Ginger: Phytochemistry

Ginger (Zingiber officinale) is an angiosperm (flowering) plant that produces a large edible rhizome or root. The rhizome is used in cuisine for its distinctive taste, as well as its antioxidant and preservative properties. Ginger is a plant that is related to turmeric, cardamom, and galangal. Chemically ginger is an interesting mixture of chemicals, many of which are responsible for the unique taste of ginger. Some of the main chemicals isolated from ginger include gingerol, shogaol, paradol, beta-sitosterol palmitate, isovanillin as well as metabolites of these chemicals. Ginger also contains vitamin C and the B vitamins thiamine, riboflavin and niacin.  The chemical composition of ginger can be altered significantly by the growing conditions, the storage conditions, the growing time, the harvest time, and the storage length. Powdered ginger may also have a slightly different chemical composition compared to fresh ginger.  

As well as its use in cuisine, ginger has a number of particular medicinal uses. One well known action of ginger is that of inhibiting inflammation. This makes ginger useful against conditions of chronic inflammation like arthritis. Subclinical conditions associated with inflammation including obesity, cardiovascular disease and cancer may also be modified in their progression by use of ginger although the effects will be less obvious and much longer in their manifestation. In terms of its biochemical effects, ginger may inhibit the synthesis of certain proinflammatory prostaglandins, particularly 5-lipoxygenase, through inhibition of the cyclooxygenase 1 and 2 enzymes. Ginger has also been shown to interfere with the vanilloid nociceptor. Ginger may also inhibit the expression of certain genes associated with inflammation including genes encoding cytokines, chemokines and cyclooxygenase 2. Ginger therefore modulates multiple pathways that can lead to inflammation, and this explains its highly effective anti-inflammatory effects. 

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RdB

Agrahari, P., Panda, P., Verma, N.K., Khan, W.U. and Darbari, S. 2015. A brief study on zingiber officinale – a review. Journal of Drug Discovery and Therapeutics. 3(28): 20-27
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Magnesium in Health

Magnesium is an essential macromineral, and the role played by magnesium ions in optimal nutrition is becoming increasingly evident. A deficiency of magnesium is not uncommon, and low intakes of magnesium have been becoming increasingly frequent in Western nations, where the diet tends not to contain magnesium rich foods. In cases of magnesium deficiency, supplements can be beneficial, and magnesium is generally cheap and relatively well absorbed. One of the most common symptoms of low magnesium intake is muscle tremors and twitches. Serious cases of magnesium deficiency can result in myocardial infarction. Magnesium is used in the body as the magnesium ion, and in this form magnesium can bind to cell membranes due to the negatively charged proteins within the membranes. This effect provides stability to membranes, and these membrane stabilising effects may be one of the most physiologically important functions of magnesium in humans. It is though that once bound to the membranes, the positive charge on the magnesium ion is able to electrically stabilise the membrane through interaction with proteins as well as by inhibiting phospholipase A2, an enzyme that can cause cleavage of the fatty acids from phosphates in phospholipids present in the membranes.  

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Saris, N.E.L., Mervaala, E., Karppanen, H., Khawaja, J.A. and Lewenstam, A. 2000. Magnesium: an update on physiological, clinical and analytical aspects. Clinica Chimica Acta. 294(1-2): 1-26
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A Nice Cup of Tea

George Orwell wrote about tea in the Evening Standard in 1946. In this article Orwell made observations about tea that are insightful and interesting. Firstly, Orwell suggested that a “nice cup of tea” really refers to Indian tea. In relation to this he suggested that China tea is cheaper and of lesser quality. Evidence today suggests that tea quality varies considerably, and cheaper tea tends to be of lesser quality and taste, corroborating Orwell’s observations. Lesser quality tea, often referred to as brick tea may also have much higher levels of fluoride. Another observation he made was that tea should be made in small quantities, with army tea from a cauldron tasting like grease and whitewash, and tea from an urn being tasteless. In terms of teapots, Orwell suggests that earthen teapots are superior, with silver and Britannia Ware pots producing a poor taste, something evidently even worse for enamel pots. Orwell also suggests that pots should be warmed before use, something that is often stated as improving the taste of tea, perhaps because it increases the brewing temperature which enhances the flavour. 

