Breastfeeding and Childhood Diabetes – full text
This continues Section 2 of "Pros and Cons of Breastfeeding in Developed Countries"
Historical data show that diabetes is apparently higher among children who have been breastfed than among children who have not been breastfed.
This section will start out looking at how highs and lows of childhood diabetes have correlated to an extraordinary degree with highs and lows of something in the environment to which infants have been exposed in greatly varying amounts. The nature of specifically how the environmental exposure could cause diabetes will be explored later, after presentation of various relevant correlations. Bear in mind that what humans eat is considered an environmental exposure, then see in the following pages how closely variations in childhood diabetes have correlated with variations in amounts of breastfeeding to which infants have been exposed, (a) over time, (b) among nations, and (c) among demographic groups.
Section 1.a: Some relevant historical data for the U.S.
According to the American Academy of Family Physicians, breastfeeding rates in the U.S. were low during the middle of the 20th century.(1) Figure 1 shows how those rates greatly increased beginning in the early 1970's.
According to the president of the American Diabetes Association, type 2 diabetes as of 2002 had "changed from a disease of our grandparents and parents to a disease of our children." At that time it was on its way to being what she called a "new epidemic" among children and young adults.(6) Considering when the children must have been born who made up the "new epidemic" that existed as of 2002, major increases in diabetes apparently occurred among those born following the major increases in breastfeeding that began in the early 1970's. Details will follow.
Unfortunately, there is little data available regarding diabetes prevalence among young people for the period of the 1970's and into the 1980's. The only readily-found study on the history of the increase of childhood diabetes states, "the rising incidence of the condition was not widely recognized until the 1980s." (7d) If the increase in the condition wasn't generally recognized until the 1980's, it seems unlikely that there was much of an increase before at least the mid-1970's; so it is probable that the beginnings of the substantial increase in childhood diabetes came some time after the start of the rapid increase in breastfeeding. And during its first two decades, this "new epidemic" was apparently only among children, the group directly affected by the recent increases in breastfeeding; the first reference found by this author (after substantial search) to inclusion of young adults within this epidemic was in 2002. Given that year as the first year for reported inclusion of young adults in the major increase of diabetes, it appears that the infancies of those included in the epidemic would not have taken place until the 1970's.
Section 1.b: Ethnic/historical data in the U.S.
The president of the American Diabetes Association pointed out in 2002 that diabetes had risen especially rapidly among African-American children;(6) in that regard, it should be noted that breastfeeding rates rose many times more rapidly among black women than among other ethnic groups in the decade just before 2002.(7) That is a very specific correlation, with regard to both an individual demographic group and a particular time period.
In this graph on the right, notice that the prevalence of type 1 diabetes (the predominant type among children) for U.S. 0-9-year-olds is highest among non-Hispanic whites, just over half as high among African Americans, and Hispanics are in between. This correlates with the well-established fact that breastfeeding rates are highest among whites, about half as high among blacks, and Hispanics are in between. (It is noteworthy that this same correlation also applies with regard to autism rates -- see Section 1.2.s.3 of http://www.pollutionaction.org/breastfeeding-and-autism-and-cancer.htm)
Section 2: International comparisons regarding childhood diabetes
Section 2.a: In Western Europe, type 1 diabetes among children aged 0-14 is 2.6 times as prevalent in the highest-breastfeeding as in low-breastfeeding countries, on average. Norway, Sweden and Finland can be easily seen at the tops of both the diabetes and the breastfeeding charts on the right. It requires a closer look to see France, Ireland and U.K. at the lower levels in both charts. Poland does not appear on this breastfeeding chart, but there is other evidence to place it basically in the lower-breastfeeding category, despite its recent increases in that area. (8)
Only Austria, as a late arrival, shares the highest levels of the breastfeeding rates chart with the three Scandinavian countries; and its trend of childhood type 1 diabetes is of interest. The only readily-found study of Austria's recent childhood diabetes trends indicates an increase of about 180% in childhood diabetes between 1989-1991 and 2001-2005,(8c) coinciding with its huge increase in breastfeeding indicated by the steep upward angle of Austria's line in this chart of breastfeeding rates.
Sweden's case is also revealing. A 1999 study showed that Sweden's childhood diabetes incidence was increasing, (8d) whereas a 2012 study reported that Sweden's childhood diabetes rate had apparently reached "a plateau." (8e) Both the increase and the subsequent extended leveling are entirely compatible with the earlier increase and the subsequent leveling/slight decline of Sweden's breastfeeding rate as shown in this chart.
It was found by Finland's national health system that their overall type 1 diabetes rates more than doubled between 1980 and 2005,(8e2) which is entirely compatible with its increases in breastfeeding shown for that same period in Figure 3 above. The conspicuous irregularity of breastfeeding rates in Finland during that overall period is also worth a close look, as follows:
a) considering just the trend for the 0-4 age group, their rate of increase in diabetes during much of the 1990's was less than half of what it had been before and what it was after that period; (8e2a)
b) in that regard, note in the above chart the slowdown in breastfeeding in Finland during the early 1990's.
Italy's trend in diabetes among the young (assessed among those age 0 to 29 in this case) also shows compatibility with the increases in breastfeeding: 60% increase in odds of being diagnosed with diabetes in 2000-2004 in northern Italy as compared with the risk in 1984-1989, (8e1) while the breastfeeding rate approximately doubled during that same interval (see Figure 2.3).
Figure 4 shows that most of Norway's breastfeeding rates increased greatly during the 1970's(8c1), as was the case for most other European countries. One article in the journal Diabetologia tells of a relevant trend, which is stated in its title: "Increasing incidence of diabetes mellitus in Norwegian children 0-14 years of age 1973-1982." (8a) (italics added) A later article by the same authors reported an end to that increase, again reflected in its title: "No increase in incidence of type I diabetes in young children in Norway 1989-1998." (8b) Knowing of the sharp increase in Norway's breastfeeding rates during the 1970's and seeing its flat breastfeeding rate in later years as shown in Figure 3 above, one doesn't have to think very hard to see a correlation between Norway's changing breastfeeding rate and a similar turn in Norway's incidence of childhood diabetes. (Figure 4 shows an increase from 80% to 90% in breastfeeding at 3 months in Norway during the 1988-1997 period, in minor conflict with the non-increase shown in the WHO data in Figure 2; in any case, whatever increase there may have been was clearly a dramatic slowdown as compared with the rapid increase that took place during the 1970's, and that major slowdown was compatible with the major drop that took place in the increase of diabetes incidence.)
