Guest post by Aman Duggal
Hi!
Today’s guest article comes from SBS Academy student Aman Duggal. Aman is part of the team behind Alpharaj – an Indian organization which focuses on being unbiased, independent and impartial, and is devoted to spreading science and critical thinking in the fitness industry.
Veganism – or the elimination of any and all animal produce from one’s diet – is perhaps one of the most misunderstood philosophies in nutrition. Proponents are often passionate to the degree of fanaticism, and the evangelical nature of many vegans is the subject of many a punchline.
“An atheist, a CrossFitter and a vegan walked into a bar. I only know because they had told everyone within the space of 2 minutes.” ~ The Internet
However, the outlandish claims made by some vegans are matched only by some of the claims made in opposition to the vegan philosophy. In this fantastic article, Aman addresses 6 of the claims made by vegans and “anti-vegans”, and delves into the body of evidence to dissect them with a laudable attention to detail and lack of bias.
Please note – we’re not going to discuss the moral, environmental or ethical arguments for or against veganism. We’re sticking strictly to the physiological in this article.
Oh, and before I leave you to read the rest of the article – the SBS Academy is opening again in 2 weeks time, on February 28th. We have some amazing early-bird deals planned, which we’ll be announcing first via our email list. If you’re interested in saving yourself some money on a SBS Academy place, make sure your name and email is on the list.
First Name
Email Address (one that you actually use…)
Enjoy the article.
Lawrence
Myth 1: Vegan food is (severely) deficient
Perhaps the most common criticism of vegan food is that it is deficient in several important nutrients. So, how deficient is vegan food? And notice how I’ve framed the question. The question is, “How deficient is vegan food?” and not “How deficient is a vegan diet?”. This is an important distinction because it is commonly stated that vegan diets are deficient in many key nutrients. The problem with this statement is the assumption that supplements are not part of a strict vegan diet. If we can supplement with a certain nutrient which vegan foods cannot provide us, then how can we say that a vegan diet is deficient in that particular nutrient?
“Why should we judge a diet by how effective it would be without supplements, when we do have access to supplements?” – Philosophy Lines
But for the sake of discussion, let’s assume that someone argues that the efficacy of a diet must be examined without the inclusion of supplements. Is vegan food really as deficient as most experts claim it is?
For this purpose, I am going to refer to Brian Rigby’s book, The Multivitamin Lie. In this book Brian formulates a vegan diet using the following foods.
Protein
8 oz. tempeh*
12 oz. tofu*
Starches
8 oz. black beans*
8 oz. lentils*
1.5 lbs. sweet potatoes*
1 lb. russet potatoes*
8 oz. of kamut (or spelt, or another whole wheat berry)*
4 oz. of quinoa (or amaranth)*
8 oz. of pasta*
8 slices of bread
Nuts & Seeds
4 oz. almonds
4 oz. sunflower seeds
4 oz. pumpkin seeds
Raw Veggies
1 lb. romaine lettuce
4 oz. tomatoes
Cooked Veggies
8 oz. white mushrooms*
4 oz. shiitake mushrooms*
1 lb. spinach*
1 lb. broccoli*
8 oz. asparagus*
8 oz. kale*
8 oz. Swiss chard*
8 oz. bok choy*
8 oz. collard greens*
1 cup tomato sauce
1 acorn squash
Fruit
4 kiwis
2 oranges
2 bananas
*Uncooked Weight
At first glance this may seem like a lot of food, but keep in mind this is for an entire week. If we consider it in the context of a single day, we get the following amounts:
3 oz. tempeh or tofu per day
2 oz. legumes per day* (about 1 cup cooked)
5.5 oz. starchy veggies per day*
1.5 oz. grains or pseudo-grains per day* (about 1 cup cooked)
1 oz. pasta per day* (less than 1/ 2 a cup cooked)
1 slice of bread per day
1.5 oz. nuts and seeds per day
1.5 oz. mushrooms per day*
10.5 oz. cooked veggies per day* (about 1.75 cups)
1 piece of fruit per day
*Uncooked Weight
Thus, when looking at what a lone day may contain, there is no cause for alarm.
