Dr Mellanby’s Travels

In the annals of popular dental research, Dr Weston Price is revered for his globe-trotting adventures chronically the general and dental health of peoples living free of dental decay. He wasn’t alone, and many distinguished researchers, including Dr May Mellanby, made similar trips.

Dr Mellanby included in her 3-volume report, Diet and the teeth: an experimental study, a final chapter which described the geographic and racial distribution of caries (dental decay).  She visited or reviewed literature on inhabtants of tropical and subtropical regions, temperate zones and the high arctic, and concluded that the main conditions responsible for immunity from dental decay are:

• Prolonged breast-feeding often for 3 or even 6 years;
• A high intake of fat soluble vitamins, especially vitamin D, and a sufficiency of calcium and phosphorus attained either by consuming much milk, eggs, or, as far as vitamin D is concerned, by exposing the body to prolonged sunshine.

A high carbohydrate diet is compatible with the production of good teeth, immune to decay as long as the vitamin D, calcium, and phosphorus intake is sufficiently high, particularly in early life.

On the other hand, decay and defectively formed teeth are common in communities where:

• Breast-feeding is short or perfunctory or where milk intake is small;
• Few eggs and little animal fats are eaten;
• Sunshine is negligible or, if plentiful, is rendered ineffective by clothing, so as to exclude the production in the body of vitamin D.

In addition to these, where cereals form a large part of the diet, especially in childhood, dental decay becomes rampant.

Dr Mellanby concluded that geographical distribution of dental caries does not suggest that oral hygiene, including the eating of hard food, the use of toothbrushes, toothpastes and other dentrifices, is essential for the prevention of tooth decay.  Many of the decay-free communities used no artificial methods for cleaning their teeth, while in her country (Britain), where oral hygiene was extensively practised, cavities and dental defects were common.

There is indeed evidence that hygiene practices are of little importance in preventing or arresting tooth decay, although the esthetic value of the toothbrush cannot be denied.

Prevention of Cavities with a Single “Massive” Dose of Vitamin D

In the 1920’s, 30’s and 40’s there was a lot of interest in the application of nutrition and vitamin supplementation, particularly vitamin D,  in the treatment of tooth decay.  This research was pioneered by May Mellanby, with significant contributions by Drs. Drain and Boyd.

In the late 1930’s, Drs. Brodsky, Schick and Vollmer studied the effect of a single “massive” dose of vitamin D on the occurrence of cavities in about 100 children residing in the Sea View Hospital, New York.  The children were between the ages of 2 and 16, and were being treated for acute tuberculosis.  The rationale was that single doses of vitamin D of 600,000IU had been used successfully to treat rickets and tetany (low blood calcium) in children.  The study was designed to test whether it would also be successful when applied to prevention of tooth decay.

All the children consumed the routine hospital diet consisting of 1 quart of milk, 5 to 10 ounces of meat or fish, 2 ounces of butter, 3 ounces of fresh fruit juice plus 1 orange or apple, 3 ounces of cooked vegetable, 3 ounces of raw vegetable and 1 egg per day.  In addition to this basic diet each child received such food as puddings or rhubarb, bread with each meal, cereals, cocoa and stewed fruits.

Group A received no supplemental vitamin D. These children were the control group.  Group B received about 305,000 IU of vitamins D2 and D3 in concentrated fish oil taken over a few days.  Group C received a single massive dose of 600,000 IU of vitamin D2 as a supplement.  None of the children showed any toxic manifestation after the administration of the single massive dose of vitamin D.

Eleven months after receiving the massive vitamin D supplement, the children were re-examined.  The incidence of new cavities decreased in a dose-dependent fashion with increasing vitamin D. Group A developed an average of 1.18 cavities per child. Group B developed and average of  0.39 cavities per child, while Group C,  developed only 0.17 cavities per child.

Group A received no vitamin D. Group B received 305,000 IU. Group C received 600,000 IU.

Administration of a single “massive” dose of vitamin D alone reduced the  incidence of tooth decay by 85%.

The 600,000IU taken by Group C is equivalent to about 1,600 IU per day, which is within the range being recommended by prominent vitamin D researchers, and well below the current safe upper limit of 2,000IU per day.

Is white bread better for teeth than wholewheat?