The above (including Austria) are the only Western European countries for which this author has been able, with reasonable search, to find information regarding changes in both childhood diabetes incidence and breastfeeding rates in recent decades. For countries outside Western Europe, see below.
"Especially striking" increases in diabetes in a specific region, specific time period and specific age group:
Rapid increases in breastfeeding and childhood diabetes came later in central and eastern Europe than in western Europe. In a study of over 29,000 cases of childhood type 1 diabetes across Europe over the period 1989-2003, the authors pointed out that "the rapid rise of type 1 diabetes in the youngest age-group in regions in central and east Europe are especially striking." (8f2) Another study, indicating increases in type 1 diabetes in Europe during 1989-98, showed that the incidence trend among the 0-4 age group in central and eastern Europe was a full 76% higher than the figure for the group with the second-highest increase, when comparing with all age groups in all six of the other European regions. (8f3)
Tracking well with the increases in childhood diabetes, extraordinary increases in breastfeeding in that same region, same time period and same age group
Take note of the abbreviation, CEE/CIS, which stands for Central and Eastern Europe and Commonwealth of Independent States (all former Soviet Bloc states); then observe in this chart which specific world region has gone through a very exceptional increase in breastfeeding rates in the last two decades, which paralleled its exceptional increase in childhood diabetes. Bear in mind from the previous paragraph that the increases in diabetes had been "especially striking" in the 0-4 age group in the CEE/CIS region, the group that would obviously have been most directly affected by the simultaneous huge increases in breastfeeding.
(During the Soviet era -- before 1990 -- exclusive breastfeeding was apparently actively discouraged in this entire CEE/CIS region. Various sources verify this fact as well as the reversal of that policy in the post-Soviet era, with extensive U.S. and international support for the transition in breastfeeding.) (8fa)
Childhood diabetes rates in this CEE region in general, at least as of before the major increases, were about one-third to one-fifth as high as those in Norway, Sweden and Finland. (8f) A study of the increasing diabetes rate among children in Hungary (in the CEE area) found that the incidence had doubled between 1989 and 2009, with the highest rate having been among the very young, (8f1) those most directly affected by the major increases in breastfeeding. According to the Chief Endocrinologist of the Republic of Armenia Ministry of Health in 2011, "in Soviet Armenia the number of diabetics used to increase by 1000 a year, while in the Republic of Armenia the number increases by 4000-5000." (8z6) He is referring to a very low diabetes incidence during the Soviet era when breastfeeding rates were also very low in that region, as compared with the many-times-higher diabetes incidence during the period when breastfeeding rates in the region more than tripled.
As indicated just above in Figure 5 and also in Figure 3, trends after 1995 in breastfeeding in the other countries discussed in this paper have been mixed and have not shown a steep average increase since 1995 that even remotely resembles that in the CEE/CIS countries. And, perhaps not by pure chance, the average increases in childhood diabetes in those other countries for that period have also been far below those of the central and eastern European countries. The two studies of childhood diabetes in Europe (referenced above) pointed out the exceptional nature of the increases in childhood diabetes in central and eastern Europe. The authors of the 1989-2003 study provide no explanation for the fact that this extraordinary development was limited to this particular region and age group, beyond referring to "several hypotheses... that have pointed to modern lifestyle habits (referring to presumably altered lifestyles in the post-Soviet era) as possible environmental factors.... (including) reduced frequency of early infections."
Many more correlations of varying levels of childhood diabetes with varying rates of breastfeeding will be presented later, but this is an appropriate time to discuss specific biological reasons why breastfeeding is probably causally related to diabetes.
Section 3: Biological / scientific reasons for seeing a relationship between breastfeeding and diabetes
It should be pointed out that diabetes type 1 is basically an autoimmune disease. Picking up on the well-established hypothesis (mentioned just above and explained more in the next paragraphs) about reduced early infections' being a cause of the rapid increases in diabetes among the very young: It should be explained that the specific mechanism of the suspected harm is reduction of microbial challenges that would otherwise stimulate development of the immune system (more on this below). In line with this "hygiene hypothesis," the microbe-destroying effect of the externally-provided immune cells in breast milk should be of concern. There is also authoritative scientific evidence about other probable harm caused by breastfeeding to the developing immune system (direct toxicity, not merely deprivation of microbial exposure), as will be described later.
It is well-known and not disputed that immune cells from the mother are transmitted to an infant in breast milk, and that is clearly helpful to an infant in areas with poor sanitation. But in developed countries, the benefits of those immune cells are very much in question. A web page of the U.S. Food and Drug Administration favorably presents a line of reasoning according to which proper infant development depends on “the necessary exposure to germs required to “educate” the immune system.... In the period immediately after birth the child’s own immune system must take over and learn how to fend for itself.” The FDA reports that this “hygiene hypothesis” is supported by epidemiological studies. A prominent doctor uses stronger language, describing the “critical importance of proper immune conditioning by microbes during the earliest periods of life.” A study found on the NIH’s website discusses “the microbial exposure which may be critical for immune priming” and suggests it would be helpful to re-name the “hygiene hypothesis” as “microbial deprivation hypothesis.” (9) According to the UCLA Food and Drug Allergy Care Center, "Overwhelming evidence from various studies suggests that the hygiene hypothesis explains most of the allergy epidemic."(9a) (Note that allergies, like diabetes, result from malfunction in the immune system.) Given the above, there are strong reasons to question whether breastfeeding's transmission of externally-sourced immune cells to an infant, and the resulting reduction in exposure to everyday microbes (below the already historically low levels in developed countries), is anything but harmful to a child's long-term health.
In addition to the above-suggested indirect effect of breast milk on development of the immune system, there are also known harmful direct effects on the immune system resulting from toxins known to be contained in breast milk. According to an extensive 2011 study on environmental toxicants and the developing immune system, toxins including dioxins, PCBs, PAHs, BPA, and phthalates can harm development of the immune system.(10) Note that all of these toxins have been found in breast milk, with dioxins in doses known to be especially high in relation to the EPA-determined safe level. Moreover, in the only comparisons that can be readily found, the doses of these toxins in human milk have been found to be many times higher than those in cow's milk or infant formula. Extensive evidence for the above statements from the EPA and other trustworthy sources can be found at www.breastfeeding-toxins.info, Section 2.
