As we have recently discussed diet and its effects on health, it seems reasonable to ask whether there is a diet that is demonstrably healthy. A recent investigation attempted to answer this question.

This study was aimed at developing a healthy diet score that is associated with health outcomes and is globally applicable. It used data from the Prospective Urban Rural Epidemiology (PURE) study and tried to replicate it in five independent studies on a total of 245 000 people from 80 countries.

A healthy diet score was developed on the basis of the data from 147 642 people from the general population, from 21 countries in the PURE study. The consistency of the associations of the score with events was examined in five large independent studies from 70 countries.

The healthy diet score was developed based on six foods each of which has been associated with a significantly lower risk of mortality [i.e. fruit, vegetables, nuts, legumes, fish, and dairy (mainly whole-fat); range of scores, 0–6]. The main outcome measures were all-cause mortality and major cardiovascular events [cardiovascular disease (CVD)].

During a median follow-up of 9.3 years in PURE, compared with a diet score of ≤1 point, a diet score of ≥5 points was associated with a lower risk of:

  • mortality [hazard ratio (HR) 0.70; 95% confidence interval (CI) 0.63–0.77)],
  • CVD (HR 0.82; 0.75–0.91),
  • myocardial infarction (HR 0.86; 0.75–0.99),
  • stroke (HR 0.81; 0.71–0.93).

In three independent studies with vascular patients, similar results were found, with a higher diet score being associated with lower mortality (HR 0.73; 0.66–0.81), CVD (HR 0.79; 0.72–0.87), myocardial infarction (HR 0.85; 0.71–0.99), and a non-statistically significant lower risk of stroke (HR 0.87; 0.73–1.03). Additionally, in two case-control studies, a higher diet score was associated with lower first myocardial infarction [odds ratio (OR) 0.72; 0.65–0.80] and stroke (OR 0.57; 0.50–0.65). A higher diet score was associated with a significantly lower risk of death or CVD in regions with lower than with higher gross national incomes (P for heterogeneity <0.0001). The PURE score showed slightly stronger associations with death or CVD than several other common diet scores (P < 0.001 for each comparison).

Association of Prospective Urban Rural Epidemiology healthy diet score vs. Events in those with and without prior cardiovascular disease in the four independent prospective studies (n = 191 476). Hazard ratios (95%) are per 20 percentile increment in the diet score. Hazard ratios (95% CI) are multivariable adjusted.

The authors concluded that consumption of a diet comprised of higher amounts of fruits, vegetables, nuts, legumes, and a moderate amount of fish and whole-fat dairy is associated with a lower risk of CVD and mortality in all world regions, but especially in countries with lower income where consumption of these natural foods is low. Similar associations were found with the inclusion of meat or whole grain consumption in the diet score (in the ranges common in the six studies that we included). Our findings indicate that the risks of deaths and vascular events in adults globally are higher with inadequate intake of protective foods.

The authors rightly stress that their analyses have a number of limitations:

First, diet (as in most large epidemiologic studies) was self-reported and variations in reporting might lead to random errors that could dilute real associations between diet scores and clinical outcomes. Therefore, the beneficial effects of a healthier diet may be larger than estimated.

Second, the researchers did not examine the role of individual types of fruits and vegetables as components in the diet score, since the power to detect associations of the different types of fruits and vegetables vs. CVD or mortality is low (i.e. given that the number of events per type of fruit and vegetable was relatively low). Recent evidence suggests that bioactive compounds and, in particular, polyphenols which are found in certain fruit or vegetables (e.g. berries, spinach, and beans) may be especially protective against CVD.

Third, in observational studies, the possibility of residual confounding from unquantified or imprecise measurement of covariates cannot be ruled out—especially given that the differences in risk of clinical events are modest (∼10%–20% relative differences). Ideally, large randomized trials would be needed to clarify the clinical impact on events of a policy of proposing a dietary pattern in populations.

