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Are Vegan Diets Bad For Your Bones?

May 25, 2021 by Dr. Steve Chaney

The Secrets To A Healthy Vegan Diet

Author: Dr. Stephen Chaney

Osteoporosis is a debilitating and potentially deadly disease associated with aging. It affects 54 million Americans. It can cause debilitating back pain and bone fractures. 50% of women and 25% of men over 50 will break a bone due to osteoporosis. Hip fractures in the elderly due to osteoporosis are often a death sentence.

As I discussed in a previous issue of “Health Tips From The Professor”, a “bone-healthy lifestyle requires 3 essentials – calcium, vitamin D, and weight bearing exercise. If any of these three essentials is presence in inadequate amounts, you can’t build healthy bones. In addition, other nutrients such as protein, magnesium, zinc, vitamin B12, and omega-3 fatty acids may play supporting roles.

Vegan and other plant-based diets are thought to be very healthy. They decrease the risk of heart disease, diabetes, and some cancers. However, vegan diets tend to be low in calcium, vitamin D, zinc, vitamin B12, protein, and omega-3 fatty acids. Could vegan diets be bad for your bones?

A meta-analysis of 9 studies published in 2009 (LT Ho-Pham et al, American Journal of Clinical Nutrition 90: 943-950, 2009) reported that vegans had 4% lower bone density than omnivores, but concluded this difference was “not likely to be clinically relevant”.

However, that study did not actually compare bone fracture rates in vegans and omnivores. So, investigators have followed up with a much larger meta-analysis (I Iguacel et al, Nutrition Reviews 77, 1-18, 2019) comparing both bone density and bone fracture rates in vegans and omnivores.

How Was This Study Done?

The investigators searched the literature for all human clinical studies through November 2017 that compared bone densities and frequency of bone fractures of people consuming vegan and/or vegetarian diets with people consuming an omnivore diet.

Vegan diets were defined as excluding all animal foods.

Vegetarian diets were defined as excluding meat, poultry, fish, seafood, and flesh from any animal but including dairy foods and/or eggs. [Note: The more common name for this kind of diet is lacto-ovo vegetarian, but I will use the author’s nomenclature in this review.]

Omnivore diets were defined as including both plant and animal foods from every food group.

The investigators ended up with 20 studies that had a total of 37,134 participants. Of the 20 studies, 9 were conducted in Asia (Taiwan, Vietnam, India, Korea, and Hong-Kong), 6 in North America (the United States and Canada), and 4 were conducted in Europe (Italy, Finland, Slovakia, and the United Kingdom).

Are Vegan Diets Bad For Your Bones?

Here is what the investigators found:

Bone density: The clinical studies included 3 different sites for bone density measurements – the lumbar spine, the femoral neck, and the total body. When they compared bone density of vegans and vegetarians with the bone density of omnivores, here is what they found:

Lumbar spine:

- Vegans and vegetarians combined had a 3.2% lower bone density than omnivores.

- The effect of diet was stronger for vegans (7% decrease in bone density) than it was for vegetarians (2.3% decrease in bone density).

Femoral neck:

- Vegans and vegetarians combined had a 3.7% lower bone density than omnivores.

- The effect of diet was stronger for vegans (5.5% decrease in bone density) than it was for vegetarians (2.5% decrease in bone density).

Whole body:

- Vegans and vegetarians combined had a 3.2% lower bone density than omnivores.

- The effect of diet was statistically significant for vegans (5.9% decrease in bone density) but not for vegetarians (3.5% decrease in bone density). [Note: Statistical significance is not determined by how much bone density is decreased. It is determined by the size of the sample and the variations in bone density among individuals in the sample.]

Bone Fractures: The decrease in bone density of vegans in this study was similar to that reported in the 2009 study I discussed above. However, rather than simply speculating about the clinical significance of this decrease in bone density, the authors of this study also measured the frequency of fractures in vegans, vegetarians, and omnivores. Here is what they found.

Vegans and vegetarians combined had a 32% higher risk of bone fractures than omnivores.

The effect of diet on risk of bone fractures was statistically significant for vegans (44% higher risk of bone fracture) but not for vegetarians (25% higher risk of bone fractures).

These data suggest the decreased bone density in vegans is clinically significant.

