DEAR DR. BLONZ: What constitutes "with meals" and "on an empty stomach" when it comes to taking medications with (or without) food? I usually eat small meals every three hours throughout the day, and am not sure if this is considered an empty stomach. -- D.H., Pleasanton, California

DEAR D.H.: There are several factors to be considered. For example, take-with-a-meal might be recommended if a medication tends to cause upset when taken on an empty stomach, or if the gradual emptying of a food-filled stomach helps with how the medicine gets absorbed. On the other hand, take-before-meals might be recommended when a medication's efficacy or bioavailability is affected by other substances found in foods or by the acid environment of a food-filled stomach. In some instances, you want the medication to have been absorbed and on the job before you eat.

All these point to the importance of following instructions that come with medications. Directions to take a medication before meals might suggest an hour before the first bite. The best advice is to check with your pharmacist for clarifications if you have any questions, as this is their area of expertise.

DEAR DR. BLONZ: What is the difference between enrichment and fortification? I notice that vitamins D and A are always added to milk. Vitamin D is probably there because of the calcium, but could you explain how they work together? And why are they adding vitamin A? -- R.Q., Evanston, Illinois

DEAR R.Q.: Vitamin D works with calcium through its role in stimulating the production of a calcium-binding protein. Once a food with calcium is eaten, digested and in solution in the small intestines, it has to combine with that binding protein to get escorted through the intestinal wall. Vitamin D does not need to be in the stomach at the same time as the calcium, but the body must be adequately nourished with vitamin D for the process to work effectively.

To address your broader question: "Enrichment" adds nutrients back to food that have gotten lost during processing. Flour is a good example of an enriched food. If a food is enriched, the label must say so, and to be valid, it has to provide at least 10% of the nutrient's daily value.

"Fortification" is when you add nutrients that are not normally found in that food. This public health policy was begun in the 1920s after data revealed that certain nutrients were chronically deficient in various population groups. The foods chosen for fortification were the staples found in most diets, including cereals and milk products.

Table salt was the first fortified food: Iodine was added to prevent iodine-deficiency goiter in Midwestern schoolchildren. Vitamin D, and later vitamin A, were added to dairy products because such widely consumed foods were considered ideal vehicles. We now find additional examples, including vitamin D, calcium and other nutrients being added to nondairy milk alternatives, and omega-3 fatty acids added to some eggs.

Generally speaking, foods and nutrients selected for fortification are those consumed in sufficient quantities to provide the desired nutritive enhancement while not presenting any dangers for excessive consumption. Fortified nutrients must also be in a form that is stable and easily absorbed.

Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I have paid the price for researching health products online -- my mailbox is constantly loaded with promotions to help everything from heart disease and digestive disorders to stress issues and cognitive decline. The advertisements are usually accompanied with customer stories raving about the products. I am 71 and in generally good health (with some arthritis), but I do like to follow developments.

My question for you is, how can products that are nonsense advertise like this? -- M.M., Scottsdale, Arizona

DEAR M.M.: It can be challenging to distinguish between legitimate research findings and the unscientific assembly of self-serving puffery and testimonials. You hear or read what appear to be true-to-life stories in support of these products, and they all seem so straightforward: It worked for them, so why not you? It's what I call "persuasive fiction."

Before food additives, prescription or over-the-counter (OTC) drugs or medical devices can be sold, they must be approved by the Food and Drug Administration (FDA). This requires extensive testing, with results being submitted and given the green light.

A foundational tenet of our legal system is "innocent until proven guilty." But this approach can have an uncertain impact in areas involving dietary supplements. Our laws have shifted the burden to the FDA to prove supplements cause harm, rather than the companies needing to prove they work.

With no need to establish efficacy before making the sale, it becomes the responsibility of the FDA to disprove benefits or show harm. The Federal Trade Commission (FTC) has the responsibility to go after dubious advertising claims. A better system would be one where product promoters shoulder the burden of substantiation before they begin to seek customers, but that is not the system we have. The problem is made worse because the extent of questionable products and unproven claims is overwhelming -- far beyond the ability of regulatory agencies to patrol.

