Eat to Beat Disease: The New Science of How Your Body Can Heal Itself

Overall score

Scientific accuracy

Reference accuracy

Healthfulness

How hard would it be to apply the book's advice? Very easy

Book published in 2019

Published by Grand Central Publishing

First Edition, Hardcover

Review posted December 4, 2019

Primary reviewer: Morgan Pfiffner

Peer reviewer: Hilary Bethancourt

Table of contents

1. Introduction
2. Scientific accuracy
3. Reference accuracy
4. Healthfulness
5. Most unusual claim
6. Other
7. Conclusion
8. Updates

Claim 1

Certain foods can reduce our risk of cancer by influencing a process called angiogenesis.

Supporting quote(s) and page number(s)

Page 357: “Foods with antiangiogenic activity can starve a tumor by cutting off its blood supply”.

Pages 3-4: “More than one hundred foods can enhance your body’s ability to starve cancer and keep those tumors small and harmless, among them soy, tomatoes, black raspberries, pomegranate, and even some surprising ones, like licorice, beer, and cheese”.

Page 105-106: “Broccoli…contains potent antiangiogenic bioactives like brassinin and sulforaphanes. Consuming one to two cups of broccoli per week is associated with a reduced risk of many cancers”

Page 108: “Seasonal berries like strawberries, raspberries, blackberries, blueberries, and cranberries can boost your body’s angiogenesis defenses. Their intense colors and tartness are a tip-off to the presence of potent bioactives, including anthocyanin and ellagic acid, both of which have antiangiogenic activity”

Criterion 1.1. How well is the claim supported by current evidence?

2 out of 4

This claim received a score of 2, meaning that the claims are weakly supported by current evidence. Throughout ETBD, a large number of foods are recommended as a way to reduce the risk of various types of cancer. The rationale for these recommendations is based on research suggesting the potential effect of some foods on angiogenesis, the process by which new blood vessels are formed. Given that cancerous tissues often rely on angiogenesis to obtain sufficient nutrients that help tumors grow, dietary factors may reduce the risk of cancer if they can disrupt their growth process.

The idea that inhibiting angiogenesis can benefit cancer is perhaps best supported by the fact that angiogenesis inhibiting medications are commonly used to treat various types of cancer, including cancers of the colon, rectum, lung, ovary, and kidney. However, it is important to note that, while clinical trials on angiogenesis inhibitors show they may improve cancer patients’ chances of survival, distinct cancer types vary in how well they seem to respond. This was perhaps most famously seen in 2011, when the FDA revoked its approval of Avastin for metastatic breast cancer after data indicated no survival benefit (in addition to considerable toxicity concerns). Furthermore, a number of cancer types, such as lung and ovarian cancer, seem to show mixed responses to angiogenesis inhibitors, with benefits to patient survival demonstrated in some studies but not others.

It is also not entirely clear to what extent food can influence angiogenesis. The existing evidence is highly preliminary, and only a few studies have been done with humans. One of the few human intervention studies found a diet rich in fiber, omega-3 fatty acids, antioxidants, and plant sterols and lower in saturated fat reduced blood levels of vascular endothelial growth factor (VEGF), an important mediator of angiogenesis. However, much of the evidence showing a possible effect of diet on angiogenesis comes from experiments on animals or cell cultures, often examining food extracts (rather than the food itself). Such experiments are hardly definitive and may not necessarily be applicable to humans.

Finally, while a dietary pattern like the one outlined in ETBD (with a focus on varied vegetables, fruits, nuts, seeds, and seafood) does generally appear associated with a lower risk of some cancers (e.g. colorectal cancer), it is unclear that any single food identified in ETBD as an “angiogenesis stimulating” or “antiangiogenic” food will have a meaningful impact on cancer risk. Importantly, although observational studies have shown an association between consumption of many of the foods recommended in ETBD and risk of cancer (many of which are outlined in the book), such studies do not demonstrate cause and effect. Moreover, any seemingly positive findings in these studies could be due to confounding (i.e., the effect of other dietary factors or health promoting behaviors that are correlated with the consumption of many purported disease-fighting foods).

Criterion 1.2. Are the references cited in the book to support the claim convincing?

2 out of 4

The references for the first claim received a score of 2 out of 4, indicating they are weakly convincing. ETBD recommends many specific foods to reduce the risk of cancer, with a primary rationale for these recommendations coming from observational studies linking consumption of a given food or food group with a lower risk of certain types of cancer. These studies are typically of high quality as far as observational studies go (e.g. prospective cohort studies). Unfortunately, the observational nature of such studies means that they are unable to isolate the protective effect of the food under investigation from the effects of other foods in the diet or other health-promoting behaviors.

