Can Diet Add Years To Your Life?

Which Foods Have The Biggest Effect On Longevity? 

Author: Dr. Stephen Chaney

Fountain Of YouthEveryone over 50 is searching for the elusive “Fountain Of Youth”.

  • We want to look younger.
  • We want to feel younger.
  • We want the energy we had in our 20s.
  • We want to be rid of the diseases of aging.

The list goes on!

But how do we do that? Pills and potions abound that claim to reverse the aging process. Most just reverse your wallet.

  • Should we train for marathons or bodybuilding contests?
  • Should we meditate or do yoga to relieve stress?
  • Should we get serious about losing weight?
  • Should we get more sleep?
  • Is there some miracle diet that can slow the aging process?

All the above probably slow the aging process, but the evidence is best for the effect of diet on aging. Several recent meta-analyses have looked at the effect of diet on the risk of premature deaths. In this issue of “Health Tips From the Professor” I review a study (LT Fadnes et al, PLoS Medicine, February 8, 2022) that combines the best of these meta-analyses into a single database and provides a provocative insight into the effect of diet on longevity.

How Was This Study Done?

Clinical StudyThis study combined data from recent meta-analyses looking at the impact of various food groups on the risk of premature deaths with the Global Burden of Disease Study which provides population-level estimates of life years lost due to dietary risk factors.

The authors then developed a new algorithm that allowed them to estimate how different diets affect sex- and age-specific life expectancy.

They divided the population into three different diet categories based on their intake of whole grains, vegetables, fruits, nuts, legumes, fish, eggs, dairy, refined grains, red meat, processed meat, white meat, sugar-sweetened beverages, and added plant oils. The diet categories were:

  • Typical Western Diet (TW). This diet was based on average consumption data from the United States and Europe. This was their baseline.
  • Optimal diet (OD). This diet is similar to a vegan or semi-vegetarian diet. However, it was not a purely vegan diet nor a purely semi-vegetarian diet. Instead, it represented the best diet people in this study were consuming.
  • Feasibility diet (FA). This diet recognizes that few people are willing to make the kind of changes required to attain an optimal diet. It is halfway between the Typical Western Diet and the Optimal Diet.

To help you understand these diets based on the foods the study participants were eating, here are the comparisons in terms of daily servings:

Food TW Diet FA Diet OD Diet
Whole grains 1.5 servings 4.3 servings 7 servings
Vegetables 3 servings 4 servings 5 servings
Fruits 2.5 servings 3.75 servings 5 servings
Nuts 0 serving* 0.5 serving* 1 serving*
Legumes 0 serving** 0.5 serving** 1 serving**
Fish 0.25 serving 0.5 serving 1 serving
Eggs 1 egg 0.75 egg 0.5 egg
Dairy 1.5 servings 1.25 servings 1 serving
Refined grains 3 servings 2 servings 1 serving
Red meat 1 serving 0.5 serving 0 serving
Processed meat 2 servings 1 serving 0 serving
White meat 0.75 serving 0.6 serving 0 serving
Sugar-sweetened beverages 17 oz 8.5 oz 0 oz
Added plant oils 2 tsp 2 tsp 2 tsp

*1 serving = 1 handful of nuts

**1 serving = 1 cup of beans, lentils, or peas

Using their algorithm, the authors asked what the effect on longevity would be if people changed from a typical western diet to one of the other diets at age 20, 60, or 80 and maintained the new diet for at least 10 years. The 10-year requirement is based on previous studies showing that it takes around 10 years for dietary changes to affect the major killer diseases like heart disease, cancer, or diabetes.

Finally, the authors improved the accuracy of their estimates of the effect of diet on longevity by taking into account the quality of each study included in their analysis. I will discuss the importance of this below.

Can Diet Add Years To Your Life?

The results were impressive.

The authors estimated that if people in the United States were to change from a typical western diet to an “optimal diet” and maintain it for at least 10 years,

…starting at age 20, men would live 13 years longer and women would live 10.7 years longer.

…starting at age 60, men would live 8.8 years longer and women would live 8 years longer.

…starting at age 80, both men and women would live 3.4 years longer.

