New study on CR in humans

[Ltldogg]

http://online.wsj.com/article/SB1000087 ... 85860.html

I don't have an opinion yet on the validity of this study; just posting it for review and discussion by others.

Cheers,
Ltldogg

EDIT: I meant to add this to the Lounge; yet, I would love to hear Jeff Novick's thoughts. Please move this thread if necessary.

[GeoffreyLevens]

My reading is that they fed them a poor quality, near starvation diet and not a CRON diet. And if they were getting real monkey food and not Purina prior to they were likely already pretty close to healthy weight. So basically, the study was a waste of effort and proves nothing either way.

[PurplePotato]

Here's a quote from Jeff I like about about CRONing:

What is most amazing is that T Shintani, MD showed in his 2 studies that when a person goes from the typical American diet to an "ad lib" (all you can eat) version of a diet just like the McDougall Diet, that due to the change in calorie density, they can eat all they want and their calorie intake would automatically be reduced by "up to" 40% which will naturally lower their body weight and give them all the benefits discussed below without ever having to go hungry.

Which is from this informative thread: Eat More, Weigh Less & Live Longer

So for a McDougaller, there is really nothing to do but enjoy the benefits, or gain even more benefits by adopting the MWL plan. Sounds good to me

[Elvin]

Please note Luigi Fontana's dissenting comments (esp regarding protein) about the study, as reported here: http://www.wired.com/wiredscience/2012/ ... n-monkeys/.

[JeffN]

The CR Society has posted a very detailed response.

http://www.crsociety.org/science/nia_monkey_study

In Health
Jeff

[drkadoch]

Hi Jeff,

Thanks for posting that critique of the NIH study, which received a lot of press. Am I safe to conclude that you agree with most of those arguments and think that the study was flawed and the results are, therefore, inaccurate?

Thanks,
Michael

[JeffN]

I think the overwhelming body of evidence to date (over 75 years) shows CR, when properly implemented is an effective strategy for both good health and long life in humans.

In Health
Jeff

[drkadoch]

Thanks a lot, Jeff. Is there a book and/or other resources that you could recommend that describes that CR evidence? I'm asking because I consider the CR science/research an important foundation for recommending a diet centered on calorie density and I'd like to be better read up on it.

Thanks,
Michael

[JeffN]

I think all the CR material available is excellent and for 75 years has supported and highlighted the positive aspects of it.

All the bad press is about this one study and no one study ever negates 75 years of research.

There are some threads were CR is mentioned in this forum but it is not a CR site or Forum and so do not want to turn it into one but would recommend you look at the CR resources available at the CR sites.

In Health
Jeff

[JeffN]

More on the study and why we should never be swayed (good or bad) by any one (or two) study(ies).

In Health
Jeff

Clinical Implications of Basic Research
Diet and Healthy Aging
Linda Partridge, Ph.D.
N Engl J Med 2012; 367:2550-2551 December 27, 2012

The primary goal of research into aging is to improve the health of older persons. The discovery in the 1930s that a reduction in food intake could greatly extend the life span of laboratory rodents was a striking demonstration that aging is malleable. These calorie-restricted animals not only lived longer than their more adipose littermates that were fed ad libitum but also were protected against much of the loss of function and diseases associated with aging, including cancer, nephropathy, sarcopenia, metabolic disease, and neurodegeneration.1 Calorie restriction has since proved to promote longevity in diverse creatures, including spiders, beetles, fish, and dogs, as well as the more standard laboratory-model organisms for biomedical research: yeast, nematode worms, fruit flies, and mice.

