August 2005    
<< Home   Volume 04 Issue 08

Favorite Five Articles from Recent Medical Journals


Cats Don't Like Sugar – They're Carnivores

Pseudogenization of a Sweet-Receptor Gene Accounts for Cats' Indifference toward Sugar by Xia Li published in the July 2005 issue of the Public Library of Science – Genetics found, "…the cat lacks the receptor likely necessary for detection of sweet stimuli. This molecular change was very likely an important event in the evolution of the cat's carnivorous behavior."  These investigators discovered the gene for the sweet-tasting taste buds is nonfunctional in cats.  However, cats do have taste buds that respond to meat – more specifically, they show a preference for selected amino acids (protein) that are plentiful in animal foods.

Comment:  Cats are obligate carnivores – they must live on a diet primarily of meat – and their taste buds reflect this by having abandoned the tongue sensors that respond to sweet-tasting carbohydrates.  Dogs are omnivores – they have retained both kinds of taste buds – those enjoying carbohydrates and amino acids.  Humans tongues respond pleasurably to sweet (carbohydrates), but have lost the taste for amino acids, placing us undeniably in the category of herbivores (plant eaters). 


Many of your friends and family are confused, thinking people are omnivores – needing both meat and plants in their diet.  We only appear to be omnivorous because we have the ability to "doctor up" meat with salt and sauces (barbecue, sweet and sour, marinara, etc.) sufficiently enough to make it palatable.  Prove this for yourself.  The next person you meet head-on who claims meat is "tasty," stop him in his tracts and insist that he eat a large plate of plain, unseasoned, boiled beef or boiled chicken in front of you – note their displeasure.  Then offer that same meal to the dog or cat and note how eagerly this critter devours the meat.  You would be hard-pressed to find a person who did not enjoy a bowl of perfect, ripe bananas – but try to get your cat to eat this sweet food.  I have a Rottweiler dog named Bodega who is a true omnivore – and enjoys bananas as much as meat.  A careful observer notices that an animal's taste buds are no mistake of nature – they clearly define the proper diet that the animal should eat.  


Li XLi WWang HCao JMaehashi KHuang LBachmanov AAReed DRLegrand-Defretin VBeauchamp GKBrand JG.  Pseudogenization of a Sweet-Receptor Gene Accounts for Cats' Indifference toward Sugar. PLoS Genet. 2005 Jul;1(1):e3.


Mammograms and Breast Exams Fail Women Again


Efficacy of breast cancer screening in the community according to risk level by Joann Elmore in the July 20, 2005 issue of the Journal of the National Cancer Institute found, "In this community-based study, screening history was not associated with breast cancer mortality." "In conclusion, we observed no appreciable association between breast cancer mortality and screening history, regardless of whether screening took place during a woman's 40s, 50s, or early 60s." 1


This study looked at the history of screening for the three years before the diagnosis of breast cancer in 1351 women who died of breast cancer between 1983 and 1998.  They compared this group with 2501 cancer-free women.  If screening with mammography and clinical examination of the breasts had been effective, then those who were free of breast cancer would have had more examinations done than those with cancer.  However, the screening rates on the two groups did not differ.  About 65% in both groups had undergone some form of screening.  Risk of death did not differ between types of exams:  mammography alone, clinical exam alone, or mammography and clinical exam together.


Comment:  This study, one of the largest ones completed to date, found breast cancer screening with mammography and/or clinical examination of the breasts, in "real world" situations, is not effective in preventing death from breast cancer.  Differences in the quality of examinations between those done in your local community and those done in studies may account for a small part of the failure.  However, the real reason for no reduction in deaths is that mammography and clinical exams are flawed methods, which are unable to detect disease until it is well advanced – on average the cancer is found 10 years after it begins, even by the best methods available.  Compounding disappointment from late detection is the ineffectiveness of modern treatments.  In most cases surgery and radiation are applied after the disease has already spread to other parts of the body, and in the case of chemotherapy, the drugs are highly toxic to the patient, but cause too little harm to the cancer.


Although not generally popular, my opinions are shared by some of the most respected scientific committees in the world.   For example, the Cochrane Review concluded, "The currently available reliable evidence does not show a survival benefit of mass screening for breast cancer… Women, clinicians and policy makers should consider these findings carefully when they decide whether or not to attend or support screening programs."2


The Canadian Task Force of Preventive Health Care concluded, "To date, 2 large randomized controlled trials, a quasi-randomized trial, a large cohort study and several case-control studies have failed to show a benefit for regular performance of BSE (breast self examination) or BSE education, compared with no BSE. In contrast, there is good evidence of harm from BSE instruction, including significant increases in the number of physician visits for the evaluation of benign breast lesions and significantly higher rates of benign biopsy results."3


So what should women do?  The more than $8 billion spent on these examinations annually just in the USA would be better directed towards teaching women (and men and children) to eat well and exercise – and cleaning up some of the toxic materials in our surroundings that are known to cause breast cancer.  If you wish to learn more about self-controlled, cost-free ways to reduce your risk of dying from breast cancer, read my May 2005 newsletter article:  The Best Breast Cancer Treatment: Diet and Exercise. 


