How to eat salads without oil dressings

[Suebee]

I don't want to stir up controversy with this post. I am NOT in favor of using oil. Please understand this. I want an honest answer to this question. I've read Dr. McDougall's answer and wasn't satisfied. It seemed to brush the findings aside. I am hoping you can shed more light on this subject, Jeff.

There was a study done and published in 2004 (Am.J.Clin.Nutr. 2004, Aug80(2);396-403). Carotenoid bioavailability is higher from salads ingested with full-fat than fat-reduced salad dressings as measured with electrochemical detection. It showed clearly that the full-fat salad dressing containing 28 g canola oil (that's 280 calories from fat) showed substantially greater absorption than even the lower fat salad dressing that had only 6 g of fat from canola oil versus almost NO absorption with the no fat salad dressing used.

I know all the reasons why fat is bad (including the popular olive oil). If this is true and I don't see how to refute it, can we then conclude that if we want to absorb all these nutrients we should AT LEAST add some avocado, some nuts or tofu dressings?

And I've read elsewhere (sorry I don't have that on hand) that in order absorb Vitamin E, Vitamin D and I think Vitamin K we all need fat in our diet. Yes, I know you will say there is some fat in most foods, including lettuce, but it certainly wasn't enough in this case, i.e. salads, which also included raw carrots. So is the answer to cook everything? Even lettuce? Or blending them? Please do not think I'm trying to be contentious.

Thank you very much.

[JeffN]

I don't want to stir up controversy with this post. I am NOT in favor of using oil. Please understand this. I want an honest answer to this question. I've read Dr. McDougall's answer and wasn't satisfied. It seemed to brush the findings aside. I am hoping you can shed more light on this subject, Jeff.

There was a study done and published in 2004 (Am.J.Clin.Nutr. 2004, Aug80(2);396-403). Carotenoid bioavailability is higher from salads ingested with full-fat than fat-reduced salad dressings as measured with electrochemical detection. It showed clearly that the full-fat salad dressing containing 28 g canola oil (that's 280 calories from fat) showed substantially greater absorption than even the lower fat salad dressing that had only 6 g of fat from canola oil versus almost NO absorption with the no fat salad dressing used.

I know all the reasons why fat is bad (including the popular olive oil). If this is true and I don't see how to refute it, can we then conclude that if we want to absorb all these nutrients we should AT LEAST add some avocado, some nuts or tofu dressings?

And I've read elsewhere (sorry I don't have that on hand) that in order absorb Vitamin E, Vitamin D and I think Vitamin K we all need fat in our diet. Yes, I know you will say there is some fat in most foods, including lettuce, but it certainly wasn't enough in this case, i.e. salads, which also included raw carrots. So is the answer to cook everything? Even lettuce? Or blending them? Please do not think I'm trying to be contentious.

Thank you very much..

Hi Sue

I am always amazed at the studies that get so much attention and are always used to endorse or defend or to rationalize unhealthy habits. And, the marketers and advertisers are sure to get right behind them and keep these studies in the news.

This is one of them

We just never see people put this same effort and attention into, or try to defend, the studies than regularly come out supporting good healthy habits. Imagine if this much effort and energy was put into eating more fruits and vegetables every day, which are continually shown to be the healthiest change people can make.

But, anyway....

First off, you absorb plenty of nutrients from the food you eat. The main reason the typical person is lacking in nutrients is not because they don't add enough oil, but because they eat a highly refined and processed junk food diet , do not eat enough unrefined plant foods, and do not chew their food properly. In fact, most people already add to much oil to their diet and they still are nutrient deficient.

Many studies, other than this one, have shown humans absorb the nutrients and phtyochemicals in foods just fine. For instance, this is how the ORAC scale was developed. If this was really true, that without oil, you absorb no nutrients, there would be a major health campaign about it and I for one, would be pouring oil all over my foods. BTW, I use not oil, and have had my carotenoid levels checked and they are out the roof. Amazing.


Second, oil is a relatively new phenomenon in human history, Relatively speaking, it is only recently we figured out how to extract oil from foods, stabilize it and use it in the food supply. So, somehow, humans have been able to absorb the nutrients from the foods they have eaten for centuries. We also know of many native cultures that still live on traditional diets that are less than 8% fat, and do not use oil, and have excellent health and very low disease rates.

Third, the math is misleading.

If you want to beleive what they say, you would then have to look at the total absorption per calories as the oil may increase absorption rates, but it also adds LOTS of calories lowering the overall nutrient density.

Lets say you have one medium tomato, which is 20 calories. And you measure, the absorption. Then you add a TB of oil, which is 120 calories

And it increases absorption. It would have to increase absorption over 600% to matter. Why? Because for the same 120 calories, I could have eaten 6 more tomatoes.

The olive oil would have supplied virtually no other nutrients, other than a few phystosterols and a little vitamin E (1.9 mgs) some vit K (8.1 mcgs) and virtually no minerals . It would have added no fiber, and it would have added almost 2 grams of saturated fat.

