nutrition

Beyond Veganuary: The Benefits of Eating Plant Based

As we begin the new month of February, so comes the end of Veganuary. Started in 2014, Veganuary is a challenge run by a non-profit organisation of the same name throughout the first month of the year to promote and encourage vegan or plant-based lifestyles. In January of 2020, 400,000 people signed up and this year 500,000 took to the challenge.

As someone who is passionate about the conservation of our planet and of animal life, I wanted to write about the benefits of eating plant-based beyond just the month of January. As we know, the livestock industry is having a large impact on on the climate crisis. Half of all greenhouse emissions that come from the food industry come from animal products alone. It has been suggested for a long time now that we need to limit our consumption of animal products, especially in the western world in order to reduce our effects on the planet.

So what are the benefits of choosing a more plant-based lifestyle?

Inflammation

The first thing I wanted to look at is inflammation as it is a theme that seems to crop up in various different areas of research. I feel it’s quite likely that many of us have heard of inflammation in recent years as the topic of inflammation and ill-health continues to gain popularity.

Inflammation is the body’s process of fighting harmful things such as infections, injuries, and toxins in order to heal itself. The inflammatory response is an incredibly important process in the body, alerting the immune system that it needs to kick in to action. The response usually lasts from a couple of hours to a couple of days however problems can occur when the inflammatory response lingers.

Chronic inflammation is where the response is activated over long periods of time, putting the body in a constant state of alertness. Chronic inflammation can be a major threat to health, contributing to[1]:

  • Cancer
  • Cardiovascular diseases
  • Diabetes
  • Rheumatoid arthritis
  • Asthma
  • Obstructive pulmonary disease
  • Alzheimer’s Disease
  • Chronic kidney disease
  • Inflammatory Bowel Disease

Plants and plant-products such as fruits, vegetables, berries, nuts and oils all contain anti-inflammatory properties and there is evidence that increased consumption of plant-based products lower inflammatory markers (C-reactive protein, leukocyte concentrations)[2][3][4][5]. When compared with diets that contain meats, vegans and vegetarians had lower scores than semi-vegetarians on the Dietary Inflammatory Index[6]. This means that diets higher in plant-based materials are potentially protective from chronic inflammation and its health complications. 

Cancer

Looking more specifically at the conditions associated with chronic inflammation, research has shown those who follow plant-based (vegetarian or vegan) diets have significantly lower cancer incidence than those who consume meat. It has been well documented for some time now that red meat and processed meat can be a carcinogen especially when eaten in excess[7][8][9].  Research has suggested that adoption of plant-based diets can help with recurrent prostate cancer[10], cancer-related fatigue[11], and may reduce risk of breast cancer[12][13], colorectal cancer[14][15] and overall cancer incidence[16].

Cardiovascular Diseases

There are many risk factors for cardiovascular diseases such as cholesterol levels, systolic blood pressure, weight, waist circumference and chronic inflammation. There have been many studies demonstrating that plant-based diets improve obesity-related inflammation[17], cholesterol levels and systolic blood pressure[18][19], and bodyweight and weight control[20][21]. One study cited that the intake of soy protein specifically is associated with reduced risk factors for cardiovascular diseases[22].  For patients already suffering with coronary artery disease, one study suggested that plant-based diets are effective for lowering C-reactive protein (an inflammatory marker) which is associated with reduced future major adverse events associated with coronary artery disease.

Diabetes

Research has suggested that the prevention and management of type 2 diabetes is significantly improved when following a plant-based diet[23][24][25]. One review suggested that the inverse association between higher adherence to a plant-based diet and lower risk of type 2 diabetes is strengthened when there is an emphasis in the diet on vegetables, whole grains, legumes and nuts. Another review suggested that when following a plant-base diet, those with type 2 diabetes experienced an improvement in emotional and physical wellbeing, quality of life, and general health. In overweight adults with no history of diabetes, a plant-based diet improves beta-cell functioning and insulin sensitivity which are both key factors in the development of type 2 diabetes[26][27].

Cognition

Lastly, plant-based diets have been found to be effective for cognition, especially in older adults[28] possibly due to the increased intake of mono- and poly-unsaturated fatty acids and a reduced intake of processed food. A review focusing on Alzheimer’s Disease and cognition in older adults suggested that the gut-brain axis has an involvement in the development of dementia suggesting that diet largely impacts the brain[29]. While this is an area that still needs a lot of research, the current research suggests that increased consumption of plant-based foods is linked to a reduced risk for dementia. For example, a study published in 2018 found that one serving of green leafy vegetables a day is associated with slower cognitive decline[30]. The decline rate for those with the highest intake of salads (1.3 servings a day) was equal to having a brain 11 years younger than their counterparts who had lower green leafy vegetable intakes. Similarly a study published last year found that in mid-life, consuming at least one portion of nuts a week is associated with a reduced risk of cognitive impairment in later life[31].

