The McDougall Newsletter

May 2008

<<< Return to Newsletter Home Page          Printer Friendly pdf

Vol. 7, No. 05

John McDougall, MD

Favorite Five Articles from Recent
Medical Journals

Should You Drink 8 Glasses of Water Daily?

Just add water by Dan Negoianu published in the June 2008 issue of the Journal of the American Society of Nephrology examines the validity of the commonly heard advice to drink 8 glasses of 8 ounces, or more, of water daily for better health and to remove dangerous poisons from the body.

 Points made by the authors:

  • People cannot survive more than a few days without water.

  • Hot weather and exertion increase water needs.

  • Fluid intake may prevent kidney stones.

  • Increased water intake does increase the clearance of various substances by the kidney, but the importance of this change is unknown.

  • Water may fight obesity by increasing satiety and thermogenesis (heat production).  However, the overall impact is unclear.

  • Studies have shown decreased fluid intake is associated with more heart disease, bladder cancer, and colon cancer.  But this may be because sick people drink less water, rather than the opposite.

  • Relief of headaches and improved skin tone has been attributed to more water intake.

The overall conclusion of the authors was, “There is no clear evidence of benefit from drinking increased amounts of water…we concede there is also no clear evidence of lack of benefit.  In fact there is simply lack of evidence in general.” 


Health advocates often present advice to drink 8 and more glasses of water a day. However, scientific research has not adequately addressed the ideal volume of water that we should consume daily.  I encourage people to drink water, based on the intensity of their thirst drive.  This highly sensitive, effective drive has kept humans and other animals alive and well for eons.  Without a thought, our needs are met. Increased activity and warmth lead to water loss due to perspiration, and this loss is compensated for by more fluid intake driven by more thirst.  The kidneys make further adjustments by retaining or losing water and associated matter. People do not have to give any extra conscious thought to drinking water.

I personally like to drink water.  Of course, this leads to many more trips to the bathroom than most people experience.  I hope all this excess fluid provides me with extra benefits, such as more efficient removal of toxins from my body. I know of no evidence of harm from drinking lots of water (except for water intoxication, which rarely occurs in people with a serious psychiatric disorder).

Certainly, the water you drink should be clean, and especially, free of environmental chemicals. This can be accomplished by buying (glass) bottled water, using an osmotic filter, or by distilling. Plastic water bottles scare me because of the presence of Bisphenol A (BPA) — a chemical commonly found in hard plastics that has been linked to female reproductive disorders and breast cancer.

Negoianu D, Goldfarb S. Just add water. J Am Soc Nephrol. 2008 Jun;19(6):1041-3.


Animal Fat May Accelerate Prostate Cancer

Saturated fat intake predicts biochemical failure after prostatectomy by Sara Strom in the June 2008 issue of the International Journal of Cancer showed, “that high prediagnostic saturated fat (HSF) intake was associated with a 2-fold increased risk of biochemical failure in this cohort of 390 Caucasian men with localized PCa treated with prostatectomy…Men who were both obese and consumed HSF diets had the shortest biochemical-failure-free-survival (19 months), and nonobese men who consumed LSF diets had the longest biochemical-failure-free-survival (46 months, p < 0.001).”1The study was based on a food frequency questionnaire. Biochemical failure was determined by a significant rise in prostate specific antigen (PSA) levels.


Studies of populations of people and laboratory studies of animals consistently show that foods, especially meat, dairy, and added free fats cause and promote the growth of prostate cancer.  This study says the diet eaten by a patient with prostate cancer can influence the growth of the cancer. Saturated fat, which is primarily found in red meat, chicken, milk, and cheese, cuts in half the time it takes for the cancer to come back (based on PSA).  It is fair to assume this same rich diet will cause the patient to die sooner.

Saturated fat is just one cancer-promoting component of the rich Western diet.  The cholesterol, animal protein, and environmental chemicals found in these foods are also known to make cancer grow faster.  Just as important are the missing ingredients.  Dietary fiber, vitamins and minerals, and thousands of other plant-derived (phyto) chemicals keep the body healthy by discouraging cancer growth.

A study by Dean Ornish has begun to show the benefits of a truly healthy diet, like ours, for prostate cancer patients.2  Published in the September 2005 issue of The Journal of Urology, his research 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. 

Because money for research comes primarily from pharmaceutical companies, and secondarily from food companies making their money from the products that are causing and promoting cancer, too little research proving the benefits of a low-fat, plant-food based diet is likely to ever be done.  The result is simply more suffering and death of your friends and relatives.

1) Strom SS, Yamamura Y, Forman MR, Pettaway CA, Barrera SL, DiGiovanni J. Saturated fat intake predicts biochemical failure after prostatectomy. Int J Cancer. 2008 Jun 1;122(11):2581-5.

