I’ve been saying all along that what you weigh is more important than what you eat for your overall health. I’ve also said that on the up day of the Alternate-Day Diet you will be eating freely, and I’m not going back on my word. After all, when I started the diet I didn’t change the way I’d been eating on my up days. In terms of calories and weight loss, it’s still how much you eat that counts. In terms of optimum health, however, the story may be a bit different. We now know that the foods we eat can significantly affect our risk for certain diseases, including heart disease, cancer, and Type 2 diabetes, and even though the evidence indicates that the Alternate-Day Diet will protect against these same diseases, I would be extremely remiss if I didn’t provide you with some basic guidelines for good nutrition.
LIFE IS NOT A CLINICAL STUDY
I’m sure you’ve noticed that in our own Asthma Study, participants were allowed to eat whatever they wanted every other day and still saw the health benefits of alternate-day calorie restriction. We didn’t specifically ask the participants in the study to report what they ate on their up days, but given that they were all overweight, it would be logical to assume that when left to their own devices, they weren’t following a particularly healthy or calorie-reduced diet.
These studies, however, were just that—studies. They were time-limited, and as far as the animals were concerned, they could eat only what they were fed, which would have been a nutritious, species-specific diet.
The real point, however, is that, for you, the Alternate-Day Diet will be a way of life, something I hope you’ll be doing from the day you start it. And it is not realistic to expect that all the people who start the Alternate-Day pattern will adhere to it perfectly for the rest of their lives. You won’t be having calorie-controlled shakes on the down days every day. You probably won’t be sticking to no more than 20 to 25 percent of your normal calorie intake on every down day forever. And you may be overeating on at least some of your up days. It would be great if you didn’t, but it’s simply not possible for anyone to be perfect. Therefore, it would be best to hedge your bets, so to speak, by eating as well as possible on as many days as possible.
By “eating well” I don’t mean going to a fine-dining restaurant; I mean eating those foods that have been shown to promote good health and avoiding foods that are known to increase the risk of disease. For example, high-glycemic carbohydrates (white flour, rice, potatoes), saturated fat (beef, dairy), and foods prepared with trans fats (french fries, doughnuts) are clearly shown to be contributors to heart disease.
According to Walter Willett, by following an optimal diet combined with a healthy lifestyle (which includes maintaining a healthy weight, exercising, and not smoking) we could eliminate 80 percent of heart attacks, 70 percent of strokes, more than 90 percent of Type 2 diabetes, and more than 70 percent of colon cancer. In other words, the world’s foremost nutritional authority is telling us a major cause of all these conditions is what we eat. It would be foolish of anyone to ignore those statistics.
NOTHING IS FORBIDDEN
Without minimizing the many benefits of following a healthy diet, my colleagues and I believe, on the basis of the Asthma Study diet, that if your calorie intake is low enough on the down days, you can eat anything you want to on the up days and still have remarkable health benefits. So I am not going to give you a list of forbidden foods. That would be the ultimate bait-and-switch, and it would also be highly unrealistic. But while no foods are forbidden on the up days of this diet, there are foods you should be eating more often, because they will help to promote good health, and others that should be eaten less often and with the understanding that they could compromise your health over time.
WHAT TO EAT FOR OPTIMAL NUTRITION
I’m sure you’ve heard it before: Eat a diet based on whole grains, fruits and leafy green vegetables, plant-based fats, and lean protein. Avoid sugary, starchy, refined carbohydrates, red meat, full-fat dairy, and trans fats. But you may have had trouble translating that advice into practical terms. The following information is designed to help you do that.
THE TRUE SKINNY ON FAT
Does eating fat make you fat and put you at greater risk for heart disease? Depending on how much as well as what kind of fat you eat, both parts of that statement may be true. But fat is also essential for building cell membranes and the protective sheaths surrounding your nerves. It is necessary for making certain hormones, controlling blood clotting, and regulating muscle contraction—including the contractions of your heart. We all need some fat in our diet, but not all fats are the same, and not all fats are equally healthy.
WHAT ARE FATS MADE OF, AND WHY DO I CARE?
All types of fat are made of a chain of carbon atoms bonded to hydrogen atoms. When a fat is saturated, it means that the carbon atoms hold as many hydrogen atoms as they can. Each carbon atom is connected to its neighbors on either side by a single bond. Examined under a microscope, saturated fats look like straight chains. You probably don’t examine your food under a microscope, but one way you can recognize a saturated fat is by the fact that it congeals and is solid at room temperature—like butter or bacon fat or the fat encircling and marbling a steak.