Furthermore, in some cases, observational studies appear to be cited selectively. For example, ETBD discusses (on page 115) the association between red wine and reduced cancer rates, pointing out the results of the European Prospective Investigation into Cancer (EPIC)-Norfolk study which found drinking one glass of wine per day was associated with a 39 percent decreased risk of colorectal cancer. However, the same study reported no association between beer consumption and colorectal cancer. This is relevant in light of a subsequent discussion (on page 116) of the potential protective role of moderate beer consumption on cancer risk. Rather than mention the lack of association between beer and colorectal cancer in the EPIC-Norfolk study, the North Carolina Colon Cancer Study is cited, which did find moderate beer consumption was associated with a reduced risk of colon cancer.

This selectivity was also noted in a section describing the potential health benefits of berries. The book (on page 108) points to another analysis of data from the EPIC study that found that people consuming an average of 1/5 cup of berries/day tended to experience a 22 percent reduced risk of developing lung cancer; consumption of stone fruits (e.g. apples, apricots, plums, cherries), on the other hand, were not associated with risk of lung cancer in that study. Nevertheless, this lack of an association is not mentioned when discussing the relationship between stone fruits and cancer in the preceding section (page 107); instead, reference is made to the NIH-AARP Diet and Health Study, which found that consuming two medium-sized stone fruits per day was associated with an 18 percent decreased risk of lung cancer in men.

The book also references some experimental trials that test the potential of certain foods to reduce cancer growth. However, these trials sometimes have shortcomings which are inadequately discussed, or their findings are misrepresented. For example, ETBD suggests (on page 108) that black raspberries can slow the growth of precancerous colon polyps, citing a 2014 clinical trial on 14 individuals with Familial Adenomatous Polyposis (FAP), a genetic condition which leads to the development of potentially pre-cancerous intestinal tumors. In this study, daily administration of powdered black raspberry via rectal suppositories for about 9 months led to a reduction in the number of large tumors but not in the total number of tumors. Moreover, there was no control group (i.e., a comparative group of people not taking black raspberry suppositories), so this study’s results should be viewed with caution. Additionally, 7 subjects were given oral black raspberry powder and these individuals experienced no change in tumor burden or number of tumors, further challenging the claim that eating black raspberries is a viable strategy to reduce the risk of colon cancer.

Finally, one of the central pieces of evidence presented in ETBD to support the idea that manipulating the rate of angiogenesis may reduce cancer risk is the existence of angiogenesis inhibiting medications, such as Avastin (bevacizumab), which are FDA approved to treat various types of cancer. The author writes,

“The first cancer to show the benefit of antiangiogenic therapy was colorectal cancer, where targeting tumor blood vessels improved survival using a treatment called Avastin. Many other cancers have become more treatable by boosting the body’s own angiogenesis counter measuring, using Avastin and more than a dozen other designer medicines that inhibit angiogenesis. These include kidney, lung, brain, thyroid, liver, cervical, ovarian, and breast cancers, as well as multiple myeloma” (Page 10).

However, as discussed in the previous section, while some cancer patients do seem to benefit from taking the angiogenesis inhibitor Avastin, these benefits are observed inconsistently and only for some types of cancer, such as colorectal and non-squamous cell lung cancer. Other cancers, such as metastatic breast cancer, do not seem to benefit from these drugs at all.

Criterion 1.3. How well does the strength of the claim line up with the strength of the evidence?

2 out of 4

The claim received a score of 2, indicating that it is moderately overstated. ETBD cites primarily observational studies to support the dietary recommendations for maintaining optimal levels of angiogenesis. In general, the book correctly describes the findings of observational studies as associations rather than a cause and effect relationship (e.g. “food X is associated with a lower risk of cancer” rather than “food X lowers the risk of cancer”). However, there are cases when cause and effect is inappropriately insinuated, such as the claim that “soy can starve your cancer and feed your health” (page 103).

Additionally, there is often inadequate evidence to support many of the claims regarding how different foods affect angiogenesis. In many cases, claims regarding the antiangiogenic effect of foods draw from experiments in which a compound found in a food is added to a (typically cancerous) cell culture and markers of angiogenesis are measured. In some cases, these experiments were performed at the author’s own research foundation and appear to be unpublished (or at least are not cited in the book). Such cell studies are inadequate for determining the effect of diet on angiogenesis in humans. Notably, the book cites few studies that examine angiogenesis in living organisms, and the few that are referenced tend to be conducted with rodents rather than humans.

Overall (average) score for claim 1

2 out of 4

Claim 2

Certain foods can increase levels of circulating stem cells, which can boost cellular regeneration and benefit vascular health.

Supporting quote(s) and page number(s)

Page 128: “We know that specific type of stem cell called endothelial progenitor cell (EPC) supports the creation of new angiogenic blood vessels, as we saw in the last chapter. But these stem cells also repair and regenerate damaged blood vessels caused by aging and high cholesterol, protecting cardiovascular health”.

