 In the previous video, I discussed some faulty logic used by a raw food website. This video will focus on the health risks and benefits to a classic raw vegan diet. I want to repeat that the criteria for raw foodism is 75% or more uncooked foods. I have the benefit of having read the responses to my previous video prior to making this one. One of the sites that embedded my video was 30 bananas a day, and they asked, But we posted some video responses to this guy. This is a raw foodism website, and I found it very useful for the kinds of experiences that most people have when starting this diet. I'll come back to that later. I was reassured to see that I pissed off most of them, and they responded with emotion-based attacks I would have expected. One person suspected I was a shill of some sort. What I was most pleased to see were several respondents who thought I made good points, even if they disagreed in the fundamentals. I can live with that. I don't claim to have all the answers. Let's start with risks. What are the possible negative health implications of raw food dieting? I'm going to list them off. 1. Tooth decay. This is not to be scoffed at. Some long-term raw foodists apparently have very bad teeth. Here's a picture of impact damage to a molar. A German study of long-term raw foodists found a significant increase in tooth erosion compared to controls. 61% of the raw food group had severe erosion on at least one tooth compared to only 32% of controls. Two theories have been advanced to explain this. One, that the high acidity of plant products like orange juice is dissolving enamel. Two, that the abrasive roughage and fiber and the sheer bulk of the food accelerates enamel decay. It's also common for a vegan to have calcium deficiency, which can further complicate dental health. Risk two, underweight. If you're looking to lose weight, then a high bulk, low calorie diet might be a good way to do so. If you're already a healthy weight, you might find it a challenge to eat sufficient calories on a raw food diet. A German questionnaire study found that 15% of men and 25% of women on our vegan raw food regimen were classified as underweight. The longer they'd been on the diet and the higher their percentage raw, the more likely they were to be underweight. The weight loss averaged 10 kilograms for men and 12 kilograms for women. That's around 25 pounds to my fellow Americans. Risk three, amenorrhea. From the same German study, about 30% of women on raw food regimens stopped getting their periods. Again, this was correlated with percent of raw and duration of diet. From these two factors, underweight and amenorrhea, the study concludes a very strict raw food diet cannot be recommended on a long-term basis. Risk four, nutrient deficiency. Vegan raw foodists need to supplement heavily to overcome the nutrient deficiencies in their diet, especially vitamin B12, iron, zinc, selenium, calcium, and vitamin D. This can be overcome by very careful planning of meals, but it's still going to be a challenge to get high quality protein. Remember that many legumes are poisonous without cooking, so nuts and seeds have to play a big role in providing protein. And a variety are needed to provide complete amino acid coverage. My own advice for raw foodists that 25% of your diet that isn't raw should be lean meats or cooked beans. Risk five, bone loss. There's a significant difference in controls and raw foodists at key points in skeletal bone mass. One study suggests that this may not be a sign of degradation, but mostly just a response to the weight loss because the markers of bone loss are stable. The risk of osteoporosis or fractures wasn't measured, and since this is a fairly new, trendy diet, the clinically important results may not be obvious for a few decades, long after raw food is no longer the end thing. I'll combine six, seven, and eight, bloating, nausea, and vomiting. These are very common. When you start this rigorous diet, your body will have a difficult time adjusting to all the fiber. You'll become bloated and you'll have digestive problems. Scanning through the blogs and websites, all the new raw foodists complain about feeling terrible. Experienced users reassure them that they'll feel better after a few weeks. I'm going to come back to these three on the very end. Risk nine, risk of infection or poisoning. Cooking kills bacteria, viruses, and actually decreases the amount of pesticide residues on fruits and vegetables. I've never advocated 100% cooked, but eating raw vegetables is associated with some risks. Many of you will remember the E. coli and Salmonella issues with raw spinach and peanut butter. Homemade fermented foods carry a risk of botulism and, well, name a foodborne pathogen. I don't want to oversell this because the risks are very low. I just think it needs to be on this list. One of the reasons we process foods is to make them safer. Now let's switch focus to the benefits of raw food dieting versus the standard omnivorous American-type diet. For the most part, the same benefits one gets from any vegan diet. I'll try to point out any differential benefits. Benefit one, decreased cholesterol. It's well known that increased fruit and vegetable consumption is protective for heart disease, diabetes, and cancer. In fact, a single extra serving of fruit or veg per day may reduce risk of ischemic stroke by 6%. Note to my American colleagues, French fries don't count. So we shouldn't be too surprised that raw vegan diets decreases cholesterol in at least one study. Unfortunately, it decreases both the good and bad forms, HDL and LDL, so the benefit is somewhat reduced. Part of this is related to the vitamin B12 deficiency, which is associated with increased heart disease risk. Although supplementation is recommended, over half the raw vegans in this study had a functional B12 deficiency, so