A well planned vegan diet requires only 1,345 calories, roughly 61% of a sedentary adult male’s caloric goal (2,200 calories) and 75% of a sedentary adult female’s caloric goal (1,800 calories) to reach 100% of the RDA (Recommended Daily Allowance) for each vitamin and mineral. The full nutrient information can be found in the table below.
%RDA/AI
Men
%RDA/AI
Women
Vitamin A
218%
280%
Vitamin B1 (Thiamin)
162%
177%
Vitamin B2 (Riboflavin)
129%
152%
Vitamin B3 (Niacin)
180%
206%
Vitamin B5 (Pantothenic Acid)
130%
130%
Vitamin B6
171%
171%
Vitamin B9 (Folate)
245%
245%
Vitamin B12
0%*
0%*
Vitamin C
291%
349%
Vitamin E
115%
115%
Vitamin K
1118%
1491%
Calcium
105%
105%
Copper
351%
351%
Iron
304%
135%
Magnesium
157%
207%
Manganese
341%
436%
Potassium
100%
100%
Phosphorus
235%
235%
Selenium
139%
139%
Zinc
101%
139%
*Vitamin B12 MUST be supplemented unless your food is sufficiently fortified
Vitamin B12 is the one exception here so vegans must supplement with it unless they are consuming foods which are sufficiently fortified with B12.
Also, you will notice that vitamin D isn’t listed in the table and that’s because it is very rarely found in food. So it’s best to supplement with vitamin D if you’re not getting enough sun exposure. And this of course applies to both vegans and non-vegans.
It may come as a surprise to some of you that iron was not limited in the vegan diet. While plant-based iron is less well-absorbed than the heme iron found in meat, many foods that vegans eat in greater amounts (such as grains, pseudo-grains, and green vegetables) are fairly high in iron. Even nutrients like zinc, magnesium and calcium, which many people believe are difficult to get from a vegan diet, can easily be acquired from food.
For a vegan consuming 100% or more of the typical calories for a sedentary adult of their sex, there will be no challenge in obtaining 100% of the RDA for even the difficult nutrients.
Bottom Line: The deficiencies and insufficiencies of vegan diets are over-exaggerated. Vegan food isn’t as deficient as most experts claim it is. And any potential deficiencies can easily be accounted for via fortified foods and supplements.
Myth 2: Where do you get your protein, bro?
Another big concern which bodybuilders and athletes have with regards to vegan diets is protein. And that concern largely stems from a few misconceptions.
The first of those happens to be this concept of labelling protein sources as complete and incomplete or first class and second class sources of protein. The term “complete” protein is something of a misnomer, because almost every source of dietary protein contains all of the essential amino acids. Some foods are just lower in certain amino acids than others. But one can always combine different (complimentary) foods to make complete proteins.
Contrary to what many experts will tell you, you don’t have to combine foods at each meal to make a “complete” protein. If the meal you eat is low in a particular amino acid, then the body can get it from the amino acid pool, which is basically a certain amount of amino acids which are always floating freely in the blood stream.
However, for athletes it is generally better to get a full spectrum of amino acids in every meal. We know that somewhere between 2-4 grams of the amino acid, leucine is required every 3-6 hours to maximize muscle protein synthesis. So for bodybuilding and athletic purposes, we want to make ensure that we’re hitting that 2-4 gram leucine threshold. On a vegan diet, this can be achieved via three methods:
Selecting vegan foods (or protein supplements) which have a complete spectrum of amino acids, in particular branched chain amino acids
Combining two “incomplete complimentary protein sources” to make a complete protein. For example, beans and grains or lentils and rice
Finding out which amino acids are lacking in your vegan meal and using isolated amino acid supplements (like BCAAs) to make a “complete protein”
Off these three methods, options 1 and 2 are my methods of choice.
