Artinian and her co-authors analyzed 74 studies conducted among U.S. adults between January 1997 and May 2007. The studies measured the effects of behavioral change on blood pressure and cholesterol levels; physical activity and aerobic fitness; and diet, including reduced calorie, fat, cholesterol and salt intake, and increased fruit, vegetable and fiber consumption.
Cardiovascular disease (CVD) is the leading cause of death in the United States. According to American Heart Association statistics, about 81.1 million adults, or one out of every three people in America, have at least one type of CVD, such as heart attack, stroke or heart failure. If cardiovascular diseases were completely eradicated, life expectancy could increase by nearly seven years.
“Lifestyle change is never easy and often under-emphasized in clinical encounters with our patients. This statement shows what types of programs work and supports the increased need for counseling and goal setting to improve healthy cardiovascular habits,” said Ralph Sacco, M.D., president of the American Heart Association. “We need to find more effective ways to make lifestyle change programs available, especially to the groups at highest risk for cardiovascular diseases – older Americans, African-Americans and people of Hispanic origin.”
Sacco added that the first step in making a change is to know your health status, “because a lot of people don't realize they're at risk for heart disease and stroke. The American Heart Association's My Life Check can help identify your risk level and offers simple steps to get started on the path to ideal cardiovascular health.”
Although obesity, physical inactivity and poor diet are well recognized as major risk factors for cardiovascular disease, it's often difficult for doctors and nurses to help patients reduce their risk for an extended period. They are faced with numerous obstacles, including time constraints, reimbursement problems and insufficient training in behavioral-change techniques, the statement authors write.
Despite these difficulties, Artinian said policy changes will eventually make critical interventions more readily available.
Federal health reform legislation includes provisions that would improve access to preventive services and help Americans make healthier food choices to control risk factors for heart disease and stroke. For example, the new law requires calorie information on restaurant menus and vending machine products and eliminates co-pays for certain preventive services under Medicare and new private health plans. The legislation also includes funding to support public health interventions at the state and local levels aimed at lowering risk factors for chronic disease.
“I'm looking forward to the future when we will have a healthcare system that gives more weight to the importance of prevention and changing lifestyle behaviors to help people stay healthy and reduce cardiovascular risk,” Artinian said.
Due to the many different ways that previous studies have investigated the association between height and heart disease, Dr Paajanen and her colleagues decided to compare the shortest group to the tallest group instead of using a fixed height limit.
From the total of 1,900 papers, the researchers selected 52 that fulfilled all their criteria for inclusion in their study. These included a total of 3,012,747 patients. On average short people were below 160.5 cms high and tall people were over 173.9 cms. When men and women were considered separately, on average short men were below 165.4 cms and short women below 153 cms, while tall men were over 177.5 cms and tall women over 166.4 cms.
Dr Paajanen and her colleagues found that compared to those in the tallest group, the people in the shortest group were nearly 1.5 times more likely to die from cardiovascular disease (CVD) or coronary heart disease (CHD), or to live with the symptoms of CVD or CHD, or to suffer a heart attack, compared with the tallest people.
Looking at men and women separately, short men were 37% more likely to die from any cause compared with tall men, and short women were 55% more likely to die from any cause compared with their taller counterparts.
“Due to the heterogeneity of studies, we cannot reliably answer the question on the critical absolute height,” write the authors in their study. “The height cut-off points did not only differ between the articles but also between men and women and between ethnic groups. This is why we used the shortest-vs.-tallest group setting.”
The findings have clinical implications. Dr Paajanen said: “The results of this systematic review and meta-analysis suggest that height may be considered as a possible independent factor to be used in calculating people's risk of heart disease. Height is used to calculate body mass index, which is a widely used to quantify risk of coronary heart disease.”
It is not known why short stature should be associated with increased risk of heart disease. Dr Paajanen said: “The reasons remain open to hypotheses. We hypothesize that shorter people have smaller coronary arteries and smaller coronary arteries may be occluded earlier in life due to factors that increase risk, such as a poorer socioeconomic background with poor nutrition and infections that result in poor foetal or early life growth. Smaller coronary arteries also might be more affected by changes and disturbances in blood flow. However, recent findings on the genetic background of body height suggest that inherited factors, rather than speculative early-life poor nutrition or birth weight, may explain the association between small stature and an increased risk of heart disease in later life. We are carrying out further research to investigate these hypotheses.”
Dr Paajanen said that it was important that short people should not be worried by her findings. “Height is only one factor that may contribute to heart disease risk, and whereas people have no control over their height, they can control their weight, lifestyle habits such as smoking, drinking and exercise and all of these together affect their heart disease risk. In addition, because the average height of populations is constantly increasing, this may have beneficial effect of deaths and illness from cardiovascular disease.”
In an editorial on the research published at the same time , Jaakko Tuomilehto, Professor of Public Health at the University of Helsinki, Helsinki, Finland, welcomed the study, writing: “The systematic review and meta-analysis on this topic . . . is well justified 60 years after the first observation and the hundreds of other papers which have been published since then on this topic. The results are unequivocal: short stature is associated with increased risk of coronary heart disease. This meta-analysis provides solid proof for this, but, as the authors conclude 'The possible pathophysiological, environmental, and genetic background of this peculiar association is not known'.”
He suspects that environmental events affecting growth before and after birth may be involved. “Socio-economic adversity in childhood is . . . associated with delayed early growth and shorter adult stature. The so-called catch-up growth during the first years of life among children who are born small has negative health effects in adulthood; much of the early growth is due to greater fat accumulation. Thus, it is most likely that short stature is the link to coronary heart disease, and that tallness is not a primary factor in preventing the disease, although it indicates healthy growth. Short stature seems to be a marker for risk.”
