidation, so it burns fat as a fuel for the body instead of burning carbohydrates," he said.

"But for an average coffee drinker, it would make only a small difference."

Mr Watson said weight loss could be attributed to coffee's ability to make you feel full.

Studies show coffee:

INCREASES alertness by acting as a stimulant, and boosts information processing by up to 10 per cent.

DOES not cause cancer. Thousands of research projects have been carried out searching for a link between coffee and cancer, and none has been found.

IS NOT a diuretic, unless you drink too much.

DOES NOT cause high blood pressure, although people who do not drink coffee regularly may experience a small short-term rise.

HAS been used as a beauty treatment by the Japanese, who have bathed in coffee grounds with pineapple pulp to reduce wrinkles.

Mr Watson agreed coffee increased stamina.

"Caffeine is actually on a list of banned drugs for the Olympics," he said.

"Because coffee burns fat, it keeps carbohydrates in reserve, which helps improve performance over a long period."

Athletes with more than 12 micrograms of caffeine in their urine are disqualified.

As a stimulant, coffee generally contributed to sleep deprivation.

"Sleep deprivation can increase stress hormones, which can lead to chronic diseases, such as heart disease," Mr Watson said.

Karen Duff, of Surrey Hills, drinks two cups of coffee a day.

"It does give you a quick fix and is a pick-me-up, but that is all," she said.

She was unaware coffee could aid weight loss.

"Because of the milk factor, and other additives, I don't think it could help you lose weight," she said.

She said she found it difficult to sleep if she had a coffee after 9pm.

From: http://www.heraldsun.news.com.au/common/story_page/0,5478,7220636%5E662,00.html

Click to expand...

...DOES not cause cancer. Thousands of research projects have been carried out searching for a link between coffee and cancer, and none has been found.

Click to expand...

M. Porta1,2, J. Vioque3, D. Ayude1,2, J. Alguacil1,4, M. Jariod1, L. Ruiz1 & J.A. Murillo1,2
1Institut Municipal d’Investigacio´ Me`dica; 2Universitat Auto`noma de Barcelona, Barcelona; 3Department of Public Health,
Universitat Miguel Herna´ndez, Alacant, Spain; 4Occupational Epidemiology Branch, Division of Cancer Epidemiology and
Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA

Accepted in revised form 6 January 2003

Abstract.

Clinical and epidemiological studies on cancer etiology seldom treat coffee drinking as a potential effect modifier. Yet caffeine exerts signifi-cant effects upon a large variety of physiologic, cellular
and molecular systems. Caffeine, ‘the world’s most popular drug’, is also a fundamental research tool, widely used in clinical studies on drug metabolism, and in experimental studies on cell cycle checkpoints, DNA repair, and apoptosis, among many other. Caffeine can profoundly alter cell cycle checkpoint function and several mechanisms of DNA repair, as well as carcinogen metabolism.

The impact of caffeine on cell cycle checkpoint function occurs in spite of it being nonmutagenic in traditional mutagenesis assays. A complex body of biologicevid ence suggests that caffeine-containing beverages can both enhance and antagonise potentially carcinogenic exposures. However, most pathways leading to the ultimate effects in human beings remain unknown. It is unclear whether any of the hundreds of compounds contained in coffee and tea exert a direct and significant carcinogenic effect per se in any human tissue at usual conditions of use.

Reasons exist to consider that coffee may sometimes be an indirect, positive confounder. The study of interactions between caffeine-containing beverages and environmental agents in well defined groups of healthy and diseased people could yield new insights into checkpoint signal transduction and other mechanisms of carcinogenesis.

Information on the use of caffeine-containing beverages should more often be integrated in studies on the role of gene–environment interactions in the pathogenesis of cancer.

Click to expand...

a. The gene mutated in the disorder ataxia telangiectasia (ATM), which is associated with neurological as well as repair deficiencies, has been found to be similar in sequence to a family of genes that include the yeast MEC1 gene, another checkpoint gene that appears to monitor progression through S phase.

b. High doses of caffeine can suppress checkpoint responses.

Click to expand...

Background:Both caffeine and the inactivation of RCC1, the guanine-nucleotide exchange factor (GEF) of Ran, induce premature chromatin condensation (PCC) in hamster BHK21 cells arrested in the S-phase, suggesting that RCC1 is a target for caffeine.

Results:Caffeine inhibited the Ran-GEF activity of RCC1 by preventing the binary complex formation of Ran-RCC1. Inhibition of the Ran-GEF activity of RCC1 by caffeine and its derivatives was correlated with their ability to induce PCC. Since caffeine is a derivative of xanthine, the bases and nucleosides were screened for their ability to inhibit RCC1. Adenine, adenosine, and all of the 2'-deoxynucleosides inhibited the Ran-GEF activity of RCC1; however, only adenine and 2'-deoxyadenosine (2'-dA) induced PCC. A factor(s) other than RCC1, should therefore be involved in PCC-induction. We found that both adenine and 2'-dA, but none of the other 2'-deoxynucleosides, inhibited the kinase activity of ATR, similar to that of caffeine. The ATR pathway was also abrogated by the inactivation of RCC1 in tsBN2 cells.