One of the clear results Lady May Mellanby’s extensive research on dental decay is what she referred to as “the cereal effect”.  Poorly mineralized teeth and tooth decay were more prevalent in both children and animals who consumed the greatest amount of cereal grains.

In diets that were deficient in vitamin D, puppies that were fed oatmeal as part of their diet developed the most defective teeth (poorly formed and poorly mineralized enamel and dentin).   Those receiving received white rice and white flour developed the best mineralized teeth.   Whole wheat flour was worse for teeth than white flour. Lady Mellanby showed that it was the amount of wheat germ in the flour that affected tooth development and calcification.  The anticalcifying agent in cereal grains could be largely, though not completely, countered with adequate intake of vitamin D.

In the diet trials with children, Lady Mellanby varied vitamin D, calcium and cereal content, and found the best results with those children who consumed a cereal-free diet, rich in vitamin D and calcium.  In these children almost no new cavities developed, and pre-existing cavities showed extensive hardening and healing.  This is in contrast to the children following vitamin D and calcium poor diets that contained extra servings of oatmeal.  Those children showed decreasing dental health with development of new cavities and no hardening or healing of existing cavities.

So what is the anticalcifying agent present in the cereal grains?  It was suspected, and later proved, to be phytic acid, or phytate, which is found naturally in nuts, seeds, and grains.  White rice and white flour have generally low levels of phytate, while whole wheat flour and oatmeal have higher levels.  When ingested, phytate can chemically bind in the gut with calcium and other minerals such as magnesium, iron and zinc, making them unavailable for absorption.  The minerals are excreted with the undigested fiber.  The effect of consuming fiber-rich cereal grains is the same as reducing the dietary intake of calcium and other minerals.

In Hawaii during the 1920’s rampant early childhood decay in the children of plantation workers was eliminated when traditional taro and sweet potatoes were substituted for the rice and bread that made up much of their diet. Taro and sweet potatoes are low in phytate.

We are all encouraged to consume more healthy, whole-grained, fiber-rich foods.  However, as Professor Harold Sandstead writes in 1992:

…it appears that some health promoters who suggest that US adults should consume 30-35 g dietary fiber daily have not done their homework or have simply ignored the carefully done research on this topic.  They appear to be unaware of the effects of phytate on mineral retention and the fact that many of the commonly consumed sources of fiber are rich in phytate, or to have been mislead by reports…[that] conclude that foods rich in fiber and phytate do not impair retention of essential minerals.”

Fortunately, for those who prefer to consume cereal grains, nuts and seeds the phytate content can be reduced by soaking, fermentation or longer rise times in breadmaking.  Nourishing Traditions by Sally Fallon provides an excellent introduction to this with recipes and directions.

Childhood Nutrition and Susceptibility to Cavities

One mild malnutrition episode occurring in the first year of life is associated with increased caries in both the baby and permanent teeth many years later. Dr J. Alvarez, 1995

Mineralization of primary (or baby) and permanent teeth begins before birth and continues with throughout the child’s life.  Unlike bones, the structure and texture of teeth is determined by the health and nutritional status at the time of tooth formation.  Like growth rings in a tree, the quality of the enamel and dentin form a permanent record of conditions during formation.  If nutrition is deficient at anytime during tooth formation, the enamel and dentin developing at that time may be poorly or underdeveloped, a condition referred to as hypoplastic.

During the 1920’s, Lady Mellanby and colleagues in England examined over 1200 baby teeth from British children.  The teeth were classified either as normal, with well developed enamel and dentin, through to very hypoplastic, with irregular and incomplete enamel and defects in the dentin.  About 21% were considered normal, and 35% very hypoplastic, with the remainder being slightly to moderately hypoplastic.

The development of cavities varied drastically with the structure of the teeth. Normal teeth with well developed enamel and dentin are highly resistant to dental decay.  Almost 80% of the normal teeth examined were cavity-free.

 

Distribution in the degree of cavities for the normal, well-mineralized teeth. Almost 80% of the well-mineralized teeth were completely free of decay.

In contrast, the very hypoplastic teeth, with incomplete and poorly formed enamel and irregular dentin, were highly susceptible to decay, with 75% having advanced decay (Category III).

Distribution in the degree of cavities for the very hypoplastic, poorly-calcified teeth. About 75% of the hypoplastic teeth showed advanced tooth decay (Catergory III).

The well mineralized teeth had 10 times fewer cavities than the poorly mineralized, hypoplastic teeth.