Page 130: “Foods that mobilize stem cells help counteract and prevent organ damage that invariably developed with aging. Stem cells can also reverse the ravages of diabetes, cardiovascular disease, smoking, high cholesterol, and obesity. Imagine if patients recovering from a heart attack of stroke, for example, could dine on a menu at the hospital or at home designed to activate stem cells to repair their hearts and brains and speed recovery. Imagine if they had started with a regenerative diet as children or young adults. They might have been able to dodge the disease altogether”.

Page 131-132: “A wide variety of foods, including cocoa, are being studied for their beneficial effects on our stem cells. By supporting out body’s regenerative defense systems, these foods can help influencing everything from repairing damaged organs to counterbalancing the effects of eating too much fat”.

Page 139: “When the researchers measured the blood vessel stiffness of people who consumed black raspberry powder, they found there was a reduction in the stiffness over the twelve weeks, reflecting healthier blood vessels and the beneficial effects of more circulating stem cells”.

Criterion 1.1. How well is the claim supported by current evidence?

2 out of 4

This claim received a score of 2, indicating the claim is weakly supported by current evidence. The possible protective role of circulating stem cells on health conditions, such as heart disease, is a source of continued research and controversy. Nonetheless, some evidence suggests certain types of stem cells may have a beneficial effect on cardiovascular health. One type, called endothelial progenitor cells (EPCs), rise in circulation immediately following a heart attack or stroke, possibly as a mechanism to help repair vascular damage accompanying these events. Lower levels of EPCs are found in relation to factors that increase cardiovascular disease risk, such as diabetes, high blood pressure, and cigarette smoking, although it is unclear to what extent the reduction in these stem cells actually contributes to cardiovascular disease in these contexts. A 2016 meta-analysis of observational studies reported a possible association between low levels of circulating progenitor cells (including certain types of EPCs) and risk of dying from cardiovascular disease. However, only some of these studies adjusted for risk factors such as diabetes, hypertension, and smoking and, additionally, the associations observed between EPC levels and cardiovascular outcomes were generally inconsistent.

Clinical evidence on the benefits of increasing circulating stem cells for cardiovascular disease reduction or prevention as it currently exists is mixed. A meta-analysis of 12 clinical trials found no evidence that coronary infusions of stem cells into the hearts of heart attack survivors protected against the risk of future heart attacks, strokes, or death. In contrast, another meta-analysis of 48 trials examining the effect of bone marrow cell therapy on a broader range of patients (including but not limited to those with heart failure and ischemic heart disease) reported small but significant improvements in some clinical outcomes, including a reduction in the risk of death. Still, one limitation with the studies included in this meta-analysis is that they often utilized a broad category of stem cells and therefore were not isolating the effect of EPCs.

Certain foods do appear to be able to influence circulating levels of stem cells. Controlled human studies have found, for instance, that fatty fish, monounsaturated fat (e.g. olive oil) as a replacement for saturated fat, and high flavanol cocoa may increase levels of EPCs in the bloodstream, although this research is somewhat preliminary. Additionally, no cardiovascular benefits of these foods has been connected to their effect on circulating EPC levels.

Criterion 1.2. Are the references cited in the book to support the claim convincing?

2 out of 4

The book’s references for this second claim received a score of 2, indicating they are weakly convincing. ETBD supports many of its claims with peer reviewed studies, including some human clinical trials. However, numerous references are to studies performed on cell cultures or animals, often using food extracts (such as chlorogenic acid and zeaxanthin) rather than food itself. Such studies are not necessarily generalizable to humans and do not convincingly support claims that whole foods will have the same health effect as concentrated extracts.

The specific foods promoted in the book for their potential to support cellular regeneration by increasing stem cells include cocoa, omega-3 fatty fish, squid ink, whole wheat, green beans, rice bran, turmeric, black raspberries, Chinese celery, mangoes, red wine, beer, green tea, and black tea. The only whole foods (excluding studies on food extracts) that were backed by references to human-based studies were high flavanol cocoa, black raspberries, red wine, beer, green tea, and black tea.

Some citations regarding the effect of foods on circulating EPC levels appear to be selectively cited. ETBD cites a study which found green tea increased EPC levels in smokers (page 143), but fails to cite a separate study which found no effect of green tea on EPC levels in people with kidney failure. While discussing potential benefits of red wine (pages 141-142), the book references a study in which daily consumption of half a glass of red wine increased EPC levels in the blood while daily consumption of beer containing the same level of alcohol did not increase EPC levels. Shortly thereafter ETBD discusses the potential benefits of beer (pages 142-143), this time referencing a different study which found daily consumption of two regular beers did increase EPC levels.