2) Ornish D, Weidner G, Fair WR, Marlin R, Pettengill EB, Raisin CJ, Dunn-Emke S, Crutchfield L, Jacobs FN, Barnard RJ, Aronson WJ, McCormac P, McKnight DJ, Fein JD, Dnistrian AM, Weinstein J, Ngo TH, Mendell NR, Carroll PR.  Intensive lifestyle changes may affect the progression of prostate cancer. J Urol. 2005 Sep;174(3):1065-1070.


Monitor Blood Pressure at Home Says the AHA

Call to Action on Use and Reimbursement for Home Blood Pressure Monitoring: Executive Summary. A Joint Scientific Statement from the American Heart Association, American Society of Hypertension, and Preventive Cardiovascular Nurses Association by Thomas G. Pickering in the May 2008 issue of the journal Hypertension noted, “There is a rapidly growing literature showing that measurements taken by patients at home are often lower than readings taken in the office and closer to the average BP recorded by 24-hour ambulatory monitors, which is the BP that best predicts cardiovascular risk. Because of the larger numbers of readings that can be taken by HBPM than in the office and the elimination of the white-coat effect (the increase of BP during an office visit), home readings are more reproducible than office readings and show better correlations with measures of target organ damage.” HBPM = Home Blood Pressure Monitoring.

They offered the following recommendations:

  1. It is recommended that HBPM should become a routine component of BP measurement in the majority of patients with known or suspected hypertension;

  2. Patients should be advised to purchase oscillometric monitors that measure BP on the upper arm with an appropriate cuff size and that have been shown to be accurate according to standard international protocols. They should be shown how to use them by their healthcare providers;

  3. Two to 3 readings should be taken while the subject is resting in the seated position, both in the morning and at night, over a period of 1 week. A total of >/=12 readings are recommended for making clinical decisions;

  4. HBPM is indicated in patients with newly diagnosed or suspected hypertension, in whom it may distinguish between white-coat and sustained hypertension. If the results are equivocal, ambulatory BP monitoring may help to establish the diagnosis;

  5. In patients with pre-hypertension, HBPM may be useful for detecting masked hypertension;

  6. HBPM is recommended for evaluating the response to any type of antihypertensive treatment and may improve adherence;

  7. The target HBPM goal for treatment is <135/85 mm Hg or <130/80 mm Hg in high-risk patients;

  8. HBPM is useful in the elderly, in whom both BP variability and the white-coat effect are increased;

  9. HBPM is of value in patients with diabetes, in whom tight BP control is of paramount importance;

  10.  Other populations in whom HBPM may be beneficial include pregnant women, children, and patients with kidney disease; and

  11. HBPM has the potential to improve the quality of care while reducing costs and should be reimbursed.

Patients should purchase oscillometric monitors* with cuffs that fit on the upper arm. They should use a proper fitting cuff, and ask a healthcare provider the correct way to use the monitors. Wrist monitors are NOT recommended. The authors suggest that a quality monitor costs $50 to $100 on the Internet and at pharmacies.

* Oscillometric monitors use the oscillometric technique, which measures the mean arterial BP directly from cuff pressure, then calculates the systolic and diastolic BP’s according to an algorithm that is unique to each device or manufacturer.  No stethoscope is used.


I agree and recommend to all my patients with concerns about their blood pressure that they buy a good quality blood pressure cuff and use it to monitor their blood pressure. I suggest they then record the values and take them to their private doctor for a discussion about their importance, and any recommended treatments.  Diet and exercise should be the first recommendations any patient gets, but all doctors are taught that their patients are too stupid and disinterested in themselves to eat better and go for a walk.  And many doctors also believe their patients are barely smart enough to take their pills and write the check at the end of the office visit.  So, as a consequence, the patients stay sick and carry around a bag full of blood pressure medications.  With home blood pressure monitoring many more patients can stay out of the medical businesses, and this is good for the patient.

The American Heart Association and the British Hypertension Society appear on the surface to exist for patients’ welfare, but in truth these organizations are funded by blood pressure monitor manufacturers and drug companies, just to name a few of their potentially corrupting sponsors.  I disagree with these organizations’ aggressive policies on treatment, such as when to initiate drug therapy (they say above 140/90 mmHg and I say above 160/100 mmHg) and how aggressively to treat (they say treat to a pressure below 135/85 mmHg or lower, and I say do not reduce blood pressure below 140/85 mmHg).  You can read more about how I treat high blood pressure by turning to my Hot Topics on hypertension.

Pickering TG, Miller NH, Ogedegbe G, Krakoff LR, Artinian NT, Goff D. Call to Action on Use and Reimbursement for Home Blood Pressure Monitoring: Executive Summary. A Joint Scientific Statement From the American Heart Association, American Society of Hypertension, and Preventive Cardiovascular Nurses Association. Hypertension. 2008 May 22.


