Denis Stewart is a herbalist from the Hunter Valley (NSW, Australia). He is an associate professor at University of Newcastle since 2002. He founded the Southern Cross Herbal School in the late 1970s.
He presents a weekly radio show on 2NUR FM, a Newcastle-based radio station, on health topics.
I am concerned about some of his material. I posted Denis a (real) letter and sent an email without receiving a response. I also sent an email to 2NUR FM listing some concerns. The general manager responded on 12 May 2017 with the comment:
To my mind Denis provides a very balanced and informative program, and while he may also express opinions about a number of subjects, he always prefaces such comments with “in my opinion” thus leaving it up to the listener to make up their own mind or to get more information about the subject.
I am happy to pass on your comments to Denis, but it seems in this case that you have differing views on a subject that you are both passionate about, and to my mind there is nothing wrong with that.
Below is a list of some of the concerns that have not been addressed.
Given the influence of Denis in our community, I believe that it is very important that these issues are addressed and that these misconceptions have an opportunity to be rectified.
I believe it is appropriate for Denis to address these concerns. It is fascinating that he attacks Ancel Keys, claiming that Keys created the conditions that led to our problems with obesity, diabetes and general state of ill-health then he lavishes praise the Mediterranean diet, apparently completely unaware of Keys’s role in defining the Mediterranean diet.
Unfortunately, Stewart completely misrepresents what we have come to know as the Mediterranean diet.
He also misunderstands the nature of inflammation in heart disease.
On a number of occasions, Denis has spoken about the importance of the Mediterranean Diet. Denis describes the Mediterranean diet as having an “emphasis on seafood, lots of fish, the incredible importance of olive oil, lots of fruit and vegetables, particularly the grape, red wine and [the diet] is spearheaded by the egg-plant.” This is significantly different to how Keys described the diet.
Ancel Keys coined the term Mediterranean Diet. He based his version of the Mediterranean Diet on the diets of Greece, southern Italy and the Mediterranean regions of France and Spain of the 1960s. He and his wife Margaret wrote three popular books espousing the virtues of this diet. 1 2 3
Below are two of Keys’s descriptions of a Mediterranean Diet.
The heart of what we now consider the Mediterranean diet is mainly vegetarian [or lactovegetarian]: pasta in many forms, leaves sprinkled with olive oil, all kinds of vegetables in season, and often cheese, all finished off with fruit, and frequently washed down with wine.
I say “leaves.” Near our second home in southern Italy, all kinds of leaves are an important part of the everyday diet. There are many kinds of lettuce, spinach, Swiss chard, purslane, and plants I cannot identify with an English name such as lettuga, barbabietole, scarola, and rape. 5
Stewart describes Aseem Malhotra as an “award-winning cardiologist”. This label is found numerous times on the internet but the nature of the awards are not stated.
Stewart repeats the popular assertion that heart disease is a disease caused by inflammation, a view that is also held by Malhotra.
Inflammation is a response to injury. It is not confined to heart disease and not all episodes of heart disease are accompanied by inflammation.
Malhotra published an article in The BMJ, Saturated Fat is not the Major Issue. 6 He starts his article by saying:
He give a citation to support that statement to the paper, Trans-fatty acids and nonlipid risk factors, which has a completely different conclusion.
This paper states that the “well-established adverse effects of serum lipids’ [cholesterol] is a real issue along with several other factors including inflammation. Changes to cell fluidity and permeability are other factors not mentioned in this paper.
Popular commentators state that inflammation is the cause of heart disease whilst neglecting to explain what causes the inflammation in the first place. The steps that lead to a heart attack are listed below.
- LDL particles, which contain cholesterol, enter the space inside the lining of the arteries.
- The cholesterol becomes oxidised.
- White blood cells recognise this as a foreign particle and engulfs the intruder.
- Plaques develop inside the artery wall. Plaques consist of dead white blood cells (macrophages), fats, cholesterol, and smooth muscle tissue.
- The plaques intrude into the arteries.
- Thrombosis (blood clot inside a blood vessel) at the site of a ruptured plaque precipitates most heart attacks.