There is also limited evidence provided in the book to support the claims that foods with the potential to increase EPC levels are actually effective at reducing the risk of cardiovascular disease. There are caveats to the referenced observational studies suggesting a cardiovascular benefit from consuming cocoa, whole wheat, red wine, and beer. First, as mentioned previously, observational studies cannot adequately isolate the effects of any given food from the effects of the overall dietary and lifestyle patterns that correlate with the consumption of that food. Second, no cited studies examined whether EPCs were a mediating factor (i.e., whether the food was associated with reduced cardiovascular disease risk because of its effect on EPCs). Furthermore, in the case of red wine and beer, it is worth noting that, while moderate alcohol consumption is sometimes associated with a lower risk of coronary heart disease, a 2017 meta-analysis found no evidence that alcohol was protective when controlling for other important factors, including people’s age, smoking habits, social status, and abstainer bias (the possibility that people who never drink alcohol often do so because of ill health). ETBD contends that certain bioactive compounds found in red wine and beer, rather than alcohol itself, account for the potential benefits of these beverages, and ETBD cautions the reader that alcohol itself is harmful. However, that simply illustrates why it is important to focus on the health effects of whole foods or beverages as opposed to just specific compounds found in a given food/beverage, and it calls into question the promotion of wine or beer, given the potential health tradeoffs of consuming them.

Criterion 1.3. How well does the strength of the claim line up with the strength of the evidence?

3 out of 4

The claim received a score of 3, indicating it is slightly overstated, particularly since most of the research cited is based on studies with animals and cultured cells and the use of extracts or isolated compounds from a given food as opposed to the whole food. ETBD tempers its claims by not stating an absolute link between dietary factors and vascular health via stem cells and does cite a handful of randomized clinical trials (RCTs) performed with humans, though of the roughly eight RCTs cited looking at the effect of dietary factors on EPCs, two used food extracts (one from Chinese celery seeds and the other from black raspberries) and only one intervention lasted longer than 30 days (at 12 weeks). Additionally, even if the cited research were to provide strong support that the recommended foods could increase circulating stem cells, it still would not in and of itself demonstrate that the increase in stem cells would be sufficient to prevent or treat cardiovascular disease to a meaningful degree.

Overall (average) score for claim 2

2.3 out of 4

Claim 3

Dietary factors can impact metabolic health by influencing the intestinal microbiome.

Supporting quote(s) and page number(s)

Page 157: “A gut bacteria called Akkermansia muciniphilia makes up 1 to 3 percent of all the bacteria in the gut microbiome. But this small population can have a mighty impact. Akkermansia can help control the immune system, improve blood glucose metabolism in the body, decrease gut inflammation, and combat obesity.”

Page 159: “Disturbances of the microbiome, called dysbiosis, are now being discovered in serious health conditions ranging from obesity to metabolic syndrome to type 2 diabetes, and more.”

Page 166: “(Lactobacillus casei and Lactobacillus rhamnosus) have been observed to have beneficial activity against gastroenteritis, diabetes, cancer, obesity, and even postpartum depression.”

Page 186: “These studies show how synthetic food can impact the microbiome. In the case of artificial sweeteners, the potential consequences may influence how the gut bacteria control blood sugar metabolism and weight gain.”

Criterion 1.1. How well is the claim supported by current evidence?

3 out of 4

This claim received a score of 3, indicating that it is moderately supported by current evidence. ETBD makes occasional reference to the notion that our microbiome influences our body weight and risk of obesity, but the role of the microbiome on body weight appears fairly uncertain. Gut microbiome changes have been associated with obesity in some studies, though this evidence is far from consistent. Probiotic supplementation may help reduce body weight, possibly demonstrating a role of the microbiome in body weight regulation, but the effects are generally small (i.e., less than a kilogram of weight loss). One study tested whether gut bacteria impact body weight by giving a fecal microbiota transplant from lean individuals to individuals with obesity. At both 6 weeks and 18 weeks following this transplant no effect on body weight was observed. A similar finding was observed in a 12 week study in which a fecal transplant from a very lean person to 22 individuals with obesity resulted in no change in BMI. Hence, it remains unclear if and how we can effectively alter the microbiome so as to promote lasting weight loss and prevent or reverse obesity.

ETBD also discusses ways in which our microbiome may influence insulin resistance and blood sugar regulation. This is an area where the evidence appears more compelling. Preliminary research has found the gut microbiome can differ across individuals with normal glucose tolerance, impaired glucose tolerance (pre-diabetes), or type 2 diabetes. Additionally, changes to the microbiome may also explain (at least partly) the effect of various interventions on blood sugar control:

• In one study, the diabetes medication Metformin seemed to improve insulin sensitivity in part by changing the gut microbiome, possibly by reducing levels of the bacteria Bacteroides fragilis.
• Ingestion of high doses of the artificial sweetener Saccharin altered the gut microbiome (including causing an increase in Bacteroides fragilis) and increased the risk of glucose intolerance in mice and 4 out of 7 humans in a series of experiments performed by a research group.
• A study on men with obesity found that taking the antibiotic vancomycin for 7 days produced changes the gut microbiome while also decreasing insulin sensitivity.
• A 2016 meta-analysis of seven randomized controlled trials reported probiotic supplementation tended to help reduce fasting blood glucose and measures of insulin resistance if supplementation lasted more than 8 weeks.