In his article, Orwell clearly prefers strong tea, and in this regard clearly makes his tea with loose leaf black tea. The idea that the pot should be taken to the kettle, as suggested by Orwell, is claimed to increase the temperature of the water as it makes contact with the tea, and this likely relates to the same benefit as warming the pot. Orwell also suggests that the cup from which the tea is drunk can considerably impact taste, an anecdote shared by many who favour a particular cup or mug. In this regard, Orwell recommends a good breakfast cup. The last comment by Orwell relates to drinking tea without sugar, and this is perhaps his best advice. Orwell’s reasons for this are the negative effects on the taste that sugar has, which is evidently true, because sugar is very sweet, whereas tea is quite bitter. However, further than this, sugar is unhealthy and can cause disease, whereas tea is healthy and can treat disease. Adding sugar is therefore the antithesis to drinking tea, whether one is interested in the taste, or its health effects. 

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RdB

Orwell, G., 2017. A nice cup of tea. SFCB.
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Broccoli: Stability of Its Nutrients During Digestion

Broccoli (Brassica oleracea) is a rich source of phytochemicals that may have significant health benefits. In particular, broccoli contains high amounts of polyphenols, glucosinolates and vitamin C, and these nutrients may explain its ability to reduce the risk of certain diseases including cancer. However, the presence of nutrients does not guarantee health effects, as the nutrients must survive digestion and then be absorbed. For example, around 69 % of glucosinolates may be lost during digestion in the stomach, although the remaining glucosinolates remain relatively stable in the intestine. In contrast, the vitamin C content of broccoli may be more stable with only 7 % loss during digestion in the stomach. During digestion, polyphenols are extensively degraded with an 80 to 84 % loss in the intestine, but much lower degradation in the stomach of around 6 to 25 %. The losses associated with nutrients in broccoli are determined by the exact conditions of digestion, and therefore losses may differ depending on the presence of other foods, as well as showing differences between individuals. Further, while phytochemicals can be degraded during digestion, it might be that the breakdown products are in turn also able to confer health effects. For example, the breakdown products of polyphenols may be absorbed and may provide many of the effects attributed to polyphenols themselves. Bacterial degradation of polyphenols in the small and large intestine is likely extensive. 

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Vallejo, F., Gil-Izquierdo, A., Pérez-Vicente, A. and García-Viguera, C. 2004. In vitro gastrointestinal digestion study of broccoli inflorescence phenolic compounds, glucosinolates, and vitamin C. Journal of agricultural and food chemistry. 52(1): 135-138
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Vitamin C in Carrots

Carrots are perhaps best known for their orange colour which derives from their high concentrations of carotenoids (60 to 134 mg per kg). In particular, carrots are high in alpha-carotene and beta-carotene, and both of these carotenoids are bioavailable and act as antioxidants in humans. Carotenoids have been linked to reductions in the risk of cancer in human studies. However, like most vegetables, carrots are also a good source of vitamin C and this improves their antioxidant capacity somewhat. For example, in one study, the vitamin C content in the cultivars of carrots tested ranged from 54 to 132 mg per kg. Higher levels of vitamin C were found in cultivars of carrots that are harvested late in the season, and storage of the carrots for 30 days resulted in a 47 % decrease in vitamin C content. Therefore the best place for carrots, if vitamin C content is a priority, is the ground, and picking them only when needed for cooking might be the best option in order to preserve the high vitamin C content. 

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Matejkova, J. and Petrikova, K. 2010. Variation in content of carotenoids and vitamin C in carrots. Notulae Scientia Biologicae. 2(4): 88-91
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Can Green Tea Increase Equol Production

Equol is a degradation product of the isoflavone daidzein. Daidzen is degraded to equol in the gut of humans under the influence of a number of bacteria. Current evidence suggests that equol may have health effects that include protection from certain cancers. Foods high in daidzein, the presence of particular bacteria in the gut, as well as genetic make-up may all influence how much equol is produced. In terms of dietary factors, foods may be able to influence equol production because they can supply daidzein, or because they alter the bacteria in the gut to a more favourable profile. Studies have suggested that one food that may be beneficial in this regard is green tea. For example, in one study, researchers assessed the diet of hospital patients and found that those with a greater ability to make equol had significantly higher levels of green tea in their diet. Of course, this does not prove cause and effect, and green tea drinkers may also make other changes to their diets that favour equol production, such as having lower sugar intakes. However, it is known that green tea can alter bacteria profiles in the gut microbiota and in this way may be able to favourably increase synthesis of equol. 