1)  Elmore JGReisch LMBarton MBBarlow WERolnick SHarris ELHerrinton LJGeiger AMBeverly RKHart GYu O,Greene SMWeiss NSFletcher SW.  Efficacy of breast cancer screening in the community according to risk level.
J Natl Cancer Inst. 2005 Jul 20;97(14):1035-43.

2)  Olsen OGotzsche PC.  Screening for breast cancer with mammography.
Cochrane Database Syst Rev. 2001;(4):CD001877.

3)  Baxter NCanadian Task Force on Preventive Health Care.  Preventive health care, 2001 update: should women be routinely taught breast self-examination to screen for breast cancer?  CMAJ. 2001 Jun 26;164(13):1837-46.


Acrylamide May Not Be a Real World Cancer Risk


Prospective study of dietary acrylamide and risk of colorectal cancer among women by Lorelei Mucci in the July 7, 2005 online version of the International Journal of Cancer found, "…no evidence that dietary intake of acrylamide is associated with cancers of the colon or rectum."  This study of 66,651 women from Sweden between 1977 and 1990 looked specifically for a relationship between foods known to be high in acrylamide, such as coffee, fried potato products, crisp bread and other breads.


Findings suggesting that acrylamide causes cancers of the lung, breast, mouth, intestine and reproductive system are mainly from experimental animals.  Epidemiologic studies of human populations and their dietary habits have so far found no association with cancer of any kind.    The authors of this study suggest the disparity between human and animal studies may be one of dose, since the studies on animals used dosages 3 to 5 times higher than people commonly consume.


Comment:  Unfortunately, the issues surrounding acrylamide have been used to bash a plant-food based diet, high in carbohydrates.  This article, as well as all others, examining human populations, shows no real life risk from acrylamide at the levels commonly consumed by Americans.  Furthermore, people following the McDougall diet avoid the biggest offenders for acrylamide formation – potato chips, French fries, snack foods, and coffee.  Thus, from the available evidence you have nothing to worry about from this potential problem.  Plus, you already knew to avoid the high-fat fried potatoes, snacks, and coffee long before this issue surfaced.


My June 2005 newsletter article, "Acrylamide Poisoning – Cancer from Overcooked Carbohydrates?" reviewed the evidence on the risk of carbohydrates cooked at high temperatures and the risk of cancer.  Acrylamide is formed from the combination of sugars (carbohydrates) and the amino acid, asparagine, cooked at temperatures above 120 degrees centigrade (240 degrees Fahrenheit).  My recommendations are to be on the safe side, "Eat fruits and vegetables uncooked whenever it is practical.  Legumes (beans, peas, and lentils) and grains are traditionally prepared in boiling water.  Steam or boil potatoes and green and yellow vegetables.  Pressure cooking should also be safe; as would pan-frying your vegetables on a dry non-stick skillet."  All of these methods keep the foods below 120 degrees centigrade.

Mucci LAAdami HOWolk A.  Prospective study of dietary acrylamide and risk of colorectal cancer among women.  Int J Cancer. 2005 Jul 7; [Epub ahead of print]


Diet Shown to Help Men with Prostate Cancer – Ornish Leads the Way Again


Intensive lifestyle changes may affect the progression of prostate cancer by Dean Ornish in the September 2005 issue of The Journal of Urology found, "Intensive lifestyle changes may affect the progression of early, low grade prostate cancer in men."  A total of 93 men with elevated PSA levels (4 to 10 ng/ml), with a Gleason score of less than 7, and who had not undergone conventional treatments, were split into two groups.  For one year, one group followed a low-fat vegan diet and the other continued with the American diet (control group).  Because of a rise in PSA levels or signs of disease progression, 6 in the control group eventually underwent conventional therapy (surgery, radiation, chemotherapy) – none in the vegan diet group required further treatment. PSA decreased 4% in the vegan diet group and rose 6% in the control American-diet group.  


Serum (a part of the blood) was taken from the patients and used to grow prostate cancer cells in the laboratory.  The serum from those on the vegan diet inhibited growth of these cells 8 times more effectively than did the serum from those on the American diet.  The stricter the patients followed the low-fat vegan diet the better the results with PSA and cancer cell growth inhibition.