Nutrition and Development of Perfect Teeth

Lady Mellanby also undertook extensive animal studies to determine the important dietary conditions that resulted in either normal, well mineralized teeth, or hypoplastic and poorly mineralized.   Her experiments with dogs paralleled those of her husband, Dr Edward Mellanby, who was studying the childhood bone disease, rickets.

When growing puppies or their pregnant mothers were fed a poor diet with limited amount of skim milk, together with cereals and lean meat, defectively formed, poorly mineralized teeth resulted.  If a source of vitamin D was added, such as cod liver oil or egg yolk, the structure of the teeth greatly improved.  The addition of extra calcium resulted in perfectly developed teeth.  Cereals have an anticalcifying action. When vitamin D or calcium intake was inadequate, and the cereal content of the diet was increased, the teeth tended to be worse in structure and poorly mineralized.

Natural development of well-mineralized, decay resistant teeth require optimal nutrition and a mineralizing diet beginning as early as the second trimester of pregnancy and continuing throughout childhood. Once formed, well mineralized teeth remain highly resistant to decay. A marked deficiency in mineralizing agents, particularly calcium and vitamin D, any time during tooth formation can result in poorly-developed or hypoplastic tooth enamel and dentin, which can lead to a lifetime of susceptibility to tooth decay.

How much vitamin D should you be taking?

It is becoming increasingly apparent that current recommendations of vitamin D intake in the range of 200 – 600 IU/day are woefully inadequate.  In 2007, a group of 15 prominent vitamin D and nutritional researchers, a veritable Who’s Who, published a plea entitled “The urgent need to recommend an intake of vitamin D that is effective”, which called for much higher daily recommended intakes.

One of those authors was researcher Dr Michael Holick, author of the recent book The Vitamin D Solution.  In his book on page 219 he presents the following recommended daily intakes of vitamin D by supplementation.

* Nursing Mothers who want to ensure that their baby is getting enough vitamin D from their breast milk should take 4,000 – 6,000 IU/day.

The above recommendations are in addition to vitamin D obtained through sensible sun exposure.

Update November 30, 2010. A medical committee from the Institute of Medicine has released their report Dietary Reference Intakes for Calcium and Vitamin D, in which they recommend a daily increase in vitamin D intake to 600IU, but no change in calcium intake.  The committee concluded:

Scientific evidence indicates that calcium and vitamin D play key roles in bone health. The current evidence, however, does not support other benefits for vitamin D or calcium intake. More targeted research should continue. However, the committee emphasizes that, with a few exceptions, all North Americans are receiving enough calcium and vitamin D. Higher levels have not been shown to confer greater benefits, and in fact, they have been linked to other health problems, challenging the concept that “more is better.”

These conclusions have brought vigorous rebuttals from several prominent vitamin D researchers and clinicians, which can be found here.

The Vitamin D Solution by Dr Michael Holick

Dr Michael Holick is arguably the preeminent vitamin D researcher of the past 30 years.  A search of the ISI Citation Index for “M.F. Holick and Vitamin D” lists 389 peer-reviewed scientific papers that he has authored or co-authored.  These papers have been cited by other researchers an incredible 13,000 times, which indicates his huge contribution to the field of vitamin D research.

The Vitamin D Solution is a synopsis of the current state-of-the-art in vitamin D research.  The impact of vitamin D on health is profound and goes way beyond absorption of calcium (although that is important).  There are vitamin D receptors in every single cell in the body, with far-reaching effects on a whole host of cellular processes within the body.

It’s a good news/bad news/good news story.  The good news is that vitamin D can prevent and treat a host of diseases including heart disease, cancer, type 1 and 2 diabetes, tooth decay, multiple sclerosis, obesity, depression and dementia, amongst others.  The bad news is that we are overwhelmingly deficient in vitamin D.  This includes the majority of young women and their babies, with enormous implications for childhood development and health.  Vitamin D deficiency is so widespread that Dr Holick uses the alarming term “pandemic”. The good news is that vitamin D deficiency can be alleviated through sensible sun exposure and/or inexpensive supplements.

In case you are unaware, vitamin D, which is actually and hormone and not strictly a vitamin, is produced naturally by the skin through exposure to sunlight (specifically the tanning UVB rays).  Vitamin D can also be obtained through diet, although this amount is very small in a typical North American diet.  Vitamin D supplements and sensible sun exposure are recommended.  Dr Holick describes the various provitamin, circulating and active forms.