Vegan protein is low in bioavailability?
Yet another common criticism of vegan diets is that plant protein is of low quality or that it is low in bioavailability. This is certainly true for some plant foods, but not all of them. And some people take this idea one step further and say that you shouldn’t count protein which comes from plant sources. To demonstrate how absurd this sounds, we have a table at the bottom which shows some common plant foods which people may consume as part of their diet.
And these foods are generally considered low quality protein sources. Take a second and look that table – that’s 95 grams of protein right there! But according to some “experts”, that accounts for nothing. So if you think about this from a logical perspective, the idea that you shouldn’t count plant protein just doesn’t make sense. It’s like saying “if it is 100% it is good, and anything less is bad”. It’s a very black and white way of looking at things.
Speaking of bioavailability, it’s important to know that there are several methods of measuring protein quality –biological value (which most of you have probably heard of), net protein utilization (NPU), PER (protein efficiency ratio) and the protein digestibility corrected amino acid score (PDCAAS). The PDCAAS is currently considered by many organizations as the “gold standard” for measuring protein quality.
Basically these different methods can tell us how much of a food consumed is retained and used by the body for protein synthesis and other functions. Something to keep in mind is that most of these models were developed to determine the protein requirements for growing children and sedentary adults. They weren’t specifically developed for bodybuilders or athletes. That doesn’t mean that they are completely useless when it comes to sports, but it’s just something to be cognisant of.
As you can see from the table above, most plant foods by themselves may not have a high score but by combining foods like rice and peas or grain and legumes, we get a full score on this scale.
Another thing I see quite often is vegans and non-vegetarians using these scores and arguing over which protein source is superior. For example, a vegan may point to this table and argue that soy is better than beef. Using another method of measuring bioavailability, a non-vegetarian may say that beef ranks higher than soy. This, in my opinion, is a pointless pursuit. We need to look at the bigger picture. Instead of worrying about the protein quality and amino acid profile of individual foods, it is better to look at the diet as a whole. If we’re getting enough protein from a variety of food sources, then we’re most likely getting all the essential amino acids in the right amounts and there’s nothing to be concerned about.
Vegan Protein Supplements
Outside of very high calorie diets, most vegan athletes will need a supplement to meet their protein requirements. And that is because most plant foods which are rich in protein usually bring with them a good chunk of carbohydrate and fat as well. So the chances of you overshooting your carbohydrate and fat targets is high when you try to hit your protein intake from just whole food on a vegan diet. And there’s a simple solution to that problem. Just like whey and casein, we have plant-based protein supplements.
I’m sure most of you are aware of soy protein supplements, but a couple of protein supplements which you may not have heard of are pea protein and rice protein. Both pea & rice are high quality proteins which have stood the test of the scientific method. The best part is that they’ve both been compared head to head with whey protein:
“Both whey and rice protein isolate administration post resistance exercise improved indices of body composition and exercise performance; however, there were no differences between the two groups.”
Joy, Jordan M et al. (2013)
“Since no difference was obtained between the two protein groups, vegetable pea proteins could be used as an alternative to Whey-based dietary products.”
Babault, Nicolas et al. (2015)
Interestingly, in the study which compared pea and whey, pea protein actually managed to outperform whey for increasing muscle thickness. Don’t get me wrong here, I’m not trying to say that pea is better than whey just based on this one study, but I think it is fair to say, that from the evidence at hand both pea and rice are high quality protein sources which can be used as alternatives to whey and casein.
My favourite plant-based protein supplement is MyProtein’s Vegan Blend (Chocolate Smooth), which as the name implies is a blend of pea, rice and hemp protein.
For reference sake, here’s an amino acid comparison table of whey, soy, rice and pea protein.
And here’s another one which I’ve borrowed from my friend Cory McCarthy. He likes to create a blend of rice and pea protein so as to get an amino acid profile which resembles whey protein.