• In the previously discussed fecal transplant study examining the effect of a microbiota transplant from lean to obese individuals, a secondary analysis observed that insulin sensitivity improved 6 weeks after the procedure, although this effect disappeared 18 weeks after the procedure (potentially due to loss of microbiome changes).

While evidence does point to a role of the microbiome in potentially influencing metabolic health, understanding how dietary factors interact with and/or affect the microbiome to produce metabolic benefits is a more challenging question.

A diet rich in fiber is frequently proposed as being beneficial to the composition of the gut microbiota. However, while dietary fiber (particularly viscous fiber) does appear to improve markers of metabolic health and insulin sensitivity (albeit with a fair amount of heterogeneity in clinical studies), it can be difficult to determine whether these benefits are due to fiber changing to the microbiome or other effects, like delaying gastric emptying and/or minimizing rises in blood glucose after meals. One study did find that consumption of fiber lowered a marker of average blood sugar (HbA1c) in people with type 2 diabetes and this effect appeared linked to changes in the microbiome. However, more research is needed to understand how microbiome changes modulate the effects of fiber on glucose control.

Another area of study involves the health-promoting gut bacteria, Akkermansia muciniphila. In addition to improving metabolic health in several mouse studies, one RCT on humans found oral supplementation of Akkermansia muciniphila seemed to boost insulin sensitivity compared to a placebo (surprisingly, this effect occurred even if the bacteria had been killed first). Preliminary evidence (drawing heavily on animal experiments) suggests certain dietary factors may increase levels of Akkermansia muciniphila, including certain polyphenols (e.g. from grapes, cranberries, and pomegranate), a ketogenic diet, and reduced calorie diets, although the evidence for these factors is fairly preliminary.

All in all, the available evidence suggests the microbiome may influence metabolic health to some extent, though its effect on body weight remains questionable. Meanwhile, the effect of diet on the microbiome and subsequent effects on metabolic health remains a complex topic requiring and deserving further study.

Criterion 1.2. Are the references cited in the book to support the claim convincing?

2 out of 4

The book’s references for claim 3 received a score of 2, indicating that they provide weak support for the claim. There are notable gaps in much of the research provided, with some cited studies indicating that certain foods may alter the composition of the gut microbiome and other studies indicating that certain foods can affect metabolic health. However, few studies provide evidence of a clear connection among each of these factors together. For example, ETBD cites human intervention studies that reported potentially beneficial shifts in the composition of the gut microbiome following consumption of certain foods and food extracts, including red wine, cocoa, cherries, kiwi, pomegranate extract, yogurt, and walnuts. These studies did not, however, examine any shifts in metabolic health outcomes, such as changes in blood sugar or insulin resistance, as a result of microbiome changes. Given remaining ambiguity regarding what even constitutes a “healthy” microbiome, it is unclear how to interpret the health implications of studies that examine diet-related shifts in the microbiome but not the downstream changes in  health markers.

In contrast, some referenced studies tested the effects of certain foods on markers of metabolic health but did not examine whether microbiome changes accounted for any of those effects. For example, it is inferred in the book that shifts in the microbiome were responsible for improvements in several metabolic health markers noted in two randomized crossover studies in response to supplementing participants’ diets with fermented versus fresh kimchi. However, neither of those studies actually tested if and how the microbiomes of their study participants actually changed in response to the fermented kimchi, much less whether those changes explained the observed improvements in metabolic health markers.

Additionally, there is heavy reliance on experiments conducted with mice and rats to suggest certain bacterial species play a role in metabolic health. Rodent studies provide a good starting point for generating hypotheses and studying the mechanisms of how diet influences the microbiome and, thereby, metabolic health. However, they cannot provide conclusive evidence that the same microbiome and metabolic shifts observed in response to a given food or diet will likewise occur in humans.

Criterion 1.3. How well does the strength of the claim line up with the strength of the evidence?

2 out of 4

The third claim received a score of 2 in this section, indicating that the claims were moderately overstated. There is evidence to support the concept that the gut microbiome influences metabolic health, at least to some extent, and the strength of the author’s claims are often in line with this. The role of diet, on the other hand, seems to be oversold, given that few studies have been able to effectively demonstrate that dietary factors lead to improvements in metabolic health as a result of changes to the microbiome. Additionally, claims related to body weight (e.g. certain commensal bacteria “combat obesity” and such bacteria can be increased via diet) seem overstated given minimal evidence of a clear relationship in this regard.

