The increase in popularity of vegan diets

The number of people choosing a vegan lifestyle has increased significantly in recent years. Research published in 2016 showed over half a million people in Britain are vegans, an increase of 360% in the last decade¹. Last year research commissioned by the Vegan Society found that over one fifth of respondents would consider becoming vegan².

Having made the decision to follow a very natural diet of healthy vegetables, fruits, nuts, seeds and wholegrains, vegans frequently eat foods wonderfully rich in a whole host of natural nutrients such as the phytonutrients, fibre, folate, magnesium, potassium and vitamins C and E.

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A high intake of fruit and vegetables has been linked in numerous studies with health benefits including a reduction in risk of a number of diseases such as cardiovascular disease and diabetes. Various mechanisms for this risk reduction have been proposed including that the high levels of antioxidant vitamins reduce oxidative stress. The phytonutrients in plant-based diets have a strong synergistic antioxidant action. In addition, fibre has many benefits for health.

On the other hand, vegan diets do need to be carefully planned to ensure adequate intake of protein, B12, vitamins A & D, iodine, iron, zinc, calcium and omega-3 fatty acids³. However, it’s not just people following a vegan diet who can be low in these nutrients, the National Nutrition and Diet Survey (2013/14)⁴ showed significant numbers of the population are low in omega-3 fatty acids, vitamin D, vitamin B12, riboflavin and iron (teenage girls and pre-menopausal women in particular are low in iron).

This blog outlines vegan sources of these nutrients and suggests where supplementation may be a good idea.

Protein: Protein sources are plentiful in vegan diets – legumes, grains, nuts and seeds. However, plant sources of proteins are of lower quality than from animal sources due to one or more limiting amino acids. If a diet is inadequate in any essential amino acid, protein synthesis cannot proceed beyond the rate at which that amino acid is available. This is called a limiting amino acid. Thus, the efficiency with which plant proteins, compared to animal proteins, can be used to synthesise human proteins is lower.

The exception to this is soya which has a protein quality score similar to that of animal proteins. One amino acid that vegans need to pay particular attention to is lysine – this is found in soya, lentils and other legumes. Quinoa, amaranth, pistachios and pumpkin seeds also provide a reasonable amount of lysine.

Vitamin B12 is really only found in animal foods. Research has found both vegans and non-vegans are often low in B12. In vegan diets some B12 is available from fortified foods and some seaweeds / fermented foods. However, most B12 in seaweeds are analogues of the vitamin and may compete with true B12 for absorption and assimilation⁵. This nutrient is important for nerve health and low levels can cause many symptoms including extreme tiredness, pins and needles, depression and problems with memory.

Low B12 can lead to raised homocysteine levels, a risk factor for cardiovascular disease and dementia. One study found raised homocysteine levels in 53% of vegans compared to 28% of vegetarians and 5% of omnivores.⁶ In another study, homocysteine was elevated in 66% of vegans and 45-50% of the omnivores and vegetarians.⁷ Supplementation of vitamin B12 is recommended.

Vitamin A: the precursor to vitamin A is beta carotene and this is found in yellow/orange vegetables such as carrots and squash. Beta carotene needs to be converted in the body to vitamin A and some people do not carry out this conversion well. Vitamin A is important for the immune system, for skin health and vision.

Some vegans may benefit from supplementation with vitamin A, particularly if prone to frequent respiratory infections or poor night vision (and vegan vitamin A supplements are available). However current or ex-smokers and pregnant women need to be careful with vitamin A supplementation. In the case of smokers, long-term high dose supplementation should be avoided, however, taking vitamin A for short periods to support immunity is ok.

Vitamin D: some types of mushrooms and fortified foods provide low levels of vitamin D in vegan diets. The government’s recommendation is 10 mcg per day (which is difficult for anyone to achieve from diet alone) and many practitioners are recommending higher intakes than this. Most people are low in vitamin D, not just vegans. Vitamin D can be synthesised by exposure to sunlight. However, at latitudes above 42 degrees, such as the UK, there is no vitamin D synthesis in winter, although excess produced in the summer can be stored in adipose tissue.

Vitamin D is well known for its role in bone health and it has many other important functions as well – deficiency can leave us vulnerable to infections (vitamin D is important for the immune system) and low levels are associated with many chronic diseases including cardiovascular disease.

To maximise vitamin D synthesis during the summer, legs and arms should be exposed (without sunscreen) on sunny days, between 10 am and 2pm, for 5 – 20 mins per day as often as possible. The skin should not be allowed to go pink or red. Cloud cover will reduce vitamin D synthesis.

