Let's look at what the submitted article, which is a press release from a university, says. "In both mice and a Phase 1 human clinical trial, long periods of not eating significantly lowered white blood cell counts. In mice, fasting cycles then 'flipped a regenerative switch,' changing the signaling pathways for hematopoietic stem cells, which are responsible for the generation of blood and immune systems, the research showed."
What's good about this line of research is that it is trying to show whether or not an observation found in a model animal will also be found in human patients. As preliminary research, this will have to be replicated by other researchers before we can rely on this finding (NOT extended fully to human patients in the current study) to guide treatment of human patients.
This is good news that people are investigating this issue. Once there has been a thorough review article on this issue published in a different journal by a different author, summing up several well designed studies, then we will really have something to talk about here on Hacker News.
I should comment on some of the other comments here. One very tricky problem in studies of human nutrition is that there isn't a good model organism for nutrition and its effect on human health. The study reported here, just like most medical intervention studies, begins in a mouse model. Mice are well understood organisms and their similarities to and differences from human beings for many medical treatments are well understood. Mice are not a particularly good model for nutrition studies, however, because mice are rodents (part of a clade of obligate herbivores) while human beings are primates (part of a clade of facultative omnivores). Moreover, human beings, the current species Homo sapiens, have evolved with co-evolution of the gut in the environment of the cultural practice of cooking food.[1] Cooking is a human cultural universal. No other animal lineage has evolved in a similar environment, so no animal provides a fully suitable model for studies of human nutritional interventions.
Human nutrition studies are HARD, because they require minute-by-minute monitoring of the subjects and exact measurements of food intake to gather meaningful experimental data. (I recall a TV news report from the 1970s about a human nutrition study in which the study volunteers, who of course were paid for this, lived confined inside a lab in which lab technicians weighed all their food to the nearest gram and controlled everything they could eat for the duration of the experiment. Alas, I've never heard of results of that study, perhaps because the sample size, with such an expensive procedure, was too small to generate meaningful data.) Yes, let's see what nutritional interventions do what for human beings, but let's be careful not to jump to conclusions too soon, because careful data gathering on this topic is especially difficult, and anecdotes crowd out data in most popular discussion of this topic.
One also has to look at the surrounding studies for context and plausibility, not just this one in isolation. For example, I think you are overcautious in your comments on nutrition data in humans for calorie restriction and fasting - there is in fact quite a large amount of support for both benefits and safety in humans, both in the context of augmenting chemotherapy and as a general health practice. There is further an enormous weight of evidence in various mammal species for the benefits of calorie restriction and fasting.
In the case of this particular item, referring specifically to alterations to the white blood cell counts and lineages, the human data only goes so far as chemotherapy patients, and not very many of them. Talking about age-altered immune systems is premature. It would not be a surprising result if validated by other researchers, as calorie restriction and fasting are already known to beneficially influence immune function over the long term, but the details here should be taken as merely interesting until someone else runs larger studies to obtain more data.
(I recall a TV news report from the 1970s about a human nutrition study in which the study volunteers, who of course were paid for this, lived confined inside a lab in which lab technicians weighed all their food to the nearest gram and controlled everything they could eat for the duration of the experiment. Alas, I've never heard of results of that study, perhaps because the sample size, with such an expensive procedure, was too small to generate meaningful data.)
I am curious what your thoughts are for a reasonable means to gather data here and draw conclusions. Something practical and do-able. Is there anything that you would think was any good?
Is calorie constriction considered nutrition? Of course animals will have evolved different food requirements, but it seems like the basic mechanism of responding to a lack of calories should be the same.
It's not my field, but I would expect it to be. We don't ingest calories, we ingest chemicals that we convert to energy. A term like "calorie constriction" masks the complicated nutrition processes behind this.
You ask a fair question. I think the large difference in body size and considerable difference in "wild" behavior between human beings and mice leaves some room for doubt about whether they share the same responses to fasting. This, of course, is an empirical question, a question the currently reported study is trying to answer in part.
What's good about this line of research is that it is trying to show whether or not an observation found in a model animal will also be found in human patients. As preliminary research, this will have to be replicated by other researchers before we can rely on this finding (NOT extended fully to human patients in the current study) to guide treatment of human patients.
This is good news that people are investigating this issue. Once there has been a thorough review article on this issue published in a different journal by a different author, summing up several well designed studies, then we will really have something to talk about here on Hacker News.
I should comment on some of the other comments here. One very tricky problem in studies of human nutrition is that there isn't a good model organism for nutrition and its effect on human health. The study reported here, just like most medical intervention studies, begins in a mouse model. Mice are well understood organisms and their similarities to and differences from human beings for many medical treatments are well understood. Mice are not a particularly good model for nutrition studies, however, because mice are rodents (part of a clade of obligate herbivores) while human beings are primates (part of a clade of facultative omnivores). Moreover, human beings, the current species Homo sapiens, have evolved with co-evolution of the gut in the environment of the cultural practice of cooking food.[1] Cooking is a human cultural universal. No other animal lineage has evolved in a similar environment, so no animal provides a fully suitable model for studies of human nutritional interventions.
Human nutrition studies are HARD, because they require minute-by-minute monitoring of the subjects and exact measurements of food intake to gather meaningful experimental data. (I recall a TV news report from the 1970s about a human nutrition study in which the study volunteers, who of course were paid for this, lived confined inside a lab in which lab technicians weighed all their food to the nearest gram and controlled everything they could eat for the duration of the experiment. Alas, I've never heard of results of that study, perhaps because the sample size, with such an expensive procedure, was too small to generate meaningful data.) Yes, let's see what nutritional interventions do what for human beings, but let's be careful not to jump to conclusions too soon, because careful data gathering on this topic is especially difficult, and anecdotes crowd out data in most popular discussion of this topic.
[1] http://www.scientificamerican.com/article/cooking-up-bigger-...
http://www.popsci.com/science/article/2012-10/eating-cooked-...
http://www.smithsonianmag.com/science-nature/why-fire-makes-...