The authors concluded, “The findings of this study suggest that both vegetarian and vegan diets are associated with lower bone density compared with omnivorous diets. The effect of vegan diets on bone density is more pronounced than the effect of vegetarian diets, and vegans have a higher fracture risk than omnivores. Both vegetarian and vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.”

The Secrets To A Healthy Vegan Diet

The answer to this question lies in the last statement in the author’s conclusion, “Both vegetarian and vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.”

The problem also lies in the difference between what a nutrition expert considers a vegan diet and what the average consumer considers a vegan diet. To the average consumer a vegan diet is simply a diet without any animal foods. What could go wrong with that definition? Let me count the ways.

Sugar and white flour are vegan. A vegan expert thinks of a vegan diet as a whole food diet – primarily fruits, vegetables, whole grains, beans, nuts, and seeds. A vegan novice includes all their favorites – sodas, sweets, and highly processed foods. And that may not leave much room for healthier vegan foods.

2) Big Food, Inc is not your friend. Big Food tells you that you don’t need to give up the taste of animal foods just because you are going vegan. They will just combine sugar, white flour, and a witch’s brew of chemicals to give you foods that taste just like your favorite meats and dairy foods. The problem is these are all highly processed foods. They are not healthy. Some people call them “fake meats” or “fake cheeses”. I call them “fake vegan”.

If you are going vegan, embrace your new diet. Bean burgers may not taste like Big Macs, but they are delicious. If need other delicious vegan recipe ideas, I recommend the website https://forksoverknives.com.

3) A bone healthy vegan diet is possible, but it’s not easy. Let’s go back to the author’s phrase “…vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.” A vegan expert will do the necessary planning. A vegan novice will assume all they need to do is give up animal foods.

As I said earlier, vegan diets tend to be low in calcium, vitamin D, zinc, vitamin B12, protein, and omega-3 fatty acids. Let’s look at how a vegan expert might plan their diet to get enough of those bone-healthy nutrients.

- Calcium. The top plant sources of calcium are leafy greens and soy foods at about 100-250 mg (10-25% of the DV) of calcium per serving. Some beans and seeds are moderately good sources of calcium. Soy foods are a particularly good choice because they are a good source of calcium and contain phytoestrogens that stimulate bone formation.

A vegan expert makes sure they get these foods every day and often adds a calcium supplement.

- Protein. Soy foods, beans, and some whole grains are the best plant sources of protein.

It drives me crazy when a vegan novice tells me they were told they can get all the protein they need from broccoli and leafy greens. That is incredibly bad advice.

A vegan expert makes sure they get soy foods, beans, and protein-rich grains every day and often adds a protein supplement.

- Zinc. There are several plant foods that supply around 20% the DV for zinc including lentils, oatmeal, wild rice, squash and pumpkin seeds, quinoa, and black beans.

A vegan expert makes sure they get these foods every day and often adds a multivitamin supplement containing zinc.

- Vitamin D and vitamin B12. These are very difficult to get from a vegan diet. Even vegan experts usually rely on supplements to get enough of these important nutrients.

4) Certain vegan foods can even be bad for your bones. I divide these into healthy vegan foods and unhealthy “vegan” foods.

- Healthy vegan foods that can be bad for your bones include.

- - Pinto beans, navy beans, and peas because they contain phytates.

- - Raw spinach & swiss chard because they contain oxalates.

- - Both phytates and oxalates bind calcium and interfere with its absorption.

- - These foods can be part of a healthy vegan diet, but a vegan expert consumes them in moderation.

- Unhealthy “vegan” foods that are bad for your bones include sodas, salt, sugar, and alcohol.

- - The mechanisms are complex, but these foods all tend to dissolve bone.

- - A vegan expert minimizes them in their diet.

5) You need more than diet for healthy bones. At the beginning of this article, I talked about the 3 essentials for bone formation – calcium, vitamin D, and exercise. You can have the healthiest vegan diet in the world, but if you aren’t getting enough weight bearing exercise, you will have low bone density. Let me close with 3 quick thoughts:

- None of the studies included in this meta-analysis measured how much exercise the study participants were getting.

- The individual studies were generally carried out in industrialized countries where many people get insufficient exercise.

- The DV for calcium in the United States is 1,000-1,200 mg/day for adults. In more agrarian societies dietary calcium intake is around 500 mg/day, and osteoporosis is almost nonexistent. What is the difference? These are people who are outside (vitamin D) doing heavy manual labor (exercise) in their farms and pastures every day.