Overall (average) score for claim 3

2.3 out of 4

Overall (average) score for scientific accuracy

2.2 out of 4

 

Reference 1

Reference

Chapter 8, reference 27.  An SY, et al. Beneficial effects of fresh and fermented kimchi in prediabetic individuals. Ann Nutr Metab. 2013;63(1-2):111-9.

Associated quote(s) and page number(s)

Pages 163-164: “Researchers from Ajou University in Korea studied twenty-one middle-aged individuals with prediabetes and metabolic syndrome…the purpose of the study was to determine if kimchi could improve their metabolic status and see if there are differences between fresh versus fermented kimchi…the fresh kimchi had 15 million Lactobacillus per milliliter, while the fermented kimchi contained 6.5 billion bacteria per milliliter, or 433 times more than the fresh…across the board, fermented kimchi, which had more bacteria, had a greater effect than fresh kimchi. Eating fermented kimchi significantly lowered body fat mass by 6 percent compared to 3.9 percent for fresh kimchi, meaning the fat loss was 1.6 times better. The fermented kimchi eating group also had a 2 percent decrease in body fat percentage, while there was no significant change in the fresh kimchi group. The group eating fermented kimchi also experienced a significant lowering of their blood pressure…the participants eating fermented kimchi had a 33 percent improvement in their glucose tolerance test.”

Criterion 2.1. Does the reference support the claim?

3 out of 4

This reference received a score of 3, indicating that it offers moderate support for the claim. The referenced study did observe a reduction in body fat in individuals eating fermented kimchi compared with fresh kimchi. Those eating the fermented kimchi also experienced a reduction in blood pressure. However, while one measure of glucose tolerance (QUICKI) suggested an improvement in the group consuming fermented kimchi, another measure of glucose tolerance (Matsuda index) showed no difference between groups.

Reference 2

Reference

Chapter 5, reference 18. Huang EY, et al. The role of diet in triggering human inflammatory disorders in the modern age. Microbes Infect. 2013 Nov;15(12):765-74

Associated quote(s) and page number(s)

Page 91: “Autoimmune conditions are increasing in modern societies. While the exact cause is not known, the phenomenon has been linked to unhealthy diets. This may also be tied to dysbiosis of the gut microbiome, which then disrupts the normal control of the immune system”.

Criterion 2.1. Does the reference support the claim?

3 out of 4

This reference received a score of 3, indicating it is moderately convincing. The reference is to a review article covering some evidence suggesting that characteristics of a so-called “Western” diet, such as high consumption of refined carbohydrates and omega-6 fatty acids from vegetable oils, may increase the risk of inflammatory diseases, such as rheumatoid arthritis and irritable bowel disease, in part through changes in gut bacteria. The evidence in this review appears sufficient to establish this as a compelling hypothesis. However, ETBD generalizes the findings from this paper to all autoimmune conditions, while this review only appears to examine a few autoimmune diseases (specifically, rheumatoid arthritis, Crohn’s, and ulcerative colitis).

Reference 3

Reference

Chapter 12, reference 4. Suresh D, Srinivasan K. Tissue distribution & elimination of capsaicin, piperine and curcumin following oral intake in rats. Indian J Med Res. 2010 May;131:682-91.

Associated quote(s) and page number(s)

Page 283: “Black pepper: Contains piperine that increases the absorption of other food bioactives, like curcumin in turmeric.”

Criterion 2.1. Does the reference support the claim?

2 out of 4

This reference received a score of 3, indicating it is weakly convincing. While this study did report an increased absorption of curcumin in rats consuming piperine, a component of black pepper, the dose used was very high at 170 mg piperine per kg of body weight. To put this in perspective, assuming a maximum piperine concentration of black pepper at around 7.4% by weight, someone weighing 70kg (154lbs) would need to consume at least 160 grams, or more than a third of a pound of black pepper, to achieve this dose. Consequently, this reference does not provide convincing support that black pepper, when consumed in the small amounts typical for most human populations, would have a meaningful impact on the absorption of bioactives from other foods.

*Note: The random number generator initially produced a reference that simply referred to an olive oil company (“Provided by Deoleo Company, in Cordoba, Spain” for the quote, “One group received extra virgin olive oil from Spain in liquid and spreadable form”) rather than an actual study or any specific claim. As a result, we randomly selected a new reference for this section.

Reference 4

Reference

Chapter 13, reference 25. Fadelu T, et al. Nut Consumption and Survival in Patients With Stage III Colon Cancer: Results From CALGB 89803 (Alliance). J Clin Oncol. 2018 Apr 10;36(11) 1112-1120.

Associated quote(s) and page number(s)

Page 302-303: “Even more stunning was the study from thirteen major cancer centers, including Harvard University, Duke University, the University of California, San Francisco, and the University of Chicago, that showed eating just two servings of tree nuts per week was associated with a whopping 53 percent reduction in the risk of death in patients with stage 3 colon cancer who were being treated with conventional chemotherapy.”

Criterion 2.1. Does the reference support the claim?