Aside from the many geographical and chronological correlations of diabetes with breastfeeding, a number of scientific studies have also pointed out such correlations, especially with type 1 diabetes (often referred to as IDDM, or insulin-dependent diabetes mellitus). In a 1995 study of 293 children in Colorado, it was found that children with an early predictor of type 1 diabetes had been breastfed for an average of 10 months, compared with an average of 8 months for the controls. (8k) Similar results were found in a study of 52 diabetic cases and 52 well-matched controls in Iran: " A large (sic) proportion of the diabetic children rather than the control children had been breast-fed, and the risk of IDDM among children who had not been breast-fed was below unity." ("below unity" = below average risk) (8l) Similar results were also found in a study of 100 diabetic children and 100 controls in Italy in 1997: The diabetic subjects had been breastfed for an average of 3 months vs. an average of 2 months for the controls. (8m) In a Finnish study, of 6200 children born in 1994-95 with follow-up in 2006, it was found that "early regular daily feeding with cow's milk-based formula tended to associate with lower risk for type 1 diabetes (OR 0.66; 95% confidence interval 0.38-1.13; P = 0.08)." (8n) In a 1990-91 study of 55 patients and 181 controls at two Ethiopian-Swedish hospitals, it was found that "introduction of bottle-feeding was significantly more frequent among unrelated controls at three months of age (9/39 diabetics versus 41/83 controls)." That is, they found that unrelated non-diabetics were over twice as likely to have been bottle-fed at three months of age as were the diabetics. (8o) In a study in Venezuela, of 40 diabetic children and 40 age, sex and race-matched controls, it was found that for "95% of controls vs 65% of IDDM (p<.001), cow's milk was given exclusively from birth, or combined with breastfeeding…;" (8x) in other words, it appears that 35% of diabetic children had received only human milk after birth, compared with only 5% of the non-diabetic children. In a study of 100 children in Sardinia (a large island off the Italian peninsula) diagnosed with diabetes between 1983 and 1994, it was found that "a larger proportion of the diabetic children rather than the control children had been breast-fed, and the risk of IDDM among children who had not been breast-fed was below unity (odds ratio [OR] 0.41; 95% CI 0.19–0.91)." (8p) (In other words, a bottle-fed infant's risk of becoming diabetic was 41% as high as that of a breastfed infant.)
The especially low risk of diabetes in Sardinia among non-breastfed-fed infants is probably related to the same kind of confounding factor that explains why breastfeeding has been found to be associated with lower rates of diabetes in some studies in the U.S. and other countries. In the U.S., U.K., Australia and some other countries, low-income and less-educated mothers are much less likely to breastfeed than women of higher socio-economic strata. So researchers looking for results that might be related to lack of breastfeeding in those countries observe what are actually the adverse health outcomes that are characteristic of children in lower-income families. (For sources on this, see www.breastfeedingprosandcons.info/appendix.htm) The researchers "associate" these worse health outcomes with lack of breastfeeding, while not properly considering an important confounding factor in their comparisons. Similarly but in the opposite direction, confounding could be taking place in Sardinia, where (at least as of the 1970's) "women in lower socioeconomic classes breastfed their infants for 6 months, while prosperous or middle class women preferred to nurse for 3 months." (8r) Some of the very low risk for diabetes found among non-breastfed Sardinian children could result from the health benefits of being in higher-income families.
Section 4: An outstanding exception to the world trend in childhood diabetes, this time at the low end, which is also an outstanding exception to the world trend in breastfeeding rates, also at the low end:
Bear in mind what was found at the high end of the generally-increasing diabetes rates (described in Section 2.b): the same region (central and eastern Europe) that had exceptionally high increases in childhood diabetes also had had what were apparently by far the world's greatest increases in breastfeeding rates. Then observe what has happened at the low end of both of these categories, again in the same identical region in both cases, as follows:
Information about childhood diabetes provided by the DiaMond (Diabetes Mondiale) Project Group, from the period 1990-1999, includes the following: "The trends estimated for continents showed statistically significant increases all over the world..., except in Central America and the West Indies where the trend was a decrease of 3.6%." (8s) Beyond mentioning this exception, the Diamond group attempted no explanation as to what should be different in this region as compared with the rest of the world. Regarding an environmental factor that could be closely related, a U.N. web page provides information about declines in breastfeeding in two of this region's countries, Guatemala and Dominican Republic. Explaining what is underlying declines in breastfeeding in the region, which stand out from trends in the rest of the world (see Figures 3 and 5), the U.N. web page points out (in Section 3.2 of the U.N.'s page), "In Central and South America and the Caribbean there is renewed interest in the role that processed complementary foods can play in providing a nutritionally complete infant and toddler food." (8w) Breastfeeding rates (exclusive, less than 6 months) are also reported to have declined in the following other Central American and West Indies countries: Honduras - - 34.9 to 29.7 (2001 to 2006); Nicaragua – 31.1 to 30.6 (2001 to 2007); Costa Rica – 35 to 15.3 (1993 to 2006); Cuba – 41.2 to 26.4 (2000 to 2006); Belize – 24 to 10.2 (1999 to 2006); Mexico, although typically considered part of North America, could logically be grouped together with its Latin sister countries in Central America; Mexico's 0-5 month exclusive breastfeeding percentage went from 38% in 1987 to 20% in 1999. Data that permits comparisons of equivalent breastfeeding rates over time in this region is limited; aside from the decreases indicated above for 7-8 countries of this region, only for El Salvador and Haiti does available information indicate anything other than a decline in breastfeeding.(8wa) Notice that most of the declines reported were substantial.
Also notice, when comparing with the world trends of breastfeeding as shown in Figures 3 and 5 that Central America and the West Indies was probably the only region in the world in which breastfeeding rates were decreasing significantly during recent decades. Bear that in mind when reviewing the authoritative finding reported (first sentence of previous paragraph) that Central America and the West Indies as a region was also exceptional in the entire world in having experienced a decline in childhood diabetes during this period.