These blends can be custom made at bulk supplement suppliers like True Nutrition.
Similarly, one can come up with more combinations by mixing and matching various plant-based protein powders to ensure that all the amino acids are supplied in the right amounts. Besides pea and rice, other plant-based protein powders available in the market include soy (being the most popular), hemp, cranberry, and pumpkin.
Non-vegans who suffer from lactose intolerance can explore these options as viable replacements for whey and casein.
Here are some files you can use for reference. Credit for these goes to the fantastic members at the VBBN (Vegan Bodybuilding & Nutrition) group on Facebook.
Vegan Whole Food Protein Sources
Vegan Meal Ideas
Vegan Ketogenic Diet or Vegan High Fat
Also check out Anastasia Zinchenko’s website for some great tasting, macro-friendly vegan recipes.
Bottom Line: Through intelligent food selection and supplementation, vegans can easily meet protein requirements to maximise health and performance
Myth 3: Soy is bad for you
Depending on who you talk to, soy is either the best protein source on the planet or it is the most dangerous food to ever hit the market. And like most things in life, the truth isn’t that simple. So in this section I’d like to briefly touch on some of the common fears people have about soy.
And perhaps the biggest fear most bodybuilders (especially men) have is that soy will decrease their testosterone and increase their estrogen production. And this idea sounds convincing in theory but let’s see what the research has to say.
In 2007, a study done by Douglas Kalman and his team found that soy protein supplementation did not have any negative effects on testosterone production in trained men. In fact, if anything, all the groups in this study showed an increase in testosterone and a decrease in estrogen. Similarly a meta-analysis by Hamilton-Reeves again showed no negative effects of soy protein on testosterone production. So remember, just like any other food, when consumed in moderation soy protein does not have any adverse effects on hormone production.
Another common criticism of soy is that it has certain compounds which affect the digestion and absorption of protein and other nutrients. While this is true to a certain extent, it is unfair to target soy specifically because this problem exists in many other foods. In fact, by selectively quoting research, one can probably make an argument of this nature against almost every single food on the market. Sugar, grains, gluten, dairy, eggs and even green vegetables have all received a bad rap in the media based on these type of arguments.
Also something to keep in mind is that the concentration of most of these compounds which hamper digestion is greatly reduced in commercially prepared soy products. For example, in something like soy protein isolate, these compounds are almost non-existent.
Here’s some more research on soy and its health effects. Credit for compiling this data goes to the brilliant Dr Christine Crumbley!
Exercise Performance, Strength & Muscle – Soy does not reduce strength in new exercisers compared to whey or placebo across age groups from 18 to 70 years old in either men or women. Body composition improvements were noted in several of these studies. (17, 18, 19, 20, 21)
66 Romanian Olympians in endurance sports increased lean body mass and strength with an additional soy supplement. (22)
Reproductive function – In several studies (1, 2, 3, 4, 5, 6, 7, 8, 9) examining soy protein or isoflavone supplementation, men did not have significant changes in testosterone, free testosterone, estrogen, sex hormone binding globulin protein, or semen quality. A decrease in prostate specific antigen (PSA), which could be beneficial for prostate cancer, was seen in men consuming soy supplements. Interestingly, one study showed no changes in testosterone levels, but decreased androgen receptor (AR) expression was observed; decreased AR could be beneficial in hormone-sensitive prostate cancer growth.
In women, soy does not appear to have a negative impact on fertility, endometrial health, or ovarian health. In a study examining women receiving fertility treatments, soy consumption was positively associated with having a live birth.
The Adventist studies link soy consumption with not having a child or becoming pregnant, but the difference in having a child was small.
“In women with high (≥40 mg/day) isoflavone intake (12% of this group of women), the adjusted lifetime probability of giving birth to a live child was reduced by approximately 3% (95% CI: 0, 7) compared to women with low (<10 mg/day) intake.”