4 out of 4

This reference received a score of 4, indicating it provides strong support for the claim. The study did find a 53 percent reduction in risk of death associated with eating at least one ounce of tree nuts more than once per week among individuals with stage III colon cancer. However, it is worth pointing out that this was an observational study that measured nut consumption through retrospective questionnaires, which can provide only rough estimates of nut intake. Moreover, it is important to remember that people eating more tree nuts may also tend to be those eating overall healthier diets and fewer unhealthy foods. In fact, because the analyses controlled for estimated total caloric intake, an increase in nut consumption (a calorically-dense food) would necessarily require a lower consumption of other calorically-dense foods. Hence, this study is unable to isolate the effects of nut consumption from the potential effects of eating fewer of the foods that people not eating nuts consume.

Reference 5

Reference

Chapter 6, reference 46. Kayashima T, et al. 1,4-Naphthoquinone is a potent inhibitor of human cancer cell growth and angiogenesis. Cancer Lett. 2009 Jun 8;278(1):34-40.

Associated quote(s) and page number(s)

Page 112: “At Hiroshima University in Japan, scientists studying vitamin K2 discovered that it potently suppresses angiogenesis and growth of colon cancer cells.”

Criterion 2.1. Does the reference support the claim?

1 out of 4

This reference received a score of 1, indicating that it is not convincing. The cited study looked at the effect of 1,4-Napthaquinone on colon cancer cell growth and tissue angiogenesis in vitro (i.e., in test tube experiments). It is misleading to suggest this study demonstrated an effect of vitamin K2. While vitamin K2 contains 1,4-Napthaquinone as part of its chemical structure, the two compounds are nevertheless different and won’t necessarily have the same effects.

Reference 6

Reference

Chapter 5, reference 14. Serrano PE, Khuder SA, Fath JJ. Obesity as a risk factor for nosocomial infections in trauma patients. J Am Coll Surg. 2010 Jul;211(1):61-7.

Associated quote(s) and page number(s)

Page 89: “Obesity suppresses the immune system. Studies show that individuals who are obese are at a higher risk for developing an infection after suffering trauma or while being in an intensive care unit compared to non-obese people. This is because their immunity is lowered by their metabolic (obese) state).”

Criterion 2.1. Does the reference support the claim?

4 out of 4

This reference received a score of 4, indicating that it offers strong support for the claim.

Reference 7

Reference

Chapter 6, reference 20.  Bhandari, S.R., Cho, MC. & Lee, J.G. Genotypic variation in carotenoid, ascorbic acid, total phenolic, and flavonoid contents, and antioxidant activity in selected tomato breeding lines Hortic. Environ. Biotechnol. (2016) 57: 440.

Associated quote(s) and page number(s)

Page 105: “A study of 119 different types of tomatoes showed that cherry tomatoes have 24 percent more lycopene than other types of tomatoes.”

Criterion 2.1. Does the reference support the claim?

4 out of 4

This reference received a score of 4, indicating that it offers strong support for the claim. Of the commercial cultivars tested, cherry tomatoes had, on average, 24% higher lycopene than non-cherry tomatoes. However, not every cherry tomato cultivar had a higher lycopene content than non-cherry tomatoes.

Reference 8

Reference

Appendix B, reference 7.  “FDA allows marketing of first direct-to-consumer tests that provide genetic risk information for certain conditions” U.S.Food and Drug Administration, Apr. 6, 2017, https://www.fda.gov/news-events/press-announcements/fda-allows-marketing-first-direct-consumer-tests-provide-genetic-risk-information-certain-conditions”

Associated quote(s) and page number(s)

Page 386: “Your saliva contains DNA, and you can send it away to test for risk markers of cancer, Parkinson’s disease, late-onset Alzheimers disease, celiac disease, and rare disorders (hereditary thrombophilia, hereditary hemochromatosis, glucose-6-phosphate dehydrogenase deficiency, early-onset primary dystonia, and alpha-1-antitrysin (sic) deficiency”.”

Criterion 2.1. Does the reference support the claim?

4 out of 4

This reference received a score of 4, indicating that it offers strong support for the claim. The linked article describes how, following FDA approval, consumers can send samples of their saliva to a company to be tested for genetic risk information, specifically whether a person’s genetic variants are associated with a higher risk of the diseases mentioned in the quote (the reference does not directly mention risk of cancer, which was approved later).

Reference 9

Reference

Chapter 8, reference 72.  Biagi E, Nylund L, Candela M, Ostan R, Bucci L, Pini E, Nikkïla J, Monti D, Satokari R, Franceschi C, Brigidi P, De Vos W. Through ageing, and beyond: gut microbiota and inflammatory status in seniors and centenarians. PLoS One. 2010 May 17;5(5):e10667

Associated quote(s) and page number(s)

Page 180-181: “Aging mice have lower levels of Firmicutes and Bacteroidetes, but shiitake consumption increased amounts of these bacteria in aging mice by 115 percent [citing a different study]. In humans, an interesting study of centenarians, or so-called super-agers, showed these same patterns of gut microbiota.”