The strong evolutionary conservation of the beneficial effects of reduced food intake suggested that common mechanisms could be at work in different species and that the simpler organisms could hence be used to discover potential drug targets that could be pharmacologically manipulated to improve human health during aging. Indeed, the nutrient-sensing signaling network consisting of insulin, insulin-like growth factor, and target of rapamycin, which is highly conserved during evolution, has turned out to mediate at least some of the effects of calorie restriction in animals.2

The idea that reduced calorie intake might ameliorate human aging received a boost in 2009, with the publication of the results of a 20-year study of rhesus monkeys.3 Control animals were provided with an ad libitum food supply, whereas the experimental animals received 70% of the ad libitum intake. The animals with restricted calories had fewer age-related deaths and were healthier as they aged, with a reduced incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. However, these promising findings have recently been challenged by a second study from the National Institute on Aging.4 In that study, a similar degree of caloric restriction improved some measures of metabolic health, reduced the incidence of diabetes, and greatly reduced the incidence of cancer but did not lower rates of either cardiovascular disease or age-related death.

At first sight, these results conflict, but differences in experimental design may both explain the discrepancy and provide hints about aspects of diet that are important for healthy aging.

First, the control groups in the two studies were treated differently. In the earlier study, the controls were fed ad libitum with no restriction imposed on intake, whereas monkeys in the later study received and consumed a fixed amount of food that was lower than ad libitum intake in order to prevent obesity. Work with laboratory animals has shown that the benefits of caloric restriction are quantitative, with stronger reductions in food intake producing a greater extension in life span, provided that malnutrition is avoided.1 The controls in the most recent study received a diet that was somewhat calorie-restricted, and indeed they were lighter in weight than controls in the earlier study. Thus, they may have had some benefits of caloric restriction, limiting the power to detect any additional benefits from the substantively restricted diet comprising the intervention.

Second, the composition of the diets in the two studies was different. Although the proportions of carbohydrate, fat, and protein were similar, sucrose made up nearly 30% of the diet in the first study but only about 4% in the second. This could explain why diabetes developed in many more controls in the first study. Studies of animal models, including rodents, have shown that reduced intake of particular nutrients, especially specific amino acids, rather than reduced calorie intake underlies the health improvements brought about by reduced food intake.5 This observation underscores the importance of dietary restriction over caloric restriction: the effects on health of reducing overall food intake will often depend on the composition of the diet that is fed to the controls.

What are the implications for diet and human health during aging? We will probably never know whether dietary restriction can extend the human life span because of low compliance to such a demanding nutrition regime. Medium-term studies of volunteers suggest that dietary restriction can improve metabolic and cardiovascular health and reduce inflammation. Epidemiologic studies have repeatedly indicated an association between the body-mass index (BMI); the degree of weight gain after the age of 18 years; the risk of cardiovascular disease, diabetes, and cancer; and the overall risk of death. Any health benefits of dietary restriction may therefore depend in part on the current BMI. Laboratory animals, including rhesus monkeys, resemble humans in that when they are fed ad libitum, they put on weight as they age, so it is not surprising that they show health benefits from dietary restriction. There may also be important messages for optimal diet composition for humans, although quantitative information on health outcomes is lacking. It is becoming clear from studies in animals that both the proportion and the composition of the protein in the diet can have substantial effects on health. Thus, adjusting dietary composition may prove to have effects on human health that are not confined to the overweight or obese.

[GeoffreyLevens]

What are the implications for diet and human health during aging? We will probably never know whether dietary restriction can extend the human life span because of low compliance to such a demanding nutrition regime.

Considering what I have seen amongst my friends I tend to agree with this. And yet, without really even thinking about calories except as an interesting "side bar", by eating the way Dr McDougall recommends and fine tuning a bit to achieve my health goals, I have reduced my calorie intake by at least 40% (very conservative estimate and could easily be, in reality, 50%). Compliance seems effortless and pleasurable to me. "They" don't know what they are missing...

[JeffN]

What are the implications for diet and human health during aging? We will probably never know whether dietary restriction can extend the human life span because of low compliance to such a demanding nutrition regime.

Considering what I have seen amongst my friends I tend to agree with this. And yet, without really even thinking about calories except as an interesting "side bar", by eating the way Dr McDougall recommends and fine tuning a bit to achieve my health goals, I have reduced my calorie intake by at least 40% (very conservative estimate and could easily be, in reality, 50%). Compliance seems effortless and pleasurable to me. "They" don't know what they are missing...