It’s saturated fat that’s primarily responsible for clogging up our arteries and raising our levels of LDL (bad) cholesterol. But not even all saturated fats are the same. You may be surprised to know that the saturated fat in butter and whole-fat dairy products has more of a worse effect on cholesterol than beef fat, and the fats in chocolate and cocoa butter have less. Regardless, saturated fats raise LDL (bad cholesterol) and have little effect on HDL (good cholesterol).
When a fat is monounsaturated, at one point along the chain two carbon atoms are connected by a double bond. This change reduces by two the number of hydrogen atoms the chain can hold and changes the shape from straight to bent. Monounsaturated fats are liquid at room temperature. In other words, they’re oils. Olive, peanut, and canola oils are all high in monounsaturated fat, and avocados as well as most nuts are also good sources.
When a fat has two or more double bonds, it is polyunsaturated and can hold even fewer hydrogen atoms. These fats look like sticks with two bends. They are divided into two categories: omega-3 and omega-6, and the main difference between them and monounsaturated fats is that our body can’t make them. We must get our polyunsaturated fats from dietary sources or supplements. The best dietary sources of these essential fats are fatty fish like tuna and salmon, as well as plant sources like corn and soybean oil, soy and soy products, and seeds.
Both monounsaturated and polyunsaturated fats lower LDL and raise HDL.
The healthiest balance between polyunsaturated and monounsaturated fat has not been established, but monounsaturated fat appears to confer greater protection against fatal heart rhythm disturbances, the commonest cause of death in heart attacks.
The last type of fat, trans fat (sometimes called partially hydrogenated vegetable oil), should be avoided as much as possible. A small amount of trans fat is present in animal fat, but most of what we consume is artificial.
About a hundred years ago, chemists discovered that they could solidify vegetable oil by heating it in the presence of hydrogen gas. Their discovery is what gave us products like margarine and Crisco. It also allowed food manufacturers to create products with a longer shelf life. At one time, it was thought that trans fats were healthier than the saturated fat found in butter, but studies since the 1970s have shown that trans fats have an even greater effect on raising levels of LDL (bad cholesterol) and creating artery-clogging plaque than saturated fat. Plus, they lower levels of HDL (good cholesterol), which saturated fat doesn’t do. Recently, the food industry has gotten the message, and the trans fat picture is steadily improving. Many margarines have been reformulated to contain zero or less than 0.5g per serving of trans fat, but you should always check the label. According to the Institute of Medicine, doughnuts and french fries are probably the commonest sources of trans fats in our diet, but many baked goods also have large quantities.
The results of the Lyon Diet Heart Study, a randomized, controlled trial that considered the effectiveness of a Mediterranean-type diet, indicate the dramatic effect of changing from a predominantly saturated animal-fat diet to a diet low in saturated fat and high in monounsaturated and polyunsaturated fats. In the study, all participants had survived a first heart attack. The experimental group—302 men and women—were put on a healthy-fat Mediterranean-type diet and compared with a control group of 303 people with similar coronary risk factors who received no specific dietary advice but were asked by their physician to eat prudently. The study was actually discontinued earlier than planned, because the results showed that those following the healthy-fat diet had a 70 percent lower risk of recurrent heart disease than the control group following the traditional diet.
Monounsaturated and polyunsaturated fats stabilize the electrical conduction system in the heart, thereby preventing the abnormal heart rhythms that are a leading cause of cardiac deaths. But you don’t have to have a heart attack before you change from saturated to monounsaturated and polyunsaturated fat!
DECODING CARBOHYDRATES
Basically, carbohydrates are the nutrients that most significantly affect your blood sugar levels. All the carbohydrates you eat are digested and broken down to sugar, but some turn to sugar more quickly than others. The best way to differentiate one type of carbohydrate from another is by how rapidly they raise your blood sugar. The glycemic index was created by nutrition researcher David Jenkins and his colleagues at the University of Toronto to measure the speed and degree to which various carbohydrates raise blood sugar levels. Foods that are high on the glycemic index raise the blood sugar level more than those that are low on the index. As a general rule, foods containing large quantities of sugar, starches (including white rice, potatoes, crackers, and most white breads), and baked goods made with refined flour have a high GI rating.