Brain function – Most studies show neutral or positive associations between soy consumption and cognition. Negative associations originally observed in studies went away with time, and some concerns were raised about formaldehyde used in processing tofu in other countries. Based on the research to date, there should be little concern about eating soy, including tofu, with regards to cognitive decline. The studies on soy and cognition are summarized here.
Suppressed thyroid hormone or hypothyroidism – There is limited evidence that people with healthy thyroids and appropriate iodine intake are negatively affected by soy consumption. Some hypothyroid patients may need to adjust their medicine’s dose to compensate for soy foods, as well as other foods that contain goitrogens (uncooked cruciferous vegetables, for example). Hypothyroid patients should discuss iodine intake and medications with their doctors.
In 2010, Tonstad, Serena et al. authored “Vegan Diets and Hypothyroidism” in which they concluded, “… a vegan diet tended to be associated with lower, not higher, risk of hypothyroid disease.”
Endocrine disruption – The phytoestrogens are much weaker than estrogens produced by your body, and they also preferentially bind to the Estrogen Receptor Beta (ERb). The ERb is associated with anti-proliferative responses, whereas the other isoform ERa largely drives estrogen-responsive growth. (10, 11)
Breast cancer risk – Long-term observational data shows no harm from soy for breast cancer risk or recurrence. The traditional Japanese diet has 25-50 mg isoflavones per day in 2-3 servings of soy and may be protective. E2 and estrogen-responsive tissues do not appear to be affected by soy in human trials. In nearly 10,000 breast cancer survivors, those who ate more soy after diagnosis had a significant 25% reduction in recurrence at 7.4 years post-diagnosis. (12, 13)
“The majority of breast cancer cases are hormone-receptor-positive; therefore, soy isoflavones should be considered a potential anti-cancer therapeutic agent and warrant further investigation.” (14)
Prostate cancer risk – There is some evidence for soy and its isoflavones to reduce prostate cancer risk, but the mechanism is unclear. Effects on hormones, prostate specific antigen (PSA), and sex hormone binding globulin (SHBG) protein could not be derived due to limitations of the reviewed data sets. In patients with localized prostate cancer, thyroid hormone and sex hormones were not significantly altered by the genistein treatments, and serum PSA was decreased. (15, 16)
Bottom Line: Soy isn’t going to kill you or make you a girl so stop worrying about it. Just like any other food, the poison is made by the dose and as long as you don’t go overboard with your soy consumption, there is nothing to be concerned about. To learn more about soy and its health effects, I strongly recommend reading these excellent write-ups by Dr Christine Crumbley and Jack Norris.
Myth 4: 80/10/10, Fruitarian and Raw Vegan Diets FTW
Part of the reason why I think veganism gets a bad reputation, especially in the scientific community is poor and biased nutrition information. “80/10/10” and raw vegan diets are classic examples of this.
An 80/10/10 diet contains 80% of calories from carbohydrates, 10% of calories from fat and 10% of calories from protein. In the same realm, we have fruitarian and raw vegan diets which as the names imply, encourage the consumption of fruit and uncooked or minimally cooked plant foods. Like many other fad diets, 80/10/10 and raw vegan diets have become popular because they’re endorsed by celebrities and attractive individuals on the internet. However, there are several problems associated with these diets.
Firstly, the whole concept of dividing macronutrients by percentages like 80/10/10 or 40/40/20 is just silly. In practice it is much better to use a bodyweight formula (for example protein is usually calculated by the formula: 1.8-2g/kg) to calculate macronutrient requirements. This gives us much better and more personalized numbers, and the chances of over consuming or under consuming a particular macronutrient is greatly reduced.
