Running with one of the few FDA-approved health claims and a mass of clinical research, why are phospholipids not a market blockbuster such as DHA? Mark J Tallon, PhD, investigates the latest research and unexploited marketing opportunities
Ask most health-product consumers what fish oils are for, or ask a sports enthusiast what creatine is. Most will be able to provide a credible comment. However, ask the same group what about phosphatidyl-choline (PC) or phosphatidylserine (PS) and you are likely to be met with silence. The easy answer is that most of the public cannot connect with science when delivered in complex language. There are very few products currently on the market leading with a consumer-friendly message to market their products. Additionally, most are multi-ingredient mixes with few carrying the FDA's required 100mg 3x-a-day dose, as with PS.
The effect of these factors makes for a poor sell with little or no emotional connection to the consumer. When fish oils first hit the market, they could connect to an ethos of a 'good for you' food source. As such, their initial pitch to the market was as fish oil and not EPA or DHA derivatives. Eventually, as the market, science and consumer education grew, manufacturers could add new front-of-pack language, like DHA. Even now we see few functional products marketed as docosahexaenoic acid or eicosapentaenoic acid, but rather on their functional influence — healthy brain or IQ, vision, etc.
Despite failures and few, if any, products making it into the functional-foods and beverages category, it is still possible to take these ingredients and make them a success. Recent publications have highlighted new avenues for application as well as new derivatives with the potential of being more efficacious than their predecessors. The following provides a modicum of basic science, and then a brief look at the latest trials on the phospholipid class of ingredients.
At present there are three main classes of glycerophospholipids being sold as dietary supplements, despite there being hundreds of phospholipids. These include phosphatidylserine (PS), phosphatidylcholine (PC), and glyceryl-phosphorylcholine (GPC). Most phospholipids are essential building blocks of cell membranes, acting not only as structural molecules but also as dynamic, functionally important components of cells. Here is a brief overview of the most recent research trials on these highly bioactive nutrients.
PS is concentrated in the brain, comprising 15 per cent (30g) of the total phospholipid pool. The average daily intake of PS is currently estimated at 130mg per day for those of us in the West.1 Because of PS location in the internal layer of cell membranes, it can directly interact and modulate the action of receptors, enzymes and ion channels.
In a recent randomised, double-blind, placebo-controlled study, the effect of oral PS supplementation was investigated on golf performance in healthy young golfers.6 Perceived stress, heart rate and the quality of the ball flight was evaluated before (pre-test) and after (post-test) 42 days of 200mg/day PS intake in the form of a nutritional bar. Subjects teed off 20 times, aiming at a green 135 meters from the tee area.
PS supplementation significantly increased the number of good ball flights, whereas placebo intake had no effect. PS supplementation showed a trend toward improving perceived stress levels during teeing off, whereas stress levels remained unchanged in the placebo group. The potential implications are improved golf scores with continued use.
PC supports the regeneration of cell membranes, as well as provides a protective effect to the liver, lungs, GI tract and kidneys.7 Delivered in supplement form PC has been shown to support healthy cholesterol,8 liver9 and brain functions,10 and exercise performance.11 It has been suggested that a large proportion of PC's beneficial effects come from its choline content, which is equal to 15 per cent of the PC molecule.
Heart health has been a major interest in condition-specific supplementation for some time. In a recent trial, researchers studied PC supplementation on risk factors (homocysteine) associated with an increased risk to cardiovascular disease.12 The objective was to investigate whether PC reduces fasting and postmethionine-loading concentrations of plasma tHcy in healthy men with mildly elevated plasma tHcy concentrations.
In a crossover study, 26 men ingested approximately 17.3g/day PC or a placebo oil mixture for two weeks in random order with methionine-loading tests performed on the first and last days of each supplementation period. PC for two weeks decreased mean fasting plasma tHcy by 18 per cent. On the first day of supplementation, a single 10g PC dose reduced the postmethionine-loading increase in tHcy by 15 per cent. PC for two weeks reduced the postmethionine-loading increase in tHcy by 29 per cent, relative to placebo. If high homocysteine concentrations are a significant cause of cardiovascular disease as research suggests, PC intake may reduce cardiovascular disease risk in humans.
GPC is a cognitive enhancer whose mode of action is considered to involve the release of free choline in a similar manner to PC. It has many potential health effects, with those on cognitive function the most widely recognised.13 Although recent trials have focused on vascular dementia and cognitive function,14 some of the most marketable applications were seen back in the 1990s.
It is well known that as we age, growth-hormone (GH) levels fall. In one trial, alpha-GPC was investigated for its potential to modulate GH levels in both young and elderly subjects.15 In order to learn what effect alpha-GPC had on GH secretion, GH-release hormone (GHRH) was given to young and old human volunteers, with or without the addition of alpha-GPC.
GH secretion was greater in the younger subjects than in the older ones, and while both had a greater GH response to the GHRH+a-GPC than to GHRH alone, it was the elderly who showed the greatest GH response to a-GPC. These findings confirm that increased cholinergic tone with a-GPC enhances GH release.
Phosphatidylinositol (PI) is the essential determinant for K+ permeability involved in gastric-proton pumping. Additionally, PI is a component of membrane phospholipids, and functions both as a signalling molecule and a compartment-specific localisation signal in the form of polyphosphoinositides. Although little work has been carried out on this phospholipid, a 2008 trial assessed the effects of PI on nonalcoholic fatty liver disease (NAFLD), a condition closely related to metabolic syndrome.16
NAFLD encompasses the spectrum of liver damage ranging from hepatic steatosis to steatohepatitis, liver fibrosis and cirrhosis, and it is emerging as the most common liver disease worldwide.
The present study examined whether dietary PI protects rats from metabolic syndrome-related NAFLD. For four weeks, rats were fed semisynthetic diets containing either seven per cent soybean oil or five per cent soybean oil plus two per cent PI. Dietary PI markedly prevented both histological and biochemical markers of liver injury. Additionally, hyperinsulinaemia was relieved by the feeding of dietary PI in rats, suggesting a further benefit of PI as a weight-loss or diabetic agent.
Transphosphatidylated-phosphatidylserine (TPS) is one of the most understudied phospholipids. TPS is a rather novel nutritional supplement, shown in rodent trials to significantly influence cognitive function.17 In a trial from Yakult Central Institute for Microbiological Research, researchers assessed TPS for its effect on learning in mice.17
The trial gave 240, 360 or 480mg/kg TPS following scopolamine-induced learning deficits. The study demonstrated that TPS enhanced learning in a dose-dependant manner, suggesting that behaviour/learning can be significantly influenced by TPS supplementation. Clearly, further work is needed in humans for both application and efficacy.
Brand managers and marketers hold the key
The approved health claim, 'Consumption of phosphatidylserine may reduce the risk of dementia in the elderly,' is a strong point and a major selling factor to the wider consumer base. Approved claims in relation to relaxation, memory enhancement and sports performance are likely to be more lucrative if positioned and branded in the right way.
The old argument of it being an expensive ingredient is not the case as compared to other bioactives offering similar effects, and there clearly is a significant volume of research to substantiate its action and safety. The phospholipid class is currently underperforming given the growth of the fish-oil market, and its future now rests at the feet of the brand manager and the company willing to transition science in consumer-friendly messages.
Mark J Tallon, PhD, is chief science officer of NutriSciences, a London-based consultancy firm specialising in health-claim substantiation, product development and technical writing.
Respond: [email protected]
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