Are there any side effects/things to watch out for with a plant-based diet?

Of course! One huge problem with plant-based diets is a risk of certain nutrient deficiencies such as B12 and iron. B12 is mainly an animal derived nutrient which, unless supplemented, is largely missing in vegetarian and especially vegan diets.  B12 plays a major role in brain development, memory performance and hippocampal structure as well as the maintenance of the central nervous system. B12 deficiencies have been associated with stroke, Alzheimer’s Disease, vascular dementia, Parkinson’s Disease and more general cognitive impairments[32][33][34]. It is usually suggested that those following a strict plant-based diet or vegan diet supplement with B12 or eat foods fortified with the nutrient such as cereals, marmite or yeast flakes.

Similarly, for iron deficiencies, it is recommended that those who follow strict plant-based diets supplement with the nutrient. The role of iron deficiency on health outcomes is less clear than that of B12 deficiency but it has been shown that iron deficiency may lead to cognitive impairments in adults and children, fatigue and anaemia, especially in young women[35][36][37].

It is generally recommended that blood tests are done relatively frequently to avoid deficiency or on the other hand, to avoid overloading/over supplementing on various nutrients.

In terms of children, a review published in 2017 found that children on vegetarian diets were generally found to be lower in the growth and body-weight reference ranges and possibly have lower levels of vitamin B12 and D, however the results from the review were extremely diverse and the authors were unable to conclude if there were any actual risks of vegetarian diets for children and adolescents[38].

Conclusion

In the last 10 years, the interest into the effects of plant-based living has exploded. Lucky for us, that means there is a lot of research out there supporting the implementation of the lifestyle, and lots more to come. I do not believe that everyone should be converting to strict vegan lifestyles as for many, this way of living is simply not plausible, but it is well known that to save our Earth from our mistakes we must eat less animal produce.

If you are thinking about making the step to being more plant-based but stuck on the how, I wrote an earlier blog post suggesting different people to follow for amazing plant based recipes!


[1] Roma Pahwa and others, ‘Chronic Inflammation’, in StatPearls (Treasure Island (FL): StatPearls Publishing, 2020) <http://www.ncbi.nlm.nih.gov/books/NBK493173/&gt; [accessed 31 January 2021].

[2] Joel C. Craddock and others, ‘Vegetarian-Based Dietary Patterns and Their Relation with Inflammatory and Immune Biomarkers: A Systematic Review and Meta-Analysis’, Advances in Nutrition (Bethesda, Md.), 10.3 (2019), 433–51 <https://doi.org/10.1093/advances/nmy103&gt;.

[3] Nikolaj Bech Poulsen, Max Norman Tandrup Lambert, and Per Bendix Jeppesen, ‘The Effect of Plant Derived Bioactive Compounds on Inflammation: A Systematic Review and Meta-Analysis’, Molecular Nutrition & Food Research, 64.18 (2020), 2000473 <https://doi.org/10.1002/mnfr.202000473&gt;.

[4] Binita Shah and others, ‘Anti-Inflammatory Effects of a Vegan Diet Versus the American Heart Association-Recommended Diet in Coronary Artery Disease Trial’, Journal of the American Heart Association, 7.23 (2018), e011367 <https://doi.org/10.1161/JAHA.118.011367&gt;.

[5] F. Eichelmann and others, ‘Effect of Plant-Based Diets on Obesity-Related Inflammatory Profiles: A Systematic Review and Meta-Analysis of Intervention Trials’, Obesity Reviews: An Official Journal of the International Association for the Study of Obesity, 17.11 (2016), 1067–79 <https://doi.org/10.1111/obr.12439&gt;.

[6] Gabrielle M. Turner-McGrievy and others, ‘Randomization to Plant-Based Dietary Approaches Leads to Larger Short-Term Improvements in Dietary Inflammatory Index Scores and Macronutrient Intake Compared with Diets That Contain Meat’, Nutrition Research, 35.2 (2015), 97–106 <https://doi.org/10.1016/j.nutres.2014.11.007&gt;.