Other international comparisons
A hypothesis has been proposed to the effect that low sun exposure and/or cold temperatures in latitudes closer to the poles may contribute to the high diabetes rates in Finland, Sweden and Norway. But that theory is partially contradicted by the case of Finland/Karelia, described just below, and also by the case of Sardinia. Sardinia is the only major location other than a Scandinavian country found to have a childhood diabetes rate at the very highest level. In that regard, note that Sardinia's breastfeeding rate is the highest in Italy. (8h) It is also relevant that there was an anti-malaria campaign in Sardinia that resulted in considerable spraying of DDT; environmental toxins such as DDT are known to become concentrated in breast milk. (see www.breastfeeding-toxins.info)
After seeing and reading (in Fig. 5 and accompanying text) how exceptionally low breastfeeding rates were in the former Soviet Bloc countries as of the early 1990s, it is interesting to compare Finland with its essentially ethnically-identical neighbor, Karelia, which was part of the Soviet Union until the latter's breakup. Diabetes (overall diabetes in this case, not just childhood diabetes) is reported to be six times higher in Finland than in Karelia. (8g) The border between these two lands separates a high-breastfeeding, high-diabetes country from a low-breastfeeding, low-diabetes land, with apparently nothing except the differences in breastfeeding to explain the immense differences in diabetes incidence.
Diabetes rates vary tremendously among countries in this region, but they have essentially identical genetic risk for type 1 diabetes; this was confirmed in a 2010 study of Lithuania and its neighbors. The HLA (human leukocytes antigen) alleles and haplotypes (which are good predictors of future incidence of type 1 diabetes) in Lithuanian children were studied in great depth and found to be "the same ... as in other European Caucasian populations, including the neighboring Nordic countries."(8g2) Yet Lithuania's rate of childhood diabetes is one fifth that of neighboring Sweden, a third of that of Norway, and a seventh that of Finland.(8g3) It is relevant to note that Lithuania (like Karelia) was formerly part of the Soviet Bloc, with that region's heritage of opposition (in medical school teaching and in hospital practice) to exclusive breastfeeding,8fa whereas its neighbors, Sweden, Norway and Finland, have very high rates of breastfeeding (see them in Figure 3).
Along the above lines, it is also of interest to look at the childhood diabetes rates of the European former Soviet-Bloc states in general, comparing them with the European countries outside that group. This author tabulated the childhood diabetes data for all of the countries in those two categories that had populations over one million and that were listed in what is apparently the only complete source for this data,8fa (table 2a) and found that the 25 non-former-Soviet countries, with their much higher breastfeeding rates, had an average childhood diabetes rate over 2½ times as high as that of the 19 former Soviet-Bloc states. Note that this echoes the differences found in diabetes rates among high- and low-breastfeeding (mostly Western European) countries in a separate tabulation by the International Diabetes Federation, as shown in Figure 3. The non-former-Soviet vs. former-Soviet comparison merely affirms this relationship when comparing a much larger and substantially different group of countries.
In the two-group comparison described above, only one non-former-Soviet-Bloc country had a childhood diabetes rate that was as low as or lower than the average of the former-Soviet-Bloc countries; that was Turkey. That country's data is worth looking at closely, as follows: A study of 217,030 Turkish children, published in 2011, found the prevalence of type 1 diabetes among primary school children to be nearly triple the rate found in that age group in Ankara 16 years earlier. Another study in Turkey, published in 2010, found a 3.5-fold increase over approximately the same period in the same age group.(8z4) It is relevant to note that the percentage of infants under the age of 6 months who were breastfed in Turkey increased about six-fold between 1998 and 2008. (8z5)
According to the DiaMond Project Group, reporting on childhood diabetes incidence worldwide as of the 1990's, the age-adjusted incidence of type 1 diabetes was found to be at a world low of 0.1 per 100,000/year in Venezuela as well as China.(8s) It is of interest that Venezuela, with its world low in childhood diabetes, also appears to be essentially at the bottom level of the world's rates of exclusive breastfeeding, sharing that level only with several African countries and Suriname. And Venezuela's extremely low level in childhood diabetes is especially noteworthy in that Venezuela's rate of diabetes among adults is at the very highest level in Latin America.(8v3) So Venezuela is a very high-risk country for diabetes in general, but for some reason its risk of childhood diabetes is exceptionally low.
Is it possible that childhood diabetes incidence could normally be low in relation to adult diabetes, and the reason the other countries don't have that same relationship is because children in the other countries are receiving heavier exposure to certain toxins than Venezuelan children? Remember from Section 4 the considerable scientific evidence concerning adverse effects of breastfeeding on development of the immune system, which system is basic to diabetes. Then remember that Venezuela's exclusive breastfeeding rate is very close to the lowest in the entire world.
Considering Venezuela's extremely low childhood diabetes combined with extremely low breastfeeding, combined with very high adult diabetes prevalence, could such a combination all be random coincidence? It's worth looking at the other countries that also have extremely low breastfeeding rates.
a) The only non-African country for which UNICEF statistics showed exclusive breastfeeding rates to be as low as or lower than Venezuela was Suriname (Venezuela's neighbor).(8v1) It is noteworthy that Suriname shares Venezuela's position not only at the bottom level of the world's breastfeeding rates but also at the bottom level of the world's childhood diabetes incidence.(8v2)
b) Of the six other countries in the entire world that were even lower in exclusive breastfeeding than Venezuela – all of them in Africa, (a) there is no information about the childhood diabetes rates for four of them, and (b) of the other two, their breastfeeding rates after 12 months are relatively high (47% and 48%, over twice the 12-month rate in the U.S.), so their not being at the world's lowest level in childhood diabetes is not very meaningful. In any case, those two countries' childhood diabetes incidences were still less than one-fifth those of high-breastfeeding Sweden and Finland.
c) Again according to UNICEF data showing the countries with the lowest exclusive breastfeeding rates in the world, the next country above Venezuela is the Dominican Republic. That country also has a childhood diabetes rate (according to the International Diabetes Federation) that is the fifth from the lowest in the world.
d) Just above Dominican Republic in the list of the Western Hemisphere's lowest-breastfeeding countries is the small Central American country, Belize, which has a childhood diabetes rate one fourteenth as high as that of the U.S.
See later in this section regarding China, at one time also at the world's bottom level in childhood diabetes, also having a very low level of breastfeeding at the period when its diabetes incidence was very low.