But what if you weren’t a vegan purist? What if you only made half the changes you would need to make to optimize your diet? The news was still good.

The authors estimated that people in the United States were to change from a typical western diet to a “feasibility diet” and maintain it for at least 10 years,

…starting at age 20, men would live 7.3 years longer and women would live 6.2 years longer.

…starting at age 60, men would live 4.8 years longer and women would live 4.5 years longer.

…starting at age 80, both men and women would live ~2 years longer.

The authors concluded, “A sustained dietary change may give substantial health gains for people of all ages for both optimized and feasible [diet] changes. [These health gains] could translate into an increase in life expectancy of more than 10 years. Gains are predicted to be larger the earlier the dietary changes are initiated in life.”

Which Foods Have The Biggest Effect On Longevity?

The algorithm the authors developed also allowed them to look at which foods have the biggest effect on longevity. The authors estimated when changing from a typical western diet to an optimal diet, the greatest gains in longevity were made by eating:

  • More legumes, whole grains, and nuts, and…
  • Less red and processed meat.

The authors concluded, “An increase in the intake of legumes, whole grains, and nuts, and a reduction in the intake of red meat and processed meats, contributed most to these gains [in longevity].”

However, this conclusion needs to be interpreted with caution. We also need to recognize that an “optimal diet” was defined as the best diet people in this study were eating. In addition, the effect of different foods on longevity depends on:

  • The quality of the individual studies with that food, and…
  • The difference in consumption of that food in going from a western diet to an optimal diet.

For example:

  • Legumes, whole grains, nuts, red & processed meat made the list because the quality of data was high and the difference in consumption between the typical western diet and optimal diet was significant.
  • The quality of data for an effect of fruits and vegetables was also high. For example, one major study concluded that consuming 10 servings a day of fruits and vegetables a day reduces premature death by 31% compared to consumption of less than 1 serving a day. However, the difference in consumption of fruits and vegetables between the western and optimal diets in this study was small, so fruits and vegetables didn’t make the list.
  • Eggs and white meat didn’t make the list because the quality of data was low for those foods. Simply put,  that means that there was a large variation in effect of those foods on longevity between studies.
  • Other foods didn’t make the list because the quality of data was only moderate and/or the difference in intake was small.

So, the best way to interpret this these data is:

  • This study suggests that consuming more legumes, whole grains, and nuts and less red & processed meats has a significant beneficial effect on health and longevity.
  • Consuming more fruits and vegetables is likely to have a significant benefit on health and longevity, but you would need to consume more than people did in this study to achieve these benefits. In the words of the authors, “Fruits and vegetables also have a positive health impact, but, for these food groups, the intake in a typical Western diet is closer to the optimal intake than for the other food groups.”
  • Other foods may impact health and longevity, but the data in this study are not good enough to be confident of an effect.

What Does This Study Mean For You?

This study is the best of many studies showing the benefit of a more plant-based diet on health and longevity. It particularly encouraging because it shows:

  • You can achieve significant benefit by switching to a more plant-based diet late in life. You get the biggest “bang for your buck” if you switch at age 20. But even making the switch at age 60 or 80 was beneficial.
  • You don’t need to be a “vegan purist”. While the biggest benefits were seen for people who came close to achieving a vegan or semi-vegetarian diet, people who only made half those changes saw significant benefits.

As I said above, this is a very strong study. However, the underlying data come from association studies, which can have confounding variables that influence the results.holistic approach

For example, people who eat more plant-based diets tend to weigh less and exercise more. And both of those variables can influence longevity. Each study attempted to statistically correct for those variables, but they still might have a slight influence on the results.

However, I don’t see that as a problem because, in my view, a holistic approach is always best. As illustrated on the right, we should be seeking a lifestyle that includes a healthy diet, weight control, and exercise.

As for supplementation, both the vegan and semi-vegetarian diets tend to leave out whole food groups. Unless you are married to a dietitian, that means your diet is likely to be missing important nutrients.

