In an effort to guard against heart disease, you may consider adding a multivitamin supplement to your menu of fatty fish, nuts and oat bran.
According to new a study published online in the American Journal of Clinical Nutrition, women who took a one-a-day supplement were 40 per cent less likely to suffer a heart attack than their peers who didn't use multivitamins.
Earlier studies that investigated the link between multivitamin use and heart risk have turned up conflicting results.
The continuing Nurses' Health Study reported that regular multivitamin use was linked with a 24 per cent lower risk of heart disease. In a study of more than one million healthy U.S. adults, multivitamins were associated with a 25 per cent lower risk of dying from heart disease.
Yet randomized controlled trials – the gold standard of scientific evidence – have offered little evidence that these supplements influence the risk of heart disease.
The current study included 33,933 Swedish women aged 49 to 83 years, the vast majority (93 per cent) having no history of heart disease. After 10 years of follow up, 1201 women had suffered a heart attack.
Among women who were free of heart disease upon enrolling in the study, taking a daily multivitamin reduced the risk of heart attack by 27 per cent. The protective effect was stronger among women who used multivitamins for at least five years. Compared with women who didn't take supplements, those who took multivitamins for five years or longer were 40 per cent less likely to have a heart attack.
When the researchers accounted for body weight, physical activity, smoking status and other heart risk factors, the results remained unchanged.
Multivitamin use did not alter the risk of heart attack among women with a history of heart disease.
The fact that the latest study findings contradict reports from randomized controlled trials may be that the ingredients and dose of multivitamins vary widely in studies. In the current study, multivitamins contained essential vitamins and minerals at doses that closely matched recommended daily intakes.
Another reason is that many randomized controlled trials were performed among people with existing heart disease. Most of the studies that determined multivitamins beneficial were conducted in healthy people. While multivitamins may help keep blood vessels healthy, they may not prevent a heart attack once heart disease has developed.
There are a number of ways in which a multivitamin may defend against heart disease. Multivitamins contain antioxidant nutrients – vitamins C and E, beta-carotene, selenium – that could lessen artery damage caused by free radicals.
Free radicals are produced naturally when we breathe, but ultraviolet light, cigarette smoking, and the consumption of alcohol are other sources.In high amounts, free radicals contribute to the formation of fatty plaques in the arteries that, if ruptured, can cause a heart attack.
Multivitamins also contain the B vitamins folate, B6 and B12, which have been shown to lower blood homocysteine, an amino acid made by the body during normal metabolism. High homocysteine is thought to damage artery walls and increase the risk of heart disease.
Magnesium – a mineral that most Canadians don't get enough of – can help prevent diabetes (a major risk factor for heart disease), reduce inflammation and promote normal blood pressure.
While a multivitamin may offer some protection, it's well established that healthy eating guards against heart disease.
The following strategies can help you lower your risk of developing heart disease.
Take a multivitamin
Look for vitamins A, C, D, E, B1, B2, niacin, B6, folic acid and B12. Choose a formula that provides 100 per cent the recommended daily intake for B6 (1.3 to 1.7 mg), B12 (2.4 mcg) and folic acid (400 mcg). Look for the minerals chromium, copper, iron, magnesium, selenium, and zinc.
Premenopausal women should choose a multivitamin supplement with 10 to 18 mg of iron; postmenopausal women and men should look for no more than five to 10 milligrams of iron.
Choose unsaturated fats
Unsaturated fats found in vegetable oils, avocado and almonds can help lower LDL cholesterol (bad cholesterol) and triglycerides (blood fats), increase HDL cholesterol (good cholesterol and reduce inflammation.
Minimize your intake of saturated and trans fats that can raise LDL cholesterol. Choose lean cuts of meat, poultry breast and low-fat dairy products (1 per cent milk fat or less). Read nutrition labels on packaged foods; choose foods with little or no trans fat.
Eat fatty fish
Salmon, trout, sardines, herring and Arctic char contain DHA and EPA, omega-3 fats linked to protection from heart attack. Eat oily fish twice a week. If you don't like fish, take a fish oil supplement that supplies 500 to 600 milligrams of DHA and EPA (combined).
When consumed in excess, sodium can increase blood pressure and worsen hypertension. Adults need no more than 1,300 to 1,500 milligrams of sodium a day. The safe daily upper limit is 2,300 milligrams.
Limit your intake of restaurant meals and processed meats such as ham, sausage and deli meats. Rely less on convenience foods such as canned soups, frozen dinners and packaged rice mixes.
Read nutrition labels to choose foods with a lower daily value (DV) for sodium. Foods with a DV of 5 per cent or less are low in sodium.
Switch to whole grain
People who eat the most whole grains have a risk of heart disease 20 to 40 per cent lower than folks who eat mainly refined (white) grains.
Aim for at least 3 whole grain servings a day, and preferably more. One serving of whole grain is equivalent to one slice of whole grain bread, ½ cup cooked oatmeal or ½ cup of cooked brown rice or whole wheat pasta.
Choose breads, cereals and crackers made from 100 per cent whole grain. Try whole wheat pasta, brown rice, wild rice, bulgur and quinoa.
Add legumes and nuts
Eating more legumes (e.g. chickpeas, kidney beans, lentils) and nuts can help lower blood pressure, reduce LDL cholesterol and keep blood sugar levels in check.
Include legumes and nuts in your diet at least four times a week. Add legumes to soups, salads, chili and tacos. Toss nuts into a stir-fry, sprinkle over hot cereal or enjoy them as a snack.
Leslie Beck, a Toronto-based dietitian at the Medcan Clinic, is on CTV's Canada AM every Wednesday. Her website is lesliebeck.com.