The lowest incidence of childhood type 1 diabetes in Europe has been reported from Macedonia. (8y) It is relevant to note that exclusive breastfeeding in Macedonia is very unusually low, as indicated in a report by the Macedonian government: "About 40 percent of infants aged 0-1 months are exclusively breastfed, and this proportion drops rapidly until it is close to zero by four months." (8z) When trying to see how that compares with other European countries, comparable data for other European countries appears not to be available following reasonable search; but information regarding breastfeeding rates in the U.S. sheds some light, as follows:
a) the U.S. is near the low end in a chart of non-exclusive breastfeeding rates in OECD (mostly European) countries (see chart on right),
b) the U.S. has an exclusive breastfeeding rate at six months of about 14%. (see far bottom right corner of Figure 1)
If Macedonia has an exclusive breastfeeding rate that is very far below that of a country that itself ranks near the low end of international breastfeeding rates, it is probable that Macedonia's breastfeeding is at (or at least very near) the lowest level in all of Europe. This should be seen in relation to the fact that Macedonia also has the lowest level of childhood type 1 diabetes in Europe.
The age-adjusted incidence of Type 1 diabetes in China was reported to be one of the two lowest in the world in data from the early 1990's (8s) (although that has changed since then). It is relevant to note that breastfeeding rates in China had reached a low during the 1980's, and what breastfeeding was done was apparently typically supplemented from an early point, owing to traditions that went back as far as writings from a 6th-Century AD dynasty. Two separate surveys in Beijing showed that breastfeeding at four months was about 16% in 1989-94. (8z2) In a rural area near Shanghai a survey found the "breastfeeding rate" to be 44.1% in the early 1990s and "the rates in urban areas were invariably lower." (8z2a) (The authors of the paper just quoted said that where the term "breastfeeding" is used without indication of duration or exclusivity, it is used to mean "any breastfeeding.") It is relevant to note that the 44%-and-less breastfeeding rate would fall at the extreme low end of the above chart of international breastfeeding rates. So it appears that China's childhood diabetes incidence being one of the two or three lowest in the world as of the 1990's would have been very compatible with China's extremely low breastfeeding rates as of the early 1990's.
But following heavy promotion of breastfeeding by the Chinese government beginning in the early 1990's, breastfeeding rates in that country increased greatly, in some cases more than tripling. (8z2) And childhood diabetes also increased greatly in that same period. A major study, published in 2012 and drawing from a 2009 survey, found that "in the past two decades" there were very large increases in overweight (often linked with diabetes) in Chinese children, and diabetes in 12-to-18-year-olds was determined to have become almost four times that in the same U.S. age group. (8z2a) That is a major reversal from its world-low level of childhood diabetes just two decades earlier, coinciding with its major transition away from a very low level of breastfeeding.
Even though major changes in breastfeeding rates have taken place in many countries over relatively short periods, it is possible that the thoroughness of the changes in China (probably including exclusiveness as well as duration) was especially great because the Chinese government (which was heavily promoting breastfeeding) exercises tight control over its population.
International highs and lows in childhood diabetes have correlated well with highs and lows in breastfeeding rates. (Section 5)
Increases and decelerations in childhood diabetes rates have tracked accurately with increases and decelerations in breastfeeding rates in all readily found international cases; that included exceptionally high increases of both in an entire region. (see Sections 1 and 2 and parts of Section 5)
While childhood diabetes incidence and breastfeeding rates were apparently both increasing in most of the world, they were both declining in only one world region, which was the same region. (see Section 4)
Childhood diabetes incidence correlated well with the only readily-found instance of a particular ethnic group's breastfeeding rate changing especially rapidly (Section 1.b).
And there is excellent scientific evidence to explain why all of these increases, decreases, highs and lows in breastfeeding and diabetes should correlate so closely, as found in Section 3.
To return to the main body of "Pros and Cons of Breastfeeding in Developed Countries", go to http://www.breastfeedingprosandcons.info
Some of the full articles below are available for free online, but to obtain the full text of some of these articles for free, you may have to visit a university library or ask at the reference desk at your local public library.
(1) "Breastfeeding, Family Physicians Supporting (Position Paper)" -- AAFP Policies -- American Academy of Family Physicians
(2) "Surgeon General's Call to Action to Support Breastfeeding, 2011," p. 33 at http://www.surgeongeneral.gov/library/calls/breastfeeding/calltoactiontosupportbreastfeeding.pdf
(2a) Arenz S, Ruckerl R, Koletzko B, von Kries R. "Breast-feeding and childhood obesity—a systematic review." Int J Obes Relat Metab Disord 2004;28:1247–1256.
(3) Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services, "Systems to Rate the Strength of Scientific Evidence, Evidence Report/Technology Assessment: Number 47" http://archive.ahrq.gov/clinic/epcsums/strengthsum.pdf
(3a) A History of Infant Feeding J Perinat Educ. 2009 Spring; 18(2): 32–39. doi: 10.1624/105812409X426314 PMCID: PMC2684040 Emily E Stevens, et al., at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684040/
(5) "Diabetes in Children and Teens," Medline Plus, U.S. National Library of Medicine, NIH at http://www.nlm.nih.gov/medlineplus/diabetesinchildrenandteens.html Also see Medline Plus Weekly Digest Bulletin, 11/25/2012 at http://www.nlm.nih.gov/medlineplus/news/fullstory_131557.html
(6) Type 2 Diabetes in Children and Young Adults: A “New Epidemic” Francine Ratner Kaufman, MD CLINICAL DIABETES • Volume 20, Number 4, 2002 at http://clinical.diabetesjournals.org/content/20/4/217.full.pdf+html Also see footnote 7b below. Also, a Univ. of Michigan article published in 2008 reported, “Recent studies suggest that there have been dramatic increases in type 2 diabetes among individuals in their 20s and 30s...." (at http://www2.med.umich.edu/prmc/media/newsroom/details.cfm?ID=422), which is compatible with origins of the epidemic in infant development after 1972.
(7) "Breastfeeding in the United States: Findings from the National Health and Nutrition Examination Survey, 1999-2006", Table 5
(7a) http://care.diabetesjournals.org/content/24/2/412.1/T1.large.jpg ; also note the 2002 comment by the president of the American Diabetes Association.
