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All,

Over on this thread about the hazards and benefits of a fruitarian diet we've talked (and debunked) about the concern that some so-called nutrition experts have about fructose, even in whole fruit. I was surprised to see that neither in that thread nor anywhere else I could find have we discussed this study [1]. With this post I will remedy that. It's a real winner and I don't mean that facetiously.

My only complaint is that it was a small study, involving only 10 people (8 men and 2 women) who were "prepared to eat a large amount of leafy vegetables" - perhaps they couldn't find too many subjects...

The participants were healthy folks, average age ~38 and average BMI ~25. That had each subject follow three different diets for two weeks each - "Vegetable Diet", "Starch Diet" and "Low-fat Therapeutic Diet" so as to serve as their own controls. All meals were prepared for each subject and delivered in pre-weighed quantities to them twice weekly. Here are the specific foods eaten for the three diets:

HNB6Em0.png


Note for the "Vegetable Diet", there were three different days of meals that subjects ate in rotation, while for the other two diets subjects ate the same thing every day for the entire two weeks. Also note that it's not clear from the text whether the olive oil in the starch or low-fat therapeutic diets was extra virgin or not.

Here is a high level nutrition breakdown of the three diets:
 

VdbyP3z.png


What's noteworthy is that the Vegetable diet looks remarkably similar to my own, whole food, plant-based diet - except for the fact that I eat a wider variety of fruits and vegetables, as well as more nuts, and therefore more fat & calories. Here are a few facts about the vegetable diet from the full text of the paper:

  • This very high intake of fruit and vegetables translated into 63 servings per day for a 2,500 kcal diet (Table 1)
  • It was 18% protein (entirely from plant sources), 22% fat (half from MUFA), and 60% carbs
  • It contained almost 140g of fiber per day
  • The total weight of food was 5.1 kg / day (~11 lbs)
  • The fecal weight during the vegetable diet was over 900g/day (~2lbs)

Yup, that's a diet after my own heart. In fact, I'd consider it nearly perfect except I'd replace some of the "chunky" veggies with "leafy" ones, add some omega-3 from walnuts/flax, and of course someone eating this way would need to supplement with at least B12 in the long term.

So what did they find?

Not surprisingly (to me anyway) the starch diet beat the low-fat therapeutic diet, but the vegetable diet kicked both their butts when it came to markers of cardiovascular health - which was the focus of the study. Here is the time course of changes to total cholesterol, Tot-chol:HDL , LDL:HDL, and APOB over the two weeks on each of the three diets:
 

vUGMkTb.png


As you can see from those graphs, and the summary changes below, on nearly every metric the vegetable diet beat the other two:
 

on0J9Y8.png


The only thing that the vegetable diet didn't excel at was reducing triglycerides. Note that it didn't raise triglycerides, despite all that fructose, but it didn't reduce them like it reduced all the other CVD indicators.

Finally, one more thing the vegetable diet excelled at - satiety:
 

With the maximum satiety rating as 3.0, satiety ratings were highest on the vegetable-based diet

(3.0) compared with the starch-based (1.9) and low-fat diets (0.7) and related to the daily weight of food

consumed (vegetable-based, 5.1 kg/d; starch-based, 1.9 kg/d; and low-fat therapeutic diet, 2.0 kg/d).


So if you are ever asked how you know your crazy whole food, plant-based diet is healthy, or how you know that all that fructose isn't spiking your triglycerides and trashing your liver, beyond sharing your own blood tests, I'd say this is the best study I've found to offer as evidence.

--Dean

----------
[1] Metabolism. 2001 Apr;50(4):494-503.

Effect of a very-high-fiber vegetable, fruit, and nut diet on serum lipids and
colonic function.

Jenkins DJ(1), Kendall CW, Popovich DG, Vidgen E, Mehling CC, Vuksan V, Ransom
TP, Rao AV, Rosenberg-Zand R, Tariq N, Corey P, Jones PJ, Raeini M, Story JA,
Furumoto EJ, Illingworth DR, Pappu AS, Connelly PW.