In summary, a bone healthy vegan lifestyle isn’t easy, but it is possible if you work at it.

The Bottom Line

A recent meta-analysis asked two important questions about vegan diets.

Do vegans have lower bone density than omnivores?

2) Is the difference in bone density clinically significant? Are vegans more likely to suffer from bone fractures?

The study found that:

Vegans had 5.5%–7% lower bone density than omnivores depending on where the bone density was measured.

Vegans were 44% more likely to suffer from bone fractures than omnivores.

The authors of the study concluded, ““The findings of this study suggest that…vegan diets are associated with lower bone density compared with omnivorous diets, and vegans have a higher fracture risk than omnivores…Vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.”

In evaluating the results of this study, I took a detailed look at the pros and cons of vegan diets and concluded, “A bone healthy vegan lifestyle isn’t easy, but it is possible if you work at it.”

For more details about study and my recommendations for a bone healthy vegan lifestyle read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

What Is An Anti-Inflammatory Diet?

July 21, 2021April 6, 2021 by Dr. Steve Chaney

Can Diet Douse The Flames?

Author: Dr. Stephen Chaney

If you have arthritis, colitis, bursitis, or any of the other “itis” diseases, you already know that inﬂammation is the enemy. Chronic, low level inﬂammation is also a contributing factor to heart disease, cancer, and many other diseases. Clearly, inﬂammation is a bad actor. It is something we want to avoid.

Obesity and diabetes are two of the biggest contributors to inﬂammation, but does diet also play a role? With all the anti-inﬂammation diets circulating on the internet, you would certainly think so. How good is the evidence that certain foods inﬂuence inﬂammation, and what does an anti-inﬂammatory diet look like?

The Science Behind Anti-Inflammatory Diets

Let me start by saying that the science behind anti-inﬂammatory diets is nowhere near as strong as it is for the eﬀect of primarily plant-based diets on heart disease and diabetes. The studies on anti-inflammatory diets are mostly small, short duration studies. However, the biggest problem is that there is no standard way of measuring inﬂammation.

There are multiple markers of inﬂammation, and they do not change together. That means that in every study some markers of inﬂammation are altered, while others are not. There is no consistent pattern from one study to another.

In spite of these methodological diﬃculties, the studies generally point in the same direction. Let’s start with the strongest evidence and work our way down to the weakest evidence.

Omega-3 fats are anti-inﬂammatory (I. Reinders et al, European Journal of Clinical Nutrition, 66: 736-741, 2011). The evidence is strongest for the long chain omega-3s found in ﬁsh and ﬁsh oil, but the shorter chain omega-3s found in foods like walnuts, ﬂaxseeds, chia seeds and ﬂaxseed oil, soybean oil, and canola oil also appear to be anti-inﬂammatory.

Inﬂammation is directly correlated with glycemic index (L. Qi and F.B. Lu, Current Opinion in Lipidology, 18: 3-8, 2007). This has a couple of important implications.

The most straightforward is that reﬁned carbohydrates and sugars (sodas, pastries, and desserts), which have a high glycemic index, increase inﬂammation. In contrast, complex carbohydrates (whole grains, most fruits and vegetables) decrease inﬂammation. No surprise there. The second implication is that it is the glycemic index, not the sugar, that is driving the inﬂammatory response.

That means we need to look more closely at foods than at sugars. Sodas, pastries and desserts are likely to cause inﬂammation, but sugar-containing foods with a low glycemic index are unlikely to be inﬂammatory.

Fruits and vegetables are anti-inﬂammatory. This has been shown in multiple studies. At this point most of the research is centered on identifying the nutrients and phytonutrients from fruits and vegetables that are responsible for the reduction in inﬂammation. I suspect the investigators are hoping to design an anti-inﬂammatory supplement and make lots of money. I will stick with the fresh fruits and vegetables.

Saturated fats are inﬂammatory. At face value, the data on saturated fats appear to be contradictory. Some studies say that saturated fats increase inﬂammation, while others say they do not. However, similar to my earlier discussion on saturated fats and heart disease), the outcome of the study depends on what the saturated fats are replaced with.

When saturated fats are replaced with reﬁned carbohydrates, sugar and highly processed foods (the standard American low-fat diet), inﬂammation doesn’t change. This doesn’t mean that a diet high in saturated fat is healthy. It just means that both diets are bad for you. Both are inflammatory.

