A year's worth of research on today's leading heart health ingredients.
Questions about heart health-and how to maintain it-have plagued Western eaters for years. But every year, we learn a little more about what makes the heart tick and which nutrients can help. In many ways, 2011 advanced cardiovascular research on ingredients common to our diets-or at least common to our natural health stores. The following is a selection of the year’s notable discoveries.
At the pace research is progressing, the world of omega-3 fatty acids is sure to give us advances in cardio science year after year. With the help of Harry Rice at the Global Organization for EPA and DHA Omega-3s (GOED; Salt Lake City), I was able to compile the results of a few of 2011’s most prominent studies.
Two prospective cohort studies stood out last year. In one NIH-funded study, researchers followed nearly 3000 healthy adults from 1992 to 2006, conducting periodic measurements of fatty acids in subject blood samples. All subjects submitted to periodical clinical examinations, during which incidence of congestive heart failure was assessed. At the close of the study, the researchers determined that circulating individual and total omega-3 fatty acid levels in humans were positively associated with lower incidence of congestive heart failure.
A second cohort study focused on Danish women for a mean follow-up period of eight years. Researchers ultimately linked low fish intake to increased risk of heart disease in this population. Moreover, when looking at a subset of women and determining who consistently and frequently ate fish for 30 weeks, those who never ate fish had a threefold greater likelihood of developing heart disease, compared to those who ate fish weekly. These appear to be positive results for omega-3s in women-who are often considered an underrepresented subgroup in omega-3 studies.
Another study sought to answer the question of just how much fish oil is needed for heart-health support. This industry-supported research analyzed eight cohort studies and concluded that consuming 250 mg of omega-3 or more daily provided a 35.1% reduced risk of sudden cardiac death, compared to consuming less than 250 mg.
“These results, when considered with the totality of the scientific evidence, suggest that the intake of 250 mg per day of omega-3 long chain fatty acids may be a minimum-rather than an optimum-target to be achieved by the general population for the promotion of cardiovascular health,” said Rice, whose GOED organization contributed to the research. “These results should be considered when establishing dietary reference intakes.”
Lastly, an intriguing finding came out of investigating which forms of fish oil appear to work best for blood cell uptake of omega-3s.
German researchers assigned 150 volunteers to a corn oil placebo, fish oil in ethyl ester (EE) form, or fish oil in the more-expensive esterified triglyceride (TG) form. After six months of daily supplementation, subjects who consumed the triglyceride-form fish oil showed a significantly improved uptake of omega-3 in red blood cells compared to subjects in the ethyl ester group.
But Katherine Bond, director of business development for Cyvex Nutrition (Irvine, CA), a subsidiary of omega-3 ingredients developer Omega Protein (Houston), says there’s no need to jump ship on ethyl ester fish oils because of this study:
Although the differences in relative increases [of blood plasma omega-3] were statistically significant, it is not clear whether the intake of triacylglycerides would result in significantly better clinical outcomes. Also, it is not clear what biochemical mechanisms can explain these findings. The bottom line is that the dietary intake of either type of supplement resulted in an increase in levels of total omega-3s in the blood of human adults. Form is a matter of preference, or sometimes application, and therefore we will continue to offer both EE and TG products.
When it comes to algal oil supplements, new science suggests the upstart omega-3 source may provide cardio support rivaling that from fish oil.
The January 1 issue of the Journal of Nutrition highlights a meta-analysis performed by researchers at the Harvard School of Public Health-a meta-analysis deemed the first of its kind on algal DHA.
In reviewing 11 clinical trials on nearly 500 healthy participants (with a mean duration of six weeks), researchers observed an average, statistically significant decrease in triglycerides and statistically significant increases in LDL (“bad”) and HDL (“good”)cholesterol. Although an overall increase in LDL was observed, that increase was accompanied by an increase in LDL particle size-something the researchers claim represents potentially “less-atherogenic LDL particles.” The overall benefit to lipids, therefore, may outweigh the seemingly detrimental LDL increase. Similar increases in LDL have been noted in fish oil meta-analyses, claim the researchers.
Martek Biosciences Corp. (Columbia, MD), a subsidiary of DSM Nutritional Products and manufacturer of Life’sDHA ingredients, hailed the meta-analysis not just for net benefits found on cardio markers, but for an added benefit found on subjects with already elevated triglyceride levels.
People with normal triglyceride levels may experience a “floor effect” with DHA, said Martek chief scientific officer Norman Salem, PhD. “If you have normal triglyceride levels, it’s hard to lower them. DHA did significantly lower normal levels in these trials, but the effects were not huge-statistically significant, but not quantitatively huge.” However, he says, people with dyslipidemia (too high or too low fat levels) did experience 25 to 30% reductions.
Martek adds that, in its own 2009 review of DHA clinical trials to date, none of the trials showed any evidence of adverse health effects-not even fishy burps.
Argan oil presents an unusual example of the potential benefit of fatty acids on heart health. Although primarily used around the world as a skin or hair care ingredient, argan oil’s rich fatty acid profile (coupled with its phytosterol content) led European researchers to investigate its heart health potential when consumed as a food. Forty healthy adults were assigned to a habitual diet which did or did not include a daily breakfast of 15 g of argan oil on toasted bread. The argan oil diet provided reductions of triglycerides (20.97%), total cholesterol (14.63%), and LDL cholesterol (16.05%) compared to placebo. The British Journal of Nutrition has now published these findings.
It’s been a big seller for years, largely due to supporting science for a benefit on blood pressure. In fact, grape seed (Vitis vinifera) extract weighed in with nearly $1.5 million in sales in 2010, making it one of the top-selling dietary supplements in mass-market channels during that time, according to the American Botanical Council’s 2011 U.S. Herb Market Report.
