Is the “Zinc challenge” test a reliable way to assess one’s zinc status?
The “Zinc challenge” test has been promoted by some websites as a way to assess a person’s zinc status. This principle of the “Zinc challenge” test is to put a liquid zinc dietary supplement into your mouth. If you experience a dry, mineral aftertaste you are diagnosed with zinc deficiency and you are recommended zinc supplements. According to Consumerlab.com, the form of zinc used in the “Zinc challenge” test is zinc sulfate monohydrate, which causes a dry mouth feel due to its specific reaction with proteins found in your mouth. Thus, regardless of your zinc status, it is very likely that you will develop a dry, mineral aftertaste. Thus, any diagnosis of zinc status using this test are likely misleading.
Is Himalayan salt a health food item or snake oil?
Many claims can be found on many websites regarding nutrient content and health advantages of using Himalayan salt. The majority if not all of these claims are completely bogus or unproven. For example, one of the claims states that Himalayan salt has been kept in an pure “environment of zero exposure to toxins and impurities” or that it contain no “pollutants.” Yet, another claim regarding this salt states that it contains 84 minerals that include “lead, lithium, arsenic, cadmium, mercury, polonium, uranium, and plutonium.” If the mineral content listed is correct, it means that Himalayan salt contains some of the most potent toxins the world has ever seen. For example, less than 10 pounds of plutonium, if distributed evenly on earth, it would poison every living soul on the planet. The claims on the health effects of the Himalayan salt are unproven, simply because no study ever has been done to support any of the claims. However, common sense would tell us that many of the claims simply cannot be true and are made up. For example, one of the claims says that it “aids in vascular health.” If anything, salt intake when ingested in higher than recommended quantity, is detrimental to vascular system. Another claim states that it “increases bone health.” Studies have shown that sodium intake is associated with calcium loss and lower bone density. Thus, if anything, salt may contribute to weakening of bone health. Individuals who make the different claims about Himalayan salt often contradict themselves in their statements (as in claiming that it contains no toxins and then listing the most potent toxins known as being among the ingredients found in the salt), which should help consumers determine whether the claims are reliable or bogus.
Is it true that a vegetarian diet can reverse atherosclerosis?
Yes, it is. All studies in which the effect of vegetarian or vegan diet on atherosclerosis was assessed have shown a regression of the disease. One of the most interesting studies showing the effectiveness of a vegetarian diet was conducted under the direction of Dr. Ornish. He included 28 individuals between 35 and 75 years old who had coronary heart disease documented by angiography. Patients, in addition to a low-fat vegetarian diet, underwent a stress management seminar and were engaged in moderate physical activity. Arterial narrowing, a result of atherosclerosis, in coronary arteries of these individuals were reduced from 40.0 to 37.8 percent after just one year of treatment. Among patients with initial deposits of 50.0 percent or higher, a reduction on average from 61.1 to 55.8 percent was noticed. Among people who did not make dietary or other lifestyle modifications included in this study, cholesterol deposits increased on average from 42.7 to 46.1 percent. Among those with initial size of these deposits higher than 50 percent, they increased from 61.7 to 64.4 percent. although these patients, in addition to consuming a vegetarian diet, also made other lifestyle changes, the best results, in terms of disease regression, were found among those with the strictest adherence to the diet. The results were summarized as follow: “Comprehensive lifestyle changes may be able to bring about regression of even severe coronary atherosclerosis after only 1 year, without use of lipid-lowering drugs.”
Is it true that virgin olive oil causes detrimental changes to arteries consistent with atherosclerosis?
The claim that extra virgin olive oil causes detrimental changes in the surface of arteries that contribute to atherosclerosis originated from a few popular promoters of a vegan diet, who, it seems have a bias against the use of any oil. This claim is not true. Please read my article on olive oil found in the Blog section of my website. I address this issue in more details in a subsection of this article.
Is it true that coconut oil is better for frying than other types of oils?