Here’s a quote from Crumbley and Zinchenko (AARR, October 2015) –
“In general, it is arbitrary to rely on macronutrient distributions given as percentages instead of the quantitative nutrient content in grams as the target for optimal food intake. With a very high calorie intake, a raw or 80-10-10 diet could potentially meet minimum recommended intakes. For example, a 60 kg (132 lb) person following an 80-10-10 diet with a low calorie intake (~1,350 kcal/day) is likely to be deficient in protein and fat, whereas the same person on a high calorie diet (~3,250 kcal/day) may meet the essential fat and protein intakes, even with a macronutrient distribution of 80-10-10 (see table)”
Overall, these diets are based on poor arguments like “cooking is bad for us” or “humans can’t digest meat”. Some of these arguments sound convincing in theory but they have very little in the way of research to support them.
However, it’s outside the scope of this article to discuss the problems associated with these diets in detail so if you’re interested in learning more about this topic, read the article “Vegan yays and nays: An objective examination of 80/10/10 and raw vegan diets” which was authored by Anastasia Zinchenko and Christine Crumbley. and published in the October 2015 edition of Alan Aragon’s Research Review.
Bottom Line: Unless you consume 4000+ Calories a day, 80/10/10, fruitarian and raw vegan diets are probably not a great idea.
Myth 5: Vegan athletes must rely heavily on supplements
The following supplements are commonly recommended to vegan athletes: vitamin B12, vitamin D3, omega 3 fatty acids, iron, zinc, magnesium, calcium, leucine (or BCAA), beta alanine and creatine.
Vitamin B12 and Vitamin D3 – There’s not much to be said about vitamin D, except for the fact that a D deficiency is a fairly common occurrence in both vegans and non-vegans, so it’s best to supplement with it if one is not getting enough sun exposure. Also vegans run the added risk of developing a B12 deficiency, so generally speaking it’s a good idea for vegans to supplement with vitamin B12 unless they’re consuming foods which are sufficiently fortified with B12.
Zinc, magnesium, calcium and iron – As we’ve already learnt, a well-planned vegan diet is more than capable of providing these minerals in the right amounts, so I would suggest that you first figure out how much you are getting from your diet and if you aren’t getting enough then you can either consider supplementation or you can increase foods which are rich in these particular minerals.
Omega 3 Fatty Acids –ALA, EPA & DHA are the three important omega 3 fatty acids which humans require. Vegans and vegetarians usually get ALA from foods like flaxseeds and walnuts and our body can convert ALA to EPA and DHA. However, this conversion of ALA to EPA and DHA seems to be limited in the human body. So just like a fish oil supplement, vegans have the option of directly getting EPA/DHA from an algae-based omega 3 supplement.
Leucine or BCAA – As previously seen, intelligent food selection and high quality protein sources like pea and rice protein are capable of providing the 2-4 g leucine threshold which is required for maximizing muscle protein synthesis. Since a serving of BCAA costs almost as much as a serving of protein powder, and given that supplemental BCAA have yet to demonstrate a clear, significant benefit, I generally advise keeping them low on the supplement check-list. Even for vegans.
Creatine and Beta-Alanine – There’s not much to be said about these two supplements except for the fact that they both have good research to show their effectiveness. And both vegans and non-vegetarians will need to supplement with these to see performance and health benefits.
Carnitine and Taurine – Both these compounds are relatively little known and found primarily in animal products, so vegans and vegetarians usually have lower plasma levels of taurine and carnitine as compared to non-vegetarians.
In the past carnitine was dismissed as a useless supplement but it’s made a good comeback in recent times. As is often discussed, plain carnitine by itself is largely useless. But, when it is paired with a transporter as is the case with something like Acetyl L-Carnitine (ALCAR) or L-Carnitine-L-Tartrate (LCLT), that’s when we start seeing some positive effects. So if you’re going to get carnitine, make sure you go for something like ALCAR or LCLT instead of just plain L-Carnitine.
Similarly, we have taurine. This again in recent times has shown some beneficial effects not only in vegans but in non-vegetarians as well. So this is also something worth considering. Most pre-workout supplements on the market have taurine and carnitine in them, so next time you purchase a pre-workout, just keep an eye out for these two ingredients.