The Bottom Line

A recent study asked whether changing from the typical western diet to a healthier, more plant-based diet could influence longevity. The results were very encouraging. The study showed that:

  • Changing to a healthier diet could add up to a decade to your lifespan.
  • The improvement in lifespan was greatest for those whose diets approached a vegan or semi-vegetarian diet, but a significant improvement in lifespan was seen for people who made only half those dietary improvements.
  • The improvement in lifespan was greatest for those who switched to a healthier diet in their 20’s, but significant improvements in lifespan were seen for people who didn’t change their diet until their 60’s or 80’s.

In terms of the foods that have the biggest effect on longevity.

  • This study suggests that consuming more legumes, whole grains, and nuts and less red & processed meats has a significant beneficial effect on health and longevity.
  • Consuming more fruits and vegetables is likely to have a significant benefit on health and longevity, but you would need to consume more than people did in this study to achieve those benefits.
  • Other foods may impact health and longevity, but the data in this study are not good enough to be confident of an effect.

The authors concluded, “A sustained dietary change may give substantial health gains for people of all ages for both optimized and feasible [diet] changes. [These health gains] could translate into an increase in life expectancy of more than 10 years. Gains are predicted to be larger the earlier the dietary changes are initiated in life.

An increase in the intake of legumes, whole grains, and nuts, and a reduction in the intake of red meat and processed meats, contributed most to these gains. Fruits and vegetables also have a positive health impact, but, for these food groups, the intake in a typical Western diet is closer to the optimal intake than for the other food groups.”

For more details about this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Do Omega-3s Add Years To Your Life?

Why Are Omega-3s So Controversial? 

Author: Dr. Stephen Chaney

ArgumentI don’t need to tell you that omega-3s are controversial. Some experts confidently tell you that omega-3s significantly reduce your risk of heart disease and may reduce your risk of cancer and other diseases. Other experts confidently tell you that omega-3s have no effect on heart disease or any other disease. They claim that omega-3 supplements are no better than “snake oil”.

The problem is that each camp of experts can cite published clinical studies to support their claims. How can that be? How can clinical studies come to opposite conclusions on such an important topic? The problem is that it is really difficult to do high quality clinical studies on omega-3s. I will discuss that in the next section.

The question of whether omega-3s affect life span has also been controversial. Heart disease and cancer are the top two causes of death in this country. So, if omega-3s actually reduced the risk of heart disease and cancer, you might expect that they would also help us live longer. Once again, there are studies on both sides of this issue, but they are poor quality studies.

We need more high-quality studies to clear up the controversies surrounding the health benefits of omega-3s. I will report on one such study in this issue of “Health Tips From The Professor”. But first let me go into more depth about why it is so difficult to do high-quality studies with omega-3 fatty acids.

Clinical Studies 101: Why Are Omega-3s So Controversial?

professor owlI have covered this topic in previous issues of “Health Tips From the Professor”, but here is a quick summary.

  1. Randomized, placebo controlled clinical trials (RCTs) are considered the gold standard for evidence-based medicine, but they ill-suited to measure the effect of omega-3s on health outcomes.
    • Heart disease and cancer take decades to develop. Most RCTs are too small and too short to show a meaningful effect of omega-3s on these diseases.
    • To make up for this shortcoming, some recent RCTs have started with older, sicker patients. This way enough patients die during the study that it can measure statistically significant outcomes. However, these patients are already on multiple medications that mimic many of the beneficial effects of omega-3s on heart disease.

These studies are no longer asking whether omega-3s reduce the risk of heart disease. They are really asking if omega-3s have any additional benefits for patients who are already taking multiple medications – with all their side effects. I don’t know about you, but that is not the question I am interested in.

    • Until recently, most RCTs did not measure circulating omega-3 levels before and after supplementation, so the investigators had no idea whether omega-3 supplementation increased circulating omega-3 levels by a significant amount.

And for the few studies where omega-3 levels were measured before and after supplementation, it turns out that for many of the participants, their baseline omega-3 levels were too high for omega-3 supplementation to have a meaningful effect. Only participants with low omega-3 levels at the beginning of the study benefited from omega-3 supplementation.Supplementation Perspective

These studies are often quoted as showing omega-3 supplementation doesn’t work. However, they are actually showing the true value of supplementation. Omega-3 supplementation isn’t for everyone. It is for people with poor diet, increased need, genetic predisposition, and/or pre-existing disease not already treated with multiple medications.