However, when saturated fat is replaced with omega-3 polyunsaturated fats (J.A. Paniagua et al, Atherosclerosis, 218: 443-450, 2011) or monounsaturated fats (B. Vessby et al, Diabetologia, 44: 312-319, 2001), markers of inﬂammation decrease. Clearly, saturated fats are not the best fat choice if you wish to keep inﬂammation in check.

I would be remiss if I did not address the claims by the low-carb diet proponents that saturated fats do not increase inﬂammation in the context of a low-carb diet. I want to remind you of two things we have discussed previously:

The comparisons in those studies are generally with people consuming a diet high in simple carbohydrates and sugars.

These studies have mostly been done in the short-term when the participants are losing weight on the low-carb diets. Weight loss decreases inﬂammation, so the reduction in inﬂammation on the low-carb diet could be coming from the weight loss.

The one study (M. Miller et al, Journal of the American Dietetic Association, 109: 713-717, 2009) I have found that compares a low-carb diet (the Atkins diet) with a good diet (the Ornish diet, which is a low-fat, lacto-ovo vegetarian diet) during weight maintenance found that the meat based, low-carb Atkins diet caused greater inﬂammation than the healthy low-fat Ornish diet.

Red meat is probably pro-inﬂammatory. Most, but not all, studies suggest that red meat consumption is associated with increased inﬂammation. If it is pro-inﬂammatory, the inﬂammation is most likely associated with its saturated fat, its heme iron content, or the advanced glycation end products formed during cooking.

What Is An Anti-Inflammatory Diet?

Anti-inﬂammatory diets have become so mainstream that they now appear on many reputable health organization websites such as Harvard Health, WebMD, the Mayo Clinic, and the Cleveland Clinic. Each have slightly diﬀerent features, but there is a tremendous amount of agreement.

Foods an anti-inﬂammatory diet includes: In a nutshell, an anti-inﬂammatory diet includes fruits and vegetables, whole grains, plant-based proteins (like beans and nuts), fatty ﬁsh, and fresh herbs and spices. Speciﬁcally, your diet should emphasize:

Colorful fruits and vegetables. Not only do they help ﬁght inﬂammation, but they are a great source of antioxidants and other nutrients important for your health.

Whole grains. They have a low glycemic index. They are also a good source of ﬁber, and ﬁber helps ﬂush inﬂammatory toxins out of the body.

Beans and other legumes. They should be your primary source of protein. They are high in ﬁber and contain antioxidants and other anti-inﬂammatory nutrients.

Nuts, olive oil, and avocados. They are good sources of healthy monounsaturated fats, which ﬁght inﬂammation.
Fatty ﬁsh. Salmon, tuna, and sardines are all great sources of long chain omega-3 fatty acids, which are incorporated into our cell membranes. Those long chain omega-3s in cell membranes are, in turn, used to create compounds that are powerful inﬂammation ﬁghters.

Walnuts, ﬂaxseeds, and chia seeds are good sources of short chain omega-3s. The eﬃciency of their conversion to long chain omega-3s that can be incorporated into cell membranes is only around 2-5%. If they ﬁght inﬂammation, it is probably because they replace some of the saturated fats and omega-6 fats you might otherwise be eating.

Herbs and spices. They add antioxidants and other phytonutrients that ﬁght inﬂammation.

Foods an anti-inﬂammatory diet excludes: In a nutshell, an anti-inﬂammatory diet should exclude highly processed, overly greasy, or super sweet foods, especially sodas and other sweet drinks. Specifically, your diet should exclude:

Reﬁned carbohydrates, sodas and sugary foods. They have a high glycemic index, which is associated with inﬂammation. They can also lead to weight gain and high blood sugar, both of which cause inﬂammation.

Foods high in saturated fats. This includes fatty and processed meats, butter, and high fat dairy products.

Foods high in trans fats. This includes margarine, coﬀee creamers, and any processed food containing partly hydrogenated vegetable oils. Trans fats are very pro-inﬂammatory.

French fries, fried chicken, and other fried foods. They used to be fried in saturated fat and/or trans fat. Nowadays, they are generally fried in omega-6 vegetable oils. A little omega-6 in the diet is OK, but Americans get too much omega-6 fatty acids in their diet. Most studies show that a high ratio of omega-6 to omega-3 fatty acids is pro-inﬂammatory.

