A host of studies indicates that garlic and fish oil are good for the heart. In many of them, diets rich in garlic led to a lowering of low-density-lipoprotein (LDL) cholesterol -- the so-called bad cholesterol. Similarly, diets high in fish or supplemented with fish-oil capsules have been shown to lower triglycerides -- fatty substances that represent a major risk factor for cardiovascular disease.
To date, however, neither food has won unconditional endorsement from cardiologists. Garlic's LDL lowering has typically been in the range of about 5 percent, well below that needed by most individuals worried about heart disease. Though fish oil's triglyceride-plummeting ability has been more impressive, on a par with that offered by prescription drugs, they come with a major drawback: a significant elevation in LDL cholesterol, itself a major risk factor for heart disease.
Currently, Holub says, people at risk of heart disease often receive advice to modify their diet -- lowering their consumption of saturated fats and cholesterol and increasing their intake of vegetables and fiber. If this doesn't bring a dramatic reduction in the artery-clogging lipids circulating in their blood, the next step is usually prescription drugs.
"We'd like to change that approach," the nutrition scientist says. Before they switch patients to expensive drugs, he would like physicians to consider prescribing "nutritional supplements that have been shown effective and safe" -- like the garlic - fish oil combo.
In other words, he'd like physicians to add nutraceuticals -- foods, food-derived compounds, dietary supplements, or natural food additives that have been demonstrated to offer health benefits -- to the pharmacopoeia of agents they now employ to treat or ward off disease.
Today, the materials that fall under this rubric often carry quite different names, including designer foods, megavitamin pills, antioxidant supplements, medical foods, functional foods, pharmafoods, and beneficial herbs. Whatever people choose to call them, they constitute nothing less than a developing revolution in medicine, DeFelice maintains. Moreover, he predicts, when clinical studies now under way are published, the burgeoning data will trigger an even more "explosive" growth in sales of these "foods that work."
For the most part, he says, drug companies and food manufacturers aren't funding studies that seek to understand how nutraceuticals function, probably because they worry that the natural products may ultimately compete with the synthetic goods they may have invested a decade and hundreds of millions of dollars into developing.
Yet "the drug companies are highly curious," DeFelice points out, often sending their representatives to meetings that his Foundation for Innovation in Medicine sponsors. However, he notes, these pharmaceutical observers often ask permission to attend informally so that their names will not appear on a registration list.
Fueling their interest, he believes, is the fact that these healthful dietary agents have become big business. According to several conservative estimates from the food industry, such dietary agents rack up billions of dollars in U.S. sales already. DeFelice's estimates run much higher, pegging the figure at around 50 percent of U.S. retail foods -- or products valued at more than $250 billion annually.
His definition of what qualifies is quite broad: all dietary supplements, sugar substitutes, fat substitutes, fiber-enriched foods, vegetables, virtually fatless meat, skim milk, and low-calorie prepared foods.
"If you define nutraceutical to be anything that has some kind of a physiological impact on the nutritional or health status of the body, then the term ceases to have any meaning," he argues.
Certainly, he notes, the term has no regulatory meaning. "There is absolutely no regulatory differentiation for something that might be called a nutraceutical." Today, such products must be termed a food (which includes food supplements) or a drug. "We at CRN would oppose very, very strongly the creation of a new category [beyond food and drugs] at this time." Especially since Congress passed the Nutrition Labeling and Education Act 4 years ago, he notes, even foods can advertise health claims -- as makers of oat products just did (FDA allows heart health claims for oats) -- provided there is ample scientific evidence to support them.
Argues Cardaro, "we think the present regulatory system has not been fully exploited" -- that is, it provides adequate opportunity for nutraceuticals to make health claims, where warranted.
DeFelice is not convinced. The Food and Drug Administration's "ground rules for [health] claims are not sufficiently industry-friendly to create large investments in nutraceutical research."
Moreover, he points out, "even after they get a health claim, you have to ask who wins." Why should one company within an industry invest all that money, only to see a competitor's products reap the bounty of that costly petition?
As a result, he predicts, health claims will be the tool of rich companies or large industry consortia for the foreseeable future.
To get around this problem, DeFelice's foundation has proposed that Congress consider a new nutraceuticals law that would give companies that fund the research to establish the health benefits of natural products an exclusive 7-year marketing right to advertise any health claim that results from that research.
For instance, in the case of the new Guelph research, this law might give whoever sponsors the research and any clinical follow-up studies an exclusive right to market garlic - fish oil supplements as products that offer heart benefits by jointly lowering LDL cholesterol and triglycerides.
Adler, A.J., and B.J. Holub. 1997. Effect of garlic and fish-oil supplementation on serum lipid and lipoprotein concentrations in hypercholesterolemic men. American Journal of Clinical Nutrition 65(February):445.
Kris-Etherton, P.M., T.D. Etherton, and S. Yu. 1997. Efficacy of multiple dietary therapies in reducing cardiovascular risk factors. American Journal of Clinical Nutrition 65(February):560.
Fackelmann, K.A. 1988. Heart studies add to fish-oil controversy. Science News 134(Nov. 26):343.
Harris, W.S., et al. 1990. Fish oils in hypertriglyceridemia: a dose-response study. American Journal of Clinical Nutrition 51(March):399.
Hunninghake, D.B. et al. 1993. The efficacy of intensive dietary therapy alone or combined with lovastatin in outpatients with hypercholesterolemia. New England Journal of Medicine 328(April 29):1213.
Radack, K.L., C.C. Deck, and G.A. Huster. 1990. n-3 fatty acid effects on lipids, lipoproteins, and apolipoproteins at very low doses: results of a randomized controlled trial in hypertriglyceridemic subjects. American Journal of Clinical Nutrition 51:599.
Raloff, J. 1997. FDA allows heart health claims for oats. Science News 151(Feb. 1).
Raloff, J. 1997. FDA helps you identify heart-y oats! Science News Online, Jan. 25.
Raloff, J. 1996. More on those "really bad" LDLs ... and the role of triglycerides. Science News Online, Sept. 21.
Raloff, J. 1996. Fat: If you can't bear to pare it. Science News 149(Feb. 17):108.
Raloff, J. 1993. Fish oil may ward off 'sudden death.' Science News 144(Dec. 4):380.
Raloff, J. 1992. Cancer-fighting food additives. Science News 141(Feb. 15):104.
Raloff, J. 1990. Beyond oat bran. Science News 137(May 26):330.
Raloff, J. 1989. Fish oil lowers even normal blood pressure. Science News 136(Sept. 16):181.
Raloff, J. 1989. Fish oil slows some developing cancers. Science News 135(June 24):390.
Raloff, J. 1988. No-fault fat: More praise for fish oil. Science News 134(Oct. 8):228.
Wickelgren, I. 1989. Revealing the finicky functions of fish oil. Science News 135(March 25):183.
Council for Responsible Nutrition
1300 19th St., NW
Washington, DC 20036-1609
Stephen L. DeFelice
Foundation for Innovation in Medicine
411 N. Avenue East
Cranford, NJ 07016
Bruce J. Holub
Department of Human Biology and Nutritional Sciences
University of Guelph
Guelph, Ontario N1G 2W1
1300 Connecticut Ave.
Washington, DC 20036
This week's Food for Thought is prepared by Janet Raloff, senior editor of Science News.
Illustration: Wendy Temple.