Correct.

If you have not seen this...

http://drmcdougall.com/forums/viewtopic.php?t=10827


What is most amazing is that T Shintani, MD showed in his 2 studies that when a person goes from the typical American diet to an "ad lib" (all you can eat) version of a diet just like the McDougall Diet, that due to the change in calorie density, they can eat all they want and their calorie intake would automatically be reduced by "up to" 40% which will naturally lower their body weight and give them all the benefits discussed below without ever having to go hungry. Here are the Shintani studies..

Obesity and cardiovascular risk intervention through the ad libitum feeding of traditional Hawaiian diet.
Shintani TT, Hughes CK, Beckham S, O'Connor HK.
Am J Clin Nutr. 1991 Jun;53(6 Suppl):1647S-1651S.
PMID: 2031501

The Hawaii Diet: ad libitum high carbohydrate, low fat multi-cultural diet for the reduction of chronic disease risk factors: obesity, hypertension, hypercholesterolemia, and hyperglycemia.
Shintani TT, Beckham S, Brown AC, O'Connor HK.
Hawaii Med J. 2001 Mar;60(3):69-73.
PMID: 11320614

And here is a video of him discussing his work...


http://vsh.voip-info.org/Shintani2.html

http://vsh.voip-info.org/Shintani.html


In Health,
Jeff

[GeoffreyLevens]

Thanks for the link, had not seen. What surprises me a bit is that this has not become more "general knowledge" in the CRON "community". I am not connected at all, don't really follow, but get the impression that most continue to struggle with extreme portion control and perhaps often unconscious feelings of deprivation when it can be done so enjoyably, easily and healthily.

[JeffN]

Thanks for the link, had not seen. What surprises me a bit is that this has not become more "general knowledge" in the CRON "community". I am not connected at all, don't really follow, but get the impression that most continue to struggle with extreme portion control and perhaps often unconscious feelings of deprivation when it can be done so enjoyably, easily and healthily.

I think part of the problem started after Dr Walford died. As you may know, if you looked closely at his teachings, he was a fan of the lower fat, higher carb, whole foods lifestyle and even recommended Pritikin in one of his books. However, after he died, it seemed like some other strong personalities took over the direction of the movement and they were all very pro The Zone and the work of Barry Sears. While they eventually moved away from most of the that, it seems they still tend towards more of a higher fat MED type diet. Of course, the more high calorie dense foods you include, the more portion control you need.

One main point I see coming through all of it is that as long as CR is practiced and ON is met (and their definition of ON is basically meeting most RDA/DRI's and keeping the bad stuff low), the program works.

So, it seems to me that the over-riding principles of it all are...

1) Plant Centered
- Center your plate and your diet around plant foods: fruits veggies, starchy veggies, roots/tubers, intact whole grains & beans, pas & lentils.

2) Minimally Processed
- Enjoy foods as close to "as grown in nature" with minimal processing that does not detract from the nutritional value &/or add in any harmful components.

3) Calorie Dilute
- Follow the principles of calorie density choosing foods that are calorie adequate, satiating and nutrient sufficient.

4) Low S-O-S
- Avoid/minimize the use of added Salts, Oils/Fats and Sugars

5) Variety
- Consume a variety of foods within the recommended food groups

In addition, include about 30-60 minutes of activity a day (including some aerobic, resistance and flexibility exercise), aim for a BMI of around 18.5-22 and get enough sleep, rest, relaxation, recreation, fresh air, pure water, etc.

If you do that, regardless of how exactly you do that, may not really matter.

In Health
Jeff

[GeoffreyLevens]

I really like that summary. Side note, friend worked in lab at UCLA down the hall from Walford. I remember her commenting on his "strange lunches", baggies of chopped veggies, fruit, etc.