CR without even the ON reduces human cancer

[Guest guest]

Hi All,

I sent the available PDF and I liked the anorexia reduces cancer

story below in PMID: 11246846 [PubMed - indexed for MEDLINE]. Its Table 2

has all the data. Note the higher (odds ratio, 3) nonHodgkin’s lymphoma,

which one of our members had and was recovering from. However, note: “Only

six patients out of the total actually had a cancer diagnosed prior to

entry, and none of these patients had a second primary cancer”. Also no

metastases were seen. Note the one of two male cancers was in a cancer that

could cause (not result from) low calories consumption. Note that it is a

model for “energy restriction” in humans in the Conclusions. Note the 20%

fewer cancers among calorie restricters. Yes, they were all humans. No

they were not rodents.

Also note:

“Under experimental circumstances in animal studies, the effect of energy

restriction can be studied in animals with sufficient amounts of vitamins

and minerals in the diet. In contrast, patients with anorexia tend to be

more generally undernourished, and their food intake may simply be too low

to assure the fundamental needs or micronutrients that may directly or

indirectly (through concomitant diseases) affect the cancer pattern. For

instance, nutritional deficiency may be positively associated with

esophageal cancer [22]. [Al: Odds ratio was 20 for this cancer in calorie

restricters.] Many organ systems may be affected by the undernutrition seen

in anorectic patients, including the endocrine and hematological systems.

Peripheral estradiol concentration is decreased among patients with anorexia

nervosa [23], which might lower the incidence of hormone-dependent cancers

such as breast cancer [24]. [Al: Odds ratio was 0.8 for this cancer in

calorie restricters.] Anorexia is also associated with immunodeficiency

[25], which in other medical conditions has been linked to increased

incidences of certain cancers, in particular non-Hodgkin's lymphoma [26].”

Regarding which, the digestive organs had an increased odds ratio in

restricters of 1.3. We CRONies are not only espousing the low calorie

diets, but also the high nutrient diets associated with better than normal

reductions in cancer risk.

Also:

“women with anorexia tend to have children later in life and to have fewer

children than the average woman [31], and these are risk factors for breast

cancer [24].”

and

“Mortality was found previously to be increased among the patients with

anorexia included in our cohort, primarily due to suicide and anorexia

nervosa, but in 10 of 108 deaths from natural causes (excluding anorexia

nervosa) the primary cause was alcoholic liver cirrhosis [35]. In accordance

with this, alcohol abuse has been positively associated with anorexia

nervosa in another setting [36]. Since excess alcohol intake is causally

linked to esophageal cancer [22], it may have caused the case of esophageal

cancer seen here among anorectic women.”

Again, we CRONies should be much better off. These numbers really in my

mind give credence to the rodent studies on cancer reduction in CR. For

anorexia nervosa, the other major human pathology, heart disease, is a

disaster area because the patients too often take laxatives that deplete

potassium that is so badly needed for normal cardiac function.

Cheers, from Al, in clapping at the beauty in the data summarized below.

“The overall cancer incidence among women with anorexia nervosa was reduced

by a

factor of 0.80 …. below that of the general population on the basis of 25

observed and 31.4 expected cases. …. may support the theory that a

low-energy diet may decrease tumor development in humans. …..”

PMID: 11246846 [PubMed - indexed for MEDLINE].

“Discussion

Our study shows that the incidence of cancer is slightly, non-significantly

reduced among women hospitalized for anorexia nervosa, but low statistical

power precluded any inference from the results for men. The collections of

data in the nationwide, population-based registers of inpatients at

psychiatric and nonpsychiatric hospital departments offered a unique chance

to establish a large cohort of patients with nonself-reported anorexia

nervosa, although we still had limited power to detect a decrease in the

risk for cancer since most of the patients were under 50 years of age during

the study period. Use of the unique personal identification number allowed

unambiguous linkage between the discharge registers, the Central Population

Register and the Cancer Registry, and thus complete follow-up information on

deaths, emigrations, and cancer cases among cohort members. Hospitalized

patients with anorexia nervosa were chosen to test the energy-restriction

hypothesis because they constitute a well-defined group of persons with a

very low intake of calories. We excluded patients with additional diagnoses

such as oligophrenia and dementia, because they are not likely to have

anorexia nervosa. We did not exclude patients with prevalent cancers

(although the cases were not included in the observed number), because the

cancer incidence rates used to calculate the expected number of cancers

include multiple cancers in one individual. Only six patients out of the

total actually had a cancer diagnosed prior to entry, and none of these

patients had a second primary cancer. There was no decreasing trend in

cancer risk by time since first hospitalization for anorexia nervosa, which

reduces the likelihood that patients with undiagnosed cancer but with

anorexia nervosa-like symptoms were selected into the cohort.

