DEAR DR. BLONZ: I have an unusual request that I hope you can help me with. My wife has been on a healing journey for a long time now, and has made great strides through nutritional and activity changes.

She now wants to start a "health consultant" business, since many people already call her up for advice. I'm not sure what qualifies one to be a nutritionist, so perhaps there are even more basic facts we need to research. I think she is primarily interested in making sure she has covered the basics, and wants to find some degree or accreditation that lets people know she has studied the subject. -- S.F., Tulsa, Oklahoma

DEAR S.F.: The questions you pose hit some thorny issues. One difficulty is that there is no official definition for "nutritionist"; many call themselves this with little or no formal training. Most good nutrition is nothing more than common sense. However, we can run into complexities regarding the relative efficacies of supplements and herbs, not to mention potential interactions with any given person's health conditions and medications.

There is a need to be able to read and interpret complex research data, evaluate evidence and new discoveries, and see how all the relevant information applies to an individual's health and daily life. It is not an easy task, and there's no shortage of acolytes foisting "miracles" on an anxious populace.

Social media provides a complicated platform: Charlatans often make compelling arguments on well-designed websites, while those with genuine expertise tend to be limited by evidence and professional ethics. Online, I have observed off-the-wall scary advice, but also some quite logical statements. As you would imagine, the field is a "buyer beware" wildcard.

We must not turn a blind eye to progress and breakthroughs, and many of today's mainstream tenets were thought to be nonsense when first proposed. So how does one tell the difference? Unless one can read and understand basic research -- i.e., published, peer-reviewed scientific journals -- it is challenging to examine discoveries with a critical eye. It takes years to develop such skills. And even then, one's knowledge has limits, which must be acknowledged and respected.

If your wife is serious about nutrition, more sophisticated training would be needed to help her fully understand and integrate cutting-edge experimental science. A good first step would be to look into community colleges offering basic and advanced nutrition courses. Identify scientific organizations and health professionals in the community, and consider employment or volunteer work to get a broader perspective on how the profession works.

There are also nutrition videos online, but be sure to stick with sources that have academic credentials and positions. This is critical, because there are pay-to-play organizations that sell you "expert" certificates with little, if any, substantive training. Someone touting themselves as a "board-certified" expert may have nothing more than a piece of paper they bought.

Always be mindful of the limits of your understanding, and build relationships with genuine experts to whom you can refer clients when something is beyond your training. Best wishes and continued good health for your family.

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 enjoy nuts and nut butters, but I am concerned about the recent recall of peanut butter due to salmonella contamination. I have stayed away from raw nuts due to this concern, but had thought that roasting killed that bacteria. Why would peanut butter made from roasted whole peanuts be recalled? -- I.D., Chicago

DEAR I.D.: When good manufacturing practices are followed, the risk of salmonella contamination is eliminated during the peanut roasting process. Both oil and dry roasting take place at temperatures well above that needed to destroy this organism. However, it has to be done right, ensuring that all the nuts get up to the right temperature.

Assuming that the roasting is not the issue, the risk must come afterward. Think, for example, of doing a great job of washing your hands, only to dry them off with a dirty towel. If a company does not have proper hygiene and food-safety protocols, its products are at risk.

Recalls are designed to either prevent or stop an outbreak while the food safety detectives identify how the food was tainted and how it got into your store. For more about the May 2022 peanut butter recall, see b.link/wpeupa. General information about salmonella can be found at b.link/uupfnh.

DEAR DR. BLONZ: I am 74 and am now taking 2 mg of warfarin daily after a heart valve replacement two months ago. I would like to go out and enjoy corned beef and cabbage, a favorite dish of mine, but I have been warned to avoid cabbage while taking warfarin. I wanted to know if this meal would be OK. -- S.B., via email

DEAR S.B.: Warfarin, also known by its brand name Coumadin, is one of several medications given to inhibit blood clotting. Various health issues can cause unwanted clots, whose medical term is venous thromboembolism. Heart valve irregularities are on that list. Of course, we want our blood to clot and stop the bleeding whenever we are cut or injured. But an errant clot can travel through the blood vessels and block the flow to vital tissues and organs, resulting in dire consequences. (Read more on blood clots at b.link/krhyn2.)

The anticoagulant medication you were prescribed works by blocking the action of vitamin K. (In fact, the "K" stands for "koagulation," the German spelling of coagulation.) For any individual, the dose of warfarin gets adjusted to achieve the desired level of anticoagulant activity. It is important to keep your intake of vitamin K pretty constant from day to day to facilitate this aspect of your therapy. Other foods, herbs, supplements and medications affecting coagulation must also be considered.

Cabbage is a pretty good source of vitamin K, so caution is dictated. Check the article at b.link/ccq4s6. It is best to talk with your pharmacist and any health professionals overseeing this aspect of your care before sitting down for that favorite meal. Consider asking for a referral to a dietitian who can help you make room for this dish by making adjustments to other foods you eat.

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 was at a large dinner party where they served sea salt with the meal. However, I have been avoiding modern sea salt if its source is evaporated seawater.

I have traveled extensively to islands in the Caribbean where seawater is channeled into successive ponds on land, where it is evaporated to salt crystals and harvested for market. These islands typically have limited sewage treatment facilities, and waste with toxic components is discharged directly into the sea. This makes me suspect of salt made this way. -- B.T., Scottsdale, Arizona

DEAR B.T.: The FDA has a strict "good manufacturing practice," or GMP, for sea salt, and products adhering to the guidelines earn GRAS status: generally regarded as safe. While there can be trace amounts of heavy metals such as lead and arsenic in evaporated sea salt, they tend to be below the level of concern.

In recent years, though, science has discovered a different potential issue with sea salts: the presence of microplastics. Check out this article in National Geographic, which found microplastics in 90% of the evaporated salts it checked from around the world (visit b.link/4xzzx).

This all makes the case for doing your homework before you buy. If considering a particular sea salt, read the product label about the purity of the water from which it was harvested. Get more answers by contacting the company, or checking online, to see if the brand has had purity issues in the past.

DEAR DR. BLONZ: You often mention epidemiology when describing research, but I am not sure what that is. Could you give me a brief explanation? -- S.F., Seattle

DEAR S.F.: Epidemiology is the science that investigates connections between specific events, such as the occurrence of a disease, and a particular behavior pattern. In matters of nutrition, this could be an association between diet, exercise and a pattern of health or disease. Epidemiological research can help suggest what's going on, but it cannot tell you what's causing what with any precision. Some findings can be informative and on target, while others may only be coincidental.

For example, one study had found that inner-city children suffering from iron-deficiency anemia were more likely to have lead poisoning. The study showed that these items were connected, but it couldn't say what was causing what. Inner-city residents often have a greater exposure to lead, which could be present in peeling lead-based paints. So, did the lead causing the anemia, or was it the other way around?

Additional studies filled in the blanks by providing a plausible mechanism behind the relationship. In this case, it was discovered that that low blood iron (anemia) facilitates lead absorption.

This is an example of epidemiology at work, but studies can also uncover strange relationships. One of my favorites, uncovered while in graduate school, came from a list of statistically "connected" phenomena. There was a finding that physicians who eat more meat and consume more alcohol have one-third the risk of dying in a plane crash. So, does that indicate that it's legitimate science to encourage doctors to grab a burger and a beer before they board their flight? Hardly.

In that case, as in all others, we need to understand a plausible mechanism before giving full credence to results from epidemiology. For more, check out the Centers for Disease Control and Prevention's lesson on epidemiology at b.link/cmx954.

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.