The current recommended daily intake of vitamin D of 400IU is described as woefully inadequate.  Dr Holick recommends that, in addition to sensible sun exposure, children and adults supplement with 1000-2000IU of vitamin D per day to maintain optimal blood levels.  Pregnant women and obese individuals require considerably more.  He considers that the “upper tolerable level” of vitamin D that can be consumed with absolute safety is upwards of 10,000IU per day.

Dr Holick takes square aim at the anti-sun zealots, especially his dermatology colleagues.  In fact, in 2004 he was forced to resign from his position as Professor of Dematology at Boston University School of Medicine for recommending modest and sensible sun exposure, and condoning the responsible use of tanning beds.

The book is divided into 2 parts.  The Part I covers the science and history of vitamin D research and its role in disease and in animal and human evolution.  This includes a checklist to determine whether you are a candidate for vitamin D deficiency, and the appropriate blood test for the major circulating form of vitamin D (the test is referred to as serum 25(OH)D test).  Optimal ranges for the serum vitamin D levels are 40-60 ng/ml, and deficient is defined as less than 20 ng/ml.

Part II describes three steps to maintaining or rebuilding your vitamin D levels, which are (1) sensible sun exposure, (2) adequate calcium intake along with good dietary sources of vitamin D, and (3) vitamin D supplementation. Dr Holick refers to vitamin D and calcium as the dynamic duo (research from Europe and Japan would also include vitamin K2 as the terrific trio).

There is also an excellent and very informative Q&A section.

My own personal grumble is that there is no mention of Sir Edward Mellanby or his wife Lady May Mellanby and their groundbreaking research in Britain during the 1920’s and 30’s, which included the discovery of vitamin D in cod liver oil, dietary cure for the childhood bone disease rickets, and Lady Mellanby’s use of vitamin D to treat tooth decay.

I give The Vitamin D Solution 4 out of 5 stars.  It is certainly required reading for those of us who are interested in health and nutrition and taking responsibility for our family’s health.  It provides a clear prescription for how to get tested for vitamin D levels, and what to do to rebuild and maintain optimal levels.  This book would appeal to the more science-oriented reader.  Others may find it a little overwhelming.  There is a vast bibliography for those of us who like to check the original references.

If you prefer not to wade through the science, you might do with a very user-friendly summary and review in November’s Oprah magazine.

Have a child, lose a tooth?

“Jedes kind kostet die mutter einen zahn” – Germany
“Un enfant, une dent” – France
“Minden gyermekért egy fogat” – Hungary

It’s a universal “old wives’ tale” repeated around the globe.  Moms know that it’s true. “I have had three pregnancies and my teeth are paying for it…” writes one Mom to us recently.

Tooth loss, cavities, gingivitis, and sensitive teeth can be unwelcomed side effects of having children.

Science has long been skeptical of these anecdotal claims. However, that appears to be changing. In a 2008 study of 2635 America women, Dr Stephanie Russell at New York University found a strong relationship between tooth loss and the number of offspring.

Women with four or more pregnancies were likely on average to have lost five or six times as many teeth compared to their childless counterparts. This was evident across all socio-economic levels and ages. According to Dr Russell, profound biological and behavioral changes related to pregnancy and child birth are likely to be a factor in tooth loss.

However, the authors of the study were not able to explain the causes of the tooth loss. Despite the data coming from the “National Health and Nutrition Examination Survey”, beyond the consumption of sugar, nutrition or nutritional deficiency was not even considered as a possible factor in the study.

Tooth loss was not shown to be related to sugar intake.

Even among women in the highest socioeconomic level, tooth loss increased with the number of pregnancies.  These women are most likely to not only have dental insurance coverage, but to also most frequently visit their dentist. So it’s not the lack of dental care either.

At The Dental Essentials we are convinced that nutritional deficiencies are at the heart of tooth decay and other dental health issues.  Correct these deficiencies, and you can eliminate up to 95% of cavities.

It’s not only for Moms. There is a strong correlation between maternal oral health and that of the offspring. If Mom has cavities, then baby is also much more likely to develop childhood tooth decay and other dental problems. So by protecting her own dental health, Mom is also giving her children the best shot at a cavity-free childhood.

