Vegan Diets Short on Omega-3 and Vitamin B12 May Increase Cardiovascular Risk

According to a new review, vegetarian and vegan diets may require additional omega-3 and vitamin B12 supplementation to reduce factors that increase heart disease risk.

A new review in the Journal of Agricultural and Food Chemistry indicates that many vegetarians, especially vegans, may unknowingly be at risk for certain cardiovascular health problems due to inadequate intakes of omega-3 fatty acids and vitamin B12.

The review stated that although meat eaters are known to have a significantly higher combination of cardiovascular risk factors than vegetarians, people following strict vegetarian and vegan diets are not invulnerable to risk. These diets tend to lack several key nutrients, including iron, zinc, vitamin B12, and omega-3 fatty acids.

Meat eaters are known to have a significantly higher incidence of certain cardiovascular risk factors compared with vegetarians, including increased BMI and waist-to-hip ratio, and higher blood pressure, plasma total cholesterol, and triglycerides. However, after reviewing 30 years of studies on vegetarianism, vegetarians and vegans typically have lower concentrations of serum vitamin B12 and omega-3 polyunsaturated fatty acid levels in tissue membrane phospholipids when compared to meat eaters.

Risks associated with low vitamin B12 and omega-3 status include an increase in blood clotting (platelet aggregation) due to increased levels of homocysteine, and decreased levels of ‘good’ HDL-cholesterol. Low HDL cholesterol and high homocysteine levels may be linked to an increase in cardiovascular and stroke risk.

The authors suggest that vegetarians, especially vegans, could benefit from increased dietary intake of omega-3 fatty acids to improve the balance and ratio of omega-3s to omega-6s. They can also benefit from increased vitamin B12 intake, including use of supplements containing vitamin B12 if necessary. Increasing dietary or supplemental omega-3 and vitamin B12 may reduce clotting tendencies that increase vegetarian and vegans’ otherwise low risk of cardiovascular disease.

Duo Li. Chemistry behind Vegetarianism. 2011. J Agric Food Chem 59(3):777–84.

Magnesium Reduces Risk of Sudden Cardiac Death in Women

A recent study involving a large group of women studied over 26 years found that those with the highest magnesium intake (and corresponding plasma levels) had a 41% lower risk of sudden cardiac death.

Magnesium has beneficial cardiovascular properties in cellular and experimental models, but its relation to sudden cardiac death (SCD) risk in humans is unclear.

In a recent study published in the American Journal of Clinical Nutrition, researchers examined the association between magnesium, as measured in diet and plasma, and risk of SCD. The association for magnesium intake was examined prospectively in 88,375 women who were free of disease in 1980 and part of the Nurses’ Health Study. Information on magnesium intake, other nutrients, and lifestyle factors was updated every 2–4 years through questionnaires. In this group of women, there were 505 cases of sudden or arrhythmic death documented over 26 years of follow-up.

After adjustment for confounders and potential intermediaries, the relative risk of SCD was significantly lower in women in the highest quartile of both dietary intake and plasma levels of magnesium (when compared to those in the lowest quartile). The inverse relation with SCD was stronger for plasma magnesium than dietary intake of magnesium, with each 0.25 mg/dL (one standard deviation) increment in plasma magnesium associated with a 41% lower risk of SCD.

In this study group of women, higher plasma concentrations and dietary intakes of magnesium were associated with lower risks of SCD. The researchers stated that if the observation is causal, interventions aimed at increasing dietary or plasma magnesium might lower the risk of sudden cardiac death.

Chiuve SE, et al. Plasma and dietary magnesium and risk of sudden cardiac death in women. 2011. Am J Clin Nutr 93(2):253-260.

High Fiber Intake Reduces Risk of Heart Disease

High dietary fiber intake, especially from a variety of sources, is related to a reduction in many cardiovascular disease risk factors.

Increased dietary fiber intake is associated with reduced risk of cardiovascular disease. The results of a study published in the December 2005 issue of the American Journal of Clinical Nutrition added unique insight to the growing body of evidence linking higher dietary fiber intake with reduced risk of heart disease.

Data was collected from roughly 2,500 men and 3,500 women (5,961 total). These individuals were already participating in the SU.VI.MAX Study, a trial designed to evaluate the effect of antioxidants on cancer and heart disease incidence over an eight year period. Participants from this study were selected because the SU.VI.MAX Study already required detailed dietary information, making it easy to estimate fiber intakes for the participants.