(7b) Trends in Hospitalizations for Diabetes Among Children and Young Adults United States, 1993–2004 JOYCE M. LEE et al., at http://care.diabetesjournals.org/content/30/12/3035.full.pdf+html
(7c) Table 27 of CDC's Health, United States, 2011 http://www.cdc.gov/nchs/data/hus/hus11.pdf#listtables
(7d) American Diabetes Assn., Diabetes, The Rise of Childhood Type 1 Diabetes in the 20th Century, Edwin A.M. Gale, Department of Diabetes and Metabolism, Division of Medicine, University of Bristol, U.K
(8) For Norway, Sweden and Finland, the average incidence is 42.1. The average incidence for the low-breastfeeding countries (U.K., France, Poland and Ireland) is 16.5. (no data for Belgium) For Poland, the only low-breastfeeding country not shown on the breastfeeding chart, information is available from WHO, Nutrition Data Banks, Global Data Bank on Breastfeeding, as follows: "...exclusive breastfeeding rate under 4 months -- Poland has increased from 1.5% in 1988 to 17% in 1995"; by comparison, from the same source, Sweden increased from 55% in 1992 to 61% in 1993. Above found at https://apps.who.int/nut/db_bfd.htm Poland's breastfeeding rates increased considerably over the following 15 years, but, after such a low start, its average breastfeeding rate for the relevant period would almost certainly still be in the lower category.
(8a) Joner G, Søvik O: Increasing incidence of diabetes mellitus in Norwegian children 0-14 years of age 1973-1982. Diabetologia 32 :79 -83,1989
(8b) Joner G, Stene LC, Søvik O: No increase in incidence of type I diabetes in young children in Norway 1989-1998 (Abstract). Diabetologia 43 (Suppl. 1) :A27 ,2000
(8c) Perinatal risk factors for early childhood onset type 1 diabetes in Austria – a population-based study (1989–2005) Thomas Waldhoer et al. DOI: 10.1111/j.1399-5448.2008.00378.x 2008 Pediatric Diabetes Volume 9, Issue 3pt1, pages 178–181, June 2008 There were three intermediate readings helping to verify a linear upward trend over the period discussed.
(8c1) Donor Milk Banking and Breastfeeding in Norway, Grovslien et al., J Hum Lact 2009 25: 206
The online version of this article can be found at http://jhl.sagepub.com/content/25/2/206
(8d) Worldwide increase in incidence of Type I diabetes – the analysis of the data on published incidence trends, Onkamo et al., Diabetologia (1999) 42: 1395-1403
(8e) Cold Spring Harb Perspect Med 2012. 2: 2012 The Pathogenesis and Natural History of Type 1 Diabetes Mark A. Atkinson: http://perspectivesinmedicine.org/content/2/11/a007641.full
(8e1) The incidence of type 1 diabetes is increasing in both children and young adults in Northern Italy: 1984-2004 temporal trends. Bruno G, et al. Diabetologia. 2009 Dec;52(12):2531-5. doi: 10.1007/s00125-009-1538-x. Epub 2009 Oct 11.
(8e2a) Time trends in the incidence of type 1 diabetes in Finnish children: a cohort study Table 1 Valma Harjutsalo, et al., Diabetes Unit, Department of Health Promotion and Chronic Disease Prevention, National Public Health Institute, Helsinki, Finland Lancet 2008; 371: 1777–82
(8e3) Lancet. 2008 May 24;371(9626):1777-82. doi: 10.1016/S0140-6736(08)60765-5. Time trends in the incidence of type 1 diabetes in Finnish children: a cohort study. Harjutsalo V, et al.,Diabetes Unit, Department of Health Promotion and Chronic Disease Prevention, National Public Health Institute, Helsinki, Finland.
(8f) See endnote (8d) above; also http://www.medscape.com/viewarticle/445672_6 and also: Diabetologia (2001) 44 (Suppl 3) B3-B8 at http://www.researchgate.net/publication/225171856_Trends_in_the_incidence_of_childhood-onset_diabetes_in_Europe_19891998 and also
EURODIAB ACE Study Group: Variation and trends in incidence of childhood diabetes in Europe. Lancet 355 :873 -876,2000
(8fa) Regarding low exclusive breastfeeding in the Soviet era, and the subsequent increases, “The medical school curriculum in all Soviet countries taught physicians that mothers must complement breastmilk with vegetable and fruit juices," according to Kim Hekimian, an Armenian and lecturer at the Institute of Human Nutrition at Columbia University and visiting professor at the American University of Armenia, quoted in "Undernutrition in Armenia: A Matter of National Security." Posted by Nanore Barsoumian on July 19, 2012 in "Armenia, Special Reports," of The Armenian Weekly. At http://www.armenianweekly.com/2012/07/19/undernutrition-in-armenia-a-matter-of-national-security/ She also adds, “There was an incredibly successful coordination of strategic intervention (promoting breastfeeding) for four years in Armenia, paid for by USAID and UNICEF,” she explained. “[It included] a social marketing campaign that involved TV, radio, brochures, and newspapers. They also paid for the in-service retraining of all pediatricians, Ob/Gyns [obstetricians, gynecologists], and most nurses in the field.” They also changed the medical school curriculum on breastfeeding, and related policies at the Ministry of Health. ” From another source, "During Soviet time immediate initiation (of breastfeeding) after delivery was prohibited.... Before 1993 exclusive breastfeeding was almost non existent. Infant formula was freely distributed in delivery hospitals...," from Armenian Case Study, presented by Confidence Health, NGO – member of IBFAN, by Susanna Harutyunyan found atwww.ennonline.net/pool/files/ife/armenian-case-study.doc. From another source, "As a member of the Soviet Union, the Republic of Kazakhstan adopted a national policy encouraging mothers to use artificial foods in lieu of breastfeeding to enable mothers to return to the workforce soon after giving birth. This practice of lactation management, used in Kazakhstan and in other republics of the former USSR, separated newborn infants from their mothers in maternity wards.... the program promoted supplementary feedings of a boiled water and glucose formula during the first days of infancy and advocated substantial supplementary feeding in the first or second months after delivery." (from Promotion of Lactation Amenorrhea Method Intervention Trial, Kazakhstan Academy of Preventive Medicine, Republic of Kazakhstan Shamil Tazhibayev, MD, et al; italics added: at http://pdf.usaid.gov/pdf_docs/PNACX991.pdf) Data verifying the low levels of breastfeeding in former Soviet states, especially before major increases took place, can also be found in Feeding and Nutrition of Infants and Young Children, Guidelines for the WHO European Region, with emphasis on the former Soviet countries, Kim Fleischer Michaelson et al., WHO Europe and UNICEF, Chapter 1, p. 30
(8f1) "Constantly rising or peaks and plateaus?" Incidence of childhood type 1 diabetes in Hungary (1989-2009)].Gyürüs E, et al. 7. 7623. Orv Hetil. 2011 Oct 16;152(42):1692-7. doi: 10.1556/OH.2011.29210. Abstract Also Twenty-one years of prospective incidence of childhood type 1 diabetes in Hungary--the rising trend continues (or peaks and highlands?). Pediatr Diabetes. 2012 Feb;13(1):21-5. doi: 10.1111/j.1399-5448.2011.00826.x. Epub 2011 Nov 8. Gyurus EK et al. For increases in another CEE country, Poland, see Incidence trends for childhood type 1 diabetes in Europe during 1989–2003 and predicted new cases 2005–20: a multicentre prospective registration study. Patterson CC, et al., the EURODIAB Study Group. Lancet 2009: 373: 2027–2033.