The claim that coconut oil is better for frying compared to other types of oils is based on the assumption that coconut oil has a very high smoke temperature, higher than the smoke temperature of other oils. In fact, the opposite is true. Coconut oil has lower smoke temperature than most other available in grocery stores oils, including extra virgin olive oil, canola oil, soybean oil, corn oil, sunflower seeds oil, or peanut oil. Some scientist suggested that, for this reason, coconut oil “is not recommended for continuous deep-fat frying because of its low smoke point, which may lead to the production of potentially carcinogenic substances upon overheating.”
What are some of the health effects of coconut water?
Both coconut water and oil have recently been heavily promoted in the media as health products. Many beneficial for our health claims have been spread via different websites and other media. Unfortunately, many of these health claims have not been based on credible research findings. Other claims have been extrapolated from studies that did not use coconut water or oil as a treatment option but used specific components that are similar to those found in coconuts (e.g. medium chain fatty acids), which may or may not be applicable to using coconuts, coconut water or oil. Consumers should keep in mind that contrary to what many proponents of coconut water or oils claim: 1) there are no miracle foods, 2) foods, even the healthiest, should be used in moderation, to ensure a variety, and 3) even food perceived to be the healthiest may have some side effects. Specifically, when it comes to coconut water, cases of hyperkalemia (high potassium in the blood) have been reported in medical literature after drinking excessive amounts (11 oz per day), (Circulation: Arrhythmia and Electrophysiology. 2014;7:180-181).
Isn’t it proven that one can live longer on a ketogenic diet than on any other type of diets?
Let me first explain what a ketogenic diet is. Normally speaking glucose is the main fuel for the body. However, when people limit intake of carbohydrates, which results in inadequate glucose supply, the body uses fat to make energy and in the process ketone bodies often referred to as ketones are formed. Ketones can be used for energy although it is not a preferred fuel source. Thus, any diet that limits carbohydrate intake (e.g. low carb/high protein/high fat diet) will result in using ketones for energy.
The idea that ketogenic (this word means making ketones) diet results in a longer lifespan than one that is high in carbohydrates is based on one study. In this study, experimental animals were given: group 1 – high carbohydrate diet; group 2 – low carbohydrate diet; and group 3 – ketogenic diet. In reality, the diet given to group 2 and group 3 was a ketogenic diet but since group 3 received less carbohydrate than group 2, that diet was called a ketogenic diet. The results showed that animals from group 3 lived the longest, while animals from group 1 the shortest.
In order to make sense of the findings we need to look into the details of this study. If we do that we will find out that these animals were not given a diet as we would consider a diet to look like. A diet is usually composed of a variety of products that include some grains, fruits, veggies, meat, etc. These animals were given: group 1 – corn meal, glucose, sucrose and soybean oil; group 2 – sucrose, soybean oil and lard; and group 3 – soybean oil and lard. In addition, animals from each group received a cocktail of vitamins and minerals. Thus, any findings of this study have NO application to any human being except for those who diet is composed of corn meal, glucose, sucrose, soybean oil and lard. I do not know of a single human being who eats or who would like to eat such a diet. In reality, a healthy diet should be composed of a variety of foods. These foods, in addition to carbohydrates, protein, fat, vitamin and minerals, are composed on tens of thousands of other compounds, such as phytochemicals. They compounds interact with each other and they have been shown to impact our health. Thus, the only conclusion that we should make based on the study described above is the following: DO NOT EAT LIKE THAT AT HOME!
Is it true that pesticides can increase risk of Alzheimer’s disease?
Yes. A number of studies linked exposures to pesticides with risk of Alzheimer’s disease. In a meta-analysis, based on seven studies, it was shown that life time exposure to pesticides increased the risk by 37%. Although more people think of fruits and veggies when it comes to pesticides, studies have shown that fish, meat and animal products are contaminated with them to much higher levels. Thus, in order to reduce pesticides exposure, consider becoming a vegetarian.
Should I be eating five or six smaller meals a day vs. three larger meals?