Foods you are allergic or sensitive to. Eating any food that you are sensitive to can cause inﬂammation. This comes up most often with respect to gluten and dairy because so many people are sensitive to one or both. However, if you are not sensitive to them, there is no reason to exclude whole grain gluten-containing foods or low-fat dairy foods from your diet.

Can Diet Douse The Flames?

In case you didn’t notice, the recommendations for an anti-inﬂammatory diet closely match the other healthy diets I have discussed previously. It should come as no surprise then that both the Mediterranean (L. Gallard, Nutrition in Clinical Practice, 25: 634-640, 2010; L. Schwingshackl and G. Hoﬀmann, Nutrition Metabolism and Cardiovascular Diseases, 24: 929-939, 2014) and DASH (D.E. King et al, Archives of Internal Medicine, 167: 502-506, 2007) diets are anti-inﬂammatory.

Vegan and vegetarian diets also appear to be anti-inﬂammatory as well. The anti-inﬂammatory nature of these diets undoubtedly contributes to their association with a lower risk of heart disease, diabetes, and cancer.

As for the low-carb diets, the jury is out. There are no long-term studies to support the claims of low-carb proponents that their diets reduce inﬂammation. The few long-term studies that are available suggest that low-carb diets are only likely to be anti-inﬂammatory if vegetable proteins and oils replace the animal proteins and fats that are currently recommended.

What does this mean for you if you have severe arthritis or other inﬂammatory diseases? An anti-inﬂammatory diet is unlikely to “cure” your symptoms by itself. However, it should deﬁnitely be a companion to everything else you are doing to reduce inﬂammation.

The Bottom Line

Obesity and diabetes are two of the biggest contributors to inﬂammation, but does diet also play a role? With all the anti-inﬂammation diets circulating on the internet, you would certainly think so. In this article I review the evidence that certain foods inﬂuence inﬂammation and describe what an anti-inﬂammatory diet looks like.

For more details read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Which Foods Affect Stroke Risk?

March 24, 2020 by Dr. Steve Chaney

Why Is Diet And Stroke Risk So Confusing?

One day we are told vegetarian diets reduce our stroke risk. The next day we are told they increase stroke risk. It’s the same with red meat, dairy, and eggs. We keep getting mixed messages. It’s enough to make your head spin. Why is diet and stroke risk so confusing?

Part of the problem is that there are two distinct types of stroke. The technical names for them are ischemic stroke and hemorrhagic stroke.

An ischemic stroke occurs when an artery in the brain becomes blocked, shutting off blood flow and damaging part of the brain. This is usually caused by the gradual buildup of fatty deposits and cholesterol plaques in the arteries. When a blood clot forms and lodges in one of the narrowed arteries leading to the brain, an ischemic stroke occurs.

Ischemic strokes account for 87% of all strokes.

Ischemic strokes are associated with obesity, elevated cholesterol, diabetes, high blood pressure, and smoking.

A hemorrhagic stroke occurs when a weakened blood vessel bursts and bleeds into the surrounding region of the brain. Because our brains are surrounded by a protective skull, that blood has nowhere to go. Pressure from the buildup of blood damages brain cells in the vicinity of the bleed.

Hemorrhagic strokes account for only for only 15% of strokes but are responsible for 40% of stroke deaths.

The most common cause of a hemorrhagic stroke is the localized enlargement of a blood vessel due to chronic high blood pressure. This weakens the wall of the blood vessel, making it prone to rupturing.

Part of the confusion about diet and stroke risk is because many earlier studies did not distinguish between the two types of stroke.

If the studies just measured the incidence of stroke, the data were dominated by ischemic strokes (87% of strokes are ischemic).

However, if the studies focused on stroke deaths, hemorrhagic stroke made a larger contribution to the data set (40% of stroke deaths are hemorrhagic).

Fortunately, recent studies have started to focus on the effect of diet on ischemic and hemorrhagic strokes separately. However, many of those studies have been too small to accurately assess the effects of diet on hemorrhagic stroke.

The latest study (TYN Tong et al, European Heart Journal, ehaa007, published February 24, 2020) is one of the largest studies to look at the effect of diet on both kinds of stroke. It has enough patients in the hemorrhagic group to get an accurate estimate of the effect of diet on hemorrhagic stroke.

How Was The Study Done?