Criterion 2.1. Does the reference support the claim?

1 out of 4

This reference received a score of 1, indicating that it does not convincingly support the book’s claim.  This study analyzed the microbiota of individuals in different age categories, specifically 20 young adults (25 to 40 years old), 22 elderly (63 to 76 years old), and 21 centenarians (99-104 years old). However, in contrast to the claim made in the book, this paper found no significant difference in the proportion of Firmicutes or Bacteroidetes bacteria of the gut microbiota of centenarians compared with the other two age groups. While decreases in bacterial “diversity” as well as some so-called “rearrangements” of bacteria among the Firmicutes phylum were observed, this is a different finding than what was claimed. Moreover, the study does not look at an effect of shiitake mushrooms on these bacteria in human populations, so the concluding sentence immediately following the claim cited (“In both mice and people, shiitake mushrooms may be able to reverse the changes to the microbiome that typically accompany old age) above is also unfounded.

Reference 10

Reference

Chapter 2, reference 7.  Petit I, Jin D, Rafii S. The SDF-1-CXCR4 signaling pathway: a molecular hub modulating neo-angiogenesis. Trends Immunol. 2007 Jul;28(7):299-307.

Associated quote(s) and page number(s)

Page 21: “Like a guided missile zeroing in on its target, the stem cell finds its landing spot. Proteins on the stem cell called receptors attach to proteins in the landing zone. They hook together like cellular velcro, ensuring the stem cells attach only to the site of injury.”

Criterion 2.1. Does the reference support the claim?

4 out of 4

This reference received a score of 4, indicating that it offers strong support for the claim.

Overall (average) score for reference accuracy

3 out of 4

Summary of the health-related intervention promoted in the book

ETBD recommends more than two hundred foods which can be included in one’s diet. The specific intervention promoted in the book is to choose 5 foods, one from each of the 5 lists (for each of the 5 health defense systems) to consume during one of 5 potential eating occasions each day. The foods on each list includes a wide variety of vegetables and fruits, as well as nuts, seeds, legumes, seafood, some dairy products, and a few grains. For instance, the list of so-called “antiangiogenic foods” includes around 30 types of fish/shellfish, 25 vegetables, 23 fruits, 13 nuts/seeds, and 6 varieties of cheeses. ETBD also discusses (to a limited degree) some foods to avoid or restrict, including grilled meats, sugar sweetened beverages, artificial sweeteners, large amounts of salt, large amounts of saturated fat, and a high intake of omega-6 (i.e. seed oils).

Condition targeted by the book, if applicable

Many common chronic, degenerative conditions are covered, with some of the prominent ones including cancer, cardiovascular disease, diabetes, Alzheimer’s disease, obesity, autoimmune disorders.

Apparent target audience of the book

This book appears to be written for a general audience, especially individuals interested in avoiding or managing chronic health conditions, such as those mentioned previously.

Criterion 3.1. Is the intervention likely to improve the target condition?

2 out of 4

The intervention received a score of 2, indicating that it is likely to slightly improve the targeted conditions. On the one hand, the recommendations could lead to a dietary pattern with at least some resemblance to a plant and seafood rich Mediterranean style diet, which some evidence suggests may protect against a number of health conditions. However, disentangling the protective elements within such a diet can be difficult, if not futile. It is not well established whether adding a handful of specific foods to one’s diet can substantially reduce the risk of the various diseases and health conditions outlined in this book, particularly if such additions do not sufficiently improve the overall quality of the diet.

Criterion 3.2. Is the intervention likely to improve general health in the target audience?

3 out of 4

The intervention received a score of 3 in this section, indicating that it would likely moderately improve general health. The extent to which the intervention would improve general health is unknown. Yet adding vegetables, fruits, nuts, seeds, legumes, and seafood while also limiting fried foods and sugar sweetened beverages would likely improve general health, at least among those who are not already consuming many healthy plant-based foods. However, the effect of the recommended diet on the general health of the target audience will likely depend on the baseline diet and the degree to which the foods recommended in the book replace (rather than just supplement) unhealthy foods in the diet. For those who already eat a whole foods diet and who consume a wide variety of plant-based foods, simply adding in a daily dose of any given food listed in this book may not lead to a substantial health improvement.

Criterion 3.3. Does the diet portion of the intervention promote an adequate nutrient intake for general health in the target audience?

3 out of 4

The diet received a score of 3 in this section, indicating that it is likely more than nutritionally adequate. Because readers are encouraged to pick and choose from lists of many different types of foods, it has the potential to lead to increased dietary variety, which should promote adequate nutrient intake.

Overall (average) score for healthfulness

2.7 out of 4