Earlier this month, headlines around the world heralded a large clinical trial dubbed JUPITER funded by Crestor maker Astrazeneca. The findings from JUPITER suggested that healthy older adults with low "bad cholesterol" levels but elevated inflammation markers could lower their risk of heart disease by 44 percent through a daily dose of statin drugs.
Few news outlets, however, added the necessary caveats. Beyond the billions in additional health care costs associated with expanding the pool of statin users to include those with normal LDL cholesterol levels for example, the net reduction in absolute risk for a major cardiovascular event was less than one percent (1.8 percent of those on a placebo suffered a "hard" cardiac event such as a heart attack, stroke or cardiovascular death during the nearly two-year-long study compared with 0.9 percent taking a statin). On the other hand, the absolute risk of diabetes increased among those taking the drug, from 2.4 percent to 3.0 percent. Other studies have cited muscle pain and weakness in 1 to 5 percent of patients as a potential side-effect of the cholesterol-blocking mechanism.
And that's not all. Clinical research has uncovered a number of genetic susceptibilities to statin drugs, including statin-induced rhabdomyolysis, which results in severe muscle damage accompanied by toxic effects on organs such as the kidneys. Other side-effects have been well documented among statin users such as blinding headaches and memory loss. For these reasons, many health care providers are justifiably concerned about the increased marketing of statin drugs to include a segment of the pediatric population recommended by the American Academy of Pediatrics this summer and presumably now to relatively healthy adults as well. The guidelines issued by the American Academy of Pediatrics called for cholesterol screening of children as young as 2—and cholesterol drugs for kids as young as 8.
The ability of statins to reduce "bad" cholesterol levels is almost universally accepted; in the JUPITER study, volunteers' already low LDL-cholesterol levels fell by an additional 49 percent, on average. And levels of C-reactive protein, a marker for acute systemic inflammation that has been associated with higher risk for cardiovascular disease, declined by 48 percent.
But how representative are all the numbers? A follow-up story in the New York Times points out that only 17,802 people were selected for the statin study out of almost 90,000 initially screened. Whittling the list of participants to those with uncomplicated medical histories is commonplace in clinical trials, and can boost the overall statistical significance, but what it means for the real world is less clear. A 2006 survey by the Slone Epidemiology Center at Boston University after all, shows that 82 percent of all adults take at least one medication every week. Among adults 65 and older, nearly 60 percent are now taking more than 5 medications every week. If any word can describe the current medical history of the average older American, it's not "uncomplicated."
The big question, then, is not whether statins work for patients at high risk for cardiovascular disease (studies suggest they do) but whether the potential costs and side-effects outweigh the benefits for lower-risk adults already likely to be on a range of other medications. Critics of this widening acceptance of statin treatment also say that there is not enough data to know if statins are safe or effective in children and the long-term effects of taking statins in adults (>5 yrs) are also not well studied. Some anecdotal evidence suggests that long-term treatment with statins can expose older adults to a greater risk of neurodegenerative diseases as cholesterol is a critical component in all cell membranes and neurons are especially sensitive to the depletion of cholesterol.
Amid all the weighty considerations of prophylactic drug regimens, scientists have consistently demonstrated the benefits of a much cheaper form of prevention: proper diet and exercise. The Boston Globe recently reminded its readers of a 2006 study by scientists at the University of Massachusetts Medical School suggesting that people with high-fiber diets were 63 percent less likely to have inflammation problems than people with low-fiber diets. And for years, researchers have been touting the heart-healthy benefits of foods rich in omega-3 fatty acid precursors, including walnuts, cold-water fish, and flax seed.
For flax seed, the secret seems to lie mainly with alpha-linolenic acid (ALA), a lipid that accounts for more than half of the seed's total fatty acid content and is a major precursor to omega-3 fatty acids. The precursors in flax seed are converted by the body into the building blocks of hormones associated with reduced inflammation, blood clotting and cell growth.
In one of the largest reviews to date, researchers at North Dakota State University published a 97-page review of flax seed's properties in the journal Advances in Food and Nutrition Research. Among the multiple studies they cited that suggested a significant benefit for cardiovascular disease prevention, a 16-year study of 76,000 women published in 2004 and a separate 14-year study of nearly 46,000 men published in 2005 found that diets rich in ALA (flax seed's main fatty acid) significantly reduced the risk of coronary heart disease. The higher the dose of ALA, the stronger the benefit, according to the 76,000-participant Nurse's Health Study. The 16-year follow-up found that women on a diet of 1.5 grams per day of ALA had a 21 percent reduced risk of dying from coronary heart disease and 46 percent reduced risk for dying from sudden cardiac death than women on a diet of 0.7 grams of ALA per day.
Other studies concluded that diets similarly high in ALA lowered the prevalence of plaques in the carotid artery, decreased the risk of death from cardiovascular disease, and lowered the risk of death due to stroke.
And the cost for this prevention? Based on current prices, a one-year supply of flax seed from GreatPlainsFlax.com runs about $90. In December 2006, one year's worth of the cheapest generic statin drug cost about $600, according to Consumers Union, while the most expensive ran to more than $1,700.
Scientists strongly believe that inflammation is a key factor in the development of coronary heart disease, as well as diabetes and other diseases. Following that line of evidence, the JUPITER statin study enrolled patients with normal "bad cholesterol" levels but elevated inflammation, as suggested by higher levels of C-reactive protein.
So can flax seed likewise reduce C-reactive protein levels, reinforcing its suggested role in decreasing inflammation and lowering the risk for cardiovascular disease without the added cost and side-effects? Within the past decade, only a handful of small peer-reviewed studies have directly or indirectly addressed that question, and they've been all over the map in terms of participants, study length, design, and even flax seed preparation. Combined, they have enrolled less than 500 participants, not even 3 percent of the JUPITER study's participation.
Even so, they've raised some intriguing questions. Earlier this year, a small study by U.S. and Chinese researchers in the British Journal of Nutrition suggested that flax seed-derived lignan (a natural plant-based compound) might modulate C-reactive protein levels in type 2 diabetics, especially among women.
In a separate study, 22 post-menopausal Danish women ate a low-fat muffin, either with or without flax seed-derived lignan, every day for six weeks. At the trial's conclusion, women who had eaten the lignan-containing muffins showed an average decline of 15 percent in their C-reactive protein levels. A similar trial involving 199 menopausal women in Quebec eating 40 grams of flaxseed every day for a year, however, found a much more limited effect.
Adding to the uncertainty, a Greek study found a positive effect for a 12-week regimen of flax seed oil in men with abnormal lipoprotein metabolism, and a Brazilian study suggested a temporary benefit for flax seed flour fed to obese patients over a two-week period. But a study in Pennsylvania found no benefit for ground flax seed-containing baked products among men and women with high levels of cholesterol in their blood. Similarly, Colorado researchers found no significant changes in C-reactive protein and other inflammatory factors after an 8-week dietary intervention of flaxseed oil capsule in healthy but obese adults.
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