The idea that it is better to eat more smaller meals a day (e.g. five or six) vs. three larger meals has been quite recently adopted by some dietitians to promote weight loss. However, there is little to no scientific credibility of this dietary advise. According to recent meta-analysis that assessed the impact of meat frequency on weight loss, “Feeding frequency was positively associated with reductions in fat mass and body fat percentage as well as an increase in fat-free mass. However, sensitivity analysis of the data showed that the positive findings were the product of a single study, casting doubt as to whether more frequent meals confer beneficial effects on body composition.” This meta-analysis was based on 15 studies. The statement above seems to indicate that the efficacy of weight loss by increasing food frequency is based on one study, which can be called an outlier. A quote from another publication seems to also cast doubts on the efficacy of the practice: “It is common practice for weight management clinicians to recommend increasing meal frequency as a strategy for weight management and to improve metabolic parameters. However, limited research exists investigating the effect of meal frequency during controlled hypocaloric dietary interventions. Furthermore, meal frequency literature often speculates with regard to efficacy of meal frequency treatments based on research using normal weight, overweight/obese, or some combination, where much diversity exists within these various populations.” The authors of this quote suggest that the idea that meal frequency is efficacious in weight loss is a speculation. I would like to also mention that there are studies that indicate that increasing meal frequency may actually be detrimental to weight loss. For example, participants of one study were divided into two group. The first was consuming three meals per day, while the other one six meals. Throughout the study, participants of the first group felt fuller, had less desire to eat and felt less hungry than their counterparts who consumed six meals. Since at least some people who are overweight or obese have a hard time controlling what and how much they eat, giving them permission to eat more frequently will certainly not help them to lose weight. Only small, growing and active children and adolescents may need the extra nutrients and calories from an additional meal of snack. Adults will do best if they limit their food intake to no more than three meals per day.
Is it better to eat margarine or butter?
Ideally, it would be best to use alternatives to margarine and/or butter, such as avocado, hummus, nut spreads, other types of spreadable mixtures made of a combinations of nuts, seeds and legumes. These alternatively are very high in dietary fiber and loaded with beneficial nutrients. Soft margarines with added omega03 fatty acids EPA and DHA along with plant sterols and stanols (such margarines have these items listed in the ingredients section on the back of the label) would be the best option from all margarines and butters. These margarines contain little to no trans fatty acids and, in addition, contain beneficial compounds that include the healthy EPA and DHA fats along with compounds isolated from plant sources, including sterols and stanols. These compounds have a variety of health effects, including lowering of cholesterol.
Are potatoes fattening?
Potatoes are among foods with the lowest calories of all foods. 100 grams or about 3.5 ounces of raw potatoes contain just less than 80 kcal. The same amount of baked potatoes contain a little over 90 kcal, while boiled potatoes contain slightly less than 90 kcal (both baked and boiled potatoes contain slightly less water compared to raw potatoes and thus are a little denser, which results in a slightly higher caloric content). Thus, potatoes contain a comparable amount of calories to the caloric content of many fruits (e.g. 100 grams of bananas contain less than 90 kcal, apples between 50 and 60 kcal, grapes about 85 kcal). What is fattening is the kind and the amount of gravy that is added to potatoes. Gravies often contain a high amount of fat. While potatoes are mainly composed on carbohydrates and each gram of carbohydrates contain 4 kcal, fat contains more than double that amount. Thus, just two table spoons of gravy may add the same amount of calories than 3.5 ounces of potatoes. Also, French fries and potato chips contain several times the amount of calories than potatoes. Potatoes are commonly consumed in cultures that live the longest. They should be a part of the overall healthy diet. Consumption of the French fries and chips should limited or better yet discarded. Careful attention should be made what is added to potatoes. The best options would be a fat free gravy.
