Women consuming too much red meat may have a higher risk of stroke than women eating less, says a new study. Red meat is high in saturated fat and cholesterol; both are risk factors for cardiovascular disease, heart attack, and stroke. The United States Centers for Disease Control and Prevention suggests lowering saturated fat intake and eating more fresh fruits and vegetables to help reduce your risk of stroke. Writing in the journal Stroke, researchers examined nearly 35,000 Swedish women, ages 39 to 73. None of the women had heart disease prior to the start of the study in 1997.
After ten years, results showed 4% of the study participants, 1,680 women, had a stroke. Those consuming the most red meat had the highest risk of stroke. Women in the top tenth of red meat intake, consuming at least 3.6 ounces each day, were 42% more likely to have a stroke, compared to women who ate just under one ounce of red meat daily.
Eating processed meat also increased stroke risk. Women eating 1.5 ounces of processed meat each day were 24% more likely to suffer a cerebral infarction, compared to woman consuming less than half an ounce of processed meat each day. Processed meat was not linked to any other form of stroke. Cerebral infarction is a type of stroke caused by a disturbance in the blood vessels supplying blood to the brain. Other types of stroke involve a rupturing of a blood vessel, called hemorrhagic strokes.
The scientists blame red meat and processed meat’s effect on raising blood pressure for the increased stroke risk. According to the World Health Organization (WHO), every year an estimated 17 million people die due to cardiovascular diseases, most notably stroke and heart attack. The WHO lists physical inactivity and unhealthy diet as the main risk factors for heart disease and major cardiac events.
The researchers also looked at the overall health profiles of rice eaters, and learned that the 19- to 50-year-olds who ate rice were less likely to be overweight or obese, had a 34% reduced risk for high blood pressure, 27% reduced likelihood of having abdominal obesity and increased waist circumference and 21% reduced risk of metabolic syndrome. No associations could be drawn for children ages two to 13; however, in children ages 14-18, body weight, waist circumference, triglycerides and diastolic blood pressure were lower (P G .05) among those who ate rice.
“This study shows that eating rice can improve overall diet and reduce risk for the major conditions that afflict more than half of all Americans — heart disease and Type II diabetes,” states Upton. “Rice is a practical solution to help consumers meet dietary guidance to eat more plant-based foods.”
U.S. national nutrition surveillance records show that rice eaters have healthier diets and less risk for chronic diseases compared to non-rice eaters. The researchers reported that rice eaters are:
- 1/3 less likely to have high blood pressure;
- 1/4 less likely to have a high waist circumference (often linked to obesity and diabetes risk);
- 1/5 less likely to have metabolic syndrome.
Research shows U.S. rice consumption has increased steadily over the past 20 years, with current per capita consumption at 26 pounds per person. Surveys show that rice is most frequently served as a side dish or one pot meal.
The research was supported by a grant from the USA Rice Federation.
Eating a Mediterranean-style diet may help people with type 2 diabetes keep their disease under control without drugs better than following a typical low-fat diet.A new study from Italy shows that people with type 2 diabetes who ate a Mediterranean diet rich in vegetables and whole grains with at least 30% of daily calories from fat (mostly olive oil) were better able to manage their disease without diabetes medications than those who ate a low-fat diet with no more than 30% of calories from fat (with less than 10% coming from saturated fat choices).
After four years, researchers found that 44% of people on the Mediterranean diet ended up requiring diabetes medications to control their blood sugars compared with 70% of those who followed the low-fat diet.
It’s one of the longest-term studies of its kind, and researchers, including Katherine Esposito, MD, of the Second University of Naples, say the results “reinforce the message that benefits of lifestyle interventions should not be overlooked.”
Best Diet for Diabetes Control
In the study, researchers randomly assigned 215 overweight people recently diagnosed with type 2 diabetes who had never been treated with diabetes medications to either a Mediterranean-style diet or a low-fat diet.
The Mediterranean diet was rich in vegetables and whole grains and low in red meat, which was replaced with fish or poultry. Overall, the diet consisted of no more than 50% of daily calories from carbohydrates and no less than 30% of calories from fat.
The low-fat diet was based on American Heart Association guidelines and was rich in whole grains and limited in sweets with no more than 30% of calories from fat and 10% from saturated fats, such as animal fats.
After four years of follow-up, the Mediterranean diet group had better glycemic (blood sugar) control and were less likely to require diabetes medications to bring their blood sugar within healthy levels.