The American public has proven quite vulnerable to health frauds and quackery. Some, perhaps like yourself, are naturally curious. But to those frightened in the face of discomfort, pain and disease, the temptation to try something new is sometimes irresistible. To individuals dissatisfied with the medical establishment, the allure of "alternative medicine," with its open arms and carefully worded messages, can be too much to disregard.

In some cases, bogus products go beyond a mere waste of time and money. When someone opts for an untried treatment rather than seeking reputable, effective medical therapy from the start, that delay can allow a condition to progress to a more severe state -- even an untreatable one.

It is a dilemma with no easy answers. That said, scientists, educators and health professionals must do their best to be open-minded. There is nothing wrong with something being new and different; many medical ideas that are now mainstream were considered ludicrous at one time. But a major difference between the scientist and the quack is the manner in which they deal with new theories and products. The true scientist puts them to the test, while the quack takes them directly to the public for profit.

Where health is concerned, the concept of "let the buyer beware" takes on particular importance.

Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: Along with the tuna itself, some canned tuna contains "vegetable broth with hydrolyzed soy protein and hydrolyzed casein." Are these ingredients unhealthy? Does a can of tuna that lists these ingredients contain MSG, which should be avoided? -- S.I., New York City

DEAR S.I.: Proteins are made up of amino acid building blocks arranged in long chains. In the last stage of being produced, these chains get twisted into three-dimensional shapes to fit their functions. Aside from the protein in tuna, products such as the one you describe also contain soy protein (from soybeans) and casein (the primary protein in milk).

A protein described as "hydrolyzed" indicates it has been broken apart into fragments of one or more amino acids. Outside the body, this gets done using enzymes or chemicals. In addition to being chewed, swallowed and treated in the stomach, proteins undergo a similar process with our digestive enzymes to break them into amino acids to facilitate their absorption. Water molecules are used in this breakdown, half on each side of the formerly linked amino acids.

Hydrolyzed proteins are used as ingredients to enhance flavors; nothing weird here. The vegetable broth is also there to enhance flavor. These ingredients are not unhealthful: They represent a blend of amino acids used to achieve a consistent flavor that manufacturers often seek. Such additives, however, could represent an unnecessary risk for the small number of people who react to monosodium glutamate, or MSG.

There has been a lot of controversy regarding MSG -- some of which may be undeserved. The nonessential amino acid glutamate is most prevalent in intact dietary proteins, where it's part of a chain in a three-dimensional structure. On its own, however, glutamate is a key molecule in cellular metabolism. As the additive MSG -- glutamate with a sodium molecule attached -- it can affect flavors. Up to 2% of individuals may have short-term reactions to MSG. Symptoms are typically mild and don't require treatment -- but there can be exceptions. Blind testing, in which your reactions to foods are assessed without you knowing whether MSG is present, can help determine your risk. For individuals found to be sensitive, the only way to prevent a reaction is to avoid foods containing MSG.

Despite concerns raised by early reports and viral proclamations, decades of research have failed to affirm that MSG ingestion must be a concern for all. As an FYI, the May 2017 issue of Food Science & Nutrition reported that the intake of glutamate from the use of MSG as a food additive is much lower than the estimated intake from glutamate naturally present in foods. (Read more on the MSG controversy at b.link/cqrp4m.)

While we are on the topic, food scientists are attempting to find ways to reduce the level of sodium in processed foods. (This is one of the many reasons I recommend focusing on whole foods.) Some are experimenting with the use of the flavor-enhancing potential of MSG. Referred to as a "salt flip," formulators can reduce sodium by substituting MSG to enhance flavor. A study in the September 2020 issue of the Journal of Food Science reported that over two-thirds of the test panel preferred the lower-sodium recipes that contained MSG. The story continues to unfold.

Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.