Some individuals claim that potatoes should not be consumed when they are trying to lose weight because potatoes have relatively high glycemic index (glycemic index is a measure to what degree a given good increases blood sugar level). Baked potatoes have the highest glycemic index of over 100. Boiled white potatoes have glycemic index of a little over 80, while sweet potatoes, depending on variety, have a lower glycemic index of between 50 to 70. In comparison ice cream has a glycemic index of about 60. Thus, if we use glycemic index as a criterion of what foods should and should not be used during the time we want to lose weight, we should prefer ice cream over most of potatoes. Yet, 100 grams of ice cream has more than 4 times the amount of calories compared to potatoes. Similarly, Suprime pizza from Pizza Hut has a glycemic index of only about 36. Thus, if we follow the glycemic index logic for weight lose we should be using pizza 3 times per day. Yet, this pizza contains more than 2.5 times the amount of calories compared to potatoes. These two simple examples illustrate the fallacy of the logic to use glycemic index as a guide to what food should and should not be eaten, while trying to lose weight.
Why do you not recommend low carbohydrate/high protein diet?
In my book “Healthy diet without secrets” I have explained this in details. In it, I pointed out that these type of diets are associated with an increase in disease risk, including risk of cardiovascular disease. I invite you to get the book and read it. Let me just state that, in addition to the fact that any type of diet that emphasizes limiting intake of carbohydrates while eating lots of protein being unhealthy, this diet has no sense, whatsoever. I say that because carbohydrates are essential source of fuel to the body. In fact, for many body cells, such as the brain cells, carbohydrates are the main source of fuel. For this reason, when the amount of ingested with food carbohydrates is limited, the body actually uses protein to make it’s own carbohydrates. The problem is, the body uses its own lean tissue or protein that are part of its own muscles to manufacture carbohydrates. Furthermore, when the supply of carbohydrates is limited, the body uses more fat for fuel than usual. This results in the syntheses of something called kitone bodies, which can be utilize as fuel. However, it is not the preferred fuel for cells. Thus, limiting carbohydrates and utilizing a lot of fat for fuel can be compared to poring 87 octans of gasoline into a car that drives on 98 octans gasoline. Such a car will not last nearly as long as one for which the fuel that the car was design to drive on is utilized. Thus, limiting carbohydrates make no sense!
Is it true that people who have cancer should not eat soy products?
No, it is not. Studies showed that people who have cancers who say soy products have lower mortality and lower rate of recurrence of cancer. Thus, intake of soy products in moderation is recommended to individuals with cancer. This recommendation is supported by the American Institute of Cancer Research.
What kind of fruits can people diagnosed with diabetes ingest, if any?
People diagnosed with diabetes are often told to limit their intake of virtually all fruits. This unfortunate recommendation is spread by many dietitian. Let me first emphasize that fruit intake decreases risk of being diagnosed with type 2 diabetes. Secondly, with a few exceptions, intake of fruits by individuals who already have diabetes improves glycemic control. Glycemic control refers to keeping blood sugar low. Thus, with only a few exceptions, such as dates or watermelons, fruits such as blueberries, bananas, grapes, apples, pears, etc. are actually helpful in terms of keeping blood sugar low. Scientists divided food based on how high they increase blood sugar level. Any given food can be classified into low, middle or high glycemic index. People who are diagnosed with diabetes should focus on ingesting plenty of foods from the low and perhaps middle glycemic group foods and avoid those from the high glycemic group foods. Many fruits are in the low glycemic group foods and their intake should not be limited. Thus, many fruits should be included as part of an overall healthy diet to help control blood glucose level.
Do milk and dairy products cause cancer?
A popular retired researcher is responsible for spreading the information that caseine, which is a type of protein found in milk and dairy products, the best most potent cause of cancer. This view has been rather blindly repeated by many individuals who focus on eating healthy. There are some problems with this suggestion. First, even if we assume that caseine does cause cancer, the studies this popular researcher has conducted were done on isolated caseine not on actually milk or dairy product. Secondly, published research studies that evaluated with association between milk and/or dairy products intake and cancer risk showed that these items may increase risk of some cancers but may also decrease risk of other cancers. For example, milk intake has been linked to an increase risk of prostate cancer in several studies. Dairy products intake has been associated with a decrease risk of colorectal cancer. Thus, the idea that milk and/or dairy products increase risk of cancer is at best only a small part of the story.
Why do I recommend cyanocobalamin rather than methylcobalamin supplements?
