Discerning the effects of various dietary products on cognition is highly complex. Many of the most basic dietary needs are inseparable from cognitive health, development and maintenance.
A special report published in 2011 in the Asia Pacific Journal of Clinical Nutrition, "Symposium on Nutrition and Cognition: Towards research and application for different life stages," addressed the role of nutrition in cognitive development, performance and degeneration, and brought attention to the complexity inherent in the assessment of cognitive functions. Taken from a symposium of the same title held in Malaysia in October 2010, the goal was to help solve the basic problems of malnutrition, including deficiencies in protein, energy, vitamin A, iron and iodine. Impacted by all these nutrients, cognition is the condition of greatest interest.
The role of protein is one of the most critical. Several amino acids, the component parts of protein metabolized from our food, serve as precursors to neurotransmitters. These are the chemicals that pass along information from one brain cell to another. Amino acids also are reassembled into the enzymes needed to effect virtually every function in the human body. And many amino acids have a direct effect on brain function. For example, tryptophan, the least abundant amino acid in dietary proteins, is the direct precursor to serotonin, necessary for learning and memory.
Transport of tryptophan across the blood-brain barrier is aided by dietary carbohydrate. But the key carbohydrate to brain function is glucose, that fundamental sugar unit that makes up virtually all of the metabolic carbohydrates humans ingest, whether as sugars or starches.
The brain contains high concentrations of long-chain fatty acids from the omega-3 family. The acronyms EPA and DHA describe 20- and 22-carbon omega-3 fatty acids common in fish oil. The human body can convert the 18-carbon omega-3 fatty acid found in vegetable sources such as walnuts, flax and soy into EPA and DHA, but not as efficiently as fish, which obtain 18-carbon omega-3 fatty acids from algae.
Functional food ingredients and herbal substances contain dozens of phytochemicals that may act in concert with several systems affecting cognition. For example, plant polyphenols in green tea called catechins include epigallocatechin gallate (EGCG). Their oxidized counterparts, known as theaflavins and thearubigins, are formed during fermentation in black (fully fermented) and oolong (partially fermented) teas and are powerful antioxidants. Studies from Japan and Singapore report higher consumption of green, black and oolong teas associated with lower incidence of age-related cognitive decline and better performance on several tests of cognitive functioning. Results were not observed with coffee.
Tea polyphenols, natural parts of traditional diets, are available for many modern food and beverage applications. "L-TeaActive, Natural L-Theanine at 98 percent purity is one of the most effective and safest ingredients you can take to improve cognition," says Cecilia McCollum, executive vice president of Blue California Inc., Rancho Santa Margarita, Calif.
"L-Theanine is associated with improved relaxation and reduction of stress and increased mental alertness, focus, memory and concentration," she continues. "It's safe for adults and children, with FDA GRAS confirmation, and can be added to functional beverages, water, flavored teas — even yogurt and ice cream. It also is stable and completely soluble, with no taste, color or odor."
"One of the more exciting cognitive health ingredients is Zembrin, a product PL Thomas launched at Supply Side West in November of 2012," says Barbara Davis, director of medical and scientific affairs for PL Thomas & Co. Inc., Morristown, N.J. "Zembrin is the world's first patented, proprietary, standardized and clinically studied extract of Sceletium tortuosum. It has been shown to relieve symptoms of stress, enhance cognitive function and elevate mood."
Plants of this genus have been used for millennia. "Standardized extract Zembrin represents the full, unaltered natural phytochemical profile derived from controlled cultivation of a selection of traditionally used raw plant material. This raw plant material is specially selected to deliver low levels of mesembrine (a natural serotonin reuptake inhibitor), reducing its stimulant properties. Zembrin has self-GRAS status and is available for formulating in both food and dietary supplement applications."
There is compelling evidence for the critical role of vitamin B12 and folate in cognitive function. Both are required for the synthesis of specific neurotransmitters. At Fortitech Inc., Schenectady, N.Y., now a part of DSM, researchers assemble a variety of macronutrients, amino acids and fatty acids, micronutrients, antioxidant phytochemicals and substances such as L-carnitine and coenzyme Q-10, believed to affect cognition, into formulations that can be applied to different food categories. Applications include juice-based beverages, confections, dairy products and smoothie formulations.
One of the more interesting ingredients for cognitive health is phosphatidyl serine (PS). Phospholipids are membrane fats that contain two fatty acids each and are assembled using B12 and folate, along with other dietary components. Phospholipids thus are key components in brain tissue. But before you hit your 30s, the body begins manufacturing less of this critical compound. As you age, these changes have an increasingly negative impact on memory and cognition. Research indicates that dying and dysfunctional brain cells, especially in the aged, are the primary cause of memory deterioration as well as other forms of cognitive decline.
While dietary sources of PS are available, the highest concentrations are in organ meats, especially bovine brains. But these are not common foods for most people, and in the case of brains, the dangers of Creutzfeld-Jakob Disease (mad cow) have taken that option literally off the table.
Lipogen Ltd., Haifa, Israel, makes its Lipogen PS Plus from soy lecithin using plant enzymes. Lipogen PS is a solvent-free "clean" ingredient that has excellent oral bioavailability and is one of the only natural brain support ingredients with an FDA qualified health claim. But it also has FDA-approved GRAS status and can be used in a number of beverage or bar formulations.
While books make wonderful food for our minds, real nutrition in the form of both macronutrients like protein and carbs and micronutrients like vitamins, phytochemicals and nutraceuticals are proving indispensible for our aging population. If processors feel they need to think long and hard before employing formulations with ingredients for brain and cognitive health, there now is a wealth of nutraceuticals for just that.
This article originally appeared in the February 2013 issue of Food Processing Magazine.