Once thought to be a simple problem of too much cholesterol, it is now widely accepted that inflammation also plays a central role in the atherosclerotic process. Inflammation, measured by a factor in blood called C-reactive protein (CRP), can lead to heart attack or stroke. Inflammation may also raise the risk of hypertension, obesity and eye disease.
Inflammation, High Blood Pressure & AMD
Picture your blood vessels as a system of pliable pipes. When more blood needs to flow through them in a hurry, they have the flexibility to expand. When less flow is required, they can contract-except, apparently, when they’re subject to inflammation. New research suggests that with inflammation, vessels become stiff and less flexible. So when a high volume of blood has to push through the constricted arteries, it creates more pressure against the artery walls and results in high blood pressure. Over time, hypertension weakens vessel walls and paves the way for heart attacks and stroke.
The inflammation-high blood pressure connection recently emerged in a Harvard University study. CRP was measured in 20,000 women who were followed for an average of 8 years. Those with the highest level of CRP at the start were about 50% more likely to end up with hypertension compared to those who started out with the lowest levels. Even women who began with relatively low blood pressure were more apt to develop hypertension if their CRP was on the high side. A CRP over 3.5 mg/L was considered quite high and was most strongly linked with developing hypertension. But even CRP in the range of 1.7-3.5 was associated with greater hypertension risk (1). CRP levels appear to raise the risk for age-related macular degeneration (AMD) as well. In the AREDS trial, those with advanced AMD had significantly higher CRP than those without this condition. Higher CRP levels were also observed in those with intermediate stage AMD (2).
Steps to Lower Inflammation
Shed extra weight. A recent study suggests that one of the most important ways to keep CRP levels down is to lose extra weight. A Tufts University study compared the weight-loss effectiveness of four different diets: Weight Watchers, Atkins, Zone and Ornish. All four diets reduced CRP, though the low-fat Ornish diet lowered it the most and promoted the greatest weight loss (3). According to the Tufts investigators, one of the best predictors of CRP is abdominal fat, and losing weight around the middle works well for lowering CRP.
Go with a lower fat, produce-rich diet. What you eat might be as important as eating to lose weight. A large scale study compared two diet patterns: one was the typical Western style diet, with more red meat, processed meat, french fries, high-fat dairy, refined grains and sweets. The other diet was high in fruits and vegetables, poultry, fish, whole grains and beans. There was only a modest difference between the two diets in terms of total, LDL and HDL cholesterol. But compared to the healthier diet, men eating the crummy diet had higher levels of CRP (4).
Fold in more fish. The omega-3 fatty acids in fish (EPA, DHA) can create more of the prostaglandins that suppress inflammation, while other fats (mostly omega-6) create prostaglandins that encourage it. A number of studies have shown that fish oil supplements or diets high in fish, can reduce the symptoms of inflammatory rheumatoid arthritis. Many scientists think that eating a better balance of omega-3 to omega-6 fatty acids could also potentially cut the risk of heart disease.
Take a “multi” supplement. Research suggests that inflammation may deplete antioxidant stores. Lower blood levels of lutein, lycopene, carotenes, vitamin C and selenium were significantly related to higher CRP levels in a recent study. This association held even after adjusting for many other factors that can affect CRP such as smoking, aspirin use, age, exercise, etc. Preliminary findings also indicate that vitamin E may be useful in lowering CRP (6).
References
1. Sesso HD et al. C-reactive protein and the risk of developing hypertension. JAMA 290:3000-2, 2003.
2. Seddon JM et al. Association between C-reactive protein and age-related macular degeneration. JAMA 291:704-10, 2004.
3. Schaefer EJ et al. Tufts University Health and Nutrition Letter. February, 2004.
4. Kerver JM. Dietary patterns associated with risk factors for CVD in healthy US adults. AJCN 78:1103-10, 2003.
5. Ford ES et al. C-reactive protein concentration and concentrations of blood vitamins, carotenoids, and selenium among US adults. Eur J Clin Nutr. 57:1157-63, 2003.
6. Devaraj S and Jialal L. Alpha tocopherol supplementation decreases serum C-reactive protein and monocyte interleukin-6 levels in normal volunteers and type 2 diabetic patients. Free Radic Biol Med 29:790-2, 2000.
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