by Richard Aiken MD PhD @rcaiken
Rooibos (Aspalathus linearis) is a bush native to the Cedarberg Mountains in the Western Cape region of South Africa where it is extensively cultivated for its commercial use as an herbal tea. After harvesting, the needle-like leaves and stems can be either fermented prior to drying or dried immediately. The unfermented product remains green in color and is referred to as green rooibos. During fermentation, the color changes from green to red with oxidation of the constituent polyphenols, so the final product is often referred to as “red tea” or “red bush tea.” The non-oxidized green version, let’s call it “green herbal tea,” would be superior in antioxidants.
Rooibos possesses antimutagenic, anticarcinogenic, anti-inflammatory and antiviral activity, as does unfermented green herbal tea.
Rooibos is especially rich in the super-antioxidant compound quercetin. Rooibos is a source of two comparatively rare antioxidants, aspalathin and nothofagin. Aspalathin helps to modify hormones in the body and reduces the output of adrenal hormones, thus reducing stress and helping to inhibit metabolic disorders. The antioxidant nothofagin demonstrates significant anti-inflammatory activity and neuroprotective functions.
As this is a tea, why not buy teabags, add hot water and drink it? Well that’s fine, but much more expensive than bulk purchase. While the process of preparing, serving, and sipping tea can be an art, we are here interested in the nutrient value – and efficiency of preparation. Steeping in hot water extracts only a portion of the water-soluble components (such as polyphenols) of the plant, i.e., that which enters into solution if the fibrous cell walls are sufficiently disrupted by the heating process – the rest is discarded in the tea bag.
But as a food, the entire leaf can be eaten and all nutrients consumed. A dose suggested from literature studies is one teaspoon.
 Joubert, E., Gelderblom, W., Louw, A., & Beer, D. D. (2008). South African herbal teas: Aspalathus linearis, Cyclopia spp. and Athrixia phylicoides – A review. Journal of Ethnopharmacology, 119(3), 376-412. doi:10.1016/j.jep.2008.06.014.
 Mckay, D. L., & Blumberg, J. B. (2006). A review of the bioactivity of south African herbal teas: Rooibos (Aspalathus linearis) and honeybush (Cyclopia intermedia). Phytother. Res. Phytotherapy Research, 21(1), 1-16. doi:10.1002/ptr.1992.
Intense physical exercise is often associated with an increase in the production of free radicals and reactive oxygen species (ROS) in various tissues, which may overwhelm the capacity of the antioxidant defense systems.
Oxidative stress, induced by the accumulation of large amounts of ROS and an imbalance between ROS and antioxidants, can lead to the destruction of tissue and cell macromolecules such as lipids, proteins, and nucleic acids. It has been suggested that exercise-induced oxidative stress may be associated with muscle fatigue, muscle damage, and a decrease in physical performance.
Use of green tea prevents oxidative stress in endurance athletes. Polyphenols from Hibiscus flowers appear to induce an endothelium-dependent relaxant effect via stimulation of nitric oxide production or a decrease of blood viscosity.
Adding hot water to tea bags help solubilize the polyphenols because the temperature softens the cells walls and increases the solubility of cellular contents; steeping 5 minutes or so is enough. But there is a “biohack” that can get the goodies into solution even faster: blending. The reason is that agitation in the aqueous environment and particle size reduction aids the extraction. High-speed blenders can get the particle size down below 100 microns and the agitation is maximal. Reduction of tea time availability: 5 minutes from “steeping” to less than 30 seconds using blending.
Here is what I do to make a “water bottle” mixture for exercise. This uses bulk tea leaves (no tea bags, which are much more expensive).
- Place one to three tablespoons of raw dried Hibiscus flowers into a blender (mine is 64 ounce capacity).
- (optional) Add one to three tablespoons green tea leaves.
- Add a tablespoon of lemon or lime juice (to protect the antioxidants when blending).
- Add ice (optional) and water to three quarters of the capacity of the blender.
- (optional) If the sour bitter taste is an issue (I actually prefer it), add a date or date syrup to taste.
 Alessio, H. M. (1993). Exercise-induced oxidative stress. Medicine & Science in Sports & Exercise, 25(2). doi:10.1249/00005768-199302000-00010
 Jówko, E., Długołęcka, B., Makaruk, B., & Cieśliński, I. (2015). The effect of green tea extract supplementation on exercise-induced oxidative stress parameters in male sprinters. European Journal Of Nutrition, 54(5), 783-791. doi:10.1007/s00394-014-0757-1
by Richard Aiken MD PhD
Zinc is an essential trace mineral, a component of hundreds of enzymes and proteins. It is required for intracellular message transmission, protein synthesis, maintenance of cell membranes, cellular and intracellular transmembrane transport, and is involved in regulation of the neuronal, endocrinal and immunological systems .
Zinc deficiency induces neurological symptoms as well as psychopathological symptoms that mostly correspond with clinical depression (e.g., poor appetite, reduced sense of taste, reduction in immune function, irritability, mood liability, cognitive impairment)
The mechanisms in which zinc is linked to antidepressant activity is a active area of research but there are indications that it is involved in the neurogenesis processes.
There is a delicate balance in the relation of zinc to copper, so supplementation is not recommended. A whole-food varied-plant diet is the best assurance of getting zinc in the correct doses and food context.
