Archive for the ‘Heart Disease’ Category

Vegan Rates of High Blood Pressure from Adventist Health Study 2

Wednesday, January 11th, 2012

In 2009, preliminary cross-sectional data on blood pressure rates among various diet groups were reported from Adventist Health Study 2. Just today, a more thorough report was posted at PubMed. The 2012 report only included whites and the results did not appear to be adjusted. But, in any case, vegans had a 63% reduced risk of having high blood pressure, as compared to regular meat-eaters, which was highly statistically significant. Lacto-ovo vegetarians had a 43% reduced rate, which was also statistically significant. More details can be seen in Table 12 of Disease Markers of Vegetarians at

Body mass index was able to account for most of the differences in blood pressure between the diet groups, though other factors probably play a small role, such as higher potassium and lower sodium intakes, and lower insulin levels and blood viscosity.


Pettersen BJ, Anousheh R, Fan J, Jaceldo-Siegl K, Fraser GE. Vegetarian diets and blood pressure among white subjects: results from the Adventist Health Study-2 (AHS-2). Public Health Nutr. 2012 Jan 10:1-8. [Epub ahead of print] Link

Brazilian Vegans have Speedier Cholesterol Removal

Monday, September 26th, 2011

Hear ye, hear ye – another cross-sectional study on vegans has been released!

This time, it’s from Brazil (1). The main focus of the study was to determine how fast various lipids (triglycerides and cholesterol) were removed from the blood.

21 vegans were compared to 29 omnivores. The vegans had lower intakes of calories, saturated fat, and total fat. Vegans had similar triglyceride removal to omnivores, but they had faster cholesterol removal. Vegans also showed a lower rate of transferring cholesterol to HDL particles which is, apparently, a good thing.

The authors conclude that these findings, along with the vegans’ lower LDL cholesterol levels, puts vegans at a lower risk for atherogensis (fatty build up in the arteries).


1. Vinagre JC, Vinagre CG, Pozzi FS, Slywitch E, Maranhão RC. Metabolism of triglyceride-rich lipoproteins and transfer of lipids to high-density lipoproteins (HDL) in vegan and omnivore subjects. Nutr Metab Cardiovasc Dis. 2011 Sep 19. Link

Carotid Intima-Media Thickness of Vegetarians in China

Friday, September 23rd, 2011

In my post of yesterday about the semi-vegetarians in Chad, I said that there is a steady flow of cross-sectional studies on semi-vegetarians from developed countries and their cardiovascular disease markers. Today I’m reporting on another one that can roughly go in that category, although the subjects were actual vegetarians (171 males) from a temple in China (1). They were mostly vegan, though some occasionally eat eggs and milk. They were compared to 129 omnivores.

Intima-media thickness is a measure of the thickness of the artery wall that has been shown to predict cardiovascular disease. To make a long story short, the vegetarians had thinner carotid intima-media indicating less atherosclerosis.

Other results were all over the board. For example, even though vegetarians had lower BMI, they had higher waist to hip ratios. Surprisingly, the vegetarians had much lower homocysteine levels, but the homocysteine levels for both groups were “off the charts” at 76 and 125 µmol/l respectively. I’ve never heard of homocysteine levels so high (normal is between 6 and 12 µmol/l) and it makes me think their measuring methods were not calibrated to other studies’ methods.

One final tidbit: Total cholesterol for vegetarians and omnivores was 164 and 193 mg/dl.

The take home message: Make sure you have a reliable source of vitamin B12. (Just kidding!)

1. Yang SY, Zhang HJ, Sun SY, Wang LY, Yan B, Liu CQ, Zhang W, Li XJ. Relationship of carotid intima-media thickness and duration of vegetarian diet in Chinese male vegetarians. Nutr Metab (Lond). 2011 Sep 19;8(1):63. Link

Ginny Messina: Tips for Bill Clinton

Friday, September 2nd, 2011

Ginny Messina: Tips to help Bill Clinton get the most out of his vegan diet

Vegetarians have Lower Risk of Metabolic Syndrome

Monday, April 25th, 2011

Metabolic syndrome is a cluster of disorders that are associated with an increased risk of diabetes and cardiovascular disease. The disorders generally include high blood pressure, triglycerides, waist circumference, blood sugar, and low HDL cholesterol.

Cross-sectional data of 773 subjects from the Adventist Health Study-2 (AHS2) showed that, when compared to regular meat-eaters, vegetarians (those eating meat or fish less than 1 time per month) had a 56% lower rate of metabolic syndrome (0.44, 0.30-0.64). Adjustments were made for age, sex, ethnicity, smoking, alcohol intake, physical activity, and caloric intake.

Semi-vegetarians (defined as consuming fish at any frequency but consuming other meats ≥ 1 time per month but < 1 time/week), had an intermediate rate (specific data not reported).

It was somewhat disturbing (though not completely surprising given a previous report from the AHS2) to see that although the vegetarians had the lowest average body mass index of the three groups, even theirs would be considered overweight at 25.7 kg/m2 (healthy is considered to be 20.0 to 25.0).

