2 results
Evaluation of the potential implications of following a vegan diet on bone health
- A. Clark, M.C. Kruger, H. Mazahery, C. Conlon, K.L. Beck, K. Mumme, R. Batty, P.R. von Hurst
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- Journal:
- Proceedings of the Nutrition Society / Volume 83 / Issue OCE1 / April 2024
- Published online by Cambridge University Press:
- 07 May 2024, E180
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Cow’s milk is the primary source of calcium in the NZ diet(1). The absence of dietary planning in a vegan diet can result in the individual unknowingly obtaining low intakes of calcium. Prolonged low calcium intakes can result in negative implications on bone mineral density by increasing the risk of osteoporosis later in life. The measurement of bone health parameters in NZ vegan adults have not been investigated. Therefore, we measured bone mineral density, markers of calcium homeostasis and assessed intake of essential nutrients for optimal bone health in vegans. This cross-sectional study included adults (>18yrs), who followed a vegan diet for 2 years minimum. Demographic and lifestyle information was obtained from questionnaires including previous history of bone fractures and background of familial osteoporosis. A 4-day food record was completed for analysis of calcium, zinc, protein, magnesium, phosphorus and vitamin C intake and compared to the Estimated Average Requirement (EAR)(2). Weight, height and BMI were obtained, bone mineral density was measured at the hip and spine via dual x-ray absorptiometry (DXA) and reported as Z and T scores. Plasma calcium concentrations were corrected for albumin. All values are presented as mean and standard deviation. The study included 212 participants, aged 39 ± 12.38 years, 71% female. T scores at the lumbar spine and femoral neck were −0.63 ± 1.22 (Z score: −0.29 ± 1.12) and −0.66 ± 1.00 (Z score: −0.24 ± 0.89), respectively. Nine participants had a Z-score of <-2.0 at the lumbar spine, and three at the femoral neck. Corrected calcium concentrations were 2.21 ± 0.33 mmol/L. Calcium intake was 917 ± 347.23 (range 195 to 2,429 mg/day) in all participants, which exceeded the EAR of 840 mg/day for adults aged 19-50 years. Men had higher intakes of calcium than women, 1,051 ± 363.7 mg/day (range 382 to 2,267 mg/day) vs. 867 ± 328.04 mg/day (range 194 to 2,428 mg/day), P-value <0.001. The main source of calcium in the vegan diet was tofu. The intake of protein (77 ± 27.80) g/day, magnesium (569 ± 181.05) mg/day, and vitamin C (145 ± 96.94) mg/day met the EAR, excluding vitamin and mineral supplements. However, the intake of phosphorus (1,472 ± 459.98) mg/day and zinc (10.6 ± 4.01) mg/day were below the EAR. The findings of this study suggest that bone health of vegans are not negatively affected by the exclusion of dairy in the diet, provided that appropriate dietary planning is included to avoid nutrient deficiencies associated with poor bone health. Despite mean intake of calcium exceeding the EAR, very low intakes demonstrated significant variations between participants.
An audit of plant-based, ultra processed vegan foods in New Zealand
- A.J. Czifra, R. Batty, K.L. Beck, P.R. von Hurst
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- Journal:
- Proceedings of the Nutrition Society / Volume 83 / Issue OCE1 / April 2024
- Published online by Cambridge University Press:
- 07 May 2024, E31
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- Article
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As concerns grow about the impact of animal farming on the environment, the appeal of plant-based diets has increased(1). The most extreme of these diets is the vegan diet which excludes all animal and insect sourced products. The vegan diet is often lauded as being beneficial for cardiovascular health, with the exclusion of saturated fats from animal meats, and the high intake of fibre from fruit and vegetables. More lately, however, there has been an exponential increase in the availability of vegan ultra-processed (UPFs), ready to eat foods which may not be so heart healthy. This study aimed to audit the vegan-labelled, plant-based meat and dairy analogues (PBMAs and PBDAs) available in New Zealand supermarkets. The objective was to compare the nutrient content against foods of animal origin that these products emulate. The audit was completed between March and June 2022 using a combination of on-site data collection and online sources. Data were collected from New Zealand’s five major supermarkets, Countdown, Fresh Choice, New World, Pak’nSave and Four Square. The audit recorded vegan and plant-based labelled products imitating animal meats (chicken, mince, beef, sausage, burgers, bacon, nuggets), and dairy (milk, cheese, yoghurt). Nutrient composition was taken from the Nutrition Information Panel (NIP) for each product and then a mean (SD) derived from a sample of each category. Nutrient composition for the comparison meat and dairy products was taken from NZ FOODFiles(2). All nutrients were reported per 100g or100ml. The PBMAs generally had higher energy, sodium and fibre, and lower protein than their meat counterparts. For example, plant-based burgers compared with beef burgers had 863kJ vs 761kJ energy, 436g vs 130g sodium, 2.3g vs 1.2g fibre, 15g vs 19g protein per 100g. Total fat and saturated fat were mostly lower in the meat products than in PBMAs, except for sausages. The plant-based milk analogues were lower in protein and fat than dairy milk, except soy (protein) and coconut (fat) milks. PBDAs were either completely lacking in calcium or were fortified to a similar level as dairy milk. Most plant-based cheeses and yoghurts were not fortified with calcium and were higher in energy, total fat and saturated fat than dairy. Vitamin B12 fortification of all plant-based products varied widely but contained less than meats and dairy. The wide range of plant-based UPFs included in this audit demonstrated little or no health advantage over animal derived meats and dairy products. The high salt and saturated fat content of these products suggest increased cardiometabolic risk if consumed as a regular part of the vegan diet despite higher fibre content.