Ok so looking at the supplements we’ve covered so far, it seems like quite a list! However, let’s compare this to the typical bodybuilding supplement stack.
The Typical Bodybuilding Supplement Stack & Plant Based Options
Whey & Casein
Can be replaced by pea, rice, soy and hemp protein
Multivitamin
Gelatin-free multivitamin or vitamin D3 & B12 taken individually
Fish Oil
Algae-based omega 3 supplement
Creatine & Beta Alanine
Same dose for vegan & non-vegan athletes
Pre-Workout
Taurine & Carnitine are usually present
I think most of you looking at this table will probably agree that the typical bodybuilding supplement stack looks something like this. A few staples are whey, creatine, multivitamins and fish oil supplements. And most recreational lifters nowadays are also taking a pre-workout supplement.
Now if we were to take this supplement stack and just replace each item on this table with a plant-based option, I think it is fair to say that a vegan athlete would have most bases covered.
Bottom Line: If we go by the general trend, the supplementation requirements of vegan and non-vegan athletes is quite similar. It’s not like vegans have to supplement with half a dozen extra ingredients.
Myth 6: Vegan diets are healthier than non-vegan diets
Strong advocates of plant-based diets often cite the acid-ash hypothesis as a reason to eliminate meat, dairy and eggs from the human diet. The acid-ash hypothesis states that a diet which includes the consumption of protein and grain foods creates an “acidic environment” (net acid load) in the body. It also suggests that to buffer this acid, our body releases calcium from bones which could potentially lead to osteoporosis and other diseases.
In the common language, this hypothesis is promoted as the “alkaline diet”. And many vegans who promote this hypothesis believe that diets rich in animal protein, dairy and grains are detrimental to human health.
But does this hypothesis stand the test of the scientific method?
In 1999, Munger et al. examined the relationship between protein intake and the risk of incurring a hip fracture in postmenopausal women. 44 cases of hip fracture incidences were studied. The study concluded that intake of dietary protein, including animal sources, was associated with a reduced incidence of hip fractures.
Similarly, in 2000, Hannan et al. showed that subjects with a lower protein intake had increased bone loss. They also concluded that protein intake is important in maintaining bone or minimizing bone loss in elderly persons. Further, higher intake of animal protein did not appear to affect the skeleton adversely. This result is in directly contradiction to the alkaline diet.
In the same vein, Promislow et al. (2002) showed that animal protein plays a protective role in the skeletal health of elderly women.
One of the earliest observations which led to the formation of the hypothesis was the higher amount of calcium found in the urine post the consumption of an “acidic” meal. A study conducted in 2005 (Kerstetter et al.) examined the effects of a high protein intake on the amount of calcium excreted in the urine. The results, “The high-protein diet caused a significant reduction in the fraction of urinary calcium of bone origin and a non-significant trend toward a reduction in the rate of bone turnover. There were no protein-induced effects on net bone balance. These data directly demonstrate that, at least in the short term, high-protein diets are not detrimental to bone.”
A meta-analysis which examined the relationship between protein and bone health in humans was conducted in 2009 (Darling, Millward, Torgerson, Hewitt, & Lanham-New). The researchers concluded that protein has a slight protective effect on bone health but may not reduce the risk of fracture in the long term.
Another meta-analysis conducted in 2009 (Fenton et al.) found that changes in acid-base intakes were directly proportional to the amount of calcium found in the urine but unrelated to net calcium balance in the body. Therefore, changes in calcium excretion do not accurately represent changes in calcium balance.
Similarly, another meta-analysis from Fenton and colleagues examined the effects of phosphate on bone loss in healthy individuals on the same parameters as the previous study. The authors concluded, “Dietary advice that dairy products, meats, and grains are detrimental to bone health due to ‘acidic’ phosphate content needs reassessment. There is no evidence that higher phosphate intakes are detrimental to bone health.”