Full text: http://sci-hub.cc/10.1053/meta.2001.21037

We tested the effects of feeding a diet very high in fiber from fruit and vegetables. The levels fed were those, which had originally inspired the dietary fiber hypothesis related to colon cancer and heart disease prevention and also may have been eaten early in human evolution. Ten healthy volunteers each took 3 metabolic diets of 2 weeks duration. The diets were: high-vegetable, fruit, and nut (very-high-fiber, 55 g/1,000 kcal); starch-based containing cereals and legumes (early agricultural diet); or low-fat (contemporary therapeutic diet). All diets were intended to be weight-maintaining (mean intake, 2,577 kcal/d). Compared with the starch-based and low-fat diets, the high-fiber vegetable diet resulted in the largest reduction in low-density lipoprotein (LDL) cholesterol (33% +/- 4%, P <.001) and the greatest fecal bile acid output (1.13 +/- 0.30 g/d, P =.002), fecal bulk (906 +/- 130 g/d, P <.001), and fecal short-chain fatty acid outputs (78 +/- 13 mmol/d, P <.001). Nevertheless, due to the increase in fecal bulk, the actual concentrations of fecal bile acids were lowest on the vegetable diet (1.2 mg/g wet weight, P =.002). Maximum lipid reductions occurred within 1 week. Urinary mevalonic acid excretion increased (P =.036) on the high-vegetable diet reflecting large fecal steroid losses. We conclude that very high-vegetable fiber intakes reduce risk factors for cardiovascular disease and possibly colon cancer. Vegetable and fruit fibers therefore warrant further detailed investigation.

PMID: 11288049

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Today's Dr. Greger video (embedded below) looks into this same "Perfect Diet" study I talked about above. Not surprisingly, Dr. Greger gives it high markers, and highlights just how remarkable the improvements of serum cholesterol and "colonic performance". He makes a humorous point about the humongous bowel movements reported by the participants when eating the very high fiber, plant-based diet. 

 

Michael says Dr. Greger has a pro-vegan agenda, which is undoubtedly true, and on occasion he stretches the data he presents a bit farther than seems warranted. But I think he's made the right interpretation of this study. Overall, I think his heart is in the right place, and I'm almost certain he's not on the payroll of anyone in the "Big Veggie" industry (e.g. Bragg's, purveyors of apple cider vinegar, as Michael ludicrously suggests here). Dr. Greger is simply trying to help people improve their diets by eating a whole-foods, (mostly) plant-based diet despite all the societal forces stacked against eating healthy, and he believes strongly in the merits of what he's doing - something I don't think even Michael can fault him for trying to do. 

 

--Dean

 

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Dean, thank you for prompting me to read Dr. Greger’s transcript and watch his video today. I am a subscriber of his newsletters.

 

You discussed the same study before Dr. Greger did. How did you get to focus on this study? So many studies are out there.

 

Also the “vegetarian diet” in the study looks to be a vegan diet as I see it. Why did they call it vegetarian instead of vegan?

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Grace,

 

I'm not sure how I came across the "perfect diet" study discussed above, and in Dr. Greger's video. I probably stumbled across it will researching some other topic on Pubmed.

 

Regarding vegan vs. vegetarian - some people call a vegan diet a "strict vegetarian" diet. So that is what the authors likely meant back in 2001. "Vegan" is a surprisingly recent term, coined in 1944 by Donald Watson, founder of the Vegan Society. But it really didn't come into the popular vernacular until around 2000. Take a look at this graph, which plots the number of times the words "vegan" or "vegetarian" appeared in New York Times articles through the years:

 

rM7EvGH.png

 

As you can see, "vegan" didn't start to be used at all widely until well after the year 2001, the year the "Perfect Diet" study (PMID: 11288049) was published. It is interesting that these days "vegan" is mentioned almost as often as "vegetarian" in the NYT, despite many more people following a vegetarian diet than a vegan one. Here is the link if you want to play with this cool NYT word frequency tool. 

 

--Dean

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I'm resuscitating this thread beacuse at least two other threads lead to it.

 

The 'near perfect diet' just looks...perfect. Too perfect (allowing more variety) to be true. 

 

5.1 kg per day... As far as i understood from the answers to another thread on Dr. Fuhrman's diet, not many people would be able to gulp down that mass of food. Surely, I wouldn't.

 

The starch diet is definitely more realistic and looks healthy as well, only it doesn't yield the same results as the 'near perfect', extreme, maybe utopistic diet.

 

The near perfect diet, would be great of course for therapeutical applications (provided the subject are able to follow it).

 

 

Dr. Greger does not appear comment too much upon it, except its fiber content. Dr. Greger's suggestions (daily dozen) differ significantly from the vegetable diet illustrated in the study.

Edited by mccoy

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Re. Dr. Greger's video: yes, his suggestion that we consider the Miocene since we are the descendants of great apes is very sensible. The Paleo community focuses only on the paleolithic (and on specific low-temperatures areas inside the paleolithic). that makes up 10% or less of the timespan of interest

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5.1 kg per day... As far as i understood from the answers to another thread on Dr. Fuhrman's diet, not many people would be able to gulp down that mass of food. Surely, I wouldn't.

 

The starch diet is definitely more realistic and looks healthy as well, only it doesn't yield the same results as the 'near perfect', extreme, maybe utopistic diet.

 

The near perfect diet, would be great of course for therapeutical applications (provided the subject are able to follow it).