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Miyanaga, N., Akaza, H., Takashima, N., Nagata, Y., Sonoda, T., Mori, M., Naito, S., Hirao, Y., Tsukamoto, T. and Fujioka, T. 2003. Higher consumption of green tea may enhance equol production. Asian Pacific Journal of Cancer Prevention. 4(4): 297-301
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Antioxidants in Cabbage

Cabbage is a healthy food that is available in a number of different varieties and cultivars. Cabbage is healthy because of the high fibre and low sugar content which support optimal blood sugar levels and reduce the risk of insulin resistance developing. This makes cabbage a great way to prevent weight gain and diseases such as diabetes and cardiovascular disease. However, cabbage also contains a number of phytochemicals, and many of these are antioxidants which have their own health effects. For example, cabbages contain vitamin C, and the amount varies between cultivars and between individual cabbages. Vitamin C is an essential nutrient and can improve extracellular antioxidant defences and increase cellular glutathione levels. Lutein is another antioxidant present in cabbages that belongs to the carotenoid family of nutrients and lutein may protect eyesight. Cabbages are not high in vitamin E, but contain reasonable amounts of alpha-tocopherol, the most important antioxidant for cell membranes. Lastly, polyphenols are also present in cabbages, as they are in all plant foods. Of the polyphenols in cabbages, anthocyanins in red cabbage are the most noticeable as they provide them with their red colour. Eating a range of cabbage varieties and cooking cabbage to help release the antioxidants from the cells is perhaps the best strategy to optimise antioxidant intake from them. 

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RdB

Singh, J., Upadhyay, A.K., Bahadur, A., Singh, B., Singh, K.P. and Rai, M. 2006. Antioxidant phytochemicals in cabbage (Brassica oleracea L. var. capitata). Scientia Horticulturae. 108(3): 233-237
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Curcumin and Reproductive Function

Curcumin is a yellow pigment found in the spice turmeric (Curcuma longa). Curcumin has been shown to have a number of medicinal effects, and this likely relates to its ability to reduce oxidative stress and inflammation. Loss of reproductive function can sometimes be attributed to oxidative stress and inflammation and it has been suggested that curcumin may be beneficial in this regard. For example, in one study researchers administered 80 mg of curcumin as a nanomicelle to a number of male subjects for 10 weeks. After 10 weeks, significant improvements in sperm count, sperm concentration, and motility were seen in the treatment group compared to the control group. These changes were accompanied by increases in the levels of blood antioxidants, and reductions in markers of oxidative stress such as malonaldehyde, C-reactive protein and tumour necrosis factor alpha. Therefore curcumin may have beneficial fertility effects in men, which may derive from its ability to reduce the oxidative stress in tissues. 

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RdB

Alizadeh, F., Javadi, M., Karami, A.A., Gholaminejad, F., Kavianpour, M. and Haghighian, H.K. 2018. Curcumin nanomicelle improves semen parameters, oxidative stress, inflammatory biomarkers, and reproductive hormones in infertile men: A randomized clinical trial. Phytotherapy Research. 32(3): 514-521
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Eggs and the Vegan Diet

Veganism is different from vegetarianism. For the vegan, all animal products are unsuitable for consumption, whereas for the vegetarian, meat and fish cannot be eaten, but other animal products such as milk and eggs can be consumed because they are not animals themselves, but products of them. Evidence to date suggests that vegans have significant shortfalls in their diet with regard to certain nutrients, and that vegetarianism is a healthier option. Some vegans claim that they do not eat animal products because of the suffering of the animals. This is personal choice and something that must be respected, although the argument is flawed in some respects. In particular, there is no real evidence that chickens suffer through laying eggs, and in fact chickens appear to enjoy being in an environment where they can roam, feed and become broody. Therefore whilst veganism is a personal choice, the arguments that justify it are sometimes flawed, and the nutritional value of the diet should sometimes be called into question. 

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The Absorption of Turmeric

Turmeric (curcuma longa) is a yellow coloured spice that is widely commercially available throughout the world. Some of the uses of turmeric include flavouring food, colouring food, and preserving food. Turmeric also has significant medicinal effects that include antioxidant and anti-inflammatory activity. The medicinal effects of turmeric may largely be related to the presence of the yellow pigment curcumin. However, for curcumin to have its effect inside the body, it needs to be absorbed. The oral bioavailability of turmeric has been shown to be poor due to its tautomer enol structure. The presence of curcumin in the gut leads to the formation of a number of metabolites including hexahydro curcumin, curcumin sulphate, curcumin glucuronide, tetrahydroxy curcumin and dihydrocurcumin. Some of these metabolites are absorbed and further metabolised in the liver, but others are passed to the colon, where they may be further metabolised by bacteria. Ultimately very little curcumin actually reaches the tissues, but effects from the metabolites of curcumin may explain the physiological response to its consumption. 

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Mughal, M.H. 2019. Turmeric polyphenols: A comprehensive review. Integrative Food, Nutrition and Metabolism. 6(10.15761)
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