You may have heard carbohydrates referred to as simple or complex. Generally speaking, complex carbohydrates are those with a low glycemic index number, such as whole grains and vegetables. These contain important nutrients called phytochemicals that protect against free-radical damage and oxidative stress. They are also the primary source of dietary fiber, which performs a variety of important functions.
Basically, fiber—what your parents probably called roughage—is required for healthy bowel function. Fiber absorbs water like a sponge and creates bulk, which allows the gut to propel the food onward. It protects against constipation, diverticulosis, and diverticulitis.
There are two kinds of fiber, soluble and insoluble. Soluble fiber dissolves, of course, and it forms a gelatinous mass. It traps bile acids and lowers cholesterol. Good sources of soluble fiber include apples, citrus fruits, peas, and oats. Insoluble fiber, from the cell walls of plants, consists of long chains of glucose molecules that our GI tract can’t break down or dissolve. The chief sources of insoluble fiber are fruits, vegetables, and whole grains.
What makes a whole grain “whole” is that none of its components have been removed in processing. The components of the grain are either intact, as with brown rice or whole oats, or, if it has been processed by grinding, all of the components are retained. The two elements that are removed in refined white wheat flour, for example, are the bran (fiber) and the wheat germ, both of which are important for preventing a variety of diseases. Whole grains not only help to reduce body weight but also reduce the incidence of stroke, Type 2 diabetes, heart disease, inflammatory disease, diverticulitis, and constipation. Whole grains may also help reduce the incidence of colorectal cancer, high blood pressure, and periodontitis (gum disease).
The recommended daily consumption is six servings per day, although one (half-cup) serving per day reduces disease risk; generally speaking, the more the better. To get more whole grains in your diet try:
• Breakfast grains: whole oats (groats), steel-cut oats, rolled long-cooking oats, oatmeal, Wheaties, Wheat Chex, Grape-Nuts, All-Bran, shredded wheat, and Kashi multigrain cereals
• Brown rice
• Pearl barley (have it as a side dish with a light vinaigrette, add it to soups or salads, or try it in chili or with beans instead of rice)
• Whole-grain crackers: Triscuits, Wheat Thin Multi-Grains, Kashi TLC, chips
• Whole-grain breads: The first ingredient listed must say whole for a bread to be a whole-grain bread, but multigrain breads are better than plain white bread
• Whole-wheat pasta
At one time, insoluble fiber was thought to prevent cancer of the colon, but recent large studies have failed to support this theory. It is, however, valuable in reducing the absorption of sugar and starch, thereby lessening glucose-insulin spikes in the bloodstream, which in turn helps to reduce heart disease and Type 2 diabetes.
WHAT YOU SHOULD KNOW ABOUT GLYCEMIC LOAD
To take the glycemic index to the next level, so to speak, and to better reflect the effect of various carbohydrates on blood sugar, Walter Willett and his colleagues at the Department of Nutrition, Harvard School of Public Health, developed another scale called the glycemic load, which takes into account not only the glycemic index rating of various foods but also the amount of carbohydrates in the food. Carrots, for example, are high on the glycemic index, but carrots also have a high water content, which means that, gram for gram, they deliver only a small amount of carbohydrates, do not create a rapid rise in blood sugar, and therefore have a low glycemic load.
“Are there certain things in food that act on the brain and set up a classic addictive process, like tolerance, withdrawal and craving?” asks psychologist Kelly Brownell of Yale University. The evidence is mounting that food addiction is real.
Addiction to drugs is manifested by changes in the brain that can be seen in MRIs, and abstinence and recovery from drug addiction produce a return to normal patterns. We believe that avoidance of high-sugar, high-fat foods by eating a diet high in vegetables can produce recovery of these brain mechanisms.
Using MRI brain imaging, psychiatrist Nora D. Volkow and her colleagues at Brookhaven National Laboratory have shown that, like amphetamine addicts, obese people have fewer receptors for dopamine, and the higher the body mass index, the fewer the dopamine receptors. The dopamine system in the brain is what is stimulated when we experience any pleasurable feeling—such as we get from eating or sex. The dopamine systems of drug addicts are overstimulated, and the withdrawal and craving they experience result from these receptors crying out for more of the drug. The craving overpowers the will of the addict, who is unable to stop using the drug.