Dr Mellanby’s Remineralizing Diet

In the 1920’s and 30’s Dr May Mellanby conducted diet trials to determine the effect of vitamin D and nutrition on the development of tooth decay.  Importantly, these trials were conducted in resident hospitals and orphanages, which allowed precise control over food intake.

Compared to the Standard Diet of the day, Dr Mellanby obtained remarkable results with the Remineralizing Diet.  Over a six month period, those children following the Remineralizing Diet experienced very few new cavities, with the widespread arrest and healing of pre-existing decay, while those children on the Standard Diet continued to developed more new cavities with no healing.

Comparison between the Standard and Mineralizing Diets. The children on the Remineralizing Diet experienced almost no new cavities, with widespread healing of existing cavities.

The second remarkable aspect of Dr Mellanby’s Remineralizing Diet was how unremarkable the food was.  Basically it consisted of balanced, though stodgy British fare, supplemented with vitamin D and rich in calcium.  It contained no organ meats, bone marrow, shellfish or fermented foods.  The meat and dairy products were likely from grass-fed animals, however it is not stated whether the dairy was raw or pasteurized.

The main features of the diet were:

• Vitamin D was supplement using cod liver oil and vitamin D supplements to about 2000 IU per day.
• Milk was served with all meals so that each child received about one quart per day.   This provided about 1200mg of calcium out of a daily total of 1700mg, and also provided considerable phosphorus;
• Added sugar (including jam and syrup) was limit to 57 g per day, or about 14 teaspoons.   Today in the US, children and adolescents consume on average 26 teaspoons of added sugar per day.
• The diet contained no cereal, bread, rice or other grains.  Carbohydrates in the diet came from potatoes, fruit and vegetables, milk and sugar.

Sample meals from the Remineralizing Diet are given below:

Breakfast	Omelet, cocoa with milk. Scrambled egg, milk, fresh salad. Omelet containing 2oz ground beef. Fish-cake with potatoes dipped in egg and fried. Bacon, fried or finely chopped with parsley and scrambled egg.
Lunch(Main meal of day)	Potatoes, steamed ground beef, carrots, stewed fruit. Irish Stew, potatoes, stewed fruit. Cold meat cut into small pieces with cold dried carrot, onion and potato, and served on lettuce leaf.
Dessert	Fresh fruit salad with egg, custard or cream. Tinned pineapple with jello. Baked apple with center filled with golden syrup before baking.
Dinner	Minced beef warmed with Bovril, green salad. Potato cakes or fish cakes. Eggs, cooked in various ways.
Evening Snack (Supper)	Fish and potatoes fried in dripping. Thick potato soup made with milk. Lentil or celery soup made with milk. Cheese, served in various ways.

Can Cavities Really Be Healed?

In a word…Yes! Dentists use the term “arrested” to describe dental caries in which the decay process has stopped and the decay is no longer active.  In lay terms, arrested can be considered the same as healed.

The arrest and healing of tooth decay has been described many times in leading dental text books and  journals.

A few examples (to paraphrase):

Teeth containing large cavities, which ordinarily would have an area of softened dentin surrounding the zone of destruction, were found instead to be very dense.  Open cavities showed no signs of progress months after they were first observed.

Dr J.D. Boyd, MD and Dr. C.L. Drain, DDS, 1928

In active decay the tissue for some distance below the surface is more or less depleted in minerals and feels “soft” to the dental probe.  In early stages of arrest the surface zone may feel rough or leathery.  In the next stage the surface is found to be hard but rough, and later the irregularities may be removed by mechanical abrasion.  This process may take months or years, but eventually the surface may become quite hard, smooth and polished, but active decay may have stopped long before this stage is reached.

Dr May Mellanby, DSc, 1933

One of the most severe tests of a nutritional program, accordingly, is the test of its power to check tooth decay completely, even without fillings.  If diet has been sufficiently improved, bacterial growth will not only be inhibited, but the leathery decayed dentin will become mineralized from the saliva by a process similar to petrification. When scraped with a steel instrument it frequently takes on a density like very hard wood and occasionally takes even a glassy surface.

Dr W.A. Price, DDS, 1934

From "Essentials of Dental Caries", Dr Edwina Kidd, 3rd Ed, 2005.

To the left is an example of an arrested cavity.  Despite the decay having advanced well into dentin, the exposed dentin was hard and shiny. The tooth had been in this state for at least 10 years.

