Vegan Diet: Benefits, Guidelines, Supplements, and More

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迈克尔·默里（Michael Murray）博士，自然疗法医师 发布日期 2023 年 03 月 14 日

Originally posted April 2018 / Updated March 2023

What Is the Vegan Diet?

A vegan diet avoids all animal products entirely, including meat and fish, shellfish, dairy, eggs, insects, and other food not considered plant food.

A vegan diet includes foods from plants such as vegetables, fruits, legumes, grains, nuts, and seeds.

Many vegans choose this eating lifestyle for ethical reasons, so often, they do not use animal products in any other part of their life. In addition to eating vegan, many vegans avoid wearing leather or using products tested on animals.

Health Benefits of a Vegan Diet

Generally, a higher intake of plant foods and a lower intake of animal foods is associated with reduced risk of heart disease, obesity, osteoporosis, and type 2 diabetes. It also has been shown to lower the risk of death due to heart disease and reduces all-cause mortality.

Vegan diets are also associated with a lower body mass index (BMI) and a reduced risk of obesity. Vegan diets have also been shown to be more effective for weight loss than an omnivorous, lacto-ovo vegetarian, or pesco-vegetarian diet. Replacing animal foods high in fat and calories with low-calorie plant foods, or even nutrient-dense plant foods such as nuts and seeds appears to help people manage their body weight more effectively.^5,6

Eating a vegan diet may help reduce the risk of chronic disease. According to a 2017 review of scientific data, a vegan diet may help to reduce a person's risk of chronic disease by as much as 15%.3 This result is expected as a diet rich in plant foods is high in dietary fiber and phytochemicals (biologically active compounds found in plants) that fight against chronic disease.³

Does The Type of Plant-Based Food Matter?

When looking at the scientific research on the benefits of a vegan diet, it is essential to differentiate between a healthy vegan diet (HVD) from an unhealthy vegan diet (UVD). The research indicates that if the vegan diet is high in high-glycemic foods such as products from refined grains (e.g., white flour), fruit juices, sugar‐sweetened beverages, sweets, and desserts, it does not provide significant health benefits.

An unhealthy vegan diet can increase the risk of heart disease, type 2 diabetes, and all-cause mortality.^1-4 Hence, the quality of plant foods consumed is a critical factor in achieving the health benefits of a vegan diet.

Guidelines for a Healthy Vegan Diet

Here are some essential guidelines for enjoying a healthy vegan diet.

Focus on Eating a Variety of Health-Promoting Foods – eating a wide variety of foods when on a vegan diet is essential. One easy way to do this is to select produce from all the colors of the rainbow as much as possible. This practice will ensure a wide range of health-promoting carotenoids and flavonoids. Also important is to mix up the selection of high-protein plant sources such as legumes, nuts, and seeds.
Only Consume Whole Grain Products – Use brown rice vs. white rice and wholegrain bread vs. white bread. And take advantage of the increased availability of ancient grains like quinoa.
Prioritize Protein – Since protein intake in vegans is often insufficient, especially in athletes, using vegan protein powder supplements to boost protein intake is a great idea. Protein is critical in building muscle mass, controlling blood sugar levels, supporting immune function, and supplying the essential building blocks for overall health. Taking 20-25 grams of vegan protein in the morning as part of a health-promoting smoothie or shake is a fantastic way to boost protein intake in vegans. Vegan sources include pea, hemp, pumpkin, soy, rice, and quinoa. California Gold Nutrition, Plant-Based Protein from iHerb delivers 20g of protein per serving from pea protein isolate, brown rice protein concentrate, flaxseed, chia seed, and sprouted black rice powders.
Avoid Vegan Junk Food – just because something is vegan does not necessarily mean it is healthy. Read food labels carefully to make sure the food is not too high in sugar.

Essential Supplements for a Vegan Diet

Generally, nutrient intake status for most nutrients is lower in vegans than in meat-eaters. Particularly important to highlight are vitamin B12, iron, zinc, and iodine. These nutrients should be taken as dietary supplements by vegans.^7,8

Vitamin B12

Vitamin B12 is found in significant quantities only in animal foods. The richest sources are liver and kidney, followed by eggs, fish, cheese, and meat. Vegans are often told that fermented foods like tempeh are excellent sources of vitamin B12. However, in addition to the tremendous variety of B12 content in fermented foods, there is some evidence that the form of B12 in these foods is different from the form that meets our body's requirements and is, therefore, useless. The same holds for certain cooked sea vegetables.

Research shows that it is essential that vegetarians supplement their diets with vitamin B12.7 There are several forms of B12 available. The most common supplemental form is cyanocobalamin. However, methylcobalamin is more active. For vegans, a daily dosage of 1,000 mcg of methylcobalamin is recommended.

California Gold Nutrition, Liposomal Vitamin B12 available at iHerb is suitable for Vegetarians and Vegans and is formulated to help improve absorption in the intestines and at the cellular level.

Iron

Iron is another nutrient that vegans often lack, especially in menstruating women and during pregnancy. Iron is critical to human life. It plays a central role in the hemoglobin molecule of red blood cells (RBC). It transforms oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs. Iron also works in several critical energy production and metabolism enzymes, including DNA synthesis.

Iron deficiency is the most common nutrient deficiency in the United States. The groups at highest risk for iron deficiency are infants under two years of age, teenage girls, pregnant women, and the elderly. Studies have found evidence of iron deficiency in as high as 30-50% of people in these groups and even higher in vegans.

In vegans, the usual recommendation is 30 mg of elemental iron daily to maintain positive iron status. California Gold Nutrition, Ferrochel Iron (Bisglycinate) is a form of iron recognized as gentle on the stomach and suitable for vegans.

Zinc

Zinc intake is also often insufficient in vegans. That results in significant disruption in body processes, especially immune function. In short, without adequate zinc intake, we lose the ability to fight off viruses and regulate overactive immune responses that lead to inflammation.

Taking a zinc supplement is recommended for vegans. In adults, the usual dosage range for zinc supplementation for general health support and during pregnancy or lactation is 15 to 20 mg. For children, the dosage range is 5 to 10 mg.

There are many forms of zinc. While many clinical studies have utilized zinc sulfate, this form is less well absorbed than other forms, such as zinc picolinate, acetate, citrate, bisglycinate, oxide, or monomethionine are all excellent forms of zinc.

Iodine

Iodine intake in vegans tends to be lower, presumably due to reduced iodized salt and seafood intake. Consuming seaweeds such as wakame, kelp, nori, and kombu is an option, but to ensure sufficient intake, vegans should take the recommended dietary intake of 150 mcg in adults, 220-250 mcg in pregnant women, and 250-290 mcg in breastfeeding women.

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