Now, on the other hand, adding in the 6 tomatoes (for the same 120 calories) would have increased the amount available to us of every single nutrient 6x. In other words, the 6 tomatoes added in

Protein 6.0 gms

Fiber 8.1 gms

Vitamin A 5635.2 IU

Total Carotenoids (26748 mcgs)
apha carotene 708 mcgs
Beta Carotene 3147 mcgs
lycopene 18039 mcgs
lutein & Zeaxanthine 862 mcgs

Folate 101.5 mcg

B1 (Thiamine) 0.3 mg

B2 (Riboflavin) 0.1 mg

B3 (Niacin) 4.0 mg

B5 (Pantothenic Acid) 0.6 mg

B6 (Pyridoxine) 0.5 mg

Vitamin C 85.9 mg

Vitamin E 3.7 mg (double what is in 120 calories of olive oil)

Vitamin K 53.4 µg (over 6x what is in the 120 calories of olive oil)

Calcium 67.6 mg

Copper 0.4 mg

Iron 1.8 mg

Magnesium 74.4 mg

Manganese 0.8 mg

Phosphorus 162.4 mg

Potassium 1603.3 mg

Zinc 1.2 mg

In the study, they used 2 TB of olive oil, so we have to double all numbers, which only makes the tomatoes look even better.

Which do you think is healthier for you from an overall picture? Adding two TB of oil, or eating 240 calories of more tomatoes (or other vegetables)? Adding in 3.6 grams of saturated fat from the olive oil, or adding in 16 more grams of fiber from the tomatoes? Increasing the percent absorption of 3992 mcgs of carotenoids (that is in the original one tomato), or adding in 53,000 mcgs (from the additional tomatoes)?

I am going for the tomatoes!


In Health
Jeff Novick, MS, RD

PS Tomatoes are around 8% fat. Romaine lettuce is around 15% fat, strawberries are around 9%.

Maybe I should cut back on my romaine consumption

[Suebee]

Thank you Jeff for your timely answer. So you are saying that even if I might not absorb the phytonutrients from the lettuce or much from raw carrots, the bulk of my already good diet would make up the difference. From my readings of other cultures, they tend not to each much raw green vegetables. Even the Chinese stir fry them (and yes, they do use oil! using the rapeseed oils--which then gives them lung cancer) or other cultures use animal fats. I don't know of too many cultures that use NO added fats to their vegetables. I already eat plenty of raw fruits, cooked vegetables. I was just wondering about the raw greens themselves. And yes, I'm already aware of the studies done that show absorption of nutrients is increased when tomatoes are cooked. I haven't used this single study as an excuse to use oil. But it did introduce nagging doubts.

[JeffN]

So you are saying that even if I might not absorb the phytonutrients from the lettuce or much from raw carrots, the bulk of my already good diet would make up the difference.

Not exactly.

What I am saying is that if they want to do the experiment and do it correctly, then they need to add in a third group, which is one that increased the amount of the vegetable in an amount to equal the calories they added from the fat, and then compared the absolute intake for all three groups. One group just vegetables. Second group vegetables plus "x" calories from oil. Third group vegetables, plus more vegetables to equal the "x" calories. Then compare the difference between group 2 and 3 and not just group 2 and 1.

Again, though, this is missing the main issue. More is not always better. Absorption of protein is slightly better from animal foods, so is that a rationale to eat animal foods? If we just want to get the highest absorption, then IV nutrients may be the solution as they are often absorbed better than any food. Forget adding oil, let us all just take a shot everyday of IV nutrients, anti-oxidants and phyto-chemicals.

What I am saying is that a unrefined plant based whole food diet, made up of a variety of foods from the known healthy food groups, will supply you with the adequate amount of nutrients you need. And, baring any major digestive health issue, if you chew your food properly, and have a variety of foods with some lightly cooked and some chopped , etc etc, you will absorb the amounts you need. Turns out cooking increases absorption as does cutting and chopping food, including raw vegetables.

Proving that I can manipulate the food in some way so you absorb more of a single nutrient or of a few nutrients is irrelevant unless you can prove that somehow that is going to result in better health and/or longer life. They have never done that. These studies were down on populations/subjects eating a diet low in fruits, vegetables, whole grains, legumes.

We have to look at the total picture and this is why I recommend we focus on foods and not isolated nutrients and why in the above experiment, the group i created, with the extra tomatoes, has the best "overall" nutritional package.

From my readings of other cultures, they tend not to each much raw green vegetables. Even the Chinese stir fry them (and yes, they do use oil! using the rapeseed oils--which then gives them lung cancer) or other cultures use animal fats. I don't know of too many cultures that use NO added fats to their vegetables.

I do not see the obsession in this culture with "added" fats. As I pointed out, everything we eat has naturally occurring fat in it, and some plant foods much more than you think. I gave 3 examples. Oatmeal is 16% fat.

