Does Red Wine Protect the Cardiovascular System?

The 'French paradox' rears its ugly head again. The reasoning goes something like this: French people eat more saturated animal fat than any other affluent nation, and have the second-lowest rate of coronary heart disease (only after Japan, which has a much higher stroke rate than France). French people drink red wine. Therefore, red wine must be protecting them against the artery-clogging yogurt, beef and butter.

The latest study to fall into this myth was published in the AJCN recently (1). Investigators showed that 1/3 bottle of red wine per day for 21 days increased blood flow in forearm vessels of healthy volunteers, which they interpreted as "enhanced vascular endothelial function". The novel finding in this paper is that red wine consumption increases the migration of certain cells into blood vessels that are thought to maintain and repair the vessels. There were no control groups for comparison, neither abstainers nor a group drinking a different type of alcohol.

The investigators then went on to speculate that the various antioxidant polyphenols in red wine, such as the molecule resveratrol, could be involved. This could be true, but there's another possible mechanism here...

Ethanol-- plain old alcohol. You could drink a 40 oz bottle of malt liquor every night and it might do the same thing.

No matter what the source, alcohol consumption is associated with a lower risk of cardiovascular disease out to about 3-4 drinks per day, after which the risk goes back up (2, 3)*. The association is not trivial-- up to a 62% lower risk associated with alcohol use. Controlled trials have shown that alcohol, regardless of the source, increases HDL cholesterol and reduces the tendency to clot (4).

Should we all start downing three drinks a day? Not so fast. Although alcohol does probably decrease heart attack risk, the effect on total mortality is equivocal. That's because it increases the risk of cancers and accidents. Alcohol is a drug, and my opinion is that like all drugs, overall it will not benefit the health of a person with an otherwise good diet and lifestyle. That being said, it's enjoyable, so I have no problem with drinking it in moderation. Just don't think you're doing it for your health.

So does red wine decrease the risk of having a heart attack? Probably, yes, just like malt liquor does. I do think it's interesting to speculate about why alcohol (probably) reduces heart attack risk. Could it be because it relaxes us? I'm going to ponder that over a glass of whiskey...


* The first study is really interesting. For once, I see no evidence of "healthy user bias". Rates of healthy behaviors were virtually identical across quintiles of alcohol intake. This gives me a higher degree of confidence in the results.

Sweet Potatoes

We can debate the nutritional qualities of a food until we're blue in the face, but in the end, we still may not have a very accurate prediction of the health effects of that food. The question we need to answer is this one: has this food sustained healthy traditional cultures?

I'm currently reading a great book edited by Drs. Hugh Trowell and Denis Burkitt, titled Western Diseases: Their Emergence and Prevention. It's a compilation of chapters describing the diet and health of traditional populations around the world as they modernize.

The book contains a chapter on Papua New Guinea highlanders. Here's a description of their diet:

A diet survey was undertaken involving 90 subjects, in which all food consumed by each individual was weighed over a period of seven consecutive days. Sweet potato supplied over 90 percent of their total food intake, while non-tuberous vegetables accounted for less than 5 percent of the food consumed and the intake of meat was negligible... Extensive herds of pigs are maintained and, during exchange ceremonies, large amounts of pork are consumed.

They ate no salt. Their calories were almost entirely supplied by sweet potatoes, with occasional feasts on pork.

How was their health? Like many non-industrial societies, they had a high infant/child mortality rate, such that 43 percent of children died before growing old enough to marry. Surprisingly, protein deficiency was rare. No obvious malnutrition was observed in this population, although iodine-deficiency cretinism occurs in some highlands populations:

Young adults were well built and physically fit and had normal levels of haemoglobin and serum albumin. Further, adult females showed no evidence of malnutrition in spite of the demands by repeated cycles of pregnancy and lactation. On the basis of American standards (Society of Actuaries, 1959), both sexes were close to 100 percent standard weight in their twenties.

The Harvard Pack Test carried out on 152 consecutive subjects demonstrated a high level of physical fitness which was maintained well into middle-age. Use of a bicycle ergometer gave an estimated maximum oxygen uptake of 45.2 ml per kilogram per minute and thus confirmed the high level of cardiopulmonary fitness in this group.

Body weight decreased with age, which is typical of many non-industrial cultures and reflects declining muscle mass but continued leanness.

There was no evidence of coronary heart disease or diabetes. Average blood pressure was on the high side, but did not increase with age. Investigators administered 100 gram glucose tolerance tests and only 3.8 percent of the population had glucose readings above 160 mg/dL, compared to 21 percent of Americans. A study of 7,512 Papuans from several regions with minimal European contact indicated a diabetes prevalence of 0.1 percent, a strikingly low rate. For comparison, in 2007, 10.7 percent of American adults had diabetes (1).

I'm not claiming it's optimal to eat nothing but sweet potatoes. But this is the strongest evidence we're going to come by that sweet potatoes can be eaten in quantity as part of a healthy diet. However, I wish I knew more about the varieties this group ate. Sweet potatoes aren't necessarily sweet. Caribbean 'boniato' sweet potatoes are dry, starchy and off-white. In the US, I prefer the yellow sweet potatoes to the orange variety of sweet potato labeled 'yams', because the former are starchier and less sweet. If I could get my hands on locally grown boniatos here, I'd eat those, but boniatos are decidedly tropical.

Instead, I eat potatoes, but I'm reluctant to recommend them whole-heartedly because I don't know enough about the traditional cultures that consumed them. I believe there are some low-CHD, low-obesity African populations that eat potatoes as part of a starch-based diet, but I haven't looked into it closely enough to make any broad statements. Potatoes have some nutritional advantages over sweet potatoes (higher protein content, better amino acid profile), but also some disadvantages (lower fiber, lower in most micronutrients, toxic glycoalkaloids).