It appears that some people may have a greater rise in dopamine levels in response to high-sugar, high-fat foods and may become “addicted” to these foods. The rapid return of “hunger” after eating high-glycemic foods may, therefore, result not simply from a drop in blood sugar from the overrelease of insulin but may indicate a deficiency of the “food drug” that causes these people to think about food in the same way addicts think about drugs.
People in developing countries whose diets are low in fat and sugar do not seem to experience these same food cravings. This could be because their dopamine receptors haven’t been damaged by high-sugar, high-fat foods, and Dr. Laub’s and my clinical experience suggests that following a diet that avoids these foods on the up days will, over time, reduce our thoughts about and cravings for food.
The overall goal is to understand which foods, and what quantities of those foods, to select or avoid on the basis of their glycemic index and glycemic load. You can find a comprehensive list of both the GI and GL of various foods at mendosa.com/gilists.htm.
MIX UP YOUR FRUITS AND VEGETABLES
Plant foods contain a variety of phytonutrients (“phyto” meaning plant-based). Accumulating research indicates that many chronic diseases may be partially caused by a relative deficiency of these plant substances. In fact, it is now well established that eating a diet high in fruits and vegetables results in lower rates of heart disease, stroke, high blood pressure, cataracts and macular degeneration, cancer (see the box on the following page), Type 2 diabetes, Alzheimer’s disease, and decline in thinking skills. For this reason, the Food and Drug Administration now recommends that we eat nine half-cup servings of a wide variety of fruits and vegetables every day.
Among those that have been studied most extensively and whose health benefits are well documented are broccoli, tomatoes (preferably cooked), spinach, onions and garlic, and carrots. I recommend that you make these your “first choice” vegetables and eat them several times a week as part of the Alternate-Day Diet.
The broader categories of fruits and vegetables to include in your diet are as follows:
• Cruciferous: broccoli, cauliflower, Brussels sprouts, cabbage, turnips, and rutabaga. They provide isothiocyanates, folate, calcium, iron, and vitamin K, which protects against cancer.
• Melon/squash family: cucumbers, zucchini, pumpkin, winter squash, and cantaloupe. Orange members of this group are rich in carotenes.
• Solanum family (actually a genus): tomatoes (rich in lycopene), peppers, and eggplant.
• Umbels: carrots (beta-carotene), parsnips, and parsley.
• Lily family: Onions, garlic, leeks, shallots, and asparagus, which contain sulfur compounds (allicin, diallyl sulfate) that may fight cancer.
• Legume family: beans, peas, and soybeans, all of which contain folate, fiber, and protease inhibitors, which protect against heart disease and cancer.
• Citrus family: lemons, limes, oranges, and grapefruit. These contain vitamin C and limonene, which have anticancer properties.
• All dark-colored berries (blue, red, black), which are rich in antioxidants and pigmented polyphenols.
It is clear that lifestyle choices—including smoking, drinking excess alcohol, inactivity, and obesity—are associated with a higher chance of developing cancer, and the expert consensus is that a diet rich in fruits and vegetables may reduce the risk of esophageal, stomach, lung, mouth, throat, ovarian, kidney, bladder, and colorectal cancer. That said, however, the best available data does not show that a diet high in vegetables and fruit reduces the overall incidence of cancer. On the other hand, the accumulated science in calorie restriction shows that it does prevent cancer in animals and humans. Studies in every- other-day feeding show that cancer rates are lowered.
PICKING THE RIGHT PROTEINS
Protein is made up of approximately twenty basic components called amino acids that are the building blocks of our cells, and we need all of them to stay alive. Some forms of protein, called complete proteins, contain all of these amino acids. Other foods provide only some and need to be eaten in combination in order to ensure that we are getting all the amino acids we need. Complete proteins are derived from animal sources including meat, poultry, fish, eggs, dairy products, and soy. As a rule, vegetable sources provide incomplete proteins.
Soy has the reputation of being beneficial for lowering cholesterol, but this idea is based on a study in which lower cholesterol levels were found in people who ate 50 grams of soy per day instead of animal protein sources (which contain saturated fat). In order to get enough to match the study, you would have to eat a pound of tofu every day (not a good idea), and later studies have not shown any effect of soy on cholesterol. Menopause-related hot flashes may be helped by soy, but the evidence is weak, as is evidence supporting the effect of soy in decreasing incidence of breast cancer and heart disease.
