Role of diet in management of cardiovascular diseases like HTN, CAD & CHF SPEAKER : DR VIVEK MAHAJAN PRECEPTOR: DR YASHPAUL SHARMA
IMPACT OF NUTRITION ON THE GLOBAL CVD BURDEN WHO: CVD causes 33%(18 million)of deaths worldwide (www.who.int) CVD accounted for 32 percent of all deaths in 2000 in India BMJ 2004; 328:807 Diet &lifestyle changes have led to increase in overweight & obesity Obesity increases incidence of type 2 diabetes Increased risk of CVD consequently Estimated 30% of deaths from coronary heart disease due to unhealthy diets (National Heart Forum 2002)
EVIDENCE OF NUTRIENT EFFECT AND CARDIOVASCULAR RISK Testing specific nutrient effects is complicated Inherent difficulties of conducting randomized, controlled clinical endpoint trials for nutritional interventions Nutrients generally cannot be subjected to the same evidence-based criteria that are used to assess drug treatments Imprecision of the dietary information Difficulty of correcting for confounding effects of other health behaviors
FRUITS AND VEGETABLES • 3 or more servings/day vs less than 1/day a/w 27% reduction in CV risk Am J Clin Nutr 2002; 76:93 • Graded risk reduction associated with higher intakes The Physicians' Health Study. Int J Epidemiol 2001; 30:130 The Women's Health Study. Am J ClinNutr 2000; 72:922 • At least 5 portions/day of a variety of fruits and vegetables recommended
WHOLE GRAINS • Whole grains a/w reduced CV risk • Effect may be related to fiber intake --Arch Intern Med 2004; 164:370 --Am CollCardiol 2002; 39:49 • Vitamins, phytoestrogens, phenols, omega-3 fatty acids, resistant starch, and minerals may contribute • 27 % reduction in CHD risk with whole grain consumption • Recommended intake of at least 3 servings/day for cardiovascular health -- J Am CollNutr 2000; 19:291S
FIBERS • Viscous (soluble) forms of dietary fiberreduce LDL • Insoluble fiber does not significantly affect LDL J Nutr1999;129:1457S-66S • Increase in viscous fiberof 5–10 g/d accompanied by 5 % reduction in LDL Federal Register 1998;63:8103-21 Federal Register 1997;62:28234-45 • In a meta-analysis of 67 trials related to oats, pectin, guar, and psyllium, significant reduction in total and LDL cholesterol noted for all sources of viscous fiber in ranges of 2–10 grams per day Am J Clin Nutr 1999;69:30-42
NUTS • Good sources of MUFAs, fiber, minerals & flavonoids • Walnuts rich in PUFAs (linoleic and alpha-linolenic acid) --J Nutr 2002; 132:1062S • Nut consumption a/w reduced CV risk • Women consuming 5 oz/week had 35 % lower risk of nonfatal MI than those eating less than 1 oz/month --Arch Intern Med 2002; 162:1382. • Men consuming twice/week or more had 47% reduction in risk for SCD & 30 percent reduction in total CHD mortality compared with those who rarely or never consumed nuts --J Nutr 2002; 132:1062S • Almond have beneficial effects on plasma lipoproteins --Circulation 2002; 106:1327
FISH • Species with high ω3 FA confer protection from IHDs Circulation 2002; 106:2747 • Intake of small quantities a/w 17% reduction in CHD mortality risk & 27 % reduction in risk for nonfatal MI, • Each additional serving/wk associated with a further reduction of 3.9% in CHD mortality Am J Prev Med 2005; 29:335
ω3 FATTY ACIDS Increased plasma levels of Eicosapentaenoic acid (EPA) & Docosahexanoic acid (DHA) predicted reduction in SCD N Engl J Med 2002; 346:1113. 1 g/day ω3 FAs lowered overall risk of death and of coronary death from 6.8% to 4.8% Lancet. 1999;354:447–455. 5.5 gm/mth of EPA plus DHA (equivalent to one portion of fatty fish/wk) a/w 50% lower incidence of SCD Enrichment of membrane phospholipids with ω3 FA results in reduction in risk for abnormal cardiac electrical conductivity Am J Clin Nutr 2000; 71:208S Antiplatelet & antiinflammatory effects Reduction in plasma triglycerides at higher doses Circulation 2002; 106:2747