Pastured Dairy may Prevent Heart Attacks

Not all dairy is created equal. Dairy from grain-fed and pasture-fed cows differs in a number of ways. Pastured dairy contains more fat-soluble nutrients such as vitamin K2, vitamin A, vitamin E, carotenes and omega-3 fatty acids. It also contains more conjugated linoleic acid, a fat-soluble molecule that has been under intense study due to its ability to inhibit obesity and cancer in animals. The findings in human supplementation trials have been mixed, some confirming the animal studies and others not. In feeding experiments in cows, Dr. T. R. Dhiman and colleagues found the following (1):

Cows grazing pasture and receiving no supplemental feed had 500% more conjugated linoleic acid in milk fat than cows fed typical dairy diets.

Fat from ruminants such as cows, sheep and goats is the main source of CLA in the human diet. CLA is fat-soluble. Therefore, skim milk doesn't contain any. It's also present in human body fat in proportion to dietary intake. This can come from dairy or flesh.

In a recent article from the AJCN, Dr. Liesbeth Smit and colleagues examined the level of CLA in the body fat of Costa Rican adults who had suffered a heart attack, and compared it to another group who had not (a case-control study, for the aficionados). People with the highest level of CLA in their body fat were 49% less likely to have had a heart attack, compared to those with the lowest level (2).

Since dairy was the main source of CLA in this population, the association between CLA and heart attack risk is inextricable from the other components in pastured dairy fat. In other words, CLA is simply a marker of pastured dairy fat intake in this population, and the (possible) benefit could just as easily have come from vitamin K2 or something else in the fat.

This study isn't the first one to suggest that pastured dairy fat may be uniquely protective. The Rotterdam and EPIC studies found that a higher vitamin K2 intake is associated with a lower risk of heart attack, cancer and overall mortality (3, 4, 5). In the 1940s, Dr. Weston Price estimated that pastured dairy contains up to 50 times more vitamin K2 than grain-fed dairy. He summarized his findings in the classic book Nutrition and Physical Degeneration. This finding has not been repeated in recent times, but I have a little hunch that may change soon...

Vitamin K2
Cardiovascular Disease and Vitamin K2
Can Vitamin K2 Reverse Arterial Calcification?

Malocclusion Posts Translated into German

It's nice to see on my website statistics program that Whole Health Source has a solid international following. As commonly as English is spoken throughout the world however, there are many people who do not have access to this blog due to a language barrier.

A gentleman by the name of Bertram has translated/summarized my series on the causes and prevention of malocclusion (misaligned teeth) into German. His site is OriginalHealth.net, and you can find the first post here, with links to the subsequent 8. It looks like an interesting site-- I wish I could read German. Thanks Bertram!

Intervew with Chris Kresser of The Healthy Skeptic

Last week, I did an audio interview with Chris Kresser of The Healthy Skeptic, on the topic of obesity. We put some preparation into it, and I think it's my best interview yet. Chris was a gracious host. We covered some interesting ground, including (list copied from Chris's post):

• The little known causes of the obesity epidemic
• Why the common weight loss advice to “eat less and exercise more” isn’t effective
• The long-term results of various weight loss diets (low-carb, low-fat, etc.)
• The body-fat setpoint and its relevance to weight regulation
• The importance of gut flora in weight regulation
• The role of industrial seed oils in the obesity epidemic
• Obesity as immunological and inflammatory disease
• Strategies for preventing weight gain and promoting weight loss

Some of the information we discussed is not yet available on my blog. You can listen to the interview through Chris's post here.

Sometimes You Just Get Lucky

I went fishing last Saturday on Fidalgo island with some friends.


That's a picture of the trophy minnow I caught after a full day of fishing. I'm thinking about having it mounted.

We made out a little better the next day.


Here are two of my other hunter-gatherer adventures for those who are interested:

Foraging
Hunting

Saturated Fat and Insulin Sensitivity, Again

A new study was recently published exploring the effect of diet composition on insulin sensitivity and other factors in humans (1). 29 men with metabolic syndrome-- including abdominal obesity, low HDL, high blood pressure, high triglycerides, and high fasting glucose-- were fed one of four diets for 12 weeks:

1. A diet containing 38% fat: 16% saturated (SFA), 12% monounsaturated (MUFA) and 6% polyunsaturated (PUFA)
2. A diet containing 38% fat: 8% SFA, 20% MUFA and 6% PUFA
3. A diet high in unrefined carbohydrate, containing 28% fat (8% SFA, 11% MUFA and 6% PUFA)
4. A diet high in unrefined carbohydrate, containing 28% fat (8% SFA, 11% MUFA and 6% PUFA) and an omega-3 supplement (1.24 g/day EPA and DHA)

After 12 weeks, insulin sensitivity, fasting glucose, glucose tolerance, and blood pressure did not change significantly in any of the four groups. This is consistent with the majority of the studies that have examined this question, although somehow the idea persists that saturated fat impairs insulin sensitivity. I discussed this in more detail in a recent post (2).

One of the questions one could legitimately ask, however, is whether SFA have a different effect on people with metabolic syndrome. Maybe the inflammation and metabolic problems they already have make them more sensitive to the hypothetical damaging effects of SFA? That's the question the first study addressed, and it appears that SFA are not uniquely harmful to insulin signaling in those with metabolic syndrome on the timescale tested.

It also showed that the different diets did not alter the proportion of blood fats being burned in muscle, as opposed to being stored in fat tissue. The human body is a remarkably adaptable biological machine that can make the best of a variety of nutrient inputs, at least over the course of 12 weeks. Metabolic damage takes decades to accumulate, and in my opinion is more dependent on food quantity and quality than macronutrient composition.