Finally I get to post about something not too many people are questioning..Protein overconsumption! 😀

Whether I talk to a body-builder or a dietician, health effects of eating too much protein do not seem to be on anyone’s radar (unless a kidney disease is suspected).

Beef it up!
In developed countries people are eating approximately 30% more protein than the RDA recommended intake (1.2g of protein/kg of body weight/day vs. 0.83g RDA). Yet this is considered harmless or even beneficial (for satiety, obesity prevention). In general, we can think of all kinds of anti-fat or anti-sugar arguments, yet protein seems to be the nutrient we don’t need to worry about. There are many protein-enriched snacks and drinks that seem to have a health halo effect. I think people are not even sure why the label claim “x grams of protein!” seems exciting or promising some sort of a benefit (unless one is a gym enthusiast). Perhaps it is the fact that we don’t know any “bad” health effects of this nutrient.

Longevity & health studies
In terms of living longer, calorie restriction(CR) is the only non-genetic intervention that can lead to life extension in different organisms (from yeast to rodents to monkeys and supposedly humans). Calorie restriction means reduced energy intake (moderate CR is about 30% less calories than recommended) without malnutrition. Studies on the famous Okinawa centenarians suggest it is their moderate eating that contributes to health and longevity.
So CR should not be confused with starving or extreme undereating- many people and cultures might do so without much thought- eating about 1700 calories/day for a person with 2000 being a goal is already calorie restriction.

In mice CR studies, general CR increases longevity and induces a reduction in the level of IGF-1 (insulin-like growth factor 1). IGF-1 is an important growth factor that mediates the growth of cells and inhibits apoptosis (cell death); it is IMPORTANT because there is considerable evidence that a reduction in IGF-1 signaling plays a key role in modulating cancer and aging in humans and rodents. HOWEVER, for us humans CR does not reduce IGF-1 concentration unless protein intake is also reduced. This suggests that protein intake is more important than calorie intake in terms of IGF-1 levels in humans.

Median protein requirement for a healthy adult, by the way, is 0.65 g/kg/day. Decreased protein intake discussed with CR does not go below this number.


I first came across the idea of not going crazy on the protein while reading about mTOR. The mammalian target of rapamycin (mTOR) signaling system seems  to be connected with aging and cancer
development (also cardiovascular and neurodegenerative diseases). The insulin/IGF-1/mTOR pathway is downregulated by calorie restriction, and in turn activates other anti-aging pathways in mammalian cells.

It is necessary to see more human studies with caloric and protein restriction and the effect on health and longevity. We all know overeating is not great- it does lead to weight gain and associated health issues. But it also might be speeding up our aging, wear&tear, and increasing chances of various chronic diseases. This could be crucial for a culture that believes protein to be a healthy macronutrient which needs no limitation 😉


Why Protein is the new “It” Ingredient

Macronutrient Balance and Lifespan


Meeting Mr. Paleo!

Is there anything more exciting than a health conference???

Well, there is always chocolate, but the conference excitement is quite comparable.

ImageArizona State University has organized a great conference “Nutrition for Optimal Health and Performance”.  Today’s lecture included speakers on athletic nutrition, debate on the High-Fructose Corn Syrup, and Paleolithic Nutrition.  Right now I shall focus on the Paleo presentation.

S. Boyd Eaton, MD from Emory University is considered the “father” of the modern paleo movement (you would know him from the Paleolithic Prescription book). He himself considers himself the “grandfather” since much of his original ideas have been somewhat transformed by other (younger) researchers (and he does not necessarily agree with all).

The Hypothesis

The presentation was not new to me, since I have read several of his papers.  In short, Dr. Eaton talked about the basis for the paleo health idea- the “discordance hypothesis“, according to which our genes and our lives are discordant (we adapted to a certain food and activity pattern, which is not matched by the modern sedentary/processed foods lifestyle)… The mismatch of the current obesogenic environment and our stone age genes are the reason we suffer from “western” diseases.  The human of 40,000 to 15,000 years ago is fundamentally identical to the modern human.Screen Shot 2013-02-08 at 8.35.37 PM

Then Dr. E talked about different % of meat subsistence of recent hunter gatherers which ranges from 20% animal products to 95%.  They/anthropologists take the 50% of animal protein in the diet  as the model due to the idea that most of us come from the savanna region of Africa (with 50% animal dietary intake).