Higher total and insoluble dietary fiber intakes were associated with reductions in the risks of elevated waist-to-hip ratio (a marker of obesity), hypertension (high blood pressure), plasma apolipoprotein B (LDL cholesterol), apolipoprotein B to apolipoprotein A-I ratio (LDL to HDL ratio), triacylglycerols, and homocysteine. Fiber from cereals was associated with a lower body mass index (BMI), blood pressure, and homocysteine concentration; fiber from vegetables with a lower blood pressure and homocysteine concentration; and fiber from fruit with a lower waist-to-hip ratio and blood pressure. Fiber from dried fruit or nuts and seeds was associated with a lower body mass index, waist-to-hip ratio, and fasting apo B and glucose concentrations.

The findings of this study illustrate the significance of increasing fiber intake from various dietary sources. The results also indicate that 25 grams total dietary fiber per day may be the minimum intake required to attain a significant protective effect against cardiovascular disease, and that total dietary fiber intakes of 30-35 grams/day might provide an even greater protective effect.

Lairon D, Arnault N, Bertrais S, Planells R, Clero E, Hercberg S, Boutron-Ruault MC. Dietary fiber intake and risk factors for cardiovascular disease in French adults. 2005. AJCN 82(6):1185-94.

Quercetin Reduces Blood Pressure in Adults with Hypertension

Quercetin, an antioxidant found in onions, berries, and apples, is associated with a reduced risk of heart disease and stroke. Supplementation with quercetin has been shown to reduce hypertension in animal models, but until now has never been tested in hypertensive humans.

Researchers at the University of Utah, in collaboration with USANA Health Sciences, conducted a randomized, double-blind, placebo-controlled, crossover study to test the effectiveness of quercetin supplementation in lowering unhealthy blood pressure levels. The subjects were divided into two groups: prehypertensives (120-139 mm Hg systolic/80-89 mm Hg diastolic) or stage 1 hypertensives (140-159 mm Hg systolic/90-99 mm Hg diastolic). Over 28 days, the participants were given either 730 mg quercetin/day or placebo.

Blood pressure remained unchanged in prehypertensives after supplementation with quercetin. In contrast, stage 1 hypertensive subjects showed significant reductions in both systolic (-7 mm Hg) and diastolic (-2 mm Hg) blood pressure after quercetin supplementation. This is the first published study to show that quercetin supplementation can reduce blood pressure in hypertensive adult humans. Additionally, it is important to note that quercetin supplementation did not influence the blood pressure of non-hypertensive individuals.

J. Nutr. 137:2405-2411, November 2007

Vitamin D Deficiency Associated with Cardiovascular Disease Prevalence

In a large sample of U.S. adults, new research indicates that vitamin D deficiency is associated with an increased prevalence of cardiovascular disease.

Inadequate vitamin D levels are known to be associated with certain cardiovascular disease (CVD) risk factors, but until recently the association between vitamin D levels and the prevalence of CVD had not been comprehensively examined in the general U.S. population.

In a recent study published in Atherosclerosis, researchers examined data from the Third National Health and Nutrition Examination Survey (NHANES), a population-based sample of more than 16,000 U.S. adults.

In the total survey population, 1,308 subjects had some form of CVD. Using the standard definition of vitamin D deficiency (a serum level below 20 ng/mL), participants with CVD had a higher incidence of vitamin D deficiency (29.3%) than those without CVD (21.4%). After adjusting for age, gender, race/ethnicity, season of measurement, physical activity, body mass index, smoking status, hypertension, diabetes, elevated cholesterol, chronic kidney disease, and vitamin D use, the researchers showed that subjects deficient in vitamin D had a 20% increased risk of CVD.

The results of this analysis indicate a significant relationship between vitamin D deficiency and CVD prevalence in a large, highly representative sample of the U.S. adult population.

Atherosclerosis 2009 Jul; 205(1):255-60.

Body Mass Index Associated with Risk of All-cause Mortality

In white adults, being overweight or obese (and possibly underweight) is associated with increased all-cause mortality. All-cause mortality is generally lowest with a BMI of 20.0 to 24.9.

A high body-mass index (BMI) is associated with increased mortality from cardiovascular disease and certain cancers, but the precise relationship between BMI and all-cause mortality remains uncertain.

A large analysis reported in the December 2, 2010 issue of the New England Journal of Medicine confirms the relationship between being overweight or obese and a greater risk of dying from all causes.

