February is Heart Health Month, giving natural products retailers an opportunity to guide customers toward heart-healthy nutrition. The basic advice is well-known: Eat abundant fruits, vegetables and whole grains, along with low-fat meat and dairy products and monounsaturated fats. Encourage customers to shop color-rich, fresh produce selections rather than packaged ones. In addition, educate them about supplements that target elevated cholesterol and triglyceride levels, precursors to a majority of heart problems.
Heart disorders fall within the larger category of cardiovascular diseases simply because many heart problems are caused by inhibited blood flow. For example, cholesterol and triglyceride deposits along the arteries? inner walls generally lead to artery narrowing. A damaged inner wall (the endothelial lining) also compromises the vascular system in other ways, such as increased likelihood of blood clots and less arterial elasticity. Each of these, in turn, can lead to high blood pressure, heart attack or stroke, among other problems.
Following are some recent research results about various nutrients that retailers can use to point customers in the direction of heart-healthy supplementation.
Also known as vitamin B3 and nicotinic acid, niacin is approved by the U.S. Food and Drug Administration for treating elevated total cholesterol. Normal daily recommended intakes for adults range from 13 mg to 20 mg/day. To control cholesterol levels, much higher dosages are needed. Results of numerous studies show niacin reduces low-density lipoprotein (bad) cholesterol by 10 percent to 25 percent and triglycerides by 20 percent to 50 percent, and raises beneficial high-density lipoproteins between 15 percent and 35 percent.1,2
Niacin causes vasodilation, resulting in niacin flush, which occurs as the capillaries open to permit more blood flow. This flush is not harmful or dangerous. Extended-release forms of niacin are helpful, reducing flushing, but care is needed since they may be toxic to the liver.3 Some people confuse niacinamide with niacin. Both are part of the B3 family, but they have different effects. Niacinamide has health benefits, but none for the heart.
Few studies have determined an optimal dose of niacin that alters lipid levels with minimal side effects. One study showed the cholesterol changes induced by lower doses were less than those seen with higher doses, but the lower dose was better tolerated.1 Women seem to have a greater LDL response to niacin but experience more side effects at higher dosages.4
A recent study suggests 2.1 g/day niacin can produce cardioprotective effects in people with heart disease risk factors, including high LDL and triglycerides and low HDL.5
Omega-3 fatty acids
In September 2004, FDA announced a qualified health claim for reduced coronary heart disease risk on conventional foods containing the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid. In 2000, FDA announced a similar qualified health claim for dietary supplements containing EPA and DHA. The claims are qualified because scientific evidence is merely suggestive, not conclusive, that omega-3s reduce CHD risk. These healthy fats are known to improve vascular function, but the underlying mechanisms are unclear.
The FDA recommends consumers not exceed more than 3 g/day of these fats, with no more than 2 g/day from a dietary supplement. The American Heart Association, however, recommends people with elevated triglycerides take 2 g to 4 g/day of EPA and DHA.6
One of the more interesting points about omega-3s is that they seem to work around the issue of cholesterol levels. Results of intervention studies using EPA and DHA in 2-4 g/day doses over a few weeks show they can lower CHD risk factors independent of cholesterol-lowering effects. This is because omega-3s work on moving blood through the arteries in other ways, including lowering triglycerides, reducing blood and plasma viscosity, and improving endothelial dysfunction.7,8 In another study, EPA and DHA improved arterial and endothelial functioning in subjects with hypercholesterolemia (high cholesterol levels).9
Plant sterol and stanol esters
Plant sterol and stanol esters are essential components of plant cell membranes that structurally resemble cholesterol. Sterols are present in small quantities and stanols occur in even smaller quantities. The major sterols—sitosterol, stigmasterol and campesterol—can be present in Western diets in amounts almost equal to dietary cholesterol (170 to 358 mg/d).10,11 In the 1950s, scientists found that adding sitosterol to the diet of chickens or rabbits lowered cholesterol levels in both species and inhibited atherosclerosis development in rabbits.10
Both esters improve cholesterol levels by helping block cholesterol absorption from the digestive tract.12 This, in turn, helps to lower blood levels of LDL cholesterol without affecting HDL. Results of clinical research show the esters work best when consumed twice daily. University of Georgia researchers say 2 g to 3 g/day decreases total cholesterol and LDL between 9 percent and 20 percent, but there is no benefit in consuming more.13 Results of a British study showed a reduction of up to 14 percent with a 2 g/day divided dose.14
These esters are present naturally in foods such as corn, wheat, rye, oats and olive oil. Functional food manufacturers add them to margarine spreads, salad oils, yogurts and, recently, orange juice. In one eight-week study, 72 mildly hypercholesterolemic subjects drank orange juice fortified with 2 g/day plant sterols. Supplementation significantly decreased total cholesterol (7.2 percent) and LDL (12.4 percent) compared with placebo. The sterol group had no significant changes in HDL or triglycerides.15
Finnish researchers compared the effects of one sterol and one stanol ester-enriched margarine (2 g/day) with placebo in 34 patients with high cholesterol who consumed the spreads as part of a low-fat diet. The researchers concluded the ester margarines reduced significantly and equally total and LDL cholesterol.16
In April 2002, the FDA issued a final rule on plant sterol/stanol esters, allowing food labels to state that the ingredients lower cholesterol and may lower the risk of heart disease when part of a diet low in saturated fat and cholesterol. FDA recommends 1.3 g or more per day of plant sterol esters in divided dosages and 3.4 g or more of plant stanol esters. People should use these esters cautiously, however. The European Commission warns that patients on cholesterol-lowering medication should use the product only under medical supervision, and that people whose vitamin A status is not optimal should avoid the products altogether because they may reduce plasma beta-carotene.17
Guggul, also called gugulipid, is an ethyl acetate extract of the gum resin from the guggul tree (Commiphora mukul). Chemicals in the resin, called guggulsterones, appear responsible for lowering total and LDL cholesterol as well as serum triglycerides by helping the liver increase the uptake of proteins that carry LDL cholesterol.18 Gugulipid also keeps LDL cholesterol from oxidizing, thus helping protect against arterial plaque build-up.19 In its unoxidized or ?native? state, LDL benignly passes through.