[7] Abou Diallo and others, ‘Red and Processed Meat Intake and Cancer Risk: Results from the Prospective NutriNet-Santé Cohort Study’, International Journal of Cancer, 142.2 (2018), 230–37 <https://doi.org/10.1002/ijc.31046&gt;.

[8] Seong Rae Kim and others, ‘Effect of Red, Processed, and White Meat Consumption on the Risk of Gastric Cancer: An Overall and DoseResponse Meta-Analysis’, Nutrients, 11.4 (2019) <https://doi.org/10.3390/nu11040826&gt;.

[9] Zhanwei Zhao, Zifang Yin, and Qingchuan Zhao, ‘Red and Processed Meat Consumption and Gastric Cancer Risk: A Systematic Review and Meta-Analysis’, Oncotarget, 8.18 (2017), 30563–75 <https://doi.org/10.18632/oncotarget.15699&gt;.

[10] Jacquelyn Y. Nguyen and others, ‘Adoption of a Plant-Based Diet by Patients with Recurrent Prostate Cancer’, Integrative Cancer Therapies, 5.3 (2006), 214–23 <https://doi.org/10.1177/1534735406292053&gt;.

[11] Brenton J. Baguley, Tina L. Skinner, and Olivia R. L. Wright, ‘Nutrition Therapy for the Management of Cancer-Related Fatigue and Quality of Life: A Systematic Review and Meta-Analysis’, British Journal of Nutrition, 122.5 (2019), 527–41 <https://doi.org/10.1017/S000711451800363X&gt;.

[12] Heidi Fritz and others, ‘Soy, Red Clover, and Isoflavones and Breast Cancer: A Systematic Review’, PLoS ONE, 8.11 (2013) <https://doi.org/10.1371/journal.pone.0081968&gt;.

[13] Krithiga Shridhar and others, ‘Dietary Patterns and Breast Cancer Risk: A Multi-Centre Case Control Study among North Indian Women’, International Journal of Environmental Research and Public Health, 15.9 (2018) <https://doi.org/10.3390/ijerph15091946&gt;.

[14] J. Godos and others, ‘Vegetarianism and Breast, Colorectal and Prostate Cancer Risk: An Overview and Meta-Analysis of Cohort Studies’, Journal of Human Nutrition and Dietetics: The Official Journal of the British Dietetic Association, 30.3 (2017), 349–59 <https://doi.org/10.1111/jhn.12426&gt;.

[15] Susan E Steck and others, ‘Index-Based Dietary Patterns and Colorectal Cancer Risk: A Systematic Review123’, Advances in Nutrition, 6.6 (2015), 763–73 <https://doi.org/10.3945/an.115.009746&gt;.

[16] Tao Huang and others, ‘Cardiovascular Disease Mortality and Cancer Incidence in Vegetarians: A Meta-Analysis and Systematic Review’, Annals of Nutrition and Metabolism, 60.4 (2012), 233–40 <https://doi.org/10.1159/000337301&gt;.

[17] Eichelmann and others.

[18] N. Wright and others, ‘The BROAD Study: A Randomised Controlled Trial Using a Whole Food Plant-Based Diet in the Community for Obesity, Ischaemic Heart Disease or Diabetes’, Nutrition & Diabetes, 7.3 (2017), e256 <https://doi.org/10.1038/nutd.2017.3&gt;.

[19] Michael Macknin and others, ‘Plant-Based, No-Added-Fat or American Heart Association Diets: Impact on Cardiovascular Risk in Obese Children with Hypercholesterolemia and Their Parents’, The Journal of Pediatrics, 166.4 (2015), 953-959.e1-3 <https://doi.org/10.1016/j.jpeds.2014.12.058&gt;.

[20] S. Mishra and others, ‘A Multicenter Randomized Controlled Trial of a Plant-Based Nutrition Program to Reduce Body Weight and Cardiovascular Risk in the Corporate Setting: The GEICO Study’, European Journal of Clinical Nutrition, 67.7 (2013), 718–24 <https://doi.org/10.1038/ejcn.2013.92&gt;.

[21] Huang and others.

[22] Tristan Chalvon-Demersay and others, ‘A Systematic Review of the Effects of Plant Compared with Animal Protein Sources on Features of Metabolic Syndrome’, The Journal of Nutrition, 147.3 (2017), 281–92 <https://doi.org/10.3945/jn.116.239574&gt;.