An international team of researchers pooled data from 19 prospective studies totaling 1,462,958 white male and female participants between the ages of 19 and 84. Body mass index (BMI), calculated by dividing a person’s weight in kilograms by the square of their height in meters, was determined for all subjects. The participants were followed for periods that ranged from a maximum of 7 to 28 years, during which 160,087 deaths occurred.

Upon enrollment, the average BMI was 26.2. Compared with women whose body mass index was between 22.5 and 24.9, having a BMI of 25 to 29.9 was associated with a 13 percent greater risk of death over the period of follow-up. This risk rose with increasing body mass index categories, with women whose BMI was 40 to 49.9 having 2.5 times the risk of death from all causes than those with a BMI of 22.5 to 24.9. Risks among men were similar. Although a small risk of death was also observed for those whose BMI was below 20, the authors suggest that the finding was in part caused by preexisting disease.

In white adults, overweight and obesity (and possibly underweight) are associated with increased all-cause mortality. All-cause mortality is generally lowest with a BMI of 20.0 to 24.9.

de Gonzalez AB, Phil D, et al. Body-Mass Index and Mortality among 1.46 Million White Adults. 2010. N Engl J Med 363:2211-9.

To learn more and calculate your BMI, see the following link: http://www.nhlbisupport.com/bmi

Compound From Olive Fruit Shows Heart Health Potential

New research shows portion-controlled meal replacement diets as more effective than standard diets at both initial weight loss and long-term weight maintenance in type 2 diabetics.
In a recent study, supplementing with hydroxytyrosol – a polyphenolic compound extracted from olives – correlated with higher activity levels of the enzyme arylesterase, an antioxidant biomarker, and lower levels of oxidized LDL cholesterol. Oxidized LDL is believed to be a major player in promoting atherosclerosis (the build-up of fatty plaques in arteries) and general cardiovascular disease.

Hydroxytyrosol is thought to be the main antioxidant compound in olive fruit, and it is believed to play a significant role in many of the health benefits attributed to olive oil. Previous research has linked the compound to cardiovascular benefits, typically reductions in LDL or “bad” cholesterol. Data has also suggested the compound may boost eye health and reduce the risk of macular degeneration.

Spanish researchers reported these most recent results in the British Journal of Nutrition. Twenty-two healthy volunteers between 20 and 45 years of age and with a BMI between 18 and 33 kg/m2 were recruited. Volunteers were randomly assigned to receive 10 to 15 grams per day of hydroxytyrosol-enriched sunflower oil or non-enriched sunflower oil for three weeks. The former provided a daily hydroxytyrosol dose of between 45 and 50 mg. After the initial three week period, volunteers had two weeks of no intervention before crossing over to receive the other intervention.

Results showed no changes in total, LDL, or HDL-cholesterol between the groups. However, consumption of the hydroxytyrosol-enriched sunflower oil produced significant reductions in oxidized LDL from 79.8 units per liter at the start of the study to 64.1 U/l after three weeks, compared to an increase from 72.7 to 86.4 U/l during the control phase. Furthermore, the activity of arylesterase increased from 235.2 to 448.9 U/l during the hydroxytyrosol phase, compared with an increase from 204.1 to 310.3 U/l during the control phase.

The researchers reported that although hydroxytyrosol-enriched sunflower oil did not significantly reduce LDL-cholesterol or increase HDL-cholesterol, it acted as a functional food by increasing arylesterase activity and reducing oxidized LDL. Based on these results, dietary sources of hydroxytyrosol appear to be capable of reducing certain risk factors associated with coronary artery disease.

Vazquez-Velasco M, et al. Effects of hydroxytyrosol-enriched sunflower oil consumption on CVD risk factors. 2010. Br J Nutr, ePub ahead of print. doi: 10.1017/S0007114510005015

Low Vitamin D Levels May Increase Heart Disease Risk

A study published in the journal Circulation showed that low levels of vitamin D may increase the risk of cardiovascular events, including heart attack, heart failure, or stroke. Individuals with both hypertension and low vitamin D levels had nearly double the risk of cardiovascular problems.