Calcium: Good vegan sources of calcium include kale, broccoli, rocket and some beans. Calcium intake is lower in vegans, however, adequate calcium intake can be achieved by including non-dairy milks – coconut, hemp or almond milk are the preferred choices; and plain soya yoghurt or tofu which will provide calcium along with some protein.

Iodine: As iodine cannot be stored in the body for a long period it must be obtained regularly via the diet. A 2003 study found that 80% of vegans were deficient in iodine⁸. Low iodine levels can lead to problems with the thyroid gland and sometimes this can be severe. Needs increase during pregnancy and breastfeeding.

Seaweed is an excellent source of Iodine and hence ideal for vegans. It is easy to buy seaweed in the shops, it is also available in supplement form as ‘kelp’. An important note of caution here is that the iodine content of different types of seaweed varies considerably. For example, nori seaweed is very low in iodine. Also, excessive iodine intake may also cause thyroid problems, so don’t overdo it. See our recent blog on Kelp.

Iron: There are plentiful sources of iron in vegan food sources such as pulses and tofu, although the iron in plant sources is not as well absorbed as from red meat (which is the most bioavailable form of the mineral iron). The EPIC-Oxford study reported average iron contents of female vegan and omnivorous diets as 14.1 mg per day and 12.6 mg per day respectively⁹. However, biochemical indices indicative of iron status are reduced in those eating a vegan diet.¹⁰ This is due to lower bioavailability of non-haem iron and constituents in vegan diets that inhibit absorption such as tannins/polyphenols, phytic acid and oxalic acid. As the phytic acid content of the diet increases, intestinal absorption of iron decreases.

Irrespective of dietary preferences women during their menstrual years, and young girls particularly, should consider supplementing their diet with iron as their need for iron is greater (a good multivitamin / mineral will provide an adequate amount for most people).

Zinc: Similar to iron, zinc is plentiful in vegan diets but the bioavailability is reduced. Good sources of zinc include hemp and pumpkin seeds, and other grains, nuts and beans. Soaking, fermenting and sprouting foods can increase nutrient bioavailability. An all-round multivitamin / mineral will provide some additional zinc.

Omega 3: Eating oily fish provides the long-chain omega-3 fatty acids DHA/EPA which are needed for human health. Flaxseeds are a good plant source of the parent omega-3, alpha linolenic acid (ALA). This can then be converted in the body to the long-chain omega-3 fatty acids EPA and DHA. However, this conversion is inefficient – less than 5-10% for EPA and 2-5% for DHA¹¹; conversion efficiency is affected by multiple factors including:

• The balance of linoleic acid and alpha linolenic acid in the diet. LA and ALA compete for conversion enzymes. Conversion of LA to AA is more efficient than ALA to EPA and DHA due to higher concentrations of LA in cellular pools¹²
• Compromised metabolism e.g. diabetes, metabolic disorders or genetics leading to limited ability to produce conversion enzymes¹³
• Suboptimal dietary intake of B3, B6, vitamin C, magnesium or zinc which are cofactors for conversion enzymes¹⁴

Studies have found vegans plasma DHA levels to be only 38% – 65% of those of omnivores.¹⁴ Some algae are high in DHA / EPA and in the last few years algal supplements have become available, harvested from microalgae.

The final piece of advice is to ensure that the diet includes a wide variety of different types of plant foods, for example, a rainbow of vegetables, plus different nuts and seeds etc. Avoid the pitfall of eating the same narrow range of foods every day.

If you have any questions regarding the topics that have been raised, or any other health matters, please do contact me (Clare) by email at any time (clare@cytoplan.co.uk)

Clare Daley and the Cytoplan Editorial Team

Related Cytoplan products: 

Foundation Formula 1 –  A superb improved two-a-day Food State multivitamin and mineral formula – ideally suited to youngsters and menstruating women. It has optimal levels of antioxidant minerals plus B vitamins, vitamin C, vitamin D, vitamin E, and with 1-3, 1-6 Beta Glucan for enhanced immune support.

Pregna-Plan – Our Pregna-Plan supplement is specifically formulated for all stages of pregnancy and breastfeeding. It’s also suitable for preconception planning for women too.

Omega 3 Vegan – An ideal vegan source of the important Omega 3 essential fatty acids EPA and DHA. One capsule will provide 334.0mg DHA and 166mg EPA (on average). This supplement will therefore provide excellent daily levels of Vegan Omega 3 for a minimum of 30 days.