He also discussed that anthropologists have rather good ways of studying old diets (human skeletal remains, archeological finds, recent hunter-gatherers, and proximate nutrient analyses).

The “Ancestral” Diet

The Paleo-Nutrition of East Africa (~50,000 years ago) is considered to be comprised of 35%, 25-35% protein, and ~35% carbohydrates. Of course the carbs, protein, and fat of long ago and the present day are not the same (obviously, less processed and more micronutrient rich; the fat was more polyunsaturated, more long chain PUFA, and less cholesterol-raising fat).  Other noted differences – vitamins and minerals were 2-8 times higher than average American intake; much higher potassioum-to-sodium ratio, the diet was more basic than modern acidic diets, and much more antioxidants than at present (generally 4x). Dr. E especially emphasized fiber- vegetables in the wild are much more fibrous.  Lastly, the energy intake was considerably higher, but caloric density was low (there was more bulk- more fiber, more water in food). Dr. E also talked about “free water intake”- most of the fluids consumed were part of the vegetables&fruits.

That’s all great, but here is something that was new to me. Dr. E himself differentiated between the “weak” and “strong” forms of the paleo prescription. It’s hard to say what all forms of “paleo” people out there are following, but my impression is that folks try to stay pretty strict with what they believe our “ancestors” ate. For a healthy normal individual, however, Dr. E’s weak form consisted of-


The strong form (which seems to be the popular form as I can tell from talking to folks) is for people with “resistant health problems or who are unable to maintain desirable biomarkers” + competitive athletes.  This diet is what you would usually recognize as “the paleo diet”completely excludes grains, dairy, and alcohol.

The AfterLecture

The most exciting part for me was listening to Dr. E talk to a group of people after the presentation. A dietitian asked about the lack of legumes and beans in the paleo diet (she was upset about such nutrition advise). He commented that this was not something he necessarily agreed with at all, and that this idea originated with a different researcher (sorry, I can not remember who).  My friend asked how he viewed a paleolithic diet without meat (she is mostly vegetarian).  He said his understanding of meat avoidance is very much justified on ethical and moral grounds, considering the treatment of animals and their health (thus, the healthiness of their meat).  And if one could get their protein adequately from other sources that was great too. So he was not particularly married to one type of the ultimate human diet. Overall, Dr. E was a pleasure to be around.

My Comments on Meat Avoidance

Another dietetics student, who I know is a vegan since we are both involved in a vegetarian study, asked how he would respond to the massive literature on the health benefits of vegetarian diets and the problem of saturated fat from meat. Dr. E “politely disagreed” that vegetarianism was necessary for health but did not elaborate as much as we hoped. I understand the doc does not view being vegetarian as necessarily more healthy (considering you could do paleo with grass-fed free range meat and all). But I also wish he could talk about this further.Screen Shot 2013-02-08 at 8.29.54 PM

As someone who was vegan for 2 years and is very familiar with various health rationales for avoiding animal products, I have come to the conclusion that it is not necessary to exclude these products from the diet for health. Many cite The China Study by T. Colin Campbell, which is a book I also used to refer to (in brief, it shows the connection between animal protein and cancer). However, after looking into people who eat “traditional” diets (e.g. the Weston A. Price foundation diet), and seeing the vibrant health they enjoy… I had to come to the conclusion that all is not as black & white as I expected. In regards to meat & cancer, I am fascinated by new information on mTOR. Since I plan to post about mTOR in depth later, I will only say that it is a pathway that can be up-regulated if excess protein levels are detected in the body…in turn this stimulates cellular proliferation and adverse mitochondrial effects. In short- too much protein= increased risk of cancer. But note here that animal protein only in excess leads to adverse health effects, not animal protein per se. Supposedly, 45-60 g of protein per day for the majority of adults is a good amount* for longevity and avoidance of disease.

It was a pleasure to actually talk to the originator of the “paleo” movement, who himself is very balanced and rational in contrast to how the idea can be taken to extremes by many different people. The one thing Dr. E said is that obviously it is not sustainable for everyone to eat a paleo style diet any more, unless we decreased the world’s population drastically. Obviously, that is a different talk altogether.

*Gedgaudas CNS, CNT, Nora T. (2011-05-27). Primal Body, Primal Mind: Beyond the Paleo Diet for Total Health and a Longer Life (p. 196). Inner Traditions Bear & Company. Kindle Edition.