Thanks, Matt and Dima.


Rizzo NS, Sabaté J, Jaceldo-Siegl K, Fraser GE. Vegetarian Dietary Patterns Are Associated With a Lower Risk of Metabolic Syndrome: The Adventist Health Study 2. Diabetes Care. 2011 Mar 16. (Link)

New Study: Vegan Heart Disease Risk

Friday, February 11th, 2011

You may have seen the recent headlines that vegans may have an increased risk of heart disease:

Vegan diet may present heart disease risk

It starts off saying, “Strict vegetarians, known as vegans, may be at an increased risk of developing conditions that can lead to heart attacks and strokes, according to a new study.”

The “study” referred to is this paper:

Li D. Chemistry behind Vegetarianism. J Agric Food Chem. 2011 Feb 9;59(3):777-84.

It is not actually a study, but a review paper citing studies that are already well known. There’s basically nothing new here other than to say that vegetarians need to make sure they get enough B12 and omega-3.

The paper ends by saying, “All of the above issues may be associated with an increased thrombotic and atherosclerotic risk in vegetarians, especially vegans. However, meat eaters have a cluster of thrombotic and atherosclerotic risk factors higher [emphasis added] than those of both ovo-lacto-vegetarians and vegans.”

Ginny Messina has written a more in-depth article about the paper:

A healthy vegan diet reduces heart disease risk

Red Meat & Heart Disease

Friday, May 28th, 2010

On March 5, news reports started to surface about a meta-analysis showing that processed meat, but not red meat, was linked to heart disease and diabetes. It was the first systematic review or meta-analysis of its kind, and the paper was released this month.

The authors broke meat down into three categories:

  • Red
  • Processed – might have included some poultry
  • Total – the above two categories combined

Averaged across studies, consumption levels in the lowest versus highest category of intake were (in servings per week):

Red – 1.1 vs. 8.3
Processed – 0.4 vs. 5.7
Total – 1.8 vs. 10.5

The results were:

Coronary Heart Disease

Per serving per day:
Red: 1.00 (0.81 – 1.23)
Processed: 1.42 (1.07 – 1.89)
Total: 1.27 (0.94 – 1.72)

Diabetes Mellitus

Per serving per day:
Red: 1.16 (0.92 – 1.46)
Processed: 1.19 (1.11 – 1.27)
Total: 1.12 (1.05 – 1.19)


Per serving per day:
Total: 1.24 (1.08 – 1.43)
No other statistically significant findings.

In other words, more servings of red meat did not increase the risk of heart disease, diabetes, or stroke, while more servings of processed meat increased the risk of heart disease and diabetes. Only more servings of total meat increased the risk of stroke, but there was not nearly as much data for stroke.

This raised the question, “Could it be that non-processed red meat – and, by proxy, saturated fat – is NOT linked to heart disease?”

Before I go and do something that really annoys me, I want to point out that it really annoys me when people nickel and dime a study to death because it disagrees with their pre-drawn conclusions. That said, I do not think you can rule out the possibility that if the researchers had included white meat in their analysis, unprocessed meat could have been linked to heart disease and diabetes. There is some evidence that people who eat no red meat or poultry have lower rates of heart disease.

Additionally, how the variables were adjusted is not clear. The authors’ state:

If multivariable models were reported with and without additional adjustment for variables that could be either confounders or intermediates (eg, high cholesterol), the multivariable model without such variables was selected. If the only multivariable model included such variables, this was selected in reference to crude or minimally adjusted models.

What this means is that if a study adjusted their results for body mass, caloric intake, or cholesterol levels, those results might have been included in the meta-analysis. This would possibly make red meat look better than it actually is because, for example, if red meat increases cholesterol levels, but you then adjust for cholesterol levels, you will lose the effect of red meat. That said, these adjustments would also have affected the processed meats category and it was not enough to ameliorate those results.

The authors note the differences between processed and unprocessed red meats:

Per 50-g serving, processed meats contained modestly higher calories and percent energy from fat and lower percent energy from protein compared with 50 g of red meats. Consistent with lower protein content, processed meats also contained less iron. Processed meats contained relatively similar saturated fat and slightly lower cholesterol, the latter perhaps related to some processed meats being derived from pork and/or lower-cholesterol deli meats. Relatively small differences were present in contents of monounsaturated fat, polyunsaturated fat, or potassium. Largest differences were seen in levels of sodium, with processed meats containing 4-fold higher levels (622 versus 155 mg per serving), as well as 50% higher nonsalt preservatives including nitrates, nitrites, and nitrosamines… Nitrates and their byproducts (eg, peroxynitrite) experimentally promote atherosclerosis and vascular dysfunction, reduce insulin secretion, and impair glucose tolerance, and streptozotocin, a nitrosamine-related compound, is a known diabetogenic compound.