This study analyzed data on diet and stroke from 418,329 participants in the EPIC (European Prospective Investigation into Cancer and Nutrition). Although the study has cancer in the title, it actually investigated the effect of nutrition on multiple diseases (Presumably, the study title was chosen because EPIC is a more appealing acronym than EPID (European Prospective Investigation into Diseases and Nutrition)).

The participants were recruited from 9 European countries (Denmark, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden, and the UK). The average age of participants was 50, and they were followed for an average of 12.7 years.

At the beginning of the study participants completed country-specific dietary and lifestyle questionnaires.

The dietary assessment was a food frequency questionnaire that asked participants about their dietary intake for the year prior to enrollment in the study. The food frequency data were used to estimate daily intake of red meat, processed meat, poultry, fish, dairy products, eggs, grains, fruits, vegetables, legumes, nuts, seeds, and dietary fiber (It measured total fiber and fiber from grains, fruits and vegetables individually).

The outcome measured was the incidence of ischemic and hemorrhagic strokes during the 12.7-year follow-up.

Which Foods Affect Stroke Risk?

For ischemic stroke:

Each 200 gram/day increase in consumption of fruits and vegetables decreased ischemic stroke risk by 13% (200 grams roughly corresponds to one large apple or one large orange without the skin).

Each 10 gram/day increase in consumption of fiber decreased ischemic stroke risk by 23%. Most of this decreased stroke risk was due to fiber from whole grains, fruits, and vegetables.

- Each 4 gram/day increase in fiber from whole grains decreased ischemic stroke risk by 10%.

- Each 4 gram/day increase in fiber from fruits and vegetables decreased ischemic stroke risk by 12%.

Dairy foods decreased ischemic stroke risk with the following breakdown:

- Each cup of milk decreased ischemic stroke risk by 5%.

- Each half cup of yogurt decreased ischemic stroke risk by 9%.

- Each ounce of cheese decreased ischemic stroke risk by 12%.

Each 50 grams/day (2 ounces) of red meat increased ischemic stroke risk by 14%.

- However, red meat was only half as likely to increase risk of ischemic stroke when the diet was also rich in fruits, vegetables, whole grains, and legumes.

For hemorrhagic stroke:

Each 20 gram/day increase in consumption of eggs increased hemorrhagic stroke risk by 25% (20 grams roughly corresponds to about 1/2 of a small egg or 1/3 of a jumbo egg).

This study did not measure the effect of salt intake on hemorrhagic stroke risk.

No other foods measured in this study had a significant effect on hemorrhagic stroke risk.

However, hemorrhagic stroke is highly associated with high blood pressure. When we look at the influence of foods on high blood pressure, here are the Harvard School of Medicine recommendations for keeping blood pressure low:

Eat more fish, nuts and beans in place of high-fat meats.

Choose fruits and vegetables instead of sugary, salty snacks and desserts.

Select whole grains rather than refined grains.Eat fruit instead of drinking fruit juice.

Use unsaturated fats like olive, canola, soybean, peanut, corn or safflower oils instead of butter, coconut oil, or palm-kernel oil.

Use herbs, spices, vinegar, and other low-sodium flavorings instead of salt; Choose low-sodium foods whenever possible.

Why Is Diet And Stroke Risk So Confusing?

As I mentioned at the start of this article, part of the reason that the headlines about diet and stroke risk are so confusing is:

Many studies did not distinguish between the two types of stroke.

Other studies were too small to reliably estimate the effect of food on hemorrhagic stroke risk.

However, there are still some unexplained inconsistencies among recently published studies. It is these inconsistencies I would like to address. For example:

1) In a recent issue of Health Tips From the Professor I reported on a major study (500,000 people followed for 8.9 years) in China. That study came to the opposite conclusion about eggs and risk of hemorrhagic than the EPIC study I discussed above. It found:

People consuming one egg per day had a 26% decrease in hemorrhagic stroke risk and a 28% decrease in hemorrhagic stroke deaths compared to people who never or rarely consumed eggs.

In other words, the two studies came to opposite conclusions. In the China study eggs decreased risk of hemorrhagic stroke. In the European study (EPIC) eggs increased risk of hemorrhagic stroke. The reason for this discrepancy is not clear, but one can speculate it might be explained by differences in the underlying diets of the two countries:

In China the diet is primarily plant-based. The addition of an egg/day may provide needed protein, fat, and cholesterol (Some cholesterol is essential. We just overdo it in this country).