2) Prospective cohort studies eliminate many of the shortcomings of RCTs. They can start with a large group of individuals (a cohort) and follow them for many years to see how many of them die or develop a disease during that time (this is the prospective part of a prospective cohort trial). This means they can start with a healthy population that is not on medications.

This also means that these studies can answer the question on most people’s minds, “Are omega-3s associated with reduced risk of dying or developing heart disease?” However, these studies have two limitations.

    • They are association studies. They cannot measure cause and effect.
    • Ideally, omega-3 levels would be measured at the beginning of the study and at several intervals during the study to see if the participant’s diet had changed during the study. Unfortunately, most prospective cohort studies only measure omega-3 levels at the beginning of the study.

3) Finally, a meta-analysis combines data from multiple clinical studies.

    • The strength of a meta-analysis is that the number of participants is quite large. This increases the statistical power and allows it to accurately assess small effects.
    • The greatest weakness of meta-analyses is that the design of the individual studies included in the meta-analysis is often quite different. This introduces variations that decrease the reliability of the meta-analysis. It becomes a situation of “Garbage in. Garbage out”

The study (WS Harris et al, Nature Communications, Volume 12, Article number: 2329, 2021) I am discussing today is a meta-analysis of prospective cohort studies. It was designed to determine the association between blood omega-3 fatty acids and the risk of:

  • Death from all causes.
  • Death from heart disease.
  • Death from cancer.
  • Death from causes other than heart disease or cancer.

More importantly, it eliminated the major weakness of previous meta-analyses by only including studies with a similar design.

How Was This Study Done?

Clinical StudyThis study was a meta-analysis of 17 prospective cohort studies with a total of 42,466 individuals looking at the association between omega-3 fatty acid levels in the blood and premature death due to all causes, heart disease, cancer, and causes other than heart disease and cancer.

Participants in the 17 studies were followed for an average of 16 years, during which time 15,720 deaths occurred. This was a large enough number of deaths so that a very precise statistical analysis of the data could be performed.

The average age of participants at entry into the studies was 65, and 55% of the participants were women. Whites constituted 87% of the participants, so the results may not be applicable to other ethnic groups. None of the participants had heart disease or cancer when they entered the study.

Finally, the associations were corrected for a long list of variables that could have influenced the outcome (Read the publication for more details).

A strength of this meta-analysis is that all 17 studies were conducted as part of the FORCE (Fatty Acids & Outcomes Research Consortium) collaboration. The FORCE collaboration was established with the goal of understanding the relationships between fatty acids (as measured by blood levels of the omega-3 fatty acids) on premature death and chronic disease outcomes (cardiovascular disease, cancer, and other conditions).

Each study was designed using a standardized protocol, so that the data could be easily pooled for a meta-analysis. In the words of the FORCE collaboration founders:

  1. The larger sample sizes of [meta-analyses] will substantially increase statistical power to investigate associations…enabling the [meta-analyses] to discover important relationships not discernible in any individual study.

2) Standardization of variable definitions and modeling of associations will reduce variation and potential bias in estimates across cohorts.

3) Results will be far less susceptible to publication bias.

Do Omega-3s Add Years To Your Life?

Omega-3sThe meta-analysis divided participants into quintiles based on blood omega-3 levels. When comparing participants with the highest omega-3 levels with participants with the lowest omega-3 levels:

  • Premature death from all causes was decreased by 16%.
    • When looking at the effect of individual omega-3s, EPA > EPA+DHA > DHA.
  • Premature death from heart disease was decreased by 19%.
    • When looking at the effect of individual omega-3s, DHA > EPA+DHA > EPA.
  • Premature death from cancer was decreased by 15%.
    • When looking at the effect of individual omega-3s, EPA > DHA > EPA+DHA.
  • Premature death from causes other than heart disease and cancer was decreased by 18%.
    • When looking at the effect of individual omega-3s, EPA > EPA+DHA > DHA.
  • The differences between the effects of EPA, DHA, and EPA+DHA were small.
  • ALA, a short chain omega-3 found in plant foods, had no effect on any of these parameters.