Fourth, the use of the median intake of each food component as a cut-off in the scoring scheme for each diet may not reflect the full range of consumption or provide a meaningful indicator of consumption associated with the disease. However, the use of quintiles instead of medians within each study or within each region yielded the same results indicating the robustness of our findings.

Fifth, the level of intake to meet the cut-off threshold for each food group in the diet score may differ between countries. However, in sensitivity analyses where region-specific median cut-offs were used to classify participants on each component of the diet score, the results were similar to using the overall cohort median of each food component. Further, with unprocessed red meat and whole grains included or excluded from the diet score in these sensitivity analyses, the results were again similar.

Sixth, misclassification of exposures cannot be ruled out as repeat measures of diet were not available in all studies. However, the ORIGIN study, in which repeat diet assessments at 2 years were conducted, showed similar results based on the first vs. second diet assessments. This indicates that misclassification of dietary intake during follow-up was not undermining the findings.

Seventh, one unique aspect of the study is the focus on only protective foods, i.e. a dietary pattern score that highlights what is missing from the food supply, especially in poorer world regions, but this does not negate the importance of limiting the consumption of harmful foods such as highly processed foods. While the PURE diet score had significantly stronger associations with events than other diet scores, the HRs were only slightly larger for PURE than for most other diet scores. However, the Planetary score was the least predictive of events. The analyses provide empirical evidence that all diet scores (other than the Planetary diet score) are of value to predicting death or CVD globally and in all regions of the world.

So, what should we, according to these findings, be looking for and how much of it should we consume? Here is the table that should answer these questions:

Fruits and vegetables 4 to 5 servings daily 1 medium apple, banana, pear; 1 cup leafy vegs; 1/2 cup other vegs
Legumes 3 to 4 servings weekly 1/2 cup beans or lentils
Nuts 7 servings weekly 1 oz., tree nuts or peanuts
Fish 2 to 3 servings weekly 3 oz. cooked (pack of cards size)
Dairy 14 servings weekly 1 cup milk or yogurt; 1 ½ oz cheese
Whole grainsc Moderate amounts (e.g. 1 serving daily) can be part of a healthy diet 1 slice (40 g) bread; ½ medium (40 g) flatbread; ½ cup (75–120 g) cooked rice, barley, buckwheat, semolina, polenta, bulgur, or quinoa
Unprocessed meatsc Moderate amounts (e.g. 1 serving daily) can be part of a healthy diet 3 oz. cooked red meat or poultry

7 Responses to So, what is a demonstrably HEALTHY diet?

  • No doubt that I am stating nothing new here.

    Average 9.3 years follow up. Shall we take a range of 5-13.6 yrs then for example (unless its Median)? “Dear sir/madam, have you been sticking to this diet since we saw you last?” – “Yes of course!” – “Good, we at the MFOR study wing, are pleased to see you have given us very robust data, see you in another 5-13.6yrs, MAYBE” (when possibly 3 changes of government, civil wars, austerity, inflation, 3 life partner changes, 2 children extra, 4 grandchildren, 2 camels, slightly manufactured global crises have occurred and maybe the planet is dust)

    The first limitation stated, diet comformity (as above), I think, practically makes all of that data afterwards nothing more than a no-doubt very expensive MFOR type study funded by the IGOANAFSS (International Group Of Aptly Named Acronyms For Scientific Studies) (MFOR – money for old rope).

    I write this as a modern, cynical viewer of “science” articles, who is hoping for more truly double blinded replicated multi centre trials of everything (R).
    The scientific method was mentioned many times in the past, but eschewed because truth is very inconvenient once solved. Intelluctual allergies are on the rise so you can expect even more junk science blended in and made Official by incentive led bureacracy.

    Am I being unfairly cynical/critical here and or impertinent? Am I just venting my frustration that with all of the Government “power” available in the world, we have nothing more than cherrypick Science on the menu?