In addition, people who followed the Mediterranean diet group also experienced improvement in other heart disease risk factors. Interestingly, weight loss was relatively comparable between the two groups by the end of the trial, suggesting that attributes of the Mediterranean diet beyond weight loss affect blood sugar control.
SOURCES: Esposito, K. Annals of Internal Medicine, Sept. 1, 2009; vol 151: pp 306-315. News release, American College of Physicians.
Researchers analyzed 84 hours of primetime and 12 hours of Saturday morning broadcast television over a 28-day period in 2004. ABC, CBS, Fox and NBC were sampled on a rotating basis to develop a complete profile of each network. The Saturday-morning cartoon segment (from 8:00 am to 11:00 am) was included to capture food advertisements marketed primarily to children.
All 96 hours of observations were videotaped and reviewed later to identify food advertisements and specific food items being promoted. Only food items that were clearly promoted for sale during an advertisement were recorded. Each food item was then analyzed for nutritional content. Observed portion sizes were converted to the number of servings.
The article indicates that the observed food items fail to comply with Food Guide Pyramid recommendations in every food group except grains. The average observed food item contained excessive servings of sugars, fat, and meat and inadequate servings of dairy, fruit and vegetables. The situation was similar for essential nutrients, with the observed foods oversupplying eight nutrients: protein, selenium, sodium, niacin, total fat, saturated fat, thiamin and cholesterol. These same foods undersupplied 12 nutrients: iron, phosphorus, vitamin A, carbohydrates, calcium, vitamin E, magnesium, copper, potassium, pantothenic acid, fiber, and vitamin D.
The authors advocate nutritional warnings for imbalanced foods similar to those mandated on direct-to-consumer drug advertisements. They recommend investigating health promotion strategies that target consumers, the food industry, public media, and regulation focusing on a three-pronged approach.
“First, the public should be informed about the nature and extent of the bias in televised food advertisements. Educational efforts should identify the specific nutrients that tend to be oversupplied and undersupplied in advertised foods and should specify the single food items that surpass an entire day's worth of sugar and fat servings. Second, educational efforts should also provide consumers with skills for distinguishing balanced food selections from imbalanced food selections. For example, interactive websites could be developed that test a participant's ability to identify imbalanced food selections from a list of options. This type of game-based approach would likely appeal to youth and adults. Third, the public should be directed to established nutritional guidelines and other credible resources for making healthful food choices.”
Over the past several decades, the food industry has reduced the amount of saturated fat in many products, and the public has reduced the amount of saturated fat in their diet. However, there has been a wide variation in the types of nutrients that have replaced this saturated fat. For example, in many products saturated fats were replaced with trans fats, which have since been determined to be detrimental; and in the overall American diet saturated fat was generally replaced with increased consumption of refined carbohydrates and grains.
“The specific replacement nutrient for saturated fat may be very important,” said lead author Dariush Mozaffarian, assistant professor in the department of epidemiology at HSPH and the department of medicine at Harvard Medical School. “Our findings suggest that polyunsaturated fats would be a preferred replacement for saturated fats for better heart health.”
Results from prior individual randomized controlled trials of saturated fat reduction and heart disease events were very mixed, with most showing no significant effects. Other trials focused only on blood cholesterol levels, which are an indirect marker of risk. Large observational studies have also generally shown no relationship between saturated fat consumption and risk of heart disease events; for example, earlier this month in the American Journal of Clinical Nutrition, researchers from HSPH and Children's Hospital Oakland Research Institute performed a pooled meta-analysis of prior observational studies and found no evidence that overall consumption of saturated fat was related to risk of coronary heart disease or stroke events.
Some of these mixed findings may relate to absence of prior focus on the specific replacement nutrient for saturated fat; in other words, was saturated fat replaced primarily with carbohydrate, monounsaturated fats such as in olive oil, or polyunsaturated fats such as in most vegetable oils?
Mozaffarian and his HSPH colleagues, Renata Micha and Sarah Wallace, performed a systematic review and meta-analysis of all randomized controlled trials through June 2009 in which participants specifically increased their polyunsaturated fat consumption as a replacement for saturated fat and in which coronary heart disease events were documented. Eight trials met the inclusion criteria, totaling 13,614 participants with 1,042 coronary heart disease events.
