In Part 1 we reviewed the research into diet and the various ways in which ones diet can impact on one’s health and the development of diseases such as psoriasis and arthritis.
Part 2 will concentrate on certain foods that can have a positive impact on one’s health and assist in the repair/healing processes.
It is known that throughout life, environmental conditions and dietary compounds influence gene expression. Only recently it has been observed that exposure to specific phytochemicals can affect gene expression via reversible epigenetic mechanisms and gets recorded in our “epigenome” through life. Epigenetics refers to heritable phenotypical differences or changes in gene expression that are not attributable to changes in DNA sequence, but rather depend on variations in DNA methylation, chromatin structure or microRNA profiles. As such, our dietary epigenetic imprint superposed on our genome may rewire gene expression patterns in the body and the host immune system, and protect against inflammatory disorders, cancer and ageing. 1
It has also been found that the metabolism of nutrients may vary person to person and ultimately result in different health status depending on the genotype of an individual. Nutrigenomic trends towards individualizing/personalizing foods (both to avoid and to consume) and nutritional supplementation, that leads to individual strategies to not only maintain good health but, more importantly, to assist in repair processes.
Phytochemicals/ phytonutrients/ phytonutriceuticals are organic compounds derived from plants that have health protective effects. Besides the common nutrients such as carbohydrates, amino acids and protein, there are certain non- nutrient phytochemicals in vegetables that have biological activity against chronic diseases. They are low in fat and like all plant products, contain no cholesterol. Most phytochemicals are found in relatively small quantities in vegetable crops. However, when consumed in sufficient quantities, phytochemicals contribute significantly towards protecting living cells against chronic diseases. 2
Cruciferous vegetables are vegetables of the family Brassicaceae (also called Cruciferae) which includes vegetable, such as kale, red and white cabbage, broccoli, brussels sprouts, cauliflower, turnip, Chinese cabbage and pak choi. This group of vegetables contains well-known antioxidants, such as vitamins C, E, carotenoids and antioxidant enzymes such as catalase, superoxide dismutase (SOD) and peroxidase, which are found in fresh vegetables. these vegetables are also rich in beneficial plant’s metabolites, which include sulfur containing glucosinolates, anthocyanins, flavonoids, terpenes, S-methylcysteine sulfoxide, coumarins and other minor compounds.4,5 Studies have also identified many compounds that have been isolated from Brassica vegetables and the pharmacological studies in vitro or in vivo have shown that they have a large spectrum of biological activities, including antiinflammatory, antibacterial, antifungal, antitumor, antimutagenic, neuroprotective and antioxidative properties. 4,5
The health potential of Brassica vegetables are partially attributed to their intricate fusion of phytochemicals and their antioxidant activity. Recently, considerable research has been aimed at the detection of plant derived natural antioxidants which can be utilized for human consumption for prevention of non-transmissible chronic diseases and promotion of health. Phytochemicals from Brassica vegetables may act on different and complementary levels. They prevent oxidative stress, induce detoxification enzymes and stimulate the immune system. Reactive oxygen species (ROS) in the body can cause lipid and protein oxidation, DNA damage, base modification and modulation of gene expression. 4,5
Antioxidants counteract, or neutralize, the harmful effects of free radicals. These antioxidants act as scavengers for these tree radicals and reactive oxygen species, thereby preventing them from disrupting the chemical stability of the cells. A variety of external factors such as inflammation, cigarette smoke, air pollutants, radiation (X-rays and ultra-violet rays) can promote free radical formation in our body. Consequently, individuals exposed to these sources of oxidants would require a greater supply of dietary antioxidants. 2 Skin is a major target of oxidative stress due to reactive oxygen species (ROS). Antioxidants attenuate the damaging effects of ROS and can impair and/or reverse many of the events that contribute to excessive growth and reproduction of skin cells. Increased ROS production in patients of psoriasis and decreased concentration of antioxidants leads to oxidative stress, which indicates lipid peroxidation. This may lead to cell damage by continuous chain reactions damaging the cell membranes and tissues. 3 Imbalance between ROS and antioxidants causes oxidative stress. Oxidative stress may be caused by antioxidant deficiency in the diets or increased production of free radicals caused by stress, smoking, environmental contaminations. Antioxidants and other bioactive compounds detoxify ROS and prevent damage to cellular macromolecules and organelles through multi-mechanisms. In human body, several mechanisms are known to defend from free radicals (for example antioxidant enzymes), however in some cases there is a need more substances to overcome their impact. Consumption of vegetables including Brassica species has been strongly associated with the reduced risk of chronic diseases, such as cardiovascular disease, diabetes, and age-related functional decline. 4,5 Antioxidants are also effective in reducing free radical damage of collagen and elastin, the fibers that support the skin structure.6
Carotenoids are yellow, red and orange pigments present in many fruits and vegetables. In the diet they act as powerful antioxidants and are believed to protect the body against free radical attack. Several studies on the bioavailability of β -carotene from vegetables in the human diet have shown that in broccoli it ranges from 22- 24%, in carrots 19-34%, and in leafy vegetables it ranges from 3-6%. Flavonols include quercetin, kaempferol, fisetin, and myricetin. Quercetin is the most important flavonoid in vegetables. It has been detected in onion. Kaempferol, myricetin, and fisetin have also been detected in onion as well as lettuce, and endive.
Anthocyanins give vegetable leaves and fruits their purple and or/red colour, such as in purple cabbage, purple broccoli, purple sweet potato, rhubarb, purple radish and onion. Anthocyanins have also been shown to protect mammalian cell lipoproteins from damage by free radicals. 2
Constant inflammation plays an essential role in many human illnesses and isothiocyanates (ITCs) slow down the activity of many inflammation mechanisms, restrain cyclooxygenase 2, and permanently inactivate the macrophage migration inhibitory factor. Studies have attributed ITCs with anti-inflammatory abilities . They have been shown to reduce carrageenan-induced rat paw oedema, lessen ear oedema formation and induce leukocyte clearance in inflamed mouse skin and in studies using Human skin organ culture, has been shown to reduce the expression and secretion of proinflammatory cytokines in human monocytes, macrophage-like cells and inflamed skin.7
As with anything diet should be balanced and any changes should be discussed with your Practitioner.
Also read our blog “PSORIASIS and DIET – Part 1, PSORIASIS and COMORBIDITIES, PSORIASIS and ALCOHOL and PSORIASIS and WATER INTAKE “.