(8f2) Incidence trends for childhood type 1 diabetes in Europe during 1989-2003 and predicted new cases 2005-20: a multicentre prospective registration study CF Patterson et al., www.thelancet.com, Vol 373, June 13, 2009
(8f3) Trends in the incidence of childhood-onset diabetes in Europe 1989-1998, A Green, CC Patterson on behalf of the EUROLAB TIGER Study Group, Diabetologia (2001) 44 (Suppl 3) B3-B8
(8g) The ‘hygiene hypothesis’ for autoimmune and allergic diseases: an update H Okada, et al., Clinical and Experimental Immunology, 2010 April; 160(1): 1–9. doi: 10.1111/j.1365-2249.2010.04139.x PMCID: PMC2841828 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2841828/
(8g2) HLA class II alleles and haplotypes in Lithuanian children with type 1 diabetes and healthy children (HLA and type 1 diabetes), Erika Skodeniene, et al., Institute of Enndocrinology, Kaunas University of Medicine. Medicina (Kaunas 2010; 46(8)
(8g3) Diabetes in the Young: a Global Perspective Global trends in childhood type 1 diabetes Gyula Soltesz et al., Department of Pediatrics, University of Pecs, Hungary, IDF Diabetes Atlas fourth edition, at http://www.idf.org/sites/default/files/Diabetes_in_the_Young.pdf
(8h) Espr European Society For Pediatric Research Siena, Italy August 31, 2005 – September 3, 2005 Pediatric Research (2005) 58, 358–358; Breastfeeding Across Geographical Areas in Italy M Giovannini et al.
(8i) The Rise of Childhood Type 1 Diabetes in the 20th Century, Edwin A.M. Gale, Diabetes. 2002; 51(12) at http://www.medscape.com/viewarticle/445672
(8l) Indian J Pediatr. 2001 Feb;68(2):107-10. IDDM and early exposure of infant to cow's milk and solid food. Esfarjani F et al., National Nutrition and Food Technology Research Institute, Shaheed Beheshti University, Tehran, IR, Iran.
(8n) Early infant feeding and type 1 diabetes. Savilahti E et al., Eur J Nutr. 2009 Jun;48(4):243-9. doi: 10.1007/s00394-009-0008-z. Epub 2009 Mar 5. Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland
(8o) The relation of early nutrition, infections and socio-economic factors to the development of childhood diabetes. Telahun M et al., Department of Paediatrics and Child Health, Faculty of Medicine, Addis Abeba University. Ethiop Med J. 1994 Oct;32(4):239-44.
(8p) IDDM and Early Infant Feeding: Sardinian case-control study Tullio Meloni, MD (+5 other MDs and one PhD) Istituto di Clinica Pediatrica e Neonatologica, University of Sassari Sassari American Diabetes Assn., Diabetes Care, Copyright © 1997 by the American Diabetes Association
(8r) Raphael, D., ed., Breastfeeding and food policy in a hungry world. New York, Academic Press, 1979. p. 75-79.
(8s) Incidence and trends of childhood Type 1 diabetes worldwide 1990-1999. DIAMOND Project Group. Diabet Med. 2006 Aug;23(8):857-66. The data for China appears to come from studies for the period 1990-94 (see endnote 8v below)
(8t) Breast feeding key to reducing malnutrition in Latin America alertnet (a Thompson/Reuters Foundation Service)// Anastasia Moloney Thu, 15 Oct 2009 14:10 GMT
(8t1) found at https://apps.who.int/nut/db_bfd.htm
(8u) A 24-year Study of Well-Nourished and Malnourished Children Living in a Poor Mexican Village Adolfo Chávez, et al.
(8v) Incidence of childhood type 1 diabetes worldwide. Diabetes Mondiale (DiaMond) Project Group.
(8v1) UNICEF Childinfo Statistics by Area/ Child Nutrition (last update Jan. 2012) at http://www.childinfo.org/breastfeeding_iycf.php
(8v2) Diabetes in the Young: a Global Perspective: Global trends in childhood type 1 diabetes Gyula Soltesz, et al., in International Diabetes Federation web page at http://www.idf.org/sites/default/files/Diabetes_in_the_Young.pdf
(8v3) International Diabetes Federation: South and Central America www.idf.org/regions/south-central-america
(8w) http://www.unsystem.org/scn/archives/rwns04/ch28.htm Section 3.5 Breastfeeding and Complementary Feeding Patterns and Trends (citing data sources from the 1990's) 4th Report on the World Nutrition Situation – Nutrition Throughout the Life Cycle January 2000 United Nations Administrative Committee on Coordination Sub-Committee on Nutrition (ACC/SCN)
(8wa) "Nutrition > Exclusive breastfeeding > % of children under 6 months (2002) by country", UNICEF, State of the World's Children, Childinfo, and Demographic and Health Surveys by Macro International.. Retrieved from
http://www.NationMaster.com/graph/hea_nut_exc_bre_of_chi_und_6_mon-breastfeeding-children-under-6-months&date=2002 Data for years other than 2002 would be available in other pages of the same site, selecting the appropriate year for viewing. Data for Mexico for 1999 from González-Cossío T et al. Breastfeeding practices in Mexico: Results from the Second National Nutrition Survey 1999. Salud Pública de México, 2003, 45:S447S489, found in UNICEF Childinfo Statistics by Area/ Child Nutrition (last update Jan. 2012) at http://www.childinfo.org/breastfeeding_iycf.php
(8w2) Trends in diabetes mellitus in Brazil: the role of the nutritional transition Sartorelli DS, Franco LJ., Departamento de Medicina Social, Faculdade de Medicina de Ribeir o Preto, Universidade de São Paulo, Brasil. Cad Saude Publica. 2003;19 Suppl 1:S29-36. Epub 2003 Jul 21.