The Chinese may use some added oil to stiry fry in, but it is not a lot and their total fat is still low. But, that is still missing the point.

The Okinawans, back in the 50s before they got westernized (who are now the longest lived population with more people over 100 then anywhere else) ate a diet that was around 9% fat with no added oils. So do the Taramhumara and Pima Indians in the Sierra Madre mountains of Mexico as did the original Hawaiians. All these diets were less than 10% fat and they were all known for their health. This info is published in mainstream medical journals. And, when we re-create these diets and put people on them today, they experience dramatic improvements in their health, very quickly.

In Health
Jeff Novick, MS, RD

[JeffN]

I'm still wondering about the raw salad business and how to absorb the nutrients.

Chop, Slice, Dice, and Mix. Or lightly cook them. Then, Chew thoroughly. All of which increase absorption.

I wondered what Jeff thought, that's all.

I think you should eat your veggies in salads, soups, stews, etc. Added fat is not required.




Be careful of overdoing pickled vegetables. This is a warning even from the cancer societies as the incidence of stomach cancer is still high in the areas of the world that have the highest intakes of pickled/fermented vegetables, probably from the high salt intake.

Also, as you will see, why do you have to increase the absorption of raw veggies (which are the lowest) when you can just cooked veggies, chopped veggies, fruit and tubers, which have almost the highest absorption rate, as is.

http://www.nap.edu/openbook.php?record_id=9810&page=354



In Health
Jeff

[Suebee]

Thank you very much for further clarification, Jeff. You are a wonderful addition to the McDougall team. And I only bring up the "culture issue" because Dr. McDougall does over and over--especially in talking about starch-based diets as the one the world has run on--except of course Eskimos. And no, I wasn't advocating pickled vegetables, although you probably added that for the benefit of the other poster. I don't eat them anymore. And my question about salads was personal because I do have digestion issues and my teeth don't work all that well (and no, aside from major surgery there is nothing I can do about it).

[dagnabit]

Thanks Jeff,

Excellent response. You are a real asset to the board. How do you find the time to be so active here and on your own site and on the speaking circuit? Maybe its the occasional "pat on the back" that keeps you going. Keep it up!

[JeffN]

In this 2007 study, Filipino school children who were fed meals of varying fat content for 9 weeks and tested for blood carotenoid levels. The absorption of carotenoids was similar in all groups including the lowest fat intake of 2.4g per meal total fat content.

“In summary, only a small amount of dietary fat (2.4 g/meal, or 21 g/d) is needed for optimal utilization of plant provitamin A carotenoids. The poor or marginal vitamin A status observed in the study participants at baseline cannot be attributed to insufficient fat intakes, but rather to insufficient intakes of food sources of vitamin A.”

The real issue was not eating enough fat, but that they were eating a poor diet with very few healthy foods. The solution is to eat more healthy foods.

Carotene-rich plant foods ingested with minimal dietary fat enhance the total-body vitamin A pool size in Filipino schoolchildren as assessed by stable-isotope-dilution methodology. Randomized controlled trial. Ribaya-Mercado JD, et al. Am J Clin Nutr. 2007 Apr;85(4):1041-9.

Abstract

BACKGROUND: Strategies for improving the vitamin A status of vulnerable populations are needed.

OBJECTIVE: We studied the influence of the amounts of dietary fat on the effectiveness of carotene-rich plant foods in improving vitamin A status.

DESIGN: Schoolchildren aged 9-12 y were fed standardized meals 3 times/d, 5 d/wk, for 9 wk. The meals provided 4.2 mg provitamin A carotenoids/d (mainly beta-carotene) from yellow and green leafy vegetables [carrots, pechay (bok choy), squash, and kangkong (swamp cabbage)] and 7, 15, or 29 g fat/d (2.4, 5, or 10 g fat/meal) in groups A, B, and C (n = 39, 39, and 38, respectively). Other self-selected foods eaten were recorded daily. Before and after the intervention, total-body vitamin A pool sizes and liver vitamin A concentrations were measured with the deuterated-retinol-dilution method; serum retinol and carotenoid concentrations were measured by HPLC.

RESULTS: Similar increases in mean serum beta-carotene (5-fold), alpha-carotene (19-fold), and beta-cryptoxanthin (2-fold) concentrations; total-body vitamin A pool size (2-fold); and liver vitamin A (2-fold) concentrations were observed after 9 wk in the 3 study groups; mean serum retinol concentrations did not change significantly. The total daily beta-carotene intake from study meals plus self-selected foods was similar between the 3 groups and was 14 times the usual intake; total fat intake was 0.9, 1.4, or 2.0 times the usual intake in groups A, B, and C, respectively. The overall prevalence of low liver vitamin A (<0.07 mumol/g) decreased from 35% to 7%.

CONCLUSIONS: Carotene-rich yellow and green leafy vegetables, when ingested with minimal fat, enhance serum carotenoids and the total-body vitamin A pool size and can restore low liver vitamin A concentrations to normal concentrations.

PMID 17413103