Fenton and his tribe were at it again in 2010. This time, to determine if a low urine pH and acid excretion in the urine can predict the risk of osteoporosis. The changes in bone density of the participants of this study were recorded for a period of 5 years. The result – “Urine pH and urine acid excretion do not predict osteoporosis risk.”
Later that year, they also showed that that milk does not make the body acidic. Further, net acid excretion is not an important influence on calcium metabolism.
Caroll et al. grabbed the baton in 2011 and published a review which studied the relationship between the intake of dairy products and bone health. They concluded that milk and dairy are good and bioavailable sources of calcium.
Schwalfenberg (2011) studied the available literature on the relationship between an alkaline diet and various diseases and systems of the body such as muscular and skeletal. They also examined the relationship between an alkaline diet and urine pH. It was found that alkaline diets result in a more alkaline urine pH and may result in reduced calcium in the urine. However, as seen in some recent reports, this may not reflect total calcium balance because of other buffers such as phosphate. No substantial evidence was found that this improves bone health or protects from osteoporosis.
A study by Hanley & Whiting in 2013 also examined the relationship between an alkaline diet and urine pH as well as calciuria and its effect on the bone. The findings were then used to give recommendations which were consistent with the evidence. It was found that an acidic diet featuring a high protein intake may be associated with an increase in calciuria but the evidence that it plays a role in the development of osteoporosis is inconsistent.
In 2014, Nicoll & McLaren Howard examined the effect of dietary acid intake with varying levels of calcium intake. The findings led them to conclude that an acid producing diet maybe detrimental to the bone if combined with a low calcium intake. But if calcium intake is high, the acid producing diet may be protective.
In the same year, Rizzoli observed the role of dairy products on reduction of fracture risks. It was found that dairy products could improve bone health and reduce the risk of fractures in later life.
Recently the alkaline diet has also been promoted for its “cancer fighting properties”. The logic behind this is that cancerous cells thrive in an acidic environment and therefore it must be the case that increasing the body’s pH (making it alkaline) will lead to a cure. Fenton & Huang (2016) studied the alkaline diet in the context of cancer prevention and concluded, “This systematic review of the literature revealed a lack of evidence for or against diet acid load and/or alkaline water for the initiation or treatment of cancer. Promotion of alkaline diet and alkaline water to the public for cancer prevention or treatment is not justified”
Besides cancer, the alkaline diet has also been promoted as a cure to a multitude of other diseases such as obesity, type 2 diabetes and cardiovascular disease. A recent review by Thorning et al. (2016) puts the final nail in the coffin. The objective was to review several studies which have studied the relationship between dairy intake and the diseases mentioned above and all-cause mortality. The results speak for themselves:
“A diet high in milk and dairy products reduces the risk of childhood obesity and improves body composition in adults. This likely contributes to lower the risk of developing type 2 diabetes. Finally, there is increasing evidence suggesting that especially the fermented dairy products, cheese and yoghurt, are associated with a reduced risk of type 2 diabetes”
“The overall evidence indicates that a high intake of milk and dairy products, that is, 200–300 ml/day, does not increase the risk of cardiovascular disease. Specifically, there is an inverse association with risk of hypertension and stroke.”
Bottom Line: There are sound ethical reasons to reduce or eliminate animal product consumption but improved health and performance is certainly not one of them. Both vegan and non-vegan athletes can be equally strong and healthy if they program their nutrition and exercise correctly.
Frequently Asked Questions & Assumptions About Vegan Diets
Lawrence again! Aman is going to be sending me blog updates over the coming months, with the answers to the following FAQs/assumptions. Stay tuned!
A vegan diet is just like any other fad diet. Vegans are a biased and zealot lot.
There may be undiscovered beneficial nutrients which cannot be achieved through a vegan diet.
I started following a vegan diet and my health and performance has sky rocketed. Vegan diets are the best!
I started following a vegan diet and my health and performance has deteriorated. Vegan diets are the worst!
Vegan food tastes terrible.
The post Top 6 Myths About Vegan Diets appeared first on Shredded By Science.