Cobalamin is the proper name of vitamin B12. Cyanocobalamin and methylcobalamin are forms of vitamin B12 with different chemical groups attached to the cobalamin compound. Some people make a strong statement that cyanocobalamin should never be used because this form contains cyanide, which is a poison. It is true that cyanocobalamin contains cyanide. However, cyanide is found in many foods, including fruits, veggies, nuts, seeds that people ingest on daily. In fact, the overall intake of cyanide from foods is up to 20 times higher to the amount of cyanide found in a 1,000 mcg of cyanocobalamin supplements. Thus, anyone concerned with cyanide intake should be on a permanent stop eating program. I actually do not recommend using cyanocobalamin over methylcobalamin. I recommend that people buy the cheapest supplements, regardless of which form, as long as they contain the correct dose. Most of the time cyanocobalamin is cheaper than methylcobalamin. However, either one can be used. Each form of vitamin B12 supplements (cyanocobalamin, methylcobalamin, hydroxocobalamin) has advantages and disadvantages. Perhaps the best practice is to use more than one type in different type periods.
In your book “Healthy diet without secrets” you recommended to eat plenty of fruits and veggies. But aren’t they contaminated with pesticides?
The best available research showed that fruits, veggies and grains are the least contaminated with pesticides products available in our grocery stores. The same research also showed that fish and eggs are the most contaminated and dairy and meats are in between. This is because animals also eat contaminated with pesticides products and they eat a lot of them. Pesticide residues get stored in animals and in their products in a process we call bioaccumulation. Also, the pesticides used in fields are washed out into rivers, lakes and ocean. Fish get to be contaminated by them since they live in the rivers, lakes and oceans. Thus, anyone concern with pesticide contamination should eat plenty of fruits and veggies and avoid using meats and animal products.
What are the benefits of drinking alkaline water?
This is a health idea that is wide spread among many who are into alternative health ideas. Many of those who promote drinking alkaline water believe that when the body becomes acidic cancer develops. They also believe that cancer cannot live in an alkaline environment. This idea has been adopted from some scammers who are trying to sell a devise that makes alkaline water (for several thousands of dollars). The idea has no scientific credibility, whatsoever. Anyone who has even a basic idea about human anatomy and physiology knows that different organelles in the different body cells work best at different pH. Some of them do prefer an alkaline pH. However, others work best at an acidic pH. For example, according to a manuscript published in the journal called Nature Review Molecular Cell Biology, the ideal pH for mitochondria is 8.0. For cytosol, it is 7.2. However, for such organelles as the Golgi network, the ideal pH is between 6 to 6.7 and for lysosome, it is as acidic as 4.7. If the body becomes too acidic it may cause some health problem. However, the same will happen when the body becomes to alkaline. In fact, the body can only live within a specific pH range. If alkaline pH would really play a role in preventing or treating cancer, all one could do is to buy baking soda for pennies rather then spending thousands for a machine that make water alkaline.
What is the impact of coconut oil on risk of cardiovascular disease?
Coconut oil is heavily promoted in the media as a healthy alternative to other oils. Among the claims we can read about coconut oil being stable in high temperature and having a high smoke temperature. In a review of evidence regarding the impact of coconut oil on blood lipids, authors included the following conclusion: “Overall, the weight of the evidence from intervention studies to date suggests that replacing coconut oil with cis unsaturated fats would alter blood lipid profiles in a manner consistent with a reduction in risk factors for cardiovascular disease.” This quote implies that we are better off using a different type of oil than coconut oil. Interestingly, the same authors included the following statement in their manuscript: “… it is suitable for single-use shallow frying, although it is not recommended for continuous deep-fat frying because of its low smoke point, which may lead to the production of
potentially carcinogenic substances upon overheating.” In fact, coconut oil has one of the lowest smoke temperature from all oils. It is ok to have a coconut now and then. I especially like coconut water (which has a completely different nutritional content compared to coconut oil) and the fresh flesh of coconut (before it becomes very hard). However, promoting coconut oil as protective against heart disease seems questionable.