From Bananas to spinach: Russian cardiologist says these healthy foods can cause real harm if consumed by these people

Not every food labelled “healthy” is safe for everyone. Dr Dmitry Yaranov, a cardiologist, says that the same nutrients that help one person can harm another.
His advice is simple and eye-opening at the same time: “Food isn’t good or bad. Food interacts with your labs, your meds, your heart.”
Here’s all we need to know about how everyday foods can create hidden trouble, and what it means for people with heart or kidney concerns.

Bananas are rich in potassium, which helps muscles and the heart function properly. But for people with weak kidneys or those taking certain heart medications like spironolactone or ARNI, potassium may build up in the blood.

When that happens, it can cause dangerously irregular heartbeats or even cardiac arrest. For such individuals, eating bananas daily or in large portions can quietly turn into a health risk rather than a benefit.

Grapefruit sounds harmless, even refreshing, but Dr Yaranov cautions that it can change how the liver processes medicines.

After heart surgery or transplant, patients rely on drugs that must stay within a safe range in the body. Grapefruit can cause those levels to spike dangerously high, leading to toxic side effects or organ rejection.

It’s not about the fruit itself, but about how it disrupts the body’s ability to balance critical medication levels.

Spinach is loaded with nutrients, yet it comes with its own warning sign. Like bananas, spinach is high in potassium, and for people on certain blood thinners like warfarin, it can also affect how the medicine works.

Dr Yaranov notes that consistency is key. Eating a stable amount of spinach helps the body adjust, but eating it in fluctuating quantities can make blood thinner levels unpredictable, and that’s a risky game for anyone with clotting issues.

Real black liquorice contains a compound called glycyrrhizin that can raise blood pressure and lower potassium levels. It often hides in herbal teas, candies, and supplements.
For people with heart rhythm problems, this mix can worsen symptoms or cause sudden spikes in pressure. It’s a reminder that “natural” doesn’t always mean “safe.”

A small bowl of soy sauce can pack an entire day’s worth of sodium. For someone with heart failure, a high-sodium meal can trigger water retention, swelling, and shortness of breath overnight.

Dr Yaranov warns that even one indulgent sushi dinner could cause up to two pounds of fluid buildup by the next day. Sodium makes the heart and kidneys work harder, a dangerous combination when they are already under strain.

While a glass of wine might seem harmless, alcohol is a direct cardiac toxin. In many patients, excessive or long-term drinking is one of the root causes of heart failure.

For those already struggling with a weak heart, even small amounts can worsen the condition or interfere with prescribed medications.

According to Dr Yaranov, the key isn’t fear, it’s awareness. Everyone’s heart and kidneys handle nutrients differently. What fuels one person can fatigue another.
“Know your body. Know your numbers. Stay ahead of this,” he says.
Balanced eating, regular lab tests, and medical guidance make all the difference.

This article is for informational purposes only and should not replace medical advice. Always consult a doctor before making dietary changes, especially if you have heart, kidney, or liver conditions, or take prescription medications.