Interest in vitamin D has been increasing in recent months with a growing number of studies linking the vitamin to protection against osteoporosis and certain cancers. There is also evidence that a higher intake of vitamin D may be helpful with regard to high blood pressure, fibromyalgia, diabetes mellitus, multiple sclerosis, and rheumatoid arthritis

In a population-based study, researchers used data from 1739 participants in the Framingham Offspring Study to study the relationship between vitamin D levels and cardiovascular health risk. Although vitamin D levels above 30 ng/mL are considered optimal for bone metabolism, only 10 percent of the participants had levels in this range. In fact, 28 percent had blood levels lower than 15 ng/mL. Participants with levels below 15 ng/mL had a 62 percent greater chance to develop cardiovascular events than those with higher levels. People with low vitamin D levels and high blood pressure (> 140/90 mmHg), were found to have double the risk of cardiovascular problems compared to people with normal blood pressure and vitamin D levels.

Vitamin D is produced in the skin on exposure to UVB radiation (sunlight) and obtained in the diet from foods like oily fish, egg yolk, and liver. Recent studies have shown, however, that sunshine levels in some northern countries are so weak during the winter months that the human body makes little to no vitamin D, leading to widespread deficiencies. In addition, increased skin pigmentation also reduces the effect of UVB radiation, meaning darker skinned people are at greater risk.

The results from this study raise the possibility that treating vitamin D deficiency, by supplementation and/or lifestyle measures, could reduce the risk of cardiovascular events.

Wang TJ, et al. Vitamin D Deficiency and Risk of Cardiovascular Disease. 2008. Circulation 117(4):503-11

Long Term Multivitamin Use in Women Reduces the Risk of Heart Attack

A new study published in the American Journal of Clinical Nutrition examined the association between multivitamin use and myocardial infarction (MI) in a large population of women.

The study included 31,671 Swedish women with no history of cardiovascular disease (CVD) and 2,262 women with a history of CVD aged 49–83 years. At the beginning of the study, the women completed a questionnaire regarding dietary supplement use, diet, and lifestyle factors. Multivitamins were estimated to contain nutrients close to recommended daily allowances.

During an average of 10.2 years of follow-up, 932 MI cases were identified in the CVD-free group and 269 cases in the CVD group. In the CVD-free group, use of multivitamins only, compared with no use of supplements, was associated with a 27% decreased risk of CVD. When multivitamins were used in conjunction with other supplements, the risk of CVD was decreased by 30%. In those that used only supplements other than multivitamins the reduction in risk was much smaller at only 7%. In women that used multivitamins for more than 5 years there was a 41% reduction in risk of CVD.

This research showed that the use of multivitamins was inversely associated with MI, especially among long-term users with no history of CVD.

Rautiainen S, Akesson A, Levitan EB, Morgenstern R, Mittleman MA, Wolk A. Multivitamin us and the risk of myocardial infarction: a population-based cohort of Swedish women. 2010. American Journal of Clinical Nutrition, Vol. 92, (5), 1251-6

Calcium and Vitamin D Enhance Heart Health Benefits of Weight Loss

Weight Loss & Heart Health

Weight loss and reduced waist circumference are related to an improvement in heart health and factors related to metabolic syndrome. According to recent research, supplementing with calcium and vitamin D during weight loss enhances heart health benefits in women with typically low calcium intakes.

Recent research has shown that overweight individuals with low calcium and dairy consumption are at increased risk of developing metabolic syndrome. These findings suggest that adequate calcium intake could create a healthier metabolic profile.

Canadian researchers investigated this issue by testing cardiovascular benefits of long-term calcium supplementation in women with low calcium intake. Healthy, overweight or obese women with a daily calcium intake of less than 800 mg/day were randomly assigned to one of two groups: a group consuming two tablets/day of a calcium + vitamin D supplement (600 mg elemental calcium and 200 IU vitamin D/tablet), or a group consuming placebo. Both groups completed a 15-week reduced calorie weight-loss program.

Significant decreases in LDL cholesterol levels, as well as the ratios of total to LDL and LDL to HDL were seen the calcium + vitamin D group. These changes were independent of changes due to fat loss and reduced waist circumference. A tendency for more beneficial changes in HDL cholesterol, triglycerides, and total cholesterol was also observed in the calcium+D group.

This was the first study to show that calcium and vitamin D enhance the beneficial effects of weight loss on cardiovascular risk factors in overweight women with typically low calcium intakes.

Major GC, et al. Supplementation with calcium + vitamin D enhances the beneficial effect of weight loss on plasma lipid and lipoprotein concentrations. 2007. American Journal of Clinical Nutrition 85(1): 54-9.