 Takeda A. Movement of zinc and its functional significance in the brain. Brain 224 Res Rev 2000;34(3):137–48.
 Swardfager W, Herrmann N, McIntyre RS, Mazereeuw G, Goldberger K, Cha DS, 226 et al. Potential roles of zinc in the pathophysiology and treatment of major 227 depressive disorder. Neurosci Biobehav Rev 2013;37(5):911–29.
 Levenson CW, Morris D. Zinc and neurogenesis: making new neurons from 388 development to adulthood. Adv Nutr 2011;2(2):96–100.
by Richard Aiken MD, PhD @rcaiken
Virtually any vegetable can be selected for sous vide cooking. Particularly excellent candidates would be those vegetables that are degraded most from high temperature cooking, such as cauliflower, carrots, green peppers, and zucchini. Green leaves can be processed with little nutrient loss or color change.
Recipe: Sous Vide
This recipe utilizes zucchini and green peppers, sensitive to high-temperature cooking. Makes enough for about 4 people.
- 1 medium size zucchini, quartered lengthwise, and cut into one half inch pieces
- 1 medium size eggplant, cut into 1/2-inch pieces (about 2 – 3 cups)
- 1 red bell pepper, chopped
- 1 onion, chopped
- 1 cup tomatoes, chopped course
- 2 garliccloves, minced
- ½ cup shredded fresh basilleaves
- ¼ teaspoon oregano
- ¼ teaspoon thymeor coriander
- Set the sous vide cooker for 185 F (85 C)
- Put the zucchini, tomatoes, bell peppers, eggplant, and onioneach in its own vacuum seal bag.
- Distribute the garlicand basil equally amongst each bag.
- Vacuum seal each bag.
- Once the waterhas reached the set-point temperature, submerge each bag.
- Set a timer for 30 minutes; once that time is up, remove the tomatoes.
- Set the timer for 30 more minutes; once that time is up, remove the zucchiniand peppers.
- Set the timer for one hour; once that time is up, remove the eggplantand onion.
- Mix the contents of each bag into a large serving bowl; season with black pepperto taste.
by Richard Aiken MD PhD @rcaiken
The US Department of Agriculture (USDA) on February 13, 2016, approved the first genetically modified (GM) apple developed to resist browning. They will go into production in the Midwest in the next few weeks (February, 2017).
Browning is caused by polyphenol oxidases (PPOs) naturally present in fruit and vegetables. When fruit is cut or bruised, these enzymes catalyze the oxidation of polyphenols to quinones, causing oxidative browning. The damage is superficial but can affect the taste and texture of the apple as well as its cosmetic qualities. In the Arctic varieties, the GM apples were genetically engineered with a transgene that produces specific RNAs to silence the expression of at least four browning PPO genes.
Is this a good idea?
The enzymes in the class polyphenol oxidase (PPO) appear to reside in the plastids of all land plants and are released when the plastid cell membrane is disrupted. PPO is thought to play an important role in the resistance of plants to microbial and viral infections and to adverse climatic conditions such as drought as although all land plants have PPO content, no PPO-like sequences have been reported in marine plants such as algae.
As stated above, in the presence of oxygen from air, the enzyme catalyzes the first steps in the biochemical conversion of phenolics to produce quinones, which undergo further polymerization to yield dark, insoluble polymers referred to as melanin. This is the same melanin that determines darkness of human skin and hair. In plants, melanin forms barriers and has antimicrobial properties that prevent the spread of infection in plant tissues.
Phenolic compounds are responsible for the color of many plants and impart taste and flavor, but more importantly, they are important phytonutrients and antioxidants.
Alteration of polyphenol oxidase
Given the activity of PPO in the adaptation of plants to, for example, plant dehydration, what are the implications of altered PPO activity on plant development, phenotype, and yield? A clear effect of PPO silencing was observed, for example, in walnut plants which developed spontaneous necrotic lesions in the leaves suggesting increased susceptibility to oxidative stress.
A potential role for PPO in photosynthesis has been speculated.
Data suggest that PPO activity can confer both a productive advantage and be associated with an increased risk of oxidative damage. While PPO activity can be associated with non-enzymatic reactive oxygen species scavenging involving flavonoid and phenolic acid substrates, a role for PPO in plant function may also be associated with its pro-antioxidant activity through the generation of secondary reaction products.
So it is obvious that the role of PPO is extensive and not fully understood. It appears premature to genetically modify plants to remove this complex molecule.
 Tran LT, Taylor JS, Constabel CP. 2012. The polyphenol oxidase gene family in land plants: lineage-specific duplication and expansion. BMC Genomics 13, 395.
 Araji S, Grammer TA, Gertzen R, et al. 2014. Novel roles for the polyphenol oxidase enzyme in secondary metabolism and the regulation of cell death in walnut (Juglans regia). Plant Physiology 164, 1191–1203.
 Vaughn KC, Duke SO. 1984. Function of polyphenol oxidases in higher plants. Physiologia Plantarum 60, 106–112
 Parveen I, Threadgill MD, Moorby JM, Winters A. 2010. Oxidative phenols in forage crops containing polyphenol oxidase enzymes. Journal of Agricultural and Food Chemistry 58, 1371–1382.
 Thipyapong P, Joel DM, Steffens JC. 1997. Differential expression and turnover of the tomato polyphenol oxidase gene family during vegetative and reproductive development. Plant Physiology 113, 707–718.