THE FRENCH PARADOX AND RED WINES High intake of SFAs but low CHD incidence & mortality Relative immunity of the French to CHD attributed in part to their custom of drinking wine with meals Red wine polyphenolic extracts (RWPE) mediate a vaso-relaxant effect via NO release 2 anthocyanins (delphinidin & petunidin), a flavonol (quercetin) and a stilbene (resveratrol) inhibit endothelin-1 synthesis RWPE reduce ICAM-1, VCAM-1 and selectin expression Increase HDL and decrease in ox-LDL
ALCOHOL • 1-2 drinks/day strongly & consistently a/w lower CHD risk than either abstention or higher intakes Rev Cardiovasc Med 2002; 3:7 • Similar relationship with CHD regardless of type of alcoholic beverages consumed BMJ 1996;312:731-6 • Major benefit of alcohol consumption related to an increase in HDL • Reduced fibrinogen, platelet aggregation & inflammation (Eur J Clin Nutr 2002; 56:1130) (Circulation 2003; 107:443) (ArteriosclerThrombVascBiol 2006; 26:995)
38,077 male health professionals free of cardiovascular disease f/u for 12 yrs Compared to men who consumed < once/week, men who consumed alcohol 3-5 or 5-7 d/wk had decreased risks of MI Risk similar among men who consumed <10 g/d and those who consumed 30 g or more. No single type of beverage conferred additional benefit
Physicians' Health Survey 87,938 men A 5.5-year follow-up Circulation 2000;102:500-505
RESVERATROL • Red wine, berries, peanuts & grapes • Polyphenolic compound • Belongs to class Phytoestrogens • Antioxidant & weak oestrogenic activity • Preconditioning effect rather than direct protection Mol Int. Feb 2006 vol 6(1) 36-47
GARLIC • Beneficial effects on serum cholesterol, TG levels and on BP • Reducing platelet aggregation and increasing fibrinolytic activity • Sulphur-containing flavonecompounds major health promoting components J Nutr. 2006 Mar;136(3 Suppl):736S-740S
PLANT STANOLS/STEROLS Plant sterols isolated from soybean and tall pine-tree oils Hydrogenating sterols produces plant stanols Available in commercial margarines Plant-derived stanol/sterol esters at dosages of 2–3 g/day lower LDL-C levels by 6–15% with little or no change in HDL or TG levels Am J Clin Nutr 1999;69:403-10 Metabolism 1999;48:575-80. Circulation1997;96:4226-31 Projected that their use should double the beneficial effect on CHD risk achieved by reducing dietary saturated fatty acids and cholesterol West J Med 2000;173:43-7
Soy protein Derived by processing of the soybean Isoflavones, fiber, and saponins Review of 16 trials: Soy protein included in a diet low in saturated fatty acids and cholesterol can lower levels of total cholesterol & LDL in individuals with hypercholesterolemia Federal Register 1998;63:62977-3015. Federal Register 1999;64:57699-733 25 g/day soy protein in a diet low in SFAs and cholesterol lowers LDL cholesterol levels by 5% Metabolism 2000;49:67-72. about 5 percent
SATURATED FATTY ACIDS Causal relationship between total & LDL cholesterol levels and CHD Saturated fatty acids increase LDL concentrations Palmitic acid (C16:0) found in meats, dairy fat, palm oil, is the most common saturated fatty acid. Palm oil major fat source in Latin America, Asia, Europe Western diets with dairy fat & meat contain myristicacid Tropical oils: coconut or palm kernel oils, have mainly lauric acid Myristic acid : strongest effect on LDL f/b lauric & palmitic acids.
WHAT SHOULD REPLACE SATURATED FATS? Controversy whether carbohydrate or unsaturated oils should replace the energy from saturated and trans unsaturated fat? If saturated fat (e.g., 25 g or 10% of total daily energy intake) is replaced by carbohydrate, monounsaturated fat, or polyunsaturated fat, LDL will decrease by 13 mg/dL, 15 mg/dL, or 18 mg/dL, respectively ArteriosclerThromb. 1992;12:911–919. So is replacement with any of these logical?
Women's Health Initiative (WHI) Randomized Controlled Dietary Modification Trial JAMA 2006; 295:655 Dietary pattern low in total fat, along with increased intakes of vegetables, fruits & grains 50,000 postmenopausal women randomized to intervention group receiving regularly scheduled individualized dietary consultations Comparison group receiving diet-related education materials only.