William Roberts is a leading cardiovascular pathologist. He is the current editor (at 2017) of the American Journal of Cardiology— a position he has held since 1982. He has published over 1,500 articles. Roberts served as the first head of the pathology service at the National Heart, Lung, and Blood Institute at the National Institutes of Health from 1964 to 1993. He has been located at Baylor Heart and Vascular Institute and Baylor University Medical Center in Dallas, Texas since 1993.
Dr Roberts has suggested cholesterol goals should be less than 150 mg/ dL (3.9 mmol/L) for total cholesterol and less than 60 mg/ dL (1.5 mmol/L) for LDL cholesterol. He also contends there is only one risk factor for heart disease— that is, “It’s the cholesterol,”and that the HDL-cholesterol is largely irrelevant. 8
Stewart is adamant that our current health crisis was bought about by Ancel Keys and his manipulation of his survey results. On several occasions, he has attacked Keys for his role in creating the conditions of ill-health in our society. Whilst this is a popular view on the internet, it is simply not true.
Popular commentators frequently accuse Keys of manipulating data in his 1953 paper, Atherosclerosis, A Problem in Newer Public Health. This study is sometimes referred as the “Six Countries Study”. A number of popular commentators think this is the Seven Countries Study— they count England & Wales as two countries. 9
This paper was presented in Amsterdam in 1952 and in January 1953 in New York.
On page 4 of this paper, Keys lists 16 countries (which includes France, Switzerland, and Sweden) and compared their all-cause death rates to the United States. United States compared unfavorably to all countries and Keys believed that what was possible for other countries “should be possible for Americans.” The mortality data was for the years 1947– 1949.
On page 17 of this 22-page paper, Keys graphed the mortality rate for degenerative heart disease and fat intake for six countries that he stated had “fully comparable dietary and vital statistics data.” The food data was obtained from FAO for the year 1949.
This graph causes a great deal of consternation in the popular press. The claim is made that Keys “cherry-picked” his data, which is stating that he was dishonest.
Yerushalmy and Hilleboe criticized this paper in the publication Fat in the Diet and Mortality from Heart Disease claiming that Keys only choose 6 countries (Japan, Italy, England & Wales, Australia, Canada, U.S.) that supported his hypothesis instead of using the World Health Organization data from the 22 countries that was available. The data for the 22 countries that Yerushalmy and Hilleboe listed were for the years 1951-1953, a period which is after the publication of Keys’s paper. 10
Even if data from all the 22 countries are included, it still shows:
- positive correlations between heart disease and total calories consumed, fat consumption, animal fat consumption, and animal protein consumption, and
- negative correlations with heart disease and carbohydrate consumption, vegetable protein consumption, and vegetable fat consumption.
This observation is clearly stated in Yerushalmy and Hilleboe’s paper.
Far too much attention is paid to one page of a discussion paper written in the early 1950s. Keys writes, “The fact that the present high rate from degenerative heart disease in the United States is not inevitable is easily shown by the comparison with some other countries.” This was the purpose of the paper.
Stewart is obviously unaware of Keys’s role in developing and promoting the virtues of the Mediterranean Diet.
Stewart does not hide the fact that he suffers from diabetes.
The result of Type 2 diabetes is that the body does not process sugar effectively, which results in high levels of glucose in the blood. High levels of glucose over an extended period of time places you at risk for many serious health problems. The usual medical advice is to prescribe a diet with very little sugar and limit starch in the diet since glucose is formed as a result of starch being digested. This does seem to be the logical solution to having too much glucose in the blood. It has been known since at least 1927 that high fat diets increase insulin resistance.11 12
Healthy, young medical students were divided into four dietary groups:
- high-carbohydrate diet consisting of sugar, candy, syrup, baked potatoes, bananas, and oatmeal, rice, and white bread
- high-fat diet consisting of olive oil, butter, mayonnaise, egg-yolks, and cream • high-protein diet consisting of lean meat, lean fish, and egg-whites
- the fourth group was placed on a fasting regime
After only two days on their experimental diets, the only group showing a normal, healthy response to the glucose tolerance test was the high-carbohydrate group.
The reasons for this were not known until the late 1990s.