The meta-analysis of the trials showed that increasing polyunsaturated fat consumption as a replacement for saturated fat reduced the risk of coronary heart disease events by 19%. For every 5% increase (measured as total energy) in polyunsaturated fat consumption, coronary heart disease risk was reduced by 10%. This is now just the second dietary intervention–consuming long-chain omega-3 fatty acids is the first — to show a reduction in coronary heart disease events in randomized controlled trials.
Currently, the Institute of Medicine guidelines recommend that a range of 5%-10% energy consumption come from polyunsaturated fats. In addition, some scientists and organizations have recently suggested that consumption of polyunsaturated fats (largely “omega-6” fatty acids) should actually be reduced due to theoretical concerns that such consumption could increase coronary heart disease risk.
The results from this study suggest that polyunsaturated fats from vegetable oils may be an optimal replacement for saturated fats, an important finding for dietary guidelines and for when food manufacturers and restaurants are making decisions on how to reduce saturated fat in their products. The findings also suggest that an upper limit of 10% energy consumption from polyunsaturated fats may be too low, as the participants in these trials who reduced their risk were consuming about 15% energy from polyunsaturated fats.
Support for this study was provided by the National Heart, Lung, and Blood Institute, NIH and a Searle Scholar Award from the Searle Funds at the Chicago Community Trust.
Beta-carotene is the precursor to vitamin A and gamma-tocopherol is a common form of vitamin E. Lutein is found in dark green leafy vegetables and is important in vision and healthy skin. All three compounds are oil soluble vitamins.
Antioxidants are of interest because oxidized low-density lipoproteins (LDL) are implicated in inflammation and plaque buildup inside blood vessels. Antioxidants should prevent LDLs from oxidizing, migrating into the blood vessel walls and causing inflammation.
“Currently, studies on antioxidants do not show major benefits,” said Kris-Etherton. “Maybe we are not studying people long enough. Maybe there is something in the food that travels with the antioxidants. The antioxidant story is very disappointing to the scientific community.”
The reason for the disappointment is that studies on specific antioxidants currently do not show health benefits, but epidemiological studies seem to indicate benefits. Many people feel that we have not figured out antioxidants yet, said Kris-Etherton.
If antioxidants are important, then pistachios fit the bill as antioxidant-laden food.
The researchers conducted a randomized, crossover design, controlled feeding experiment to test the effects of pistachios on antioxidant levels when added to a heart healthy moderate-fat diet. Controlled feeding experiments provide all the food eaten by study subjects for the duration of the study period.
The participants began the study by eating a typical American diet consisting of 35 percent total fat and 11 percent saturated fat for two weeks. They then tested three diets for four weeks each with about a two-week break between each diet. All three diets were variations on the Step I Diet, a cholesterol-lowering diet in general use. The diets included, as a control, a Step I Diet with no pistachios and about 25 percent total fat and 8 percent saturated fat. The pistachio-enhanced diets were Step I Diets with 10 and 20 percent of the energy supplied by pistachio nuts, respectively. The 10 percent pistachio diet had 30 percent total fat and 8 percent saturated fat and the 20 percent pistachio diet had 34 percent total fat and 8 percent saturated fat.
The actual amounts of pistachios included in each diet were 1.5 ounces and 3 ounces for the 10 and 20 percent diets, respectively.
Both pistachio diets produced higher blood serum levels of beta-carotene, lutein and gamma-tocopherol than the typical American diet. Compared to the pistachio free Step I Diet, the pistachio-enhanced diets produced greater blood plasma levels of lutein and gamma-tocopherol. After eating both pistachio-enriched diets, the participants had lower oxidized-LDL concentrations in their blood than after the control Step I Diet.
When the researchers controlled for the change in LDL-cholesterol produced by the pistachio-enhanced diets, increases in beta-carotene and gamma-tocopherol were still associated with decreased oxidized-LDL for the 3-ounce pistachio-enhanced diet.
“Our results suggest that a heart-healthy diet including pistachios contributes to a decrease in serum oxidized-LDL levels, in part through cholesterol lowering, and also due to an added benefit of the antioxidants in the pistachios,” said Kris-Etherton.
Other researchers in the study include Sheila West, associate professor of biobehavioral health, Penn State; Sarah Gebauer, U.S. Department of Agriculture, Beltsville, Md. and Colin D. Kay, lecturer, University of East Anglia.
The Western Pistachio Association supported this work. Partial support also came from the NIH- supported General Clinical Research Center at Penn State.