Women's Health Initiative (WHI) Randomized Controlled Dietary Modification Trial Reduction in total fat intake between the intervention and control groups (28.8 % vs 37 % of calories) (p<0.001) No significant effects of the intervention on CHD, stroke, or CVD were observed during the 8-year follow-up Lack of benefit on CVD endpoints might be related to minimal change in LDL due to counterbalancing effects of saturated fat and polyunsaturated fats. Modulation of total dietary fat intake within the range consumed in general population does not alter CVD risk JAMA 2006; 295:655
HIGH PUFA TRIALS Corn, safflower, sunflower & soybean oils prescribed to hypercholesterolemic patients in the 1960s and 1970s. Patients instructed to drink the vegetable oils, as well as to use them in cooking or salads PUFAs studied mainly ω6 class and not include the ω3 PUFAs from fish Linoleic and α-linolenic acids increased in these trials. Coronary events are reduced by 2% for every 1% reduction in total cholesterol Am J Cardiol. 1995;76:10C–17C
Standard Western diet Total fat 38% Saturated fat 17% Monounsaturated fat 14% Polyunsaturated fat 7% Carbohydrates 42% Protein 20% Cholesterol 400 mg/day
Step 1 diet Reduced total fat intake to 30% Saturated fat10% Dietary cholesterol 300 mg Replacing saturated fat mainly with carbohydrate. Monounsaturated 15% Polyunsaturated fat 10% similar to the initial diet Protein 15%
low-fat diet Total fat 20% Saturated fat 7% Monunsaturated and polyunsaturated fats decreased to 10% and 5%, Carbohydrate increased to 65%. Protein 15% Cholesterol is reduced to 200mg/day
Mediterranean diet Saturated fat replaced with veg oils (olive, canola, corn, safflower or sunflower oil, or oils from nuts Contain mainly monounsaturated and polyunsaturated fatty acids. Total fat content remains at 38% Dietary cholesterol is reduced to 100 mg/day
Predicted effects on coronary artery disease Circulation. 1999;99:779–785
Olive oil rich in MUFAs Extravirgin olive oil contains a considerable amount of phenolic compounds, hydroxytyrosol and oleuropein, having antioxidant & other potent biological activities Refined olive oil contains less phenolic compounds : large fraction of potentially beneficial bioactive compounds(such as flavonoids) lost in processing Eurolive project: Ongoing research on phenolic compound hydroxytyrosol for anti-platelet effect
LYON DIET HEART STUDYMEDITERRANEAN DIET TRIAL 423 patients with documented CAD f/u mean of 3.8 yrs Experimental diet: increased amounts of fruits, vegetables, legumes, and fiber Reductions of meats, butter, and cream (but not cheese) Margarine enriched in alpha-linolenic acid, ω3 FA precursor of longer chain EPA & DHA found in fatty fish. Total fat approximately 31 percent in both diets. . Circulation.1999;99:779–785
LYON DIET HEART STUDYMEDITERRANEAN DIET TRIAL • Significant reductions occurred in all outcome measures: • All-cause mortality (56 percent) • Cardiac mortality (65 percent) • Nonfatal myocardial infarction (70 percent) • Particularly important role for increased omega-3 fatty acid intake was responsible Circulation.1999;99:779–785
Indian Heart Study Fruit & vegetable intake 3 times higher in the experimental than in the control group Total fat intake 24% - 26% of energy in both groups Experimental group had higher intake of polyunsaturated fats, fiber, vitamins C and E, carotene, and potassium Experimental group had lower intake of SFAs and cholesterol Carbohydrates shifted from refined to complex sources 2 to 3 days after the acute myocardial infarction BMJ. 1992;304:1015–1019.
Indian Heart Study • Body weight, LDL, TG, BP & serum glucose significantly decreased, and HDL increased in experimental group • Significant reduction in coronary events of 36% in experimental grp after only 12 weeks • After 1 year of treatment, significant decreases in • All-cause mortality by 45% • Coronary deaths by 42%, • Nonfatal myocardial infarction by 38% • The vegetarian diet also reduced ventricular ectopy BMJ. 1992;304:1015–1019.
LIFE-STYLE HEART TRIALEXTREME LOW FAT & LIFE STYLE MODIFICATION Vegetarian diet with 10 percent total fat Aerobic exercise training, stress management, smoking cessation, and psychosocial support 48 men with coronary artery disease were allocated to intervention and control groups 35 completed a 5-year follow-up JAMA 1998; 280:2001
LIFE-STYLE HEART TRIALEXTREME LOW FAT & LIFE STYLE MODIFICATION Av diameter stenosis decreased by 7.9% in experimental grpcompared to control group which had 11.8% increased after 5 years (p = 0.001) 25 cardiac events in 28 experimental grp pts vs 45 events in 20 control grp patients during the 5yr f/u (RRR for any event for control group, 2.47 [95 % CI, 1.48-4.20]) Intervention program vs control resulted in significant 40% versus 1% reduction of LDL &17% versus 4% reduction in body weight No significant changes in HDL, TG or BP JAMA 1998; 280:2001
CARBOHYDRATES Important determinant of glycemic index is glucose content of carbohydrates Bread and baked goods, and sugars in juices and soda have high glycemic index Whole grains, beans, nuts, and vegetables have lower glycemic index, probably because the digestion and absorption of the glucose is slow. HDL decreases when dietary fat is replaced by carbohydrates, whatever the type of carbohydrate High glycemic index foods cause glucose & insulin to increase substantially Low glycemic index foods cause less increase in TGs