[23] Anastasios Toumpanakis, Triece Turnbull, and Isaura Alba-Barba, ‘Effectiveness of Plant-Based Diets in Promoting Well-Being in the Management of Type 2 Diabetes: A Systematic Review’, BMJ Open Diabetes Research & Care, 6.1 (2018), e000534 <https://doi.org/10.1136/bmjdrc-2018-000534&gt;.

[24] Frank Qian and others, ‘Association Between Plant-Based Dietary Patterns and Risk of Type 2 Diabetes: A Systematic Review and Meta-Analysis’, JAMA Internal Medicine, 2019 <https://doi.org/10.1001/jamainternmed.2019.2195&gt;.

[25] Yujin Lee and Kyong Park, ‘Adherence to a Vegetarian Diet and Diabetes Risk: A Systematic Review and Meta-Analysis of Observational Studies’, Nutrients, 9.6 (2017) <https://doi.org/10.3390/nu9060603&gt;.

[26] Hana Kahleova, Andrea Tura, and others, ‘A Plant-Based Dietary Intervention Improves Beta-Cell Function and Insulin Resistance in Overweight Adults: A 16-Week Randomized Clinical Trial’, Nutrients, 10.2 (2018) <https://doi.org/10.3390/nu10020189&gt;.

[27] Hana Kahleova, Rebecca Fleeman, and others, ‘A Plant-Based Diet in Overweight Individuals in a 16-Week Randomized Clinical Trial: Metabolic Benefits of Plant Protein’, Nutrition & Diabetes, 8.1 (2018), 58 <https://doi.org/10.1038/s41387-018-0067-4&gt;.

[28] Xi Chen and others, ‘Dietary Patterns and Cognitive Health in Older Adults: A Systematic Review’, Journal of Alzheimer’s Disease: JAD, 67.2 (2019), 583–619 <https://doi.org/10.3233/JAD-180468&gt;.

[29] Andrea Ticinesi and others, ‘Gut Microbiota, Cognitive Frailty and Dementia in Older Individuals: A Systematic Review’, Clinical Interventions in Aging, 13 (2018), 1497–1511 <https://doi.org/10.2147/CIA.S139163&gt;.

[30] Martha Clare Morris and others, ‘Nutrients and Bioactives in Green Leafy Vegetables and Cognitive Decline: Prospective Study’, Neurology, 90.3 (2018), e214–22 <https://doi.org/10.1212/WNL.0000000000004815&gt;.

[31] Yi-Wen Jiang and others, ‘Consumption of Dietary Nuts in Midlife and Risk of Cognitive Impairment in Late-Life: The Singapore Chinese Health Study’, Age and Ageing, afaa267, 2020 <https://doi.org/10.1093/ageing/afaa267&gt;.

[32] Yi-Wen Jiang and others, ‘Consumption of Dietary Nuts in Midlife and Risk of Cognitive Impairment in Late-Life: The Singapore Chinese Health Study’, Age and Ageing, afaa267, 2020 <https://doi.org/10.1093/ageing/afaa267&gt;.

[33] Eileen Moore and others, ‘Cognitive Impairment and Vitamin B12: A Review’, International Psychogeriatrics, 24.4 (2012), 541–56 <https://doi.org/10.1017/S1041610211002511&gt;.

[34] J. David Spence, ‘Metabolic Vitamin B12 Deficiency: A Missed Opportunity to Prevent Dementia and Stroke’, Nutrition Research, 36.2 (2016), 109–16 <https://doi.org/10.1016/j.nutres.2015.10.003&gt;.

[35] Betsy Lozoff and Michael K. Georgieff, ‘Iron Deficiency and Brain Development’, Seminars in Pediatric Neurology, Iron Metabolism and its Disorders in Neurology, 13.3 (2006), 158–65 <https://doi.org/10.1016/j.spen.2006.08.004&gt;.

[36] Laura E Murray-Kolb and John L Beard, ‘Iron Treatment Normalizes Cognitive Functioning in Young Women’, The American Journal of Clinical Nutrition, 85.3 (2007), 778–87 <https://doi.org/10.1093/ajcn/85.3.778&gt;.

[37] John Beard, ‘Iron Deficiency Alters Brain Development and Functioning’, The Journal of Nutrition, 133.5 (2003), 1468S-1472S <https://doi.org/10.1093/jn/133.5.1468S&gt;.

[38] S. Schürmann, M. Kersting, and U. Alexy, ‘Vegetarian Diets in Children: A Systematic Review’, European Journal of Nutrition, 56.5 (2017), 1797–1817 <https://doi.org/10.1007/s00394-017-1416-0&gt;.

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