In the words of the authors: “These findings suggest that higher circulating levels of long chain omega-3 fatty acids are associated with a lower risk of premature death. Similar relationships were seen for death from heart disease, cancer, and causes other than heart disease and cancer. No associations were seen with the short chain omega-3, ALA [which is found in plant foods]”.

What Does This Study Mean For You?

confusionIf you are thinking that 15-19% decreases in premature death from various causes don’t sound like much, let me do some simple calculations for you. The average lifespan in this country is 78 years.

  • A 16% decrease in death from all causes amounts to an extra 12.5 years. What would you do with an extra 12.5 years?
  • A 19% decrease in death from heart disease might not only allow you to live longer, but it has the potential to improve your quality of life by living an extra 15 years free of heart disease.
  • Similarly, a 15% decrease in death from cancer might help you live an extra 12 years cancer-free.
  • In other words, you may live longer, and you may also live healthier longer, sometimes referred to as “healthspan”.

Don’t misunderstand me. Omega-3s are not a magic wand. They aren’t the fictional “Fountain of Youth”.

  • There are many other factors that go into a healthy lifestyle. If you sit on your couch all day eating Big Macs and drinking beer, you may be adding the +12.5 years to a baseline of -30 years.
  • Clinical studies report average values and none of us are average. Omega-3s will help some people more than others.

I will understand if you are skeptical. It seems like every time one study comes along and tells you that omega-3s are beneficial, another study comes along and tells you they are worthless.

This was an extraordinarily well-designed study, but it is unlikely to be the final word in the omega-3 controversy. There are too many poor-quality studies published each year. Until everyone in the field agrees to some common standards like those in the FORCE collaboration, the omega-3 controversy will continue.

The Bottom Line 

A recent meta-analysis looked at the association between omega-3 fatty acid levels in the blood and premature death due to all causes, heart disease, cancer, and causes other than heart disease and cancer.

The meta-analysis divided participants into quintiles based on blood omega-3 levels. When comparing participants with the highest omega-3 levels with participants with the lowest omega-3 levels:

  • Premature death from all causes was decreased by 16%.
  • Premature death from heart disease was decreased by 19%.
  • Premature death from cancer was decreased by 15%.
  • Premature death from causes other than heart disease and cancer was decreased by 18%.

In the words of the authors: “These findings suggest that higher circulating levels of long chain omega-3 fatty acids are associated with a lower risk of premature death. Similar relationships were seen for death from heart disease, cancer, and causes other than heart disease and cancer.”

For more details about study and what this study means for you read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 

 

Will Plant Proteins Help You Live Longer?

Is A Vegan Diet Healthiest?

Author: Dr. Stephen Chaney

Fountain Of YouthUnless you are Rip Van Winkle and have been asleep for the past 40 years, you have probably heard that whole food, primarily plant-based diets are good for you.

  • They help you control your weight.
  • They reduce inflammation.
  • They reduce your risk of diabetes and heart disease.
  • They even reduce your risk of some cancers.

But do they help you live longer? If we take that question literally, the answer appears to be no. There is no “Fountain Of Youth”. There are no diets that extend our lives significantly.

However, what if you could reduce your risk of premature death? It would be tragic to have your life cut short by a heart attack or some other major disease. What if you could prevent that?

And what if you could live healthier longer? It would be equally tragic to spend your golden years debilitated by chronic diseases like heart disease, diabetes, or dementia. What if you could delay these diseases and live healthier longer?

The study I discuss this week (Y Sun, Journal of the American Heart Association, 10:e015553, 2021) looks at the effect of different dietary protein sources on premature death.

This study, like many others, suggests that primarily plant-based diets are healthier than meat-based diets. But what does this mean for you? Should you go completely meatless? Is a vegan diet healthier than other plant-based diets? I discuss what we know and what we do not know about the vegan diet compared to other plant-based diets.

How Was This Study Done?

Clinical StudyThe data for this study were drawn from the Women’s Health Initiative (WHI). The Women’s Health Initiative was designed to help identify strategies for preventing heart disease and other diseases in postmenopausal women. It enrolled 161,000 postmenopausal women from 40 sites across the US between 1993 and 1998 and followed them through 2017.