In one 12-week Indian study, patients took 500 mg of gugulipid. In 80 percent of the patients, cholesterol levels dropped an average of 24 percent and triglycerides 23 percent.20 In another Indian study involving 233 patients, researchers compared gugulipid to the lipid-lowering drug clofibrate. Those taking gugulipid lowered their cholesterol by 11 percent and their triglycerides by 17 percent. HDL cholesterol increased 60 percent. The clofibrate group saw a 10 percent cholesterol drop and a 22 percent triglycerides decrease, but no benefit on HDL levels.21 Gugulipid has also been shown to reduce the stickiness of platelets.22
These results have been countered, however, in a U.S. study. More than 100 hypercholesterolemic adults were given 1,000 mg or 2,000 mg gugulipid or a placebo three times daily. After eight weeks, both doses of gugulipids raised LDL levels by 4 percent compared with placebo, which showed a decrease of 5 percent. There were no significant changes in levels of total cholesterol, HDL or triglycerides.23 So the jury may still be out on gugulipids.
There is also a note of caution. In September, results of a study were published showing gugulipid can break down various prescription drugs, including some AIDS and cancer medications.24 In addition, guggulsterone stimulates cell receptors for the hormones estrogen and progesterone,25 having potential consequences for women, especially those on hormone replacement therapy. Thus, people taking prescription medications should use caution when taking gugulipid.
Guggul extracts are now standardized for guggulsterone content. The herb naturally contains about 2 percent guggulsterones. Quality extracts contain a minimum of 2.5 percent.
Polymethoxylated flavones are plant flavonoid antioxidants. They exist in a variety of fruits and vegetables, as well as in tea and red wine. PMFs have shown promise in animal studies to lower LDL cholesterol.
A joint effort between the U.S. Department of Agriculture and a Canadian nutraceutical company studied PMFs isolated from orange and tangerine peels and concentrated in citrus pectin. Hypercholesterolemic hamsters, fed food containing 1 percent PMFs, experienced LDL cholesterol reductions of 32 percent to 40 percent, with no effect on HDL and no observable negative side effects.26 For comparison, some hamsters were given the flavanones hesperetin and naringenin. These flavonoids also lowered LDL cholesterol, but doses were three times as large to yield the benefit seen with PMFs. This is likely, in part, because the flavanones are carbohydrate-linked (not ?free? like the PMFs), making them less bioavailable and able to work.
Earlier this year, SourceOne Global Partners in Mentor, Ohio, announced that Sytrinol, a patented complex of PMFs and tocotrienols, will be the subject of a phase III human clinical trial. According to the company, the first two phases have shown beneficial results.
Red wine polyphenols
Wine has more than 500 components.27,28 It is generally believed that red wine flavonoids, particularly polyphenols, help inhibit heart disease. Red wine flavonoids have been shown to reduce heart disease risk by decreasing platelet aggregation (atherosclerosis) and LDL oxidation.29,30,31 Red wine is fermented with grape skins, seeds and stems, which contain the greatest concentration of flavonoids.27 White wine is not fermented with them and thus has a significantly lower content.27
There is some question regarding the relevance of alcohol. European studies show certain red wines provide greater heart health benefits than other alcoholic beverages. But results of American studies have shown little variation in benefits between different types of wine or other alcoholic beverages. Many American researchers have linked drinking alcohol in general to a lower risk of heart disease and stroke.
In debate of the alcohol connection, English researchers conducted a study to determine whether polyphenols would be beneficial when extracted from red wine. Twenty healthy male volunteers were given regular daily amounts of red or white wine or capsules containing polyphenol extract. Benefits from the capsules, gauged by blood levels of substances that show LDL oxidation, were very similar to those of red wine.32
In all, there are a variety of supplements that can benefit the cardiovascular system, either by lowering triglycerides or cholesterol levels or by helping to repair damaged endothelial linings. February is a good month to remind customers what options they have.
p class="authorbio">Lisa Anne Marshall has been writing about nutrition and health for more than a decade. She resides in Broomfield, Colo. Her website is www.WriteItRight.biz.
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Natural Foods Merchandiser volume XXV/number 12/p. 40, 42