The funding sources for the study were the Bill & Melinda Gates Foundation/World Health Organization Global Burden of Diseases, Risk Factors, and Injuries Study; the National Heart, Lung, and Blood Foundation, National Institutes of Health; and the Searle Scholars Program. The authors listed no conflicts of interest.

In conclusion, processed meats increase the risk of heart disease and diabetes. Unprocessed red meat may not be harmful at the levels measured in this analysis, but there are still some unanswered questions before that should be considered definitive. Total red meat may increase the risk of diabetes and stroke.

NPR Story: Fruits and Veggies Prevent Cancer?

Wednesday, April 7th, 2010

NPR ran an article today, Fruits and Veggies Prevent Cancer? Not So Much, It Turns Out…


“A huge nine-year study of diet and cancer, involving nearly a half-million Europeans in 10 countries, finds only a very weak association between intake of fruits and vegetables and cancer incidence. The study is in the current issue of the Journal of the National Cancer Institute. Those who get an extra two servings of fruits and veggies a day lower their cancer risk by only four percent.”

Not the best news, but at least it cuts the risk by 4%. I’m inclined to think this study is correct, that fruits and vegetables help prevent cancer, but not by a lot. Good news is later in the article:

“But meanwhile, there’s a pretty strong reason for everybody to continue eating lots of fruits and vegetables. It’s called cardiovascular disease. A 2004 study in the JNCI found that eating five servings of fruits and vegetables a day is associated with a 28 percent lower risk of heart disease and stroke, compared to people who eat fewer than 1.5 servings a day.”

How Unhealthy are Eggs?

Friday, January 15th, 2010

As foods go, eggs are very high in cholesterol. Back when it was thought that eating cholesterol caused an increase in blood cholesterol, people with high cholesterol or heart disease were warned away from eggs. But then it was found that while some people’s cholesterol levels rise significantly from eating cholesterol, most people’s do not. So where does that leave eggs?

The findings have been somewhat mixed over the years. The most recent paper I found was a 2008 report from the Physicians’ Health Study (a trial to study low dose aspirin and beta-carotene’s effects on the primary prevention of cardiovascular disease and cancer among US male physicians) (1). They found the following when comparing consumption of 7+ eggs per week to less than 1 per week:

  • No correlation with stroke or heart attacks
  • A 23% increased risk of mortality (1.23, 1.11-1.36)
  • A doubled risk of mortality among men with type 2 diabetes (2.01, 1.26-3.20)

These results were adjusted for age, body mass index, smoking, hypertension, vitamin intake, alcohol consumption, vegetable consumption, breakfast cereal consumption, physical activity, treatment group, atrial fibrillation, diabetes mellitus, hypercholesterolemia, and parental history of premature myocardial infarction.

The authors of this paper reviewed the previous literature on eggs and mortality:

“Limited and inconsistent data have been reported on the association between egg consumption and coronary heart disease. Among 514 Australian Aborigines, consumption of 2+ eggs per week was associated with a 2.6-fold increased risk of coronary heart disease in a prospective analysis (2). Mann et al. (3) reported a 2.7-fold increased risk of death with a higher egg consumption (6+ per week) among British subjects. In contrast, other large prospective cohorts with longer follow-ups did not observe any association between egg consumption and CHD or mortality (4-7).”

They discussed other research showing 7+ eggs increased the risk of heart disease in men and women with diabetes (5).

In conclusion, it appears that in comparison to less than one egg per week, eating 7+ egg per week could increase your risk of early death, especially if you have type 2 diabetes.


1. Djousse L, Gaziano JM. Egg consumption in relation to cardiovascular disease and mortality: the Physicians’ Health Study. Am J Clin Nutr. 2008 Apr;87(4):964-9.

2. Burke V, Zhao Y, Lee AH, et al. Health-related behaviours as predictors of mortality and morbidity in Australian Aborigines. Prev Med 2007;44:135–42. [PubMed: 17069878]

3. Mann JI, Appleby PN, Key TJ, Thorogood M. Dietary determinants of ischaemic heart disease in health conscious individuals. Heart 1997;78:450–5. [PubMed: 9415002]

4. Dawber TR, Nickerson RJ, Brand FN, Pool J. Eggs, serum cholesterol, and coronary heart disease. Am J Clin Nutr 1982;36:617–25. [PubMed: 7124663]

5. Hu FB, Stampfer MJ, Rimm EB, et al. A prospective study of egg consumption and risk of cardiovascular disease in men and women. JAMA 1999;281:1387–94. [PubMed: 10217054]

6. Nakamura Y, Okamura T, Tamaki S, et al. Egg consumption, serum cholesterol, and cause-specific and all-cause mortality: the National Integrated Project for Prospective Observation of Noncommunicable Disease and Its Trends in the Aged, 1980 (NIPPON DATA80). Am J Clin Nutr 2004;80:58–63. [PubMed: 15213028]

7. Nakamura Y, Iso H, Kita Y, et al. Egg consumption, serum total cholesterol concentrations and coronary heart disease incidence: Japan Public Health Center-based prospective study. Br J Nutr 2006;96:921–8. [PubMed: 17092383]