This study excluded women who had heart disease or cancer when they entered the WHI study and women who had incomplete data on either their diet or their use of postmenopausal hormone therapy. They were left with 102,521 women, age 50-79 at time of entry, who were followed for 18 years.

Each woman filed out an extensive dietary survey at the beginning of the study. There were 25,976 deaths during the study. The cause of death was determined by reviewing death certificates, medical records, autopsy reports or by linkage to the National Death Index.

The investigators asked whether women who ate more plant proteins were healthier than those who ate primarily meat protein. To answer this question, they correlated protein sources in the diet with all-cause mortality and deaths from various diseases.

The greatest difficulty with this type of study is that people who eat more plant protein tend to have a healthier diet and a healthier lifestyle. That makes it hard to separate out the benefits of eating plant proteins from benefits associated with other aspects of their diet and lifestyle. So, the authors corrected their data for every factor known to influence the risk of heart disease, diabetes, dementia, and premature death.

Specifically, the data were statistically corrected for age, race/ethnicity, socioeconomic status, hormone use, lifestyle (smoking status, physical activity, and alcohol intake), baseline health status (diabetes and/or high blood cholesterol), family history of heart attack/stroke, dietary factors (calorie intake, dietary fiber intake, whole grain consumption, fruit and vegetable consumption, sugar-sweetened beverage consumption, glycemic load (effect of foods in the diet on blood sugar), and percentage of saturated fats, polyunsaturated fats, monounsaturated fats, and trans fats), and weight (BMI).

In short, the authors corrected for every other factor that could influence disease risk and/or premature death. By doing so, they were able to focus on the effect of protein sources on disease risk and/or premature death.

Will Plant Proteins Help You Live Longer?

Plant ProteinsThe investigators divided the study participants into quintiles with respect the kind and amount of protein they consumed.

  • For animal protein, the intake ranged from 4 ounces/day in the lowest quintile to 9 ounces a day in the highest quintile (For comparison, 3 ounces is roughly equivalent to the size of a deck of cards).
  • For plant protein, the intake ranged from 2 ounces/day in the lowest quintile to 3.5 ounces/day in the highest quintile.
  • When you combine plant and animal protein in these women’s diet, plant protein ranged from 18% of total protein intake in the lowest quintile to 48% of total protein intake in the highest quintile.

When women who had the highest intake for plant protein were compared with women who had the lowest intake of plant protein, the women with the highest plant protein intake had:

  • 12% lower risk of premature death from heart disease.
  • 21% lower risk of premature death from dementia.
  • 9% lower risk of premature death from all causes.

There was an inverse relationship between the amount of plant protein in the diet and premature death. Specifically, every 3 ounces of animal protein that was replaced with 3 ounces of plant protein resulted in:

  • 22% lower risk of premature death from heart disease.
  • 19% lower risk of premature death from dementia.
  • 14% lower risk of premature death from all causes.

The Effect Of Individual Animal Proteins On Mortality

Fatty SteakThe authors also looked at the effect of various animal proteins on premature death. For example:

Red Meat: Women with the highest consumption of red meat had:

  • 14% higher risk of premature death from heart disease.
  • 20% higher risk of premature death from dementia.
  • 10% higher risk of premature death from all causes.

Eggs: Women with the highest consumption of eggs had:

  • 24% higher risk of premature death from heart disease.
  • 14% lower risk of premature death from dementia.
  • 14% higher risk of premature death from all causes.

Dairy: Women with the highest consumption of dairy had:

  • 11% higher risk of premature death from heart disease.

The authors concluded, “In this large prospective cohort study, we found that higher plant protein intake and substitution of animal protein with plant protein were associated with lower risk of all-cause mortality, cardiovascular mortality, and dementia mortality…Our findings support the need for consideration of protein sources, in addition to the amount of protein intake, in future dietary guidelines.”

Is A Vegan Diet Healthiest?

Vegetarian DietYears ago, as my brother-in-law was coming out of anesthesia at the end of quadruple bypass surgery, the first question he asked was, “Does this mean I need to eat tofu?” Obviously, nothing terrified him more than the thought of eating tofu the rest of his life. In the same vein, some of you are probably asking, “Does this mean I need to go vegan?”