 

I'd say go with a diet that you can live with long term, that also gives you the best results when it comes to biomarkers of health.  I do think 5.1kg/day would be difficult for anyone to sustain long term, but also keep in mind that this was for 2700kcal which is somewhat on the high side.  Some reasonable "cheats" that won't compromise those biomarkers - get more calories from sweet potatoes, nuts, grains, avocados, and high phenol extra virgin olive oil.  My lunch is always my biggest meal of the day, out of curiosity I weighed mine today, it was almost exactly 4 lbs of food.  More variety than this study used, is better.  Specific foods can also be targeted for their known propensities to lower LDL or boost immune function for example. 

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I'll resurrect this thread yet again with two questions I've had since reading this paper some years back. I agree that this is a fantastic study that applies to a lot of our diets here.
 
1) How would the starch diet have fared if it were zero dietary cholesterol like the vegetable diet. Also, it could be that the dates and raisins were enough to raise triglycerides and LDL cholesterol, and potentially lower HDL, which sugar is known to do.

2) How would a half-starch/half-vegetable diet have fared, especially since this is the most realistic.
 
For fun, here's a somewhat similar study:
 
Metabolism. 1997 May;46(5):530-7.
Effect of a diet high in vegetables, fruit, and nuts on serum lipids.
Jenkins DJ1, Popovich DG, Kendall CW, Vidgen E, Tariq N, Ransom TP, Wolever TM, Vuksan V, Mehling CC, Boctor DL, Bolognesi C, Huang J, Patten R.
 
Abstract
We assessed the effect of a diet high in leafy and green vegetables, fruit, and nuts on serum lipid risk factors for cardiovascular disease. Ten healthy volunteers (seven men and three women aged 33 +/- 4 years [mean +/- SEM]; body mass index, 23 +/- 1 kg/m2) consumed their habitual diet (control diet, 29% +/- 2% fat calories) and a diet consisting largely of leafy and other low-calorie vegetables, fruit, and nuts (vegetable diet, 25% +/- 3% fat calories) for two 2-week periods in a randomized crossover design. After 2 weeks on the vegetable diet, lipid risk factors for cardiovascular disease were significantly reduced by comparison with the control diet (low-density lipoprotein [LDL] cholesterol, 33% +/- 4%, P  
 

Diet
The aim for the vegetable diet was to provide the maximum amount
of green leafy vegetables (cabbage, bok choy, chard, spinach, brussels sprouts, and leeks), flowers (broccoli and cauliflower), and other low-calorie vegetables (tomatoes, red, yellow, and green peppers, zucchini, cucumbers, carrots, green beans, bean sprouts, celery, rad- ishes, mushrooms, eggplant, and okra) that could theoretically be eaten raw. The goal for leafy vegetable consumption was set at 600 g/d. Garden peas, sweet yellow corn, and eggplant were recommended at levels of 500 g/d. When cooked, vegetables were boiled or steamed. Some foods were eaten raw such as carrots, tomatoes, green peas, fruit, and nuts. The major sources of fat, raw almonds, cashews, peanuts, and avocado, were to be eaten in limited amounts (nuts, 60 to 120 g/d). Water was the recommended beverage; however, fruit and vegetable juices and plain tea and coffee were permitted. For individuals who required milk, soya milk was allowed. Higher levels of fruit and nut consumption were advised if weight loss was noted in the first week. Subjects were given lists of foods from which to select vegetables and fruit. These were divided into three categories: foods for which a minimum set weight was required to be eaten daily, foods from which the bulk of the diet was selected, and foods (fruit and nuts) to be eaten in moderation. The only foods to contain significant amounts of starch were peas and corn. Frozen

 

Sorry I can't figure out how to directly post pics for the life of me (is this even possible?)

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James Cain, thanks for the link.

 

Btw,  if anyone is interested,  here is a recent review of lipid-lowering nutraceuticals/phytochemicals categorized by mechanism of action:

 

Lipid lowering nutraceuticals in clinical practice: position paper from an International Lipid Expert Panel

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5575230/

 

AMS-13-30429-g001.gif
 
Nutraceuticals acting as inhibitors of liver cholesterol synthesis
AMS-13-30429-g003.gif
 
Nutraceuticals acting on fatty acids
AMS-13-30429-g002.gif
 
Nutraceuticals acting as inhibitors of intestinal cholesterol absorption and enhancers of cholesterol excretion
Edited by Sibiriak

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For fun, here's a somewhat similar study:    Metabolism. 1997 May;46(5):530-7.  Effect of a diet high in vegetables, fruit, and nuts on serum lipids.

 

 

I was able to download a PDF copy here:

 

https://pdflegend.com/download/effect-of-a-diet-high-in-vegetables-fruit-and-nuts-on-serum-lipids-_59ff8ae3d64ab29c6446bdd1_pdf

Edited by Sibiriak

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