it's a common problem. This effect may actually outweigh the benefits from increased fruit and vegetables. So if you must eat raw, make sure your B12 levels are sufficient. It's worth noting that several studies have shown that lacto-ovo-vegetarians, those that eat eggs and dairy, actually have lower heart disease risk than full vegans, and this study may explain why. Benefit two, decreased inflammation. This is one of the clearest benefits. Cook foods are much more likely to stimulate the immune system to cause an inflammatory response. This is important in food allergy and in inflammatory intestinal diseases like colitis. There seems to be a general decrease in immune markers for inflammation, which should be good for arthritis and fibromyalgia. Some studies find a subjective response in these conditions, others don't. I'll come back to that. Benefit three, probiotics. It's relatively clear that eating foods fermented with lactobacillus has a probiotic effect. Good bacteria colonize the gut and that can cause some good things to happen, like better digestive health and decreased colon cancer risk. The effect is very temporary as we are finding all probiotics to be. When you stop eating lactobacillus, your flow are almost immediately reverged to a previous condition. Increased fiber consumption is usually associated with decreased colon cancer risk. Although I couldn't find any studies confirming that specifically for raw foods. Benefit four, weight loss. This fits in both benefit and risk, but weight loss can be beneficial for the obese or overweight. Because of the difficulty of getting enough calories from raw plant sources, this would certainly seem to be a fast way to drop a lot of weight while feeling quite full. Benefit five, low sodium. A raw vegan diet is very low in sodium and usually doesn't include the added salt that may come with processing. One study measured a hypotensive effect, a lowering of blood pressure for people who ate raw vegan. I think this might be one of the most differential benefits of raw versus cooked vegan diets because we usually add salt during cooking and preparing foods. I don't have any citations on that, so take it with a grain of salt, pun intended. It would be nice to see more studies done on this topic. Benefit six, lastly, according to one study, a raw vegan diet may have increased antioxidants compared to omnivorous cooked diet, which is good for overall health, cancer risk, diabetes, and lots of other chronic conditions. However, the favorable comparison is from raw and vegan to omnivore and cooked. When we look at another study that compares matched vegan diets, but simply puts one of the two plates into the microwave for two minutes, the benefits were the same for the cooked vegan and uncooked vegan over a period of one week. The raw versus cooked didn't have much of an effect on markers of health status. This is an important study, but unfortunately it's not in a journal I can locate, so I'm having to rely on the abstract from PubMed. But this type of study is exactly what we need to see if cooking is really as toxic as the raw foodists claim. I'd like to see it repeated over longer periods of time and with larger populations because it would seem to address my primary suspicion that uncooked is less important than high vegetable and fruit in any form. I want to examine in more depth a particular study because it deals with one final issue that needs to be addressed, the discomfort and difficulty of this diet. You recall that I mentioned the bloating diarrhea, vomiting and general digestive distress. That's a problem if this diet really does have net benefit. It's hard to keep people on it. That's what I found most striking about one study on rheumatoid arthritis. The study started with 22 patients in the raw food group, but eight dropped out because of nausea, diarrhea, and difficulties with the taste. Only five of the 22 would agree to drink the fermented wheat drink supplement because of the taste. And by the end of the three month study, only one person was still able to stomach it. Nine of the 22 had deviations from the diet more than once a day. Half of the raw food group simply couldn't finish the three month study period. The outcome of the study was fairly neutral. The raw dieters lost weight in spite of eating calorie match diets. They had subjective relief of their RA symptoms, but none of the objective criteria improved. The authors conclude that there may be some placebo effect from what patients perceived as a mystical diet. As we discovered in previous videos, the more intense the sensation, the more the placebo effect works. Is there something like that at work here? I don't know, but what really strikes me is how unpleasant this diet is to new people. How can anything that's all natural and good for you cause so much discomfort and be so difficult to stay on? Perhaps our bodies are suggesting that we maintain a little more diversity and balance. It's not a useful diet if you can't adhere to it, obviously. If you're really thinking about trying out this diet, I have one and only one bit of advice for you. Talk with a healthcare professional first. The sheer amount of bad information on the internet makes it unreliable as a basis for health advice. The way people get talked into these types of trendy new diets is usually peer pressure, curiosity, and a steady stream of misinformation. My only goal with this video was to lay out what I see as the real risks and benefits. My final summary from what I've read is that you probably get all the benefits of a raw food diet just by eating a cooked vegan diet, with the one exception that raw food is usually quite low in sodium. However, there are going to be risks with any diet, and if your body is trying to tell you something, you might try listening to it. Good health, and thanks for watching.