The good news is that none of the women in this study were consuming a vegan diet. They were consuming a typical American diet with varying amounts of plant and animal protein. The group with the highest plant protein consumption were still getting 52% of their protein from animal sources.

This study shows that even people consuming a typical American diet can become healthier by simply swapping out some of the animal protein in their diet with plant protein.

However, you are probably thinking, “Plant protein is good for us, and a vegan diet is 100% plant protein. Does that mean a vegan diet is healthier than other plant-based diets?

The answer is………”Maybe”

If the linear relationship between plant protein consumption and risk of premature death could be extrapolated all the way to 100% plant protein, the answer would be obvious. Vegan diets would be healthier than other plant-based diets. But that extrapolation is an assumption. It might not be true.

For example, some recent studies suggest that completely eliminating meat, eggs, and dairy from your diet may slightly increase your risk of heart disease and stroke:

  • One recent study found that adding 1.4 ounces of fish/day to a primarily vegetarian diet decreases the risk of stroke by 20%.
  • Another study reported that adding one egg/day to a primarily vegetarian diet decreases the risk of heart disease by 12% and stroke by 10-26%.

These studies need to be confirmed, but they do suggest we need to be cautious about assuming that vegan diets are healthier than other primarily plant-based diets. This is why, when I recommend primarily plant-based diets, I include everything from vegan through semi-vegetarian, Mediterranean, and DASH.

They are all healthy diets. My advice is to choose the one that best fits your lifestyle and food preferences. And focus on whole foods, not processed foods.

The Bottom Line 

A recent study asked whether women who ate more plant proteins were healthier than those who ate primarily meat protein. To answer this question, the investigators correlated protein sources in the diet with all-cause mortality and deaths from various diseases.

When women who had the highest intake for plant protein were compared with women who had the lowest intake of plant protein, the women with the highest plant protein intake had:

  • 12% lower risk of premature death from heart disease.
  • 21% lower risk of premature death from dementia.
  • 9% lower risk of premature death from all causes.

There was an inverse relationship between the amount of plant protein in the diet and premature death. Specifically, every 3 ounces of animal protein that was replaced with 3 ounces of plant protein resulted in:

  • 22% lower risk of premature death from heart disease.
  • 19% lower risk of premature death from dementia.
  • 14% lower risk of premature death from all causes.

[Note: A 3-ounce serving is roughly equivalent to a deck of cards.]

The authors concluded, “In this large prospective cohort study, we found that higher plant protein intake and substitution of animal protein with plant protein were associated with lower risk of all-cause mortality, cardiovascular mortality, and dementia mortality…Our findings support the need for consideration of protein sources, in addition to the amount of protein intake, in future dietary guidelines.”

Years ago, as my brother-in-law was coming out of anesthesia at the end of quadruple bypass surgery, the first question he asked was, “Does this mean I need to eat tofu?” Obviously, nothing terrified him more than the thought of eating tofu the rest of his life. In the same vein, some of you are probably asking, “Does this mean I need to go vegan?”

I discuss the answer to that question in the article above.

For more details and a discussion about the vegan diet versus other primarily plant-based diets read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Can You Improve Your Healthspan?

Can You Live Healthier, Longer?

Ever since Ponce de Leon led an expedition to the Florida coast in 1513, we have been searching for the mythical “Fountain Of Youth”. What does that myth mean?

Supposedly, just by immersing yourself in that fountain you would be made younger. You would experience all the exuberance and health you enjoyed when you were young. There have been many snake oil remedies over the years that have promised that. They were all frauds.

But what if you had it in your power to live longer and to retain your youthful health for most of those extra years. The ability to live healthier longer is something that scientists call “healthspan”. But you can think of it as your personal “Fountain Of Youth”.

Where are we as a nation? Americans ranked 53rd in the world for life expectancy. We have the life expectancy of a third-world country. We are in sore need of a “Fountain Of Youth”.

That is why I decided to share two recent studies from the prestigious Harvard T.H. Chan School of Public Health with you today.

How Were The Studies Done?