In the words of Harvard’s Walter Willett, soy “may have a dark side.” In fact, estrogen-sensitive breast cancer may be adversely affected by soy, which has its own estrogenic properties and can interfere with tamoxifen, an important breast cancer treatment drug. Seventh-day Adventist women, who are vegetarian and eat soy, show a rising rate of breast cancer the longer they are vegetarian. The claim that breast cancer occurs less in Japanese women because they eat soy is clearly wrong. Breast cancer is rare throughout Asia, but most Asian populations do not eat soy.
In addition, there is evidence that decline in cognitive function, memory loss, and age-related brain atrophy may be worse in older men who eat more than two servings of tofu per week. Finally, there is also uncertainty about the effect of soy on prostate cancer.
These persistent negative indications lead me to recommend that you eat soy products a few times per week at most.
As far back as 1972, Robert Atkins was advocating eating a high-protein, low-carbohydrate diet for weight loss. It took nearly thirty years before medical scientists began to study his claims that people lose weight faster and with less hunger on this diet. Although he was not the first to advocate this scheme, his name has now become synonymous with the diet that allows you to eat unlimited amounts of steaks, burgers, eggs, and dairy products. But the lack of sufficient fruits and vegetables, whole grains, and cereal fiber, along with the unlimited consumption of saturated fat, fly in the face of the new science of nutrition. More recently, the South Beach Diet has advocated healthier sources of protein in the form of fish and fowl, both of which provide healthier fats than red meat.
There is evidence from a variety of sources that both Atkins and South Beach work for short-term weight loss. One year after starting a diet, however, there appears to be no significant difference in success rate than that seen on any other common diet plan. If the overall test of whether a diet “works” is the degree to which people voluntarily adopt the plan, lose weight, and maintain the weight loss in a free-living environment, it is evident that no diet has yet been successful.
The Mayo Clinic studied the citizens of Multnomah County, Oregon, and found that they were more aware of the Atkins Diet than other diets and would use it as a first choice for weight loss. The problem was that the population as a whole was gaining weight, just as the rest of the country was. This may be because people who are in a chronic state of attempting to stick with high-protein foods become hungry for carbohydrates. So they order the largest steak on the menu and then have some dessert anyway. If they followed the Atkins Diet for a discrete period to lose a specific amount of weight and then switched to a nutritionally healthy diet, it might be a good way to lose weight. But they are no more able to sustain the high-protein pattern over time than they are to comply with any diet that requires the daily restriction of amount or type of food.
Protein may, indeed, help to increase satiety or satiation (the period of time until hunger returns), and there may also be value in the ketosis created by eating a primarily noncarbohydrate diet. (The Alternate-Day Diet also produces ketosis—elevated hydroxy butyrate—which appears to increase the brain’s resistance to stress and may also contribute to suppression of hunger.)
That said, however, no diet that requires the consumption or restriction of any particular macronutrient or component will produce long-term weight loss, because all of the factors that determine appetite are too powerful and overwhelm our conscious effort to control our eating.
According to the latest dietary guidelines, we need to eat about 7 grams of protein for every 20 pounds of body weight, but for the most part, no one should really have to think about getting enough protein—it’s almost impossible not to. The only issue would be for strict vegetarians to eat enough variety to be certain that they are getting all the various amino acids they require.
IT’S WHAT YOU GET ALONG WITH YOUR PROTEIN THAT COUNTS
Except for simple sugars, almost no food comprises just one nutrient. So while pretty much all kinds of protein are equally healthy, what comes along with them is not. Beef, for example, is a great source of complete protein, but it comes bound up with a lot of unhealthy, saturated animal fat. Poultry and fish are also complete proteins, and the fat they contain is mainly unsaturated, which makes them much healthier sources than red meat. Full-fat dairy products, because they come from animals (cows, sheep, and goats), are also high in saturated fat.
In terms of fat content, plant proteins—including nuts, seeds, legumes, vegetables, and grains—are the healthiest choices of all, as long as you eat enough variety to ensure that no essential amino acids are missing from your diet.
WHAT DOES A HEALTHY MEAL LOOK LIKE?