    I accept corrections of opinion to my 3monkeysATnullnullnada email address. (seriously though P)

  • Ahhh, what exactly does ‘healthy’ mean in the context of what an individual consumes through their oral cavity (food, drink, air) and via their skin – including chemicals from showering/bathing/sun block/skin creams etc etc.
    I visited my doctor many years ago for a minor concern which cleared up within a few days. However, during the consultation the good doctor tested my cholesterol – when I returned for the result he said my cholesterol was slightly high (very scientific – not!). I was handed a standard diet sheet on leaving the surgery – the doctor had no idea if I was a vegan/vegetarian or if I had any food allergies, but I seem to remember him mentioning something about ‘five-a-day.’
    I discovered that five-a-day has no medical, scientific or rational basis. In fact, the phrase was coined by a farmer’s trade association in America years ago – they were attempting to convince the general public they should eat more fruit & veg. Sounds like a good idea, however they later admitted that five portions was probably insufficient for optimum health because of the significant depletion of important vitamins & minerals in the soil over a period of decades, but if they had campaigned for a higher number than five, the public wouldn’t have ‘swallowed’ the suggestion – pun intended.
    Since then, the World Health Organisation has jumped on the five-a-day bandwagon – interestingly they include a portion of baked beans in their list of ‘acceptable’ foods, even though baked beans are usually drenched in salt and sugar!

    • ‘Mike Grant’ wrote “…because of the significant depletion of important vitamins & minerals in the soil…”

      I’m very interested to see a list of these important vitamins (not the minerals) that were/are in the soil.

      • Hello Pete, I will be delighted to send you a comprehensive list of depleted ‘important vitamins’ that you are perhaps not aware of. The list will include reference to a well known pharmaceutical company that owned a famous blackcurrant drink that claimed on the label the drink contained a significant amount of Vitamin C. The company (GSK) were fined one-million New Zealand dollars for making a false claim when it was discovered by an independent lab that this alleged ‘healthy drink’ contained virtually no detectable Vitamin C. GSK then sold the Ribena Brand.
        You can search for this report in the news media. Maybe you’re not aware that Vitamin C comes from plants that grow in soil? Apparently oranges also contain Vitamin C.
        I can also send you numerous references listing vitamins that have become significantly depleted over recent decades. I assume you are not aware that vitamins are obtained from plants that grow in soil. If you write to me at: [email protected] I will be pleased to assist in your education. Best wishes.
        p.s. I am impressed you spent your valuable time making a ‘forensic study’ of my comments that are backed up by independent reports. Best in health!

      • More info for Pete Attkins: There is a complex, symbiotic chemical process occurring in soil that nourishes plants we humans include in our diet.
        “Most of the B vitamins have been shown to occur in ARABLE SOIL, their presence being attributable to release from vitamin-containing plant and animal residues, liberation from the roots of growing plants and synthesis by micro-organisms”.

        • @ Mike “not my real name as I wish to protect my clients and prevent unannounced visits from retards”[1] Grant,

          This is what I wrote:

          ‘Mike Grant’ wrote “…because of the significant depletion of important vitamins & minerals in the soil…”

          I’m very interested to see a list of these important vitamins (not the minerals) that were/are in the soil.
          END OF QUOTE

          It’s very simple, ‘Mike Grant’. You made your claims in the comments above. Your decision to ignore the red banner Please remember: if you make a claim in a comment, support it with evidence does not absolve you from providing supporting evidence in your comments, here, NOT SOMEWHERE ELSE.

          Just post the list of “important vitamins”, the “significant depletion” of which in the soil has reduced the nutritional value of fruits and vegetables; because without that list, your comment on Saturday 29 July 2023 at 15:23 stinks of BS.


          • The tree frog is my company logo and represents our concerns and support of sustainability and conservation issues. You and anyone else on this forum is welcome to visit me at my London office where you can see the man behind the name. How about you posting a similar invitation?


            Mike “not my real name as I wish to protect my clients and prevent unannounced visits from retards” Grant had invited us all to visit his London office. Now that we have his email address, perhaps we can email him and book an announced visit to learn about vitamins in soil?

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