Wholefood Iron – This is a gentle non-constipating and bioeffective bound form of iron that follows food metabolic pathways and is contained in an easy-to-take capsule. Wholefood Iron is made from hydroponically-grown brassica (a member of the broccoli family) and is suitable for vegans.

Vitamin B12 Hydroxo Sublingual – A higher potency of 1mg (1,000µg) per tablet. It is ideal to start supplementation if one has both a folate and vitamin B12 deficiency, in order to prevent permanent damage to the central nervous system.

Vitamin B12 sublingual (as methylcobalamin and adenosylcobalamin) – A high potency active B12 supplement containing 1mg of methylcobalamin and adenosylcobalamin, both of which provide great benefit to the body.

Organic Kelp – Our kelp supplement comes in gluten-free capsules and contains 3 species of wild bladderwrack (the type of seaweed). The kelp is not only organically rich source of iodine but also naturally ‘nutrient dense’ containing a broad spectrum of minerals, trace elements, micro-nutrients and vitamins, prebiotics and carotenoids. These act as catalysts in the body and stimulate vital enzyme reactions.

Vitamin D3/K2 – This product is designed to elevate levels of K2/D3 and is ideally used in conjunction with any of our multiformulae.  The product contains 100ug (4,000 i.u.) Vitamins D3 from lichen and 100ug Vitamin K2 (Mk-7).

Cyto-biotic Active – A live native bacteria powder comprising 9 strains plus a small amount of the prebiotic inulin which stimulate the growth of bifidobacteria and other healthy native bacteria in the gut. With antibiotic resistant strains and stable at room temperature – so no need to refrigerate.

Organic Flaxseed Oil – This supplement comprises 500ml of cold pressed organic flaxseed oil. The fresh oil of the flax seed is the richest omega 3 edible oil, containing on average 55% linolenic acid. Cytoplan liquid organic flax seed oil is grown in the UK in a certified organic facility.

Vitamin A – Our Vitamin A is in the form of Retinol Palmitate and is a vegan product. Vitamin A has been shown to be essential for the integrity of mucosal membranes and therefore plays an important role in supporting the digestive and immune systems as well as brain health.

References

1. https://www.vegansociety.com/whats-new/news/find-out-how-many-vegans-are-great-britain
2. https://www.vegansociety.com/whats-new/news/vegan-lifestyle-winning-hearts-and-minds-across-britain-survey-shows
3. Rogerson, D. (2017) ‘Vegan diets: practical advice for athletes and exercisers. J Int Soc Sports Nutr, 14, 36.
4. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/551352/NDNS_Y5_6_UK_Main_Text.pdf
5. Rauma, A.L et al. (1995) ‘Vitamin B12 status of long-term adherents of a strict uncooked vegan diet (“Living Food Diet”) is compromised. J Nutr, 125, pp.2511-2515.
6. Krajcovicoa-Kudlackova, M. et al (2000) – Traditional & alternative nutrition – levels of homocysteine and lipid parameters in adults. Scand J Clin Lab Invest, 60, 8, pp.657-64.
7. Majchrzak, D. et al (2006)) ‘B vitamin status and concentrations of homocysteine in Austrian omnivores, vegetarians and vegans. Ann Nutr Metab. 50(6):485-91.
8. Krajčovičová-Kudláčková M. et al. (2003) ‘Iodine Deficiency in Vegetarians and Vegans’. Ann Nutr Metab, 47:183–185.
9. Davey, G.K., et al. (2003) ‘EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33,883 meat eaters and 31,546 non meat-eaters in the UK’. Public Health Nutr. 6, 3, pp.259-69.
10. Wiwanitkit, m.D. et al. (2004) – Red blood cell parameters of Thai vegans compared with non vegetarians. Journal of Nutritional and Environmental Medicine, 14, 4, pp.303-306.
11. Davis, B.C. and Kris-Etherton, M. (2003) ‘Achieving optimal essential fatty acid status in vegetarians: crrent knowledge and practical implications. Am J Clin Nutr, 78 (suppl), 640S-6S.
12. Williams, C.M. ad Burdge, G. (2006) – Long-chain n-3 PUFA: plant v marine sources. Proceedings of the Nutrition Society, 65, pp.42-50.
13. Simopoulos, A.P. (1999) ‘Essential fatty acids in health and chronic disease’. Am J Clin Nutr
14. Erasmus, U. (1993) – Fats that Heal, Fats that Kill. Alive Publishing Group Inc.

Last updated on 12th July 2018 by cytoffice