In Europe the diet is already high in protein, saturated fat, and cholesterol. Getting more of them from eggs may not be such a good thing.

In short, if your diet is primarily plant-based, the addition of an egg/day may be a good thing. However, if your diet is already high in meat, saturated fat, and cholesterol, the addition of an egg/day may not be a good thing.

2) In another recent issue of Health Tips From the Professor I reported on the EPIC-Oxford study that claimed vegetarians had 20% increased risk of hemorrhagic stroke compared to meat eaters.

Interestingly, the EPIC-Oxford study represented a very small portion (~10%) of the overall EPIC study and differed from the rest of the EPIC study in two important ways.

It looked at the effect of diets rather than foods on stroke risk.

Oxford was the only one of the 22 research centers involved in the EPIC study to invite people following a vegetarian diet to enroll in the study, so it had a much higher proportion of vegetarians than other centers that participated in the study.

The current study did not find any evidence that fruits, vegetables, nuts, seeds, beans, or whole grains influenced the risk of hemorrhagic stroke. In other words, in this much larger data set there was no evidence that the foods associated with a vegetarian diet increased hemorrhagic stroke risk.

However, most of the participants in larger EPIC study were also eating meats. They were not following a pure vegetarian diet.

As I said previously, “If the data on hemorrhagic stroke risk in the EPIC-Oxford study are true, it suggests it may not be a good idea to completely eliminate meat from our diet. However, you don’t need to add much meat to a vegetarian diet. The fish eaters in this study were consuming 1.4 ounces of fish per day. That was enough to eliminate the increased risk of hemorrhagic stroke.”

What Does This Mean For You?

For ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)

Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.

These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.

If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.

A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.

The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

In terms of an overall take-home lesson on diet and stroke risk, my advice is: “A primarily plant-based diet is a good idea, but you don’t need to become a vegan purist. Nor do you want to follow fad diets that eliminate whole food groups. We have 5 food groups for a reason. Eliminating any of them may not be a good idea.”

The Bottom Line

A recent study examined the effect of various foods on the risk of the two major forms of stroke.

For ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)

Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.

These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.

If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.

A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.

The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Does Diet Affect Sperm Quality?

March 3, 2020 by Dr. Steve Chaney

Do Real Men Eat Meat?

Meat has a certain mystique among some men. They believe real men eat meat, especially red meat. The belief is that eating red meat makes them bigger, stronger, and more virile. In that world view, vegetarianism is effeminate.

How much of that is true? Let’s start by looking at the bigger and stronger part:

Animal proteins are higher in the branched chain amino acids, especially leucine, which help drive the increase in muscle mass associated with exercise. However, meat protein is digested slowly.

Milk protein is also high in branched chain amino acids and is digested more quickly. That’s why many body building supplements are whey protein based.

In addition, leucine is now being added to some of the plant protein supplements. Those supplements are often as effective as whey protein supplements at driving the increase in muscle mass associated with exercise

But what about virility? Does meat make men more virile? Fortunately, we now have an answer to these questions. A recent study (L Nassan et al., JAMA Network Open, 2020; 3(2) :e1921610) has looked at the effect of diet on sperm count and sperm quality.

How Was The Study Done?

In Denmark, all men are required to undergo a physical examination around age 18 to determine their fitness for military service. Research staff at the University Department of Growth and Reproduction at Rigshospitalet in Copenhagen approached young men undergoing their physical exams and invited them to participate in this study.

The men filled in a food frequency questionnaire, answered questions about their lifestyle and medical history and provided semen and blood samples for the study prior to undergoing their physical exam. 2935 men who were unaware of their fertility status and not using anabolic steroids were included in the data analysis.

The average age of participants in the study was 19 and 78% of them were of normal body weight.

The participants were divided into four groups based on their diet:

1. Western Diet characterized by a higher intake of pizza, French fries, processed and red meats, snacks, refined grains, sugary beverages and sweets.

2. Danish Diet characterized by a higher intake of cold processed meats, whole grains, fruits, mayonnaise, cold fish, condiments, and dairy.

3. Vegetarian Diet characterized by a higher intake of vegetables, soymilk, and eggs, without red meat or chicken.

4. Prudent (Healthy) Diet characterized by a higher intake of fish, chicken, vegetables, fruit, nuts, and water.

The effect of these diets on sperm count and sperm quality were compared.

Does Diet Affect Sperm Quality?

