Researchers studied over 4,000 Japanese adults taking blood pressure medication to understand if using special “functional foods” (foods marketed to treat health conditions) affects how well people take their prescribed medications. They found that people using functional foods for blood pressure were 24% more likely to skip or forget their regular medications compared to those not using these foods. This is concerning because skipping blood pressure medication can be dangerous. However, because this was a snapshot study rather than long-term research, scientists can’t say for certain that the foods cause people to take less medication—just that the two seem connected.

The Quick Take

  • What they studied: Whether people with high blood pressure who use special health foods are less likely to take their prescribed blood pressure medications regularly
  • Who participated: 4,063 Japanese adults with high blood pressure who were already taking blood pressure medication (586 used functional foods; 3,477 did not)
  • Key finding: People using functional foods for blood pressure were 24% more likely to have poor medication adherence (not taking their pills as prescribed) compared to those not using these foods
  • What it means for you: If you use special health foods to manage blood pressure, be extra careful to take your prescribed medications exactly as your doctor directs. Don’t assume functional foods can replace your regular medication. Talk to your doctor before adding any new foods or supplements to your routine.

The Research Details

This was a cross-sectional study, which means researchers took a snapshot of a group of people at one point in time (December 2024-January 2025) rather than following them over months or years. They used data from a large Japanese internet survey called JACSIS 2024. Participants answered questions about whether they used functional foods specifically to treat their high blood pressure and how well they took their prescribed medications. The researchers then compared medication-taking habits between those who used functional foods and those who didn’t, while accounting for other factors like age, income, and overall health status.

This approach is useful for spotting patterns and connections between behaviors, which can help doctors understand what might be happening in real life. However, cross-sectional studies are like taking a single photograph—they can show us what’s happening at one moment but can’t prove that one thing causes another.

Strengths: Large sample size of over 4,000 people, published in a respected journal, researchers adjusted for many other factors that might affect the results. Weaknesses: People self-reported their behaviors (which can be inaccurate), the study only shows correlation not causation, and it only included Japanese adults so results may not apply to other populations.

What the Results Show

Among the 4,063 adults with high blood pressure taking medication, 586 (about 14%) reported using functional foods specifically to treat their condition. The study found that functional food users were significantly more likely to have poor medication adherence—meaning they weren’t taking their blood pressure pills as consistently as prescribed. Specifically, functional food users had a 24% higher risk of low adherence compared to non-users (risk ratio 1.24). This difference remained even after researchers accounted for age, sex, income, education, and other health factors that might influence medication-taking behavior.

The researchers measured medication adherence using a validated 8-question scale (the Morisky Medication Adherence Scale). Low adherence was defined as scoring below 6 on this scale. The association between functional food use and poor adherence was statistically significant, meaning it’s unlikely to have happened by chance alone.

This research adds to growing evidence that people with chronic diseases sometimes use alternative or supplementary approaches (like functional foods) alongside or instead of prescribed medications. Previous studies have shown similar patterns with supplements and other alternative health products. This study is one of the first to specifically examine this relationship in a large Japanese population with high blood pressure.

The biggest limitation is that this is a cross-sectional study—it’s like a snapshot, so we can’t determine whether functional foods cause poor medication adherence or whether people with poor medication adherence are simply more likely to try functional foods. Both the functional food use and medication adherence were self-reported, which means people might not remember accurately or might answer differently than their actual behavior. The study only included Japanese adults, so the findings may not apply to other populations. Additionally, the researchers didn’t know why people were using functional foods or what specific products they were using.

The Bottom Line

If you have high blood pressure and take prescribed medication, continue taking your medication exactly as your doctor prescribed—this is the most important step. If you’re interested in using functional foods or supplements, discuss this with your doctor first. Don’t assume that functional foods can replace or reduce your need for medication. Keep taking your blood pressure medication consistently while exploring other approaches with your healthcare provider’s guidance.

This is especially important for people with high blood pressure who are considering using functional foods or supplements as part of their treatment. It’s also relevant for doctors and healthcare providers who counsel patients about blood pressure management. People who are already struggling to take their medications regularly should be particularly cautious about relying on functional foods instead.

Blood pressure medication typically works best when taken consistently every day. Benefits appear within weeks to months of regular use. If you stop taking medication or become inconsistent, your blood pressure can rise within days to weeks, increasing your risk of heart attack or stroke.

Want to Apply This Research?

  • Track daily medication adherence by logging each time you take your blood pressure medication, and separately log any functional foods or supplements you consume. This creates a clear record to discuss with your doctor and helps you spot any patterns in your medication-taking habits.
  • Set daily medication reminders in your app at the same time each day (such as with breakfast or bedtime). If you want to add functional foods to your routine, log them separately and schedule a conversation with your doctor to review both your medication and functional food use together.
  • Track your medication adherence weekly and monthly to identify patterns. Also monitor your blood pressure readings if you have a home monitor. If you notice your adherence dropping or your blood pressure rising, this is a signal to talk with your doctor before making any changes to your routine.

This research suggests an association between functional food use and lower medication adherence in people with high blood pressure, but cannot prove that functional foods cause poor medication adherence. This information is for educational purposes only and should not replace professional medical advice. If you have high blood pressure, always follow your doctor’s prescribed treatment plan and consult with your healthcare provider before adding functional foods, supplements, or making any changes to your medication routine. High blood pressure is a serious condition that requires consistent medical management to prevent heart disease and stroke.