Conclusion:The effect of caffeine on cell-cycle control mimics the biological effect of adenine and 2'-dA, both of which inhibit ATR. dATP, a final metabolite of adenine and 2'-dA, is suggested to inhibit ATR, resulting in PCC.

Click to expand...

No drinking coffee when you're pregnant...unless you smoke

Caffeine intake and the risk of first-trimester spontaneous abortion.

Cnattingius S, Signorello LB, Anneren G, Clausson B, Ekbom A, Ljunger E, Blot WJ, McLaughlin JK, Petersson G, Rane A, Granath F.

Department of Medical Epidemiology, Karolinska Institute, Stockholm, Sweden.

BACKGROUND: Some epidemiologic studies have suggested that the ingestion of caffeine increases the risk of spontaneous abortion, but the results have been inconsistent. METHODS: We performed a population-based, case-control study of early spontaneous abortion in Uppsala County, Sweden. The subjects were 562 women who had spontaneous abortion at 6 to 12 completed weeks of gestation (the case patients) and 953 women who did not have spontaneous abortion and were matched to the case patients according to the week of gestation (controls).

Information on the ingestion of caffeine was obtained from in-person interviews. Plasma cotinine was measured as an indicator of cigarette smoking, and fetal karyotypes were determined from tissue samples. Multivariate analysis was used to estimate the relative risks associated with caffeine ingestion after adjustment for smoking and symptoms of pregnancy such as nausea, vomiting, and tiredness.

RESULTS: Among nonsmokers, more spontaneous abortions occurred in women who ingested at least 100 mg of caffeine per day than in women who ingested less than 100 mg per day, with the increase in risk related to the amount ingested (100 to 299 mg per day: odds ratio, 1.3; 95 percent confidence interval, 0.9 to 1.8; 300 to 499 mg per day: odds ratio, 1.4; 95 percent confidence interval, 0.9 to 2.0; and 500 mg or more per day: odds ratio, 2.2; 95 percent confidence interval, 1.3 to 3.8).

Among smokers, caffeine ingestion was not associated with an excess risk of spontaneous abortion. When the analyses were stratified according to the results of karyotyping, the ingestion of moderate or high levels of caffeine was found to be associated with an excess risk of spontaneous abortion when the fetus had a normal or unknown karyotype but not when the fetal karyotype was abnormal. CONCLUSIONS: The ingestion of caffeine may increase the risk of an early spontaneous abortion among non-smoking women carrying fetuses with normal karyotypes.

Click to expand...

Ann Emerg Med. 1997 Jan;29(1):178-80. Related Articles, Links


Myocardial infarction resulting from caffeine overdose in an anorectic woman.

Forman J, Aizer A, Young CR.

Yale University School of Medicine, New Haven, Connecticut, USA.

A 20-year-old bulimic woman ingested 20 g of caffeine in a suicide attempt. After being evaluated and discharged from the emergency department, she was readmitted with ECG changes and ultimately found to have sustained a subendocardial infarction. This case highlights the wide-ranging health consequences of eating disorders and the toxicity of caffeine overdose.

Click to expand...

Am J Epidemiol. 1990 Sep;132(3):479-88. Related Articles, Links


Coffee use prior to myocardial infarction restudied: heavier intake may increase the risk.

Klatsky AL, Friedman GD, Armstrong MA.

Department of Medicine, Kaiser Permanente Medical Center, Oakland, CA 94611.

Because of conflicting evidence about the relation of coffee use to coronary artery disease, the authors conducted a new cohort study of hospitalizations among 101,774 white persons and black persons admitted to Kaiser Permanente hospitals in northern California in 1978-1986. In analyses controlled for eight covariates, use of coffee was associated with higher risk of myocardial infarction (p = 0.0002). Compared with nondrinkers of coffee, the following relative risks (RRs) were found: at 1-3 cups/day, RR = 1.14 (95% confidence interval (CI) 0.91-1.42); at 4-6 cups/day, RR = 1.42 (CI 1.10-1.84), p = 0.007; and at greater than 6 cups/day, RR = 1.41 (CI 1.00-1.99), p = 0.05. The relation remained significant when also controlled for blood cholesterol, blood glucose, blood pressure, and adiposity, singly or combined. Tea use was unrelated to myocardial infarction; neither coffee nor tea was related to other coronary diagnoses. Although causality remains unestablished and uncertainty remains, the authors conclude that 1) these data suggest a weak independent relation of coffee use to acute myocardial infarction, not mediated by an effect on blood cholesterol; and 2) persons at risk of myocardial infarction should consider limitation of coffee intake to less than 4 cups/day.

PMID: 2389752 [PubMed - indexed for MEDLINE]

Click to expand...

I'm sure caffeine does help with weight loss, especially if you read enough about it. The worry is sure to sweat off a few kilo's