When the authors measured sperm counts in the study participants, the results were as follows:

Greatest adherence to a prudent diet resulted in a sperm count of 167 million.

Greatest adherence to a vegetarian diet resulted in a sperm count of 151 million.

Greatest adherence to a Danish diet resulted in a sperm count of 146 million.

Greatest adherence to a Western diet resulted in a sperm count of only 122 million -27% lower than for men eating a prudent diet.

Similar results were reported for measure of sperm quality, such as sperm motility (how fast the sperm can swim) and normal sperm morphology (sperm without visible defects).

These results are similar to several earlier studies showing that men eating a healthy diet have greater sperm count and sperm quality.

The authors concluded: “Our findings support the evidence that adhering to generally healthy diet patterns is associated with better semen quality and more favorable markers of testicular function. Because diet is modifiable, these results suggest the possibility of using dietary intervention as a potential approach to improving testicular function in men of reproductive age.”

Do Real Men Eat Meat?

Now it is time to come back to the original question, “Do real men eat meat”. Or more specifically, does red meat consumption increase virility? Of course, the whole question of whether a single food affects virility, or any other aspect of manliness, is bogus.

Individual foods don’t affect our health. Diets do. So, let’s review how diets affect men’s sperm count and sperm quality.

The highest sperm count and sperm quality was associated with the prudent diet. This diet relied primarily on fish and chicken as protein sources but did not exclude red meat. It was also a diet high in vegetables, fruits, nuts, and water (in place of sugary beverages).

The second highest sperm count and sperm quality was associated with the vegetarian diet. This diet relied on beans and eggs as the primary protein sources. It specifically excluded red meat and chicken but did not exclude fish. It was also high in fruits and nuts. Soy milk, tea, and coffee were the main beverages.

The third highest sperm count and sperm quality was associated with the Danish diet. This diet relied on cold processed meats (some of which were red meats), cold fish, and dairy for protein. However, it also was rich in whole grains and fruits. Water and sugary beverages were consumed in equal proportions.

The lowest sperm count and sperm quality was associated with the Western diet. This diet relied on red and processed meats as the primary protein source. However, it was also high in refined grains, snacks, sugary beverages, sweets, and junk foods.

So, if we are using sperm count and sperm quality as a measure of virility, it is clear that real men don’t eat red meat. Or put another way, a diet rich in red meat is more likely to reduce sperm count and sperm quality than it is to increase it.

However, a small amount of red meat as part of an overall healthy diet can be consistent with good sperm count and quality.

In short, diet does affect sperm quality. For example, based on this study:

An 8-ounce steak with French fries, cherry pie, and a soft drink (or, in our part of the country, sweet tea) may not be good for your sex life.

If you don’t want to give up red meat, a better choice might be 3-ounces of steak in a vegetable stir fry, fruit for dessert, and water or tea as your beverage.

If you want to maximize sperm count and sperm quality, an even better choice would be chicken, fish, or beans with vegetables, fruit for dessert, and water or tea as your beverage.

The Bottom Line

Meat has a certain mystique among some men. They believe real men eat meat, especially red meat. The belief is that eating red meat makes them bigger, stronger, and more virile.

How much of that is true. We already know that meat has no magical power to make men bigger and stronger. But what about virility? Does meat make men more virile? Fortunately, we now have an answer to that question. A recent study has looked at the effect of diet on sperm count and sperm quality.

The highest sperm count and quality was associated with a prudent diet. This diet relied primarily on fish and chicken as protein sources but did not exclude red meat. It was also a diet rich in vegetables, fruits, nuts, and water (in place of sugary beverages). In other words, it was a healthy diet.

The lowest sperm count and quality was associated with the Western diet. This is a diet that relies on red and processed meats as the primary protein source. However, it is also high in refined grains, snacks, sugary beverages, sweets, and junk foods.

However, a small amount of red meat as part of an overall healthy diet can be consistent with good sperm count and sperm quality.

In short, it appears that diet does affect sperm quality:

An 8-ounce steak with French fries, cherry pie, and a soft drink (or, in our part of the country, sweet tea) may not be good for your sex life.

If you don’t want to give up red meat, a better choice might be 3-ounces of steak in a vegetable stir fry, fruit for dessert, and water or tea as your beverage.

If you want to maximize sperm count and sperm quality, an even better choice would be chicken, fish, or beans with vegetables, fruit for dessert, and water or tea as your beverage.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.