Previously published science suggests that polyphenols called proanthocyanidins-along with a host of other complex antioxidant compounds-may be key to purported benefits linked to grape seed extract as well as wine, grapes, and other related products.
While ongoing research must still iron out the wrinkles in grape seed extract research, a 2011 meta-analysis provides some of the best support yet. Researchers from Yale University and the University of Connecticut analyzed the results of nine placebo-controlled clinical trials on 390 human subjects supplementing with grape seed extract. In viewing all of the data, researchers concluded that subjects experienced an average 1.54-mm mercury reduction in blood pressure and a drop in heart rate by 1.42 bpm-changes that, although seemingly small, could be of benefit in the long run.
“The level of systolic blood pressure reduction is very modest in comparison to reductions seen with prescription antihypertensive drugs,” said lead author of the study, Craig Coleman, PhD. “However, this modest effect may still be noteworthy on a population basis. It has been estimated that every 3-mm (mercury) reduction in systolic blood pressure could reduce the risk of all-cause mortality by 4%, mortality after stroke by 8%, and mortality after coronary artery disease by 5%.”
Choosing the right grape seed extract is still proving to be a hurdle, though. A number of factors account for a quality grape seed extract, including how the actual fruit source is prepared. Anil Shrikhande, PhD, president of Polyphenolics (Madera, CA), manufacturer of MegaNaturalBP grape seed extract, says the quality of his company’s ingredient rests firmly on its close sourcing of grapes from the wine house Constellation Wines U.S.
“Constellation is one of the largest premium wine companies, and it has a large facility right here in the Central Valley of California,” says Shrikhande. “So seed preparation and seed quality are maintained to the fullest extent. We can separate the seeds right away and attend to seed storage and all other factors. Other grape seed extracts may come from wineries where seeds are collected from different locations. By the time collection is done, the freshness of seeds can be impaired. Browning may even occur.”
But why focus only on grape seed? What about the rest of the grape?
Opting for a whole-grape ingredient rather than grape seed might just provide added advantages. It’s for this reason that Ethical Naturals (San Anselmo, CA) chooses to not only offer grape seed extract, but also offer grape skin extract and an extract from whole grape. Company president Cal Bewicke reminds us that different parts of the grape are rich in different types of beneficial phytochemicals.
“Grape seed content is relatively higher in proanthocyanidins, but grape skin contains more anthocyanidins and resveratrol (at a low level),” says Bewicke. “Our ORAC-15M Grape extract is from whole grape and is standardized to a special polyphenols profile that contributes an ORAC value of 15,000 ORAC units/g of powder. This compares to common grape seed extract, which only shows an ORAC value of about 5000 units/g.”
Potassium’s contribution to cardiovascular research continues to grow, even if its popularity is dwarfed by newer, perhaps more provocative, heart-health ingredients.
Historic cohort studies and clinical trials seem to routinely link potassium supplementation and potassuim dietary intake to reductions in systolic and diastolic blood pressure. Such benefits, especially seen in hypertensive patients, are at least in part due to potassium’s ability to force sodium excretion from the body.
A new meta-analysis of clinical trials further supports this theory of potassium benefiting blood pressure. Published in the journal Stroke, the meta-analysis compiles results from 10 independent studies on more than 268,000 participants and nearly 9,000 cases of stroke. When a patient’s dietary intake of potassium increased by 1000 mg, it was accompanied by an 11% reduced risk of total stroke and ischemic stroke.
“Potassium absolutely has a positive impact on heart health, no question about it,” says Ram Chaudhuri, senior executive vice president and chief scientific officer for premix specialist Fortitech Inc. (Schenectady, NY). “I would say that it is being used more in food and beverage because there are limitations to how much of it can be used in a supplement-and because of the added benefit that it is an electrolyte. There is good reception for potassium as far as applications for foods and beverages are concerned.”
Industry’s embrace of potassium stems, in large part, from growing interest at the regulatory level. In 2010, the European Food Safety Authority (EFSA; Parma, Italy) approved an article 13 health claim linking dietary potassium to the maintenance of normal blood pressure. The United States has also bumped up its potassium awareness, listing potassium in its 2011 Dietary Guidelines as a nutrient whose national intake is “low enough to be of public health concern for both adults and children.”
Many plant foods contain natural levels of phytosterols, but research on cholesterol improvements with higher doses of phytosterols continues to raise eyebrows in a good way.
One phytosterol supplier claims that more than 200 human intervention studies have been performed on phytosterols, showing average LDL cholesterol reduction in the area of 9%. In February 2011, the journal Nutrition, Metabolism, and Cardiovascular Diseases published a clinical trial on 108 patients, which found that phytosterol yogurt outperformed control yogurt on cholesterol benefits-even when patients retained their habitual Western-type diets.
For years the flood gates have been open for phytosterol-enriched foods-from traditional fat and oil applications to a host of other foods and recently even beverages. Common sources for these products include soy, rape seed, tall oil, and also pine, as evidenced by Danisco’s (Copenhagen) new pine-derived PinVita ingredient.
“Around half of the world’s phytosterol market today is from pine source,” says Bram van Hulsen, regional director for Danisco in Singapore. “The key benefits of pine-derived sterols are that they are from a non-GMO raw material and that the raw material is more stable in terms of supply and price compared to soy-derived phytosterols.”
Note that some researchers still hold concern over the long-term safety of phytosterols, as there is an absence of safety studies relating to long-term exposure.