Tuesday, June 7, 2011

High Fat Diet Decreases Blood Flow To Placenta, Increases Stillbirth Risk

Stillbirth is a major problem in wealthy nations, and overweight or obese women have higher risks than lean women. [1]

Consistent with the evidence indicating that high fat diets increase blood coagulation activity, researchers have found that a high fat diet probably decreases blood flow to the placenta, increasing the risk of stillbirth (abstract).

The high fat diet produced a 38-56% decrease in blood flow from mother to placenta.  It also increased inflammatory markers.

Do you think this could also cause other pregnancy complications?  The authors of this study think so.[2]

OK, I know some will object that this was done on Japanese macques, not humans.  The researchers chose macques because they have a placental structure similar to humans.  Genetically, macques have DNA  93% similar to humans


Mrs. S said...

So here is my question: what diet would you recommend to a pregnant woman in terms of what to eat, what not to eat and what balance of carbs/fat/protein?

mamaloo said...
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mamaloo said...

My question is: what is the natural diet of the Japanese Macaque? A bit of Google foo shows that while the Japanese Macaque is omnivorous (like humans) the bulk of their diet consists of fruits and herbaceous plants. So, feeding the Macaques a diet that is higher in animal fats would cause problems, regardless of how close we are genetically or whether our placentas are functionally identical.


So, they DIDN'T find that high fat diets raise stillbirth rates via poor placental functioning. What they found was that non-natural diets contribute to poor functioning placentas which lead to a rise in stillbirth rates.

Another case of reading into the data what you want to see?

Beth@WeightMaven said...

Jenny over at Diabetes Update had pretty much the same response as mamaloo. See her post for a study that actually looked at the impact of low-fat diets on women with diabetes.

Beth@WeightMaven said...

Mrs S, re your question, I'd suggest checking out Chris Kresser's Healthy Baby Code.

Brandon Berg said...

I don't have access to the full text. What are the composition of the "high-fat" and control diets? As you may know, researchers can be a bit sloppy when it comes to this sort of thing, and sometimes use the term "high-fat diet" to refer to diets which differ from the control diet in ways other than an isolcaloric substitution of fat for carbohydrate.

Matt Schoeneberger MS said...

The control diet consisted of 26.8/58.5/14.7% PRO/CHO/FAT. The high-fat diet: 16.1/52.3/31.6. The control diet contained 2.87 kcal/g and the high-fat diet 3.8 kcal/g. Cholesterol came in at 83 ppm and 946 ppm for control and high-fat diet, respectively.

32% of calories from fat is not what I would consider high-fat, especially for carry-over to humans. Some of the fat came at the expense of protein and this is definitely NOT a low-carb, high-fat approach.

The thing I find the most interesting is that while 60% of the animals that were fed high fat gained weight and became insulin sensitive, 40% showed no change in either measure. So, what makes some animals responders and others not after four years on the diet?

Bill Strahan said...

I don't think it matters much that they have a similar placental structure. What I can find says that macaques get around 90% of calories from fruit if it's available, the balance nuts, seeds, bark, dirt, bugs, and very small animals like bird chicks and lizards.

I also am curious what the fat was that made it "high fat". Three diets with 32% of calories from fat that comes from animal fat, coconut oil, or soybean oil will have remarkably different effects in humans.

I can't even imagine what happens when you load up a fruit-eater on soybean oil. But I do imagine it's not good.

Helder Correia said...

I totally agree with all comments above, and there's my own wife's experience. High-(sat)fat/low-carb diet and delivered her first baby at home with a 2h labor, perfectly healthy. I'm getting a bit sick of these non-sense studies that try to prove something bad around fat. Either the researchers are dumb or not well-intentioned at all. I think Tom Naughton's Science for Smart People explains it really well: http://www.youtube.com/watch?v=y1RXvBveht0

Stan (Heretic) said...

I don't have an access to the full paper, but if what Matt Schoeneberger reported about the diet composition is correct, namely that:

- the supposedly "high fat" diet consisted of only 32% fat (by cal) and 52% carbs (probably dextrose as usual in those kind of studies)

(I would venture a guess that those 32% fat was probably also mostly "Crisco" or something dodgy like that, typically used in animal feed.)

Then - this study must be garbage!

Don, I am sure you can do better than that in terms of studies selection. Have you ran out of suitable papers? If I had more time I would have helped you. Of hand, if I wanted to stir up some legitimate non-laughable controversy I would look into Kitava and Tarahumara cases. I would also search for some more data on those 130-years old Andean villagers (potatoes! or ?)

Stan (Heretic)


I don't think Paleo and high fat low carb diets are the only healthy eating around (especially for non-diabetics!), but any reasonable HF & LC does definitely help to maintain one's health for those like me too lazy or too busy to bother with regular exercizing!

- anybody out there who is diabetic should definitely look seriously at Paleo, Atkins etc rather than bothering with the futile attempt at controlling glucose and hunger on any high carbohydrate. Because it does work and is hundred times easier than the alternatives! Don, please be careful not to discourage diabetics or other chronically ill against the LC in general; you may be doing them more harm than you think. Trust me!

M & M said...
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Don said...

The Japanese macque's natural diet is indeed low in fat. A 32% fat diet is high in fat for a macque.

Perhaps it is also high for a human. In non-industrialized developing nations, fat intake is typically <20% of calories, very commonly around 15%.

Perhaps that in part explains their higher fertility rate. Maybe they have more successful pregnancies than in wealthy nations.

Eaton et al, Richard Lee, and Burkitt and Trowell all produced evidence that a typical hunter-gatherer diet would have only about 20% of calories from fat. 32% fat would be more than 50% greater fat intake.

Infertility is a growing problem in the West, with a high fat intake, but not in Asia, with a low fat intake...despite their eating lots of starch and some sugar.

Perhaps some of you missed the first reference? Stillbirth is a major problem in WEALTHY nations, with the risk high among overweight or obese women.

Let's see, is wealth associated with higher or lower fat consumption?

How about obesity? Definitely, most studies find that obese or overweight people eat more fat than lean people.

If you had a successful pregnancy on a high fat diet, I'm glad it went well. No one said that every pregnancy on a high fat diet would go awry, just that a high fat diet increases the risk of it going awry. If you like doing things the more risky way, have at it.

I don't see how anyone can claim these researchers are not well-intentioned. They are trying to figure out why people in industrialized nations have so many stillbirths. So they check on the effect of fat on blood flow to the placenta and find adverse effects. How is that mal-intentioned? There is no evidence that a low fat diet would cause harm during pregnancy, provided that essential fatty acid needs are met, a pregnant woman would need only ~25-30 g of total fat per day to fulfill nutritional requirements for fat.

What to eat during pregnancy? Whole food starches, vegetables (land and sea), fruits, nuts, seeds, seafoods and fish. 60-70% carbohydrate, 15-25% protein, 15-20% fat.

Anonymous said...

My fertility has tremendously improved with a high protein, meat-focused diet, with some starches and veggies. I was under 100g carbs during my pregnancy and under 200g while lactating (still lactating, have an ample milk supply with no nutrient deficiencies!) my infant is 99+% percentile for strength, weight and height and is developmentally ahead on all milestones by many months.

The stillbirths in my area that I am familiar with (PacNW) come from women with wholegrains and legume-based diets and very little fat or meat consumption, not from the women with higher protein and fat consumption. Also, black American women, who consume averagely a low/medium fat diet (lots of sugar consumption, not much meat actually), have the highest likelihood of stillbirth.

This study is not extrapolatable in the way you're claiming.