Well, it could look like a lot of different things. How about a bowl of whole-wheat pasta with marinara sauce, a piece of whole-wheat bread dipped in olive oil, and a green salad with vinaigrette dressing? Here are a few other healthy up-day choices you may not have considered:
Turkey burger on a whole-wheat bun (with ketchup, mayonnaise made with olive or soybean oil, and a slice of onion)
An ear of corn
Salad made with romaine lettuce, reduced-fat blue cheese, and olive-oil-and-vinegar dressing
Chicken breast dipped in egg white and whole-wheat bread crumbs sautéed in olive oil
Baked sweet potato
Grilled asparagus with a squirt of lemon juice
Poached salmon
Cucumber salad
Brown rice
Tuna packed in olive oil
Mixed with cooked white (cannellini) beans and seasoned with chopped fresh basil and/or Italian parsley
Egg white vegetable omelet cooked in vegetable oil
Whole-wheat toast
Despite the American Egg Board’s ongoing promotion of the “incredible edible egg,” eggs have been getting a bad rap for years. But according to nutritionist Walter Willett, “Eggs aren’t just packets of cholesterol. They are very low in saturated fat and contain many other nutrients that are good for you. . . . So their effect on heart disease risk can’t be predicted by considering only their cholesterol content. . . . No research has ever shown that people who eat more eggs have more heart attacks than people who eat few eggs. . . . The most comprehensive study to date looked at the egg-eating habits of almost 120,000 men and women. Healthy men and women who ate up to an egg a day were no more likely to have developed heart disease or to have had a stroke over many years of follow-up than those who ate less than one egg a week.”
Notice that I haven’t given any quantities for the above choices. Your up days are not about restricting calories (although stuffing yourself is not a good idea either) but about choosing to get the calories you do eat from healthier sources.
In Chapter 9, I’ll be giving you lists of various foods with portion sizes and calorie counts to keep you on track during your down days. For a selection of healthy, nutritious down-day menus and recipes, go to Chapter 11.
SHOULD YOU TAKE DIETARY SUPPLEMENTS? IF SO, WHICH ONES, AND WHY?
It has been estimated that the DNA in each of our cells sustains 10,000 injuries per day from free radicals. The resulting damage can in rare cases result in cancer or other life-threatening illnesses. Our main defense against this kind of damage lies with the thousands of antioxidants we get from food and dietary supplements that neutralize free radicals.
Among the most common known antioxidants are vitamins C and E, beta-carotene and other carotenoids, selenium, and manganese. Other antioxidants now being studied with growing interest are glutathione, coenzyme Q10, alpha-lipoic acid, flavonoids, polyphenols, and phytoestrogens. Every type of antioxidant plays a slightly different role in the elaborate protective mechanism, and for that reason it is important to consume all the different types that are found in a healthy diet.
Many studies have shown that it’s both safer and more effective to get your vitamins and antioxidants from food sources than from pills. In fact, according to the most recent analysis of prospective randomized trials of antioxidant supplements, beta-carotene, vitamin A, and vitamin E were associated with higher mortality rates, and vitamin C and selenium showed no benefit. Overall, the authors of the analysis estimated a 5 percent increase in mortality—caused mainly by cancer and heart disease—among people taking antioxidant supplements.
Some studies, however, do support the value of some antioxidant supplements. For example, in the Nurses’ Health Study and the Health Professionals Follow-Up Study, vitamin E tended to reduce the incidence of heart disease, although the difference was not statistically significant. And there is also some weak evidence supporting cancer reduction in men taking antioxidant supplements.
The antioxidant effect of two carotenoids—lutein and zeaxanthin—probably help slow the progression of macular degeneration, the commonest cause of blindness in older people. These are available in supplements whose label indicates that they are for “eye health.”
Further trials will be necessary to determine whether or not taking supplements of single antioxidants is of value for reducing disease.
It appears to be particularly dangerous to take high doses of vitamins. Men taking more than seven multivitamin pills per week showed a severalfold increase in advanced and fatal prostate cancer, although the overall incidence of prostate cancer did not change, meaning that some cases of localized prostate cancer were transformed into advanced and fatal cancer. And the overall incidence of prostate cancer was also increased in men who took selenium, folic acid, or vitamin E along with their multivitamins.
A number of other studies have also shown risks for taking vitamins in doses above the recommended daily allowance (RDA).
That said, however, there are some vitamins we don’t get enough of even from the most nutritious diet. Among these are three of the B vitamins—B9 (folic acid), B6, and B12—all of which may reduce the risk for heart disease and cancer. They help to recycle homocysteine, a byproduct of eating protein, by turning it into amino acids instead of allowing it to build up and clog the arteries. High levels of homocysteine have been shown to increase the risk of heart disease. All three of these B vitamins are available in multivitamin capsules.