One exception may be the craniopharyngioma observed in a male cohort member:

since tumors of the structures of the midline of the brain are known to

mimic anorexia nervosa [11], the tumor may well have been the primary

disease in this case.

To our knowledge, the present study is the first to investigate the cancer

risk among patients with anorexia nervosa. Several studies have been

conducted on mortality among such patients [12, 13], but none provided risk

estimates for mortality from cancer. In a recent prospective study from the

US, men with a body mass index below 18.5 kg/m2 had lower cancer mortality

than men of normal weight, while there was no difference in cancer mortality

between the leanest women and normal-weight women [14]. In general, the

results of epidemiological studies on energy intake and cancer risk are

equivocal [15, 16], perhaps due to the difficulties in the assessment of

energy intake in epidemiological studies, or to inadequate control for

physical activity, which is strongly related to energy intake [17]. Studies

of energy intake do not necessarily provide information on the effect of

energy restriction if the lowest level of energy intake is higher than the

effective level of energy restriction. Studies in experimental animals show

that the tumor incidence is reduced only when the energy restriction is

greater than 10% [1]. A study of eight obese persons showed a reduction in

rectal-cell proliferation when caloric intake was decreased [18], but energy

restriction in obesity may not be comparable to restriction in persons of

normal weight.

The timing of energy restriction may also be relevant. It has been proposed

that energy restriction during puberty reduces the risk for breast cancer

later in life, and this hypothesis is supported by an ecological study in

which the incidence of breast cancer was found to be lower in women who were

experiencing puberty during the Second World War in Norway, when energy

intake was lower than that of women experiencing puberty before or after the

War [19]. In contrast, a cohort study of women in the Netherlands who

suffered severe undernutrition at adolescence during the Second World War

provided no clear evidence for the hypothesis [20].

Energy restriction during other periods of growth, such as childhood, may

also be relevant, as indicated by an English cohort study in which energy

intake during childhood was positively associated with mortality from cancer

later in life [21]. A considerable proportion of patients with anorexia are

adolescents, but they represented too small a group in our cohort for a

separate analysis.

Under experimental circumstances in animal studies, the effect of energy

restriction can be studied in animals with sufficient amounts of vitamins

and minerals in the diet. In contrast, patients with anorexia tend to be

more generally undernourished, and their food intake may simply be too low

to assure the fundamental needs or micronutrients that may directly or

indirectly (through concomitant diseases) affect the cancer pattern. For

instance, nutritional deficiency may be positively associated with

esophageal cancer [22]. Many organ systems may be affected by the

undernutrition seen in anorectic patients, including the endocrine and

hematological systems. Peripheral estradiol concentration is decreased among

patients with anorexia nervosa [23], which might lower the incidence of

hormone-dependent cancers such as breast cancer [24]. Anorexia is also

associated with immunodeficiency [25], which in other medical conditions has

been linked to increased incidences of certain cancers, in particular

non-Hodgkin's lymphoma [26].

Patients with anorexia nervosa may differ from the general population in

respect to lifestyle. For instance, they tend to have a high level of

physical activity [27, 28], which may reduce the incidence of cancers such

as colorectal [29] and breast cancer [30]. Conversely, women with anorexia

tend to have children later in life and to have fewer children than the

average woman [31], and these are risk factors for breast cancer [24].

Sexual functioning is often poor in anorectic women [32], and low sexual

activity may be an underlying explanation for the reduced risk of cervical

neoplasia [33]. Avoidance of sun exposure in this population of patients may

contribute to a decrease in their risk of skin cancer [34].

Mortality was found previously to be increased among the patients with

anorexia included in our cohort, primarily due to suicide and anorexia

nervosa, but in 10 of 108 deaths from natural causes (excluding anorexia

nervosa) the primary cause was alcoholic liver cirrhosis [35]. In accordance

with this, alcohol abuse has been positively associated with anorexia

nervosa in another setting [36]. Since excess alcohol intake is causally

linked to esophageal cancer [22], it may have caused the case of esophageal

cancer seen here among anorectic women.

In conclusion, patients with anorexia nervosa differ from the background

population in respect to medical constitution and lifestyle factors that may

influence their cancer incidence in opposite directions, as described above.

The net consequence is difficult to determine. The weakly reduced risk for

cancer among women with anorexia found in our study must be evaluated

cautiously, although it may support the hypothesis that energy restriction

reduces tumor incidence in humans. We intend to continue to follow the

cohort of patients with anorexia nervosa for cancer occurrence over the

coming years as more cohort members reach ages of higher cancer incidence

rates.”