A few days ago, my friend came to me with a question about corn. They had been told it was nutritionally redundant and were advised to drop it from their dietary repertoire. My friend wanted to know my thoughts on corn. I began by gently asking how they might feel about a life without barbecued corn cob, corn chips and guacamole, nachos, popcorn, and cornbread, not to mention the whimsical delight that is baby corn in stir fry. I think when we hear nutritional rhetoric that advocates the removal of any foods, let alone whole food groups, it is worth pausing to reflect how this will impact our well-being as a whole. In terms of nutrition, corn actually has a LOT going on. As do other yellow foods, which is the topic of this post. While I cannot hope to even scratch the surface of a whole plant colour in one post, I hope to inspire you to seek out these yello plant beauties to include them in ways that bring you enjoy. Since I’m already up on my high horse about corn, let’s start there… CornAs a starchy vegetable, corn is a rich source of carbohydrate, which is the most important fuel for our cells, particularly in the context of fertility. Corn is also a wonderful source of both soluble and insoluble fibres for healthy bowel movements, and prebiotic fibres to feed our gut bugs. Corn also contains lutein, a phytonutrient from the carotenoid family (which I introduced in the orange fruit and veg post). Lutein is famously known for its relationship to a lowered risk of age-dependent macular degeneration; however, it is also gaining attention as a potent antioxidant that can confer benefits to other organ systems, such as our cardiovascular system. Prebiotic BananaBanana is well-known for its rich potassium content which we need for nerve conduction, muscle contraction, and cell fluid balance. Bananas are also rich sources of important prebiotic fibres: inulin, pectin, and resistant starch (particularly green or just-ripe bananas), which are preferred foods of beneficial gut bugs such as Roseburia and Bifidobacteria species. In a study of 31 healthy women, 2 bananas a day for 60 days increased mean levels of Bifidobacteria species and were associated with lower levels of bloating (Mitsou et al. 2016). Bifidobacteria are a beneficial inhabitant of the gut. When they ferment prebiotic fibres they produce compounds that strengthen the intestinal barrier, reduce inflammation, balance hormones, and support your metabolism. All great news for fertility! PineapplePineapple contains a digestive enzyme called bromelain, which has been shown to increase the abundance of beneficial Akkermansia muciniphila in mice, as well as to support gut barrier integrity (Kostiuchenko, 2022). Akkermansia muciniphila is an important species in the gut, as it acts as a sentry in our mucus – eating just enough to prompt our colon cells to regenerate the mucus. Because bromelain is a digestive enzyme, it acts like a pair of scissors, chopping up nutrients into smaller nutrients so we can better absorb them. For this reason, bromelain has a cleansing effect on the gastrointestinal tract, contributing to good gastrointestinal health (Minich, 2019). Citrus Fruits for Fertility The inevitable eye-twitching, face-scrunching, cheek-sucking response to lemon juice is our body registering the citric acid and ascorbic acid (vitamin C). Combining acidic foods, such as citrus, with carbohydrate-rich foods, can help lower the rate at which our blood sugar spikes by 20-50%. Stable blood glucose levels are important for our cardiovascular health, as well as our fertility.I’m just in this moment reflecting on the wisdom of lemon juice + sugar on crepes… but I digress… It is not only the acid in citrus that make them a nutritional powerhouse for fertility. Introducing naringenin, an antioxidant found in citrus fruits. Naringenin has been observed to improve insulin sensitivity, metabolic disturbances, and inflammation (Mulvihill, Burke, & Huff, 2016). 8 weeks of naringenin treatment in PCOS rat models reduced ovarian damage, improved ovarian function, regulated sex hormone levels, and improved insulin sensitivity; it also increased the expression of occludin and claudin-1 (proteins crucial for intestinal barrier function and strength) and increased beneficial bacteria known to reduce inflammation via the production of short chain fatty acids (Wu et al, 2022). Naringenin has also been observed to ameliorate testicular toxicity in rats from Bisphenol A (BPA) (Alboghobeish, 2019). Effects of BPA on rats without naringin treatment included:
While the quantity administered in this study was in far higher doses than can be found from food (around the equivalent of ½ grapefruit per kg of body weight – so… 50 grapefruits a day for a 100kg male!), the exposure to BPA was far more concentrated too. Nobiletin is an anti-inflammatory flavonoid found in citrus fruit peel. Wei and colleagues (2018) administered nobiletin to mouse models of endometriosis and noted up to 67% reduction in endometriotic lesion size in mice given 20 mg/kg per day of nobiletin, as well as significantly reduced inflammation. Again, these doses are far higher than can be derived from consuming citrus fruit alone, and yet it is interesting that in an epidemiological study, an anti-endometriotic lesion effect was observed to track with increased citrus fruit intake (Harris, 2018). Finally, I want to tell you about rutin, yet another antioxidant found in citrus. When administered to rats, it was observed to prevent the development of endometriosis through antioxidant activity (Talebi et al, 2021). Rutin has also been observed to reduce oxidative stress and inflammation that contribute to testicular dysfunction (Rotimi, elebiyo, & Ojo, 2023). As a potent antioxidant, rutin has been observed to confer the following health benefits: anti-ageing (on skin); anti-neuro-degenerative; anti-hyperglycaemic; anti-dyslipidaemic; protective in liver damage and cardiovascular disorders. As if that’s not cool enough, when rutin is broken down (for example by our microbiota) the break-down products (Q-glc and Q) also confer potent health benefits. By consuming sources of rutin, we can increase the abundance of species that create these break-down products (Riva et al, 2020). Author: Emily Hahn, APD
References Alboghobeish S, Mahdavinia M, Zeidooni L, Samimi A, Oroojan AA, Alizadeh S, Dehghani MA, Ahangarpour A, Khorsandi L. Efficiency of naringin against reproductive toxicity and testicular damages induced by bisphenol A in rats. Iran J Basic Med Sci. 2019 Mar;22(3):315-523. doi: 10.22038/ijbms.2019.29757.7184. PMID: 31156794; PMCID: PMC6528718. Harris HR, Eke AC, Chavarro JE, Missmer SA. Fruit and vegetable consumption and risk of endometriosis. Hum Reprod. 2018 Apr 1;33(4):715-727. doi: 10.1093/humrep/dey014. PMID: 29401293; PMCID: PMC6018917. Ijaz, MU Tahir, A Samad, A Anwar, H (2021) Nobiletin ameliorates nonylphenol-induced testicular damage by improving biochemical, steroidogenic, hormonal, spermatogenic, apoptotic and histological profile. Human & Experimental Toxicology, 40(3), 403- 416 doi: 10.1177/0960327120950007 Kostiuchenko O, Kravchenko N, Markus J, Burleigh S, Fedkiv O, Cao L, Letasiova S, Skibo G, Fåk Hållenius F, Prykhodko O. Effects of Proteases from Pineapple and Papaya on Protein Digestive Capacity and Gut Microbiota in Healthy C57BL/6 Mice and Dose-Manner Response on Mucosal Permeability in Human Reconstructed Intestinal 3D Tissue Model. Metabolites. 2022 Oct 26;12(11):1027. doi: 10.3390/metabo12111027. PMID: 36355110; PMCID: PMC9696696. Minich, DM (2019) A Review of the Science of Colourful, Plant-Based Foods and Practical Strategies for Eating the Rainbow’, Journal of Nutrition and Metabolism, Volume 2019, Article ID 2125070. E.K. Mitsou, E. Kougia, Tz. Nomikos, M. Yannakoulia, K.C. Mountzouris, A. Kyriacou, Effect of banana consumption on faecal microbiota: A randomised, controlled trial, Anaerobe, Volume 17, Issue 6, 2011, Pages 384-387, ISSN 1075-9964, https://doi.org/10.1016/j.anaerobe.2011.03.018. Comments are closed.
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