Eat Yourself Impotent

Erectile dysfunction: the new harbinger for major adverse cardiac events in the diabetic patient by Carmine Gazzaruso in the May 2008 issue of the Journal of the American College of Cardiology found, “…ED is a powerful predictor of cardiovascular morbidity and mortality in diabetic patients with silent CAD…”1 An accompanying study, Erectile dysfunction predicts coronary heart disease in type 2 diabetes, in this same issue by Ronald Ching-Wan Ma found, “In type 2 diabetic men without clinically overt cardiovascular disease, the presence of ED predicts a new onset of CHD events. Symptoms of ED should be independently sought to identify high-risk subjects for comprehensive cardiovascular assessments.”2


The same diet that closes the arteries to the heart (heart attacks) and brain (stroke) also closes the arteries to the penis—the result is erectile dysfunction (ED), which means a delay in time to maximal erection, reduced rigidity, and decreased ability to sustain an erection.  An interesting question asked in an accompanying editorial was, “ Why does ED seem to precede symptoms of CAD in patients with a vascular etiology for ED?”3 The answer, “…this phenomenon relates to the size or diameter of the blood vessels.  For example, the penile artery has a diameter of 1 to 2 mm, whereas the proximal left anterior descending coronary artery is 3 to 4 mm in diameter. An equally sized atherosclerotic plaque burden in the smaller penile arteries would more likely first compromise flow and cause ED compared with the same amount of plaque in the larger coronary artery causing angina.”

People with ED also have higher risks for heart attacks, heart surgery, strokes, transient ischemic attack (TIA), congestive heart failure, cardiac arrest, and cardiac arrhythmia. The reason is these conditions are all diseases of sick blood vessels—atherosclerosis.  Patients with health problems are also more likely to be taking medications, such as blood pressure pills, that commonly cause sexual dysfunction.

Fortunately, with a change in diet and a little exercise most of our patients are able to lower their blood pressure and get off of their “erection deflating” medications, and they are able to reduce their “plaque burden” by reversing the underlying atherosclerosis.  My male patients (and sometimes their mates) often share with me tales of their renewed vigor and vitality.  Now there’s a valid reason to eat vegetables. For more on the damage to male sexual functions from meat- and dairy-eating see the end of my July 2003 newsletter article, “Meat in the Human Diet.”

1) Gazzaruso C, Solerte SB, Pujia A, Coppola A, Vezzoli M, Salvucci F, Valenti C, Giustina A, Garzaniti A.  Erectile dysfunction as a predictor of cardiovascular events and death in diabetic patients with angiographically proven asymptomatic coronary artery disease: a potential protective role for statins and 5-phosphodiesterase inhibitors. J Am Coll Cardiol. 2008 May 27;51(21):2040-4.

2) Ma RC, So WY, Yang X, Yu LW, Kong AP, Ko GT, Chow CC, Cockram CS, Chan JC, Tong PC.  Erectile dysfunction predicts coronary heart disease in type 2 diabetes. J Am Coll Cardiol. 2008 May 27;51(21):2045-50.

3) Kloner RA.  Erectile dysfunction: the new harbinger for major adverse cardiac events in the diabetic patient. J Am Coll Cardiol. 2008 May 27;51(21):2051-2.


Vitamin Supplements May Increase Breast Cancer

Multivitamin-multimineral supplement use and mammographic breast density by Sylvie Bérubé in the May 2008 issue of the American Journal of Clinical Nutrition reported that, “Regular multivitamin-multimineral supplement use was found to be associated with higher mean breast density among premenopausal women…Because breast density is strongly and positively related to breast cancer risk, these findings do not support any benefit from multivitamin-multimineral supplement use on breast cancer risk. Instead, they suggest that such multivitamin-multimineral supplement use should be studied for its possible association with an increased risk of breast cancer.”1


Taking various vitamin supplements, like beta-carotene, vitamin E, and/or folic acid has been found in multiple studies to increase the risk of cancer, heart disease, and overall death.2 Many observational studies have found that a high intake of fruits and vegetables, which are also filled with antioxidant, folic acid, and other vitamins, is associated with a decreased risk of cancer.  Foods are not the same as supplements. When isolated, concentrated nutrients are ingested, as with multivitamin and multimineral supplements, chemical imbalances are created within the cells—the end result, as many studies have shown, is an increased risk of disease and earlier death.2

More than half of the women in the US take supplements; therefore, even a small percentage increase in illness will mean many people are affected.  People should be getting their nutrients in their original packages—starches, vegetables, and fruits. Supplements should be considered medicines, at best, and should carry appropriate warnings on their labels, at least.

1) Bérubé S, Diorio C, Brisson J. Multivitamin-multimineral supplement use and mammographic breast density. Am J Clin Nutr. 2008 May;87(5):1400-4.

2) Bjelakovic G, Nikolova D, Simonetti RG, Gluud C. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database Syst Rev. 2008 Apr 16;(2):CD007176.


<<< Return to Newsletter Home Page

Email this page to a friend or coworker

  You may subscribe to this free McDougall Newsletter at
Newsletter archive

2008 John McDougall All Rights Reserved