(8x) V Mijac et al., Role of environmental factors in the development of insulin-dependent diabetes mellitus (IDDM) in Venezuelan children (in Spanish but good abstract in English), Invest Clin. 1995 June;36(2): 73-82 at http://www.ncbi.nim.nih.gv/pubmed/7548302
(8y) HLA-DR-DQ haplotypes and type 1 diabetes in Macedonia. Ilonen J, et al., Immunogenetics Laboratory, University of Turku, Turku, Finland. Hum Immunol. 2009 Jun;70(6):461-3. doi: 10.1016/j.humimm.2009.03.014. Epub 2009 Mar 27
(8z) Republic of Macedonia - Multiple Indicator Cluster Survey 2005-2006. Final Report, Skopje, State Statistical Office of the Republic of Macedonia.
(8z2) Breastfeeding in China: a review Fenglian Xu1 et al., Medical College of Shihezi University; Xinjiang International Breastfeeding Journal 2009, 4:6 doi:10.1186/1746-4358-4-6. Most data drawn from "Results" section. Found at http://www.internationalbreastfeedingjournal.com/content/4/1/6
(8z2a) Child diabetes levels higher in China than in U.S., study finds Thurs. July 5, 2012 At http://uncnews.unc.edu/content/view/5418/71/
(8z3) A cohort study of infant feeding practices in city, suburban and rural areas in Zhejiang Province, PR China
Liqian Qiu1, et al., Women's Hospital, School of Medicine, Zhejiang University, PR China International Breastfeeding Journal 2008, 3:4 doi:10.1186/1746-4358-3-4 online at: http://www.internationalbreastfeedingjournal.com/content/3/1/4
(8z4) Prevalence of type 1 diabetes mellitus in 6–18-yr-old school children living in Istanbul, Turkey. Akesen, E.et al., (2011), Pediatric Diabetes, 12: 567–571. doi: 10.1111/j.1399-5448.2010.00744.x
(8z6) Number Of Diabetics Rises In Republic Of Armenia Yerevan Report, Nov 15th, 2011 at http://www.yerevanreport.com/96191/number-diabetics-rises-republic-armenia/
(9) http://www.fda.gov/biologicsbloodvaccines/resourcesforyou/consumers/ucm167471.htm Also Clin Exp Allergy. 2006 April; 36(4): 402–425. Blackwell Publishing Ltd "Too clean, or not too clean: the Hygiene Hypothesis and home hygiene," SF Bloomfield et al. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1448690/ Also Cell Research advance online publication 24 April 2012; doi: 10.1038/cr.2012.65 "Early exposure to germs and the Hygiene Hypothesis" Dale T Umetsu Division of Immunology, Karp Laboratories, Children's Hospital Boston, Harvard Medical School, Boston, MA http://www.nature.com/cr/journal/vaop/ncurrent/full/cr201265a.html
(10) "Environmental toxicants and the developing immune system: a missing link in the global battle against infectious disease?" Bethany Winans, et al., Reprod Toxicol. 2011 April; 31(3): 327–336. Published online 2010 September 22. doi: 10.1016/j.reprotox.2010.09.004 PMCID: PMC3033466 NIHMSID: NIHMS245165 accessed at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3033466/ citing the following:
Heilmann C, Grandjean P, Weihe P, Nielsen F, Budtz-Jorgensen E. "Reduced antibody responses to vaccinations in children exposed to polychlorinated biphenyls." PLoS Med. 2006;3:e311. [PMC free article
Weisglas-Kuperus N, Patandin S, Berbers GA, Sas TC, Mulder PG, Sauer PJ, et al. "Immunologic effects of background exposure to polychlorinated biphenyls and dioxins in Dutch preschool children." Environmental health perspectives. 2000;108:1203. [PMC free article]
Glynn A, Thuvander A, Aune M, Johannisson A, Darnerud P, Ronquist G, et al. "Immune cell counts and risks of respiratory infections among infants exposed pre- and postnatally to organochlorine compounds: a prospective study". Environmental Health. 2008;7:62. [PMC free article]
Dallaire F, Dewailly E, Muckle G, Vezina C, Jacobson SW, Jacobson JL, et al. "Acute infections and environmental exposure to organochlorines in Inuit infants from Nunavik." Environ Health Perspect. 2004;112:1359–63. [PMC free article]
Dewailly E, Ayotte P, Bruneau S, Gingras S, Belles-Isles M, Roy R. "Susceptibility to infections and immune status in Inuit infants exposed to organochlorines.” Environ Health Perspect. 2000;108:205–11. [PMC free article]
Jedrychowski W, Galas A, Pac A, Flak E, Camman D, Rauh V, et al. "Prenatal ambient air exposure to polycyclic aromatic hydrocarbons and the occurrence of respiratory symptoms over the first year of life." European journal of epidemiology. 2005;20:775–82.
Weisglas-Kuperus N, Vreugdenhil HJ, Mulder PG. "Immunological effects of environmental exposure to polychlorinated biphenyls and dioxins in Dutch school children." Toxicol Lett. 2004;149:281–5.
Guo YL, Lambert GH, Hsu CC, Hsu MM. Yucheng: "Health effects of prenatal exposure to polychlorinated biphenyls and dibenzofurans." Int Arch Occup Environ Health. 2004;77:153–8.
Vos JG, Moore JA. "Suppression of cellular immunity in rats and mice by maternal treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin." International archives of allergy and applied immunology.
Screening for Type 2 Diabetes, Report of a World Health Organization and International Diabetes Federation meeting World Health Organization, Department of Noncommunicable Disease Management 2003 at http://www.who.int/diabetes/publications/en/screening_mnc03.pdf
Type 2 Diabetes in Children and Adolescents, American Diabetes Association at http://www.utpa.edu/bho/PDF_Documents/ADA%20Type 2 diabetes in children.pdf
Epidemiology of Type 1 Diabetes Mellitus at http://books.google.com/books?id=64Z8LjJ3deIC&pg=PA228&lpg=PA228&dq=latency+period+for+diabetes&source=bl&ots=wQk_EU6kAI&sig=4g-itdVKMucovtmaLWjpemTrUI8&hl=en&sa=X&ei=pdnxUIS7Asvy2gWc04GIBg&ved=0CFAQ6AEwBTgK#v=onepage&q=latency period for diabetes&f=false
At http://www.jdf.org/index.cfm?page_id=101982: (Juvenile Diabetes Research Foundation)