Normally, insulin attaches to protein receptors on the cell’s surface and signals the cell membrane to allow glucose to enter. If there is an accumulation of fat in the cell, it interferes with insulin’s signaling process and glucose cannot enter the cell. Fat can accumulate inside muscle cells even in slim people. The real cause of type 2 diabetes is not an excess of sugar or carbohydrates. It is an accumulation of fat inside the cells that interferes with the muscle cells’ ability to respond to insulin. The muscle cells are unable to access glucose, which is required for energy production. 13 14
The usual response to treat diabetes is to limit the amount of all carbohydrates which includes complex carbohydrates such as starches. This results in an increase of fats and proteins which compounds the problem.
A low-fat diet is so effective in controlling diabetes that if a person is taking diabetic medication then there is a real danger of a hypoglycaemic response.
- Keys, Ancel, and Margaret Keys. 1975. How to Eat Well and Stay Well the Mediterranean Way. Doubleday, Garden City, NY.
- Dixon, Joseph L. 2015. Genius and Partnership Ancel and Margaret Keys and the Discovery of The Mediterranean Diet. New Brunswick, NJ: Joseph L. Dixon Publishing.
- Harding, Richard. 2017. Low-Carbohydrate Mania: The Fantasies, Delusions, and Myths. Balboa Press.
- Truswell, A. Stewart. 2010. Cholesterol and Beyond: The Research on Diet and Coronary Heart Disease 1900-2000. Springer Netherlands.
- Steinberg, Daniel. 2007. The Cholesterol Wars: The Skeptics vs. the Preponderance of Evidence. San Diego, CA: Academic Press.
- Keys, Ancel, and Margaret Keys. 1959. Eat Well and Stay Well. Doubleday, Garden City, NY.
- Keys, Ancel, and Margaret Keys. 1967. The Benevolent Bean. New York: Doubleday, Garden City, NY.
- Keys, Ancel, and Margaret Keys. 1975. How to Eat Well and Stay Well the Mediterranean Way. Doubleday, Garden City, NY.
- Keys, Ancel, and Margaret Keys. 1975. How to Eat Well and Stay Well the Mediterranean Way. Doubleday, Garden City, NY. p4
- Keys, Ancel. 1995. “Mediterranean Diet and Public Health : Personal Reflections.” American Journal of Clinical Nutrition 61 (6):1321S–1323S.
- Malhotra, A. 2013. “Saturated Fat Is Not the Major Issue.” BMJ 347 (oct22 1):f6340–f6340. https://doi.org/10.1136/bmj.f6340.
- Wallace, Sarah K., and Dariush Mozaffarian. 2009. “Trans-Fatty Acids and Nonlipid Risk Factors.” Current Atherosclerosis Reports 11 (6):423.
- Roberts, William Clifford. 2010. “It’s the Cholesterol, Stupid!” American Journal of Cardiology 106 (9):57–73.
- Keys, Ancel. 1953. “Atherosclerosis: A Problem in Newer Public Health.” Journal of Mt Sinai Hospital July-Aug; 20 (2):118–39.
- Yerushalmy, Jacob, and Herman E. Hilleboe. 1957. “Fat in the Diet and Mortality from Heart Disease.” New York State Journal of Medicine 57 (14):2343–54.
- Sweeney, J. Shirley. 1927. “Dietary Factors That Influence the Dextrose Tolerance Test.” Archives of Internal Medicine 40 (6):818–30.
- Sweeney, J. Shirley. 1928. “A Comparison of the Effects of General Diets and of Standardized Diets on Tolerance for Dextrose.” Archives of Internal Medicine 42 (6):872–76.
- Jacob, Stephan, Jürgen Machann, Kristian Rett, Klaus Brechtel, Annette Volk, Walter Renn, Elke Maerker, et al. 1999. “Association of Increased Intramyocellular Lipid Content With Insulin Resistance in Lean Nondiabetic Offspring of Type 2 Diabetic Subjects.” Diabetes 48 (21):1113–19.
- Bachmann, Oliver P., Dominik B. Dahl, Klaus Brechtel, Michael Haap, Thomas Maier, Mattias Loviscach, Michael Stumvoll, et al. 2001. “Effects of Intravenous and Dietary Lipid Challenge on Intramyocellular Lipid Content and the Relation With Insulin Sensitivity in Humans.” Diabetes 50 (13):2579–84.