This example is admittedly not very attractive (to say the least), but does show that tooth decay can heal even when it has advanced beyond the enamel and well into the dentin.

Note that while the decay has been arrested, the cavity does not infill.

From "Oral Histology: Development, structure and function", Dr A.R. Ten Cate, 2nd Ed., 1985. (click for larger image)

When a tooth is attacked by decay or suffers an injury such as a chip, if nutrition is good, it responds by depositing what is referred to today as reparative or tertiary dentin.  (In Dr Mellanby’s time it was called secondary dentin).  The reparative dentin forms only in the area affected by decay or injury, and is an attempt by the tooth to protect the pulp.

As healing progresses, the decayed and exposed dentin can become remineralized, ultimately forming a hard, dense, glassy surface.

In her careful experiments, Dr May Mellanby demonstrated that the same nutritional conditions that support development of strong, well mineralized teeth, also support the arrest of dental decay, development of reparative dentin and tooth remineralization.  That is, optimal supplementation of vitamin D, together with adequate calcium and phosphorus and a calcifying diet with restricted intake of sugar and cereal grains. Dr Weston Price found even better results when vitamin K2 was also supplemented.

From Dr May Mellanby

This is an example of a healed tooth viewed under the microscope after treatment with the calcifying diet rich in vitamin D, calcium and phosphorus.  The decay has been fully arrested. There is a thick layer of well-calcified reparative dentin (2D) protecting the pulp, and the surface is hard and smooth with no decay.

When tooth decay is active, the goal of nutritional supplements and diet is to create the optimal dietary and nutritional environment that harnesses the body’s defenses and supports the natural arrest of the decay and remineralization of the affected areas.  In other words, to create the conditions that allow teeth to heal…naturally and without dental intervention.

Taro and Sweet Potato

If the carbohydrate in the diet consisted of rice, bread and grain food, the teeth decayed and disintegrated quickly.  If the carbohydrate was in the form of poi and sweet potato, defective teeth do not decay and eventually become hard and smooth.  We regard the role of bacteria as relatively unimportant, since their effect upon teeth may be controlled by diet.

Dr Martha R. Jones

Captain Cook landed in Hawaii in 1778.  He found people who were tall, brown skinned with great muscular strength and broad dental arches.  Dental decay was rare or unknown.  The principal food crops were taro, usually consumed as poi,  and sweet potato, which together made up 60 to 75% of the diet.   Coconuts, fruit, fish and shellfish made up most of the remainder.  Milk and grain foods were unknown.

Fast forward to the 1920’s.  Rice, bread and other grain products had largely replaced taro and sweet potatoes as the staple.  Early childhood caries (ECC) were rampant amongst the breast-fed children of plantation labourers.   Tooth decay was so aggressive that it was frequently necessary for infants to have teeth removed before they reached their first birthday.  By 2 years, almost 100% of those children were affected.  Almost all of the plantation babies had pitted, soft chalky teeth from which the enamel was sometimes completely absent.  The decay progressed in broad lines across the teeth, rather than in pits and fissures, and was associated with growth “spurts”.  Active children who played outside in the sun were more susceptible.  Rampant decay rarely occurred in those who did not eat grains, but instead consumed the traditional taro and sweet potatoes.

The children appear to have been grossly deficient in calcifying minerals, especially calcium, and possibly phosphorus and magnesium.  A study was undertaken whereby 11 babies were provided diets rich in calcium, phosphorus and vitamins with supplementation by a quart of cow’s milk per day for nine months, together with fruit vegetable, egg and meats.   When consumed with a diet where 30 to 40% of the calories came from grains, this supplementation did not prevent the rampant decay.  However, when taro and sweet potatoes were substituted for the grains in the diet, rampant caries was prevented in 39 out of the 42 (or 93%) of the infants.

It apparently matters not whether the teeth are crooked or well spaced; whether the oral hygiene is practiced or not; whether the tooth structure is hypoplastic or perfect, or whether there is even any enamel present.  We have never known a case of active caries in a normal adult who obtains 60 to 70% of the calories of his diet from poi and sweet potatoes.

Jones, M.R., and others, 1934: Taro and sweet potatoes versus grain foods in relation to health and decay in Hawaii”, The Dental Cosmos, 74, 395-409. [Link]