Unlike the B vitamins, however, vitamin D—which helps the body to absorb calcium, protects the skin against sun damage, and has been shown to reduce the incidence of various cancers—is not found in high enough doses in multivitamins. It is present in the diet and is produced in the skin in response to sun, but to reap its anticancer benefits most people require at least 1,000 IU (international units) a day, which requires taking a separate pill. People over the age of seventy should take more than younger people. A large meta-analysis recently showed that optimal treatment with vitamin D would prevent 250,000 cases of colorectal cancer and 350,000 cases of breast cancer worldwide. The researchers’ recommendation was to take 2,000 IU per day and spend 15 to 20 minutes in the sun exposing 40 percent of your skin. A blood test to measure 25-hydroxy vitamin D is the best way to know if you are getting the right dose. Taking vitamin D supplements is one of the most important steps you can take to reduce your likelihood of cancer.
Calcium may also require supplementation if you are receiving less than 500 mg per day through dietary sources. Contrary to what many people believe, dairy products—because they are high in calories and saturated fat—are not the best sources of dietary calcium. Some good nondairy food sources of calcium include dark-green leafy vegetables, fish (including salmon, sardines, and ocean perch), and tofu.
Determining whether or not to take supplements and which ones to choose can be a confusing and daunting prospect. Although some could be beneficial, others might well be unnecessary or even detrimental to your health. The supplement industry is largely unregulated, and manufacturers are allowed to suggest all kinds of health benefits whether or not they’ve been proved. In fact, they are not even required to guarantee that the ingredients stated on the label accurately reflect what you’re getting in the bottle. And yet approximately half of all adult Americans are taking one or more supplements to benefit their health.
The following are supplements that have established scientific evidence to recommend them; just be sure that if you do decide to take one or more of them, you choose a brand from a reputable manufacturer. When it comes to your health, it’s not a good idea to pinch pennies.
Omega-3 Fatty Acids: These essential polyunsaturated fatty acids, which your body cannot manufacture, play important roles in cellular function, especially in the brain, and are necessary for maintaining a normal heart rhythm. To be sure you are getting a sufficient supply you would need to eat about 12 ounces of fatty fish per week. A simpler and perhaps safer source, given the mercury content of some fish, is fish oil capsules, which are made with oil from fatty fish that’s been purified to remove mercury and other toxins. Fish oil capsules are available at drugstores, grocery stores, and discount and large-box stores. The dose that appears to confer protection from cardiovascular disease, mainly by preventing fatal heart rhythms, is three 1-gram capsules per day, each containing 180 mg of eicosapentaenoic acid and 120 mg of docosahexaenoic acid. Higher doses probably don’t improve heart health.
For rheumatoid arthritis, you’d need to take ten capsules a day to get the anti-inflammatory effect.
Alpha-Lipoic Acid: Alpha-lipoic acid affects age-related mitochondrial function and may, therefore, treat a variety of age-related health problems, including heart disease, diabetes, Alzheimer’s, diminished muscle strength, and decline in brain function. In combination with acetyl-L-carnitine (see below), it has been shown to reverse cognitive decline in old rats, and human studies are now under way. Because your body does not manufacture it, you need to take supplements in order to get its potentially powerful antioxidant benefits. The usual recommended daily dose is 800 mg taken as 400 mg twice a day.
Acetyl-L-carnitine (ALCAR): This mitochondrial “food” when taken in combination with alpha-lipoic acid restores age-related damage to mitochondria, which translates as improvement in cognitive function. A number of randomized controlled trials have shown significant improvement in cognitive impairment and mild Alzheimer’s disease, as well as in diabetic neuropathy.
Coenzyme Q10: This supplement is recommended for people with high blood pressure, those taking statin drugs, those with risk factors for heart disease, and older people in general. Published reports indicate that a dose of up to 1,200 mg per day (taken as 400 mg three times a day) has beneficial effects on lowering blood pressure and reducing migraine headaches, and may protect against heart attack and neurodegenerative brain disorders such as Parkinson’s.
THE BOTTOM LINE
Following the Alternate-Day Diet will help you to lose weight and live longer. Making sure the majority of the foods you eat on your up day are nutritious and healthful will enhance its protective effects, and taking a few supplements that have been scientifically proved to reduce or reverse the effects of age-related illnesses will keep you even healthier longer.
Calorie restriction is the most powerful potential mechanism to improve human health and the Alternate-Day Diet makes the application of this theory possible for most people.