Ornish's Exact Recommendations:

A vegan diet, predominantly fruits, vegetables, whole grains (complex carbohydrates),   legumes and soy products (tofu plus 58 gm of a fortified soy protein powdered beverage) – low in simple carbohydrates and with approximately 10% of calories from fat

Fish oil (3 gm daily)

Vitamin E (400 IU daily), selenium (200 mcg daily) and vitamin C (2 gm daily)

Moderate aerobic exercise (walking 30 minutes 6 days weekly)

Stress management techniques (gentle yoga based stretching, breathing, meditation,        imagery and progressive relaxation for a total of 60 minutes daily)

A 1-hour support group once weekly to enhance adherence to the intervention

McDougall Note: For other health reasons I do not recommend soy concentrates, vitamin E, and fish oil.  Explanations found in my newsletter archives.


Comment:  "Why continue throwing gasoline on a fire?"  Research accumulated over the past 50 years clearly shows that the rich Western diet is at the foundation of the cause of prostate cancer.  Dairy products, red meat, and all kinds of fats and oils have been the focus of research pointing to practical means for the cause and prevention of this potentially fatal disease.  Therefore, you would expect your doctor to be recommending, with great enthusiasm, a healthy diet for people who already have prostate cancer.


Unfortunately, few doctors offer dietary advice to their patients with prostate cancer – or breast cancer, or heart disease, or type-2 diabetes, etc.  This oversight is as serious as a doctor failing to offer a lifesaving surgery or medication to a needy patient.  Someday, somewhere, this will be remedied almost overnight when a talented attorney wins a multimillion dollar malpractice suit over the failure of a doctor to offer a patient the well-researched benefits of a plant-food based diet – a treatment clearly established as highly effective by thousands of scientific studies available to all physicians – as easily available and as close as  Ignorance of the benefits of diet and lifestyle changes will be an inadequate defense in a court of law.


For now, patients interested in the best that medicine has to offer will have to fend for themselves – and this means learning on your own the benefits of a plant-food based, low-fat diet.  This is especially important because your doctor is not going to save you – standard medicine has pitifully little to offer for early detection, prevention, and treatment of prostate cancer.  (See my February and March 2003 lead newsletter articles – and my May 2005 article:  "What's New in Prostate Cancer Treatment?")  


Ornish DWeidner GFair WRMarlin RPettengill EBRaisin CJDunn-Emke SCrutchfield LJacobs FNBarnard RJ,Aronson WJMcCormac PMcKnight DJFein JDDnistrian AMWeinstein JNgo THMendell NRCarroll PR.  Intensive lifestyle changes may affect the progression of prostate cancer. J Urol. 2005 Sep;174(3):1065-1070.


Fish Oil May Increase Heart Trouble


Fish oil supplementation and risk of ventricular tachycardia and ventricular fibrillation in patients with implantable defibrillators: a randomized controlled trial by Merritt Raitt published in the June 15, 2005 issue of the Journal of the American Medical Association found, "Among patients with a recent episode of sustained ventricular arrhythmia and an ICD (implantable cardioverter defibrillator), fish oil supplementation does not reduce the risk of VT/VF (ventricular tachycardia/ventricular fibrillation) and may be proarrhythmic in some patients." Hoffman-LaRoche Inc. provided the fish oil capsules and part of the funding.

The authors concluded with this recommendation, "…routine use of fish oil in patients with ICDs and recurrent arrhythmias should be avoided."



The investigators and the drug company sponsor (Hoffman-LaRoche Inc.) were surprised by these outcomes since previous research has led many to believe that fish oil supplements and eating fish are good for the heart.  Unfortunately, people trying to prevent early death and disability from heart disease have been led down the wrong stream.  Fish is not health food and because of high levels of methylmercury contamination, fish actually increases the risk of heart disease. (See my March 2005 newsletter article:  Fish Can Cause You Heart Disease.)  In addition to the proarrhythmic effects (encouraging irregular heart beats), fish oil will raise LDL "bad" cholesterol, increase risk of bleeding, and suppress the immune system with a real possibility of more infection and cancer. (Read my February 2003 newsletter article: Fish Is Not Health Food.)


Raitt MHConnor WEMorris CKron JHalperin BChugh SSMcClelland JCook JMacMurdy KSwenson RConnor SL,Gerhard GKraemer DFOseran DMarchant CCalhoun DShnider RMcAnulty J.  Fish oil supplementation and risk of ventricular tachycardia and ventricular fibrillation in patients with implantable defibrillators: a randomized controlled trial.  JAMA. 2005 Jun 15;293(23):2884-91.

Copyright © 2002-2019 Dr. McDougall's Health & Medical Center,
P.O. Box 14039, Santa Rosa, CA 95402 All Rights Reserved