While more work is needed to understand the exact nature of the mechanisms at work, he writes that information on height can be used now for the prevention of heart disease and other chronic diseases linked to shortness. “Full term babies who are born small are likely to be short as adults. They should receive preventive attention early on. The primordial prevention of chronic diseases should start during foetal life, and health promotion should be targeted to all pregnant women with the aim of health development of the foetus. Low birth weight and some other birth characteristics can reveal potential problems during this period of life. After that, in babies with low birth weight, it is important to avoid excessive catch-up growth, i.e. early-life fatness.”
In adult life it becomes more difficult to discover best practices, but Prof Tuomilehto, thinks it is likely short adults would benefit from more aggressive risk factor reduction.
He concludes: “Most of us know approximately our own height ranking, and, if we are at the low end, we should take coronary risk factor control more seriously. On the other hand, tall people are not protected against coronary heart disease, and they also need to pay attention to the same risk factors as shorter people.”
In all, researchers say the study demonstrates that a grape-enriched diet can have broad effects on the development of heart disease and metabolic syndrome and the risk factors that go along with it.
“The possible reasoning behind the lessening of metabolic syndrome is that the phytochemicals were active in protecting the heart cells from the damaging effects of metabolic syndrome. In the rats, inflammation of the heart and heart function was maintained far better,” says Steven Bolling, M.D., heart surgeon at the U-M Cardiovascular Center and head of the U-M Cardioprotection Research Laboratory.
The researchers also looked for signs of inflammation, oxidative damage and other molecular indicators of cardiac stress. Again, the rats who consumed the grape powder had lower levels of these markers than rats who did not receive grapes.
There is no well-accepted way to diagnose metabolic syndrome which is really a cluster of characteristics: excess belly fat (for men, a waist measuring 40 inches or more and for women, a waist measuring 35 inches or more); high triglycerides which can lead to plague build-up in the artery walls; high blood pressure; reduced glucose tolerance; and elevated c-reactive protein, a marker for inflammation in the body.
Those with metabolic syndrome are at higher risk for cardiovascular disease and type 2 diabetes.
But the U-M study suggests that it may be possible that grape consumption can change the downhill sequence that leads to heart disease by prolonging the time between when symptoms begin to occur and a time of diagnosis.
“Reducing these risk factors may delay the onset of diabetes or heart disease, or lessen the severity of the diseases,” says E. Mitchell Seymour, Ph.D., lead researcher and manager of the U-M Cardioprotection Research Laboratory. “Ultimately it may lessen the health burden of these increasingly common conditions.”
Rats were fed the same weight of food each day, with powered grapes making up 3 percent of the diet. Although the current study was supported in part by the California Table Grape Commission, which also supplied the grape powder, the researchers note that the commission played no role in the study's design, conduct, analysis or preparation of the presentation.
Research on grapes and other fruits containing high levels of antioxidant phytochemicals continues to show promise. U-M will further its research this summer when it begins a clinical trial to test the impact of grape product consumption on heart risk factors.
“Although there's not a particular direct correlation between this study and what humans should do, it's very interesting to postulate that a diet higher in phytochemical-rich fruits, such as grapes, may benefit humans,” Bolling says.
Bolling says that people who want to lower their blood pressure, reduce their risk of diabetes or help with weakened hearts retain as much pumping power as possible should follow some tried-and-true advice to eat a healthy diet low in saturated fat, trans fat and cholesterol, achieve a desirable weight and increase physical activity.
Brown Rice and Angiotensin II
The subaleurone layer of Japanese rice, which is located between the white center of the grain and the brown fibrous outer layer, is rich in oligosaccharides and dietary fibers, making it particularly nutritious. However, when brown rice is polished to make white rice, the subaleurone layer is stripped away and the rice loses some of its nutrients. The subaleurone layer can be preserved in half-milled (Haigamai) rice or incompletely-milled (Kinmemai) rice. These types of rice are popular in Japan because many people there believe they are healthier than white rice.
The Temple team and their colleagues at the Wakayama Medical University Department of Pathology and the Nagaoka National College of Technology Department of Materials Engineering in Japan sought to delve into the mysteries of the subaleurone layer and perhaps make a case for leaving it intact when rice is processed. Because angiotensin II is a perpetrator in such lethal cardiovascular diseases, the team chose to focus on learning whether the subaleurone layer could somehow inhibit the wayward protein before it wreaks havoc.
First, the team removed the subaleurone tissue from Kinmemai rice. Then they separated the tissue's components by exposing the tissue to extractions of various chemicals such as ethanol, methanol and ethyl acetate. The team then observed how the tissue affected cultures of vascular smooth muscle cells. Vascular smooth muscle cells are an integral part of blood vessel walls and are direct victims of high blood pressure and atherosclerosis.
During their analysis, the team found that subaleurone components that were selected by an ethyl acetate extraction inhibited angiotensin II activity in the cultured vascular smooth muscle cells. This suggests that the subaleurone layer of rice offers protection against high blood pressure and atherosclerosis. It could also help explain why fewer people die of cardiovascular disease in Japan, where most people eat at least one rice-based dish per day, than in the U.S., where rice is not a primary component of daily nutrition.
“Our research suggests that there is a potential ingredient in rice that may be a good starting point for looking into preventive medicine for cardiovascular diseases,” said Dr. Eguchi. “We hope to present an additional health benefit of consuming half-milled or brown rice [as opposed to white rice] as part of a regular diet.”