Clinical StudyThese studies started by combining the data from two major clinical trials:

  • The Nurse’s Health Study, which ran from 1980 to 2014.
  • The Health Professional’s Follow-Up Study, which ran from 1986-2014.

These two clinical trials enrolled 78,865 women and 42,354 men and followed them for an average of 34 years. During this time there were 42,167 deaths. All the participants were free of heart disease, type 2 diabetes, and cancer at the time they were enrolled. Furthermore, the design of these clinical trials was extraordinary.

  • A detailed food frequency questionnaire was administered every 2-4 years. This allowed the investigators to calculate cumulative averages of all dietary variables.
  • Participants also filled out questionnaires that captured information on disease diagnosis every 2 years with follow-up rates >90%. This allowed the investigators to measure the onset of disease for each participant during the study. More importantly, 34 years is long enough to measure the onset of diseases like heart disease, diabetes, and cancer – diseases that require decades to develop.
  • The questionnaires also captured information on medicines taken and lifestyle characteristics such as body weight, exercise, smoking and alcohol use.
  • For analysis of diet quality, the investigators use something called the “Alternative Healthy Eating Index”. [The original Healthy Eating Index was developed about 10 years ago based on the 2010 “Dietary Guidelines for Americans”. Those guidelines have since been updated, and the “Alternative Healthy Eating Index” is based on the updated guidelines.] You can calculate your own Alternative Healthy Eating Index below, so you can see what is involved.
  • Finally, the investigators included five lifestyle-related factors – diet, smoking, physical activity, alcohol consumption, and BMI (a measure of obesity) – in their estimation of a healthy lifestyle. Based on the best available evidence, they defined “low-risk” in each of these categories. Study participants were assigned 1 point for each low-risk category they achieved. Simply put, if they were low risk in all 5 categories, they received a score of 5. If they were low risk in none of the categories, they received a score of 0.
  • Low risk for each of these categories was defined as follows:
    • Low risk for a healthy diet was defined as those who scored in the top 40% in the Alternative Healthy Eating Index.
    • Low risk for smoking was defined as never smoking.
    • Low risk for physical activity was defined as 30 minutes/day of moderate or vigorous activities.
    • Low risk for alcohol was defined as 0.5-1 drinks/day for women and 0.5-2 drinks/day for men.
    • Low risk for weight was defined as a BMI in the healthy range (18.5-24.9 kg/m2).

Can You Live Healthier Longer?

Older Couple Running Along BeachThe investigators compared participants who scored as low risk in all 5 categories with participants who scored as low risk in 0 categories (which would be typical for many Americans). For the purpose of simplicity, I will refer to people who scored as low risk in 5 categories as having a “healthy lifestyle” and those who scored as low risk in 0 categories as having an “unhealthy lifestyle”.

The results of the first study were:

  • Women who had had a healthy lifestyle lived 14 years longer than women with an unhealthy lifestyle (estimated life expectancy of 93 versus 79).
  • Men who had a healthy lifestyle lived 12 years longer than men with an unhealthy lifestyle (estimated life expectancy was 87 versus 75).
  • It was not necessary to achieve a perfect lifestyle. Life expectancy increased in a linear fashion for each low-risk lifestyle behavior achieved.

The authors of the study concluded: “Adopting a healthy lifestyle could substantially reduce premature mortality and prolong life expectancy in US adults. Our findings suggest that the gap in life expectancy between the US and other developed countries could be narrowed by improving lifestyle factors.”

The results of the second study were:

  • Women who had a healthy lifestyle lived 11 years longer free of diabetes, heart disease, and cancer than women who had an unhealthy lifestyle (estimated disease-free life expectancy of 85 years versus 74 years).
  • Men who had a healthy lifestyle lived 8 years longer free of diabetes, heart disease, and cancer than men who had an unhealthy lifestyle (estimated disease-free life expectancy of 81 years versus 73 years).
  • Again, disease-free life expectancy increased in a linear fashion for each low-risk lifestyle behavior achieved.

The authors concluded: “Adherence to a healthy lifestyle at mid-life [They started their analysis at age 50] is associated with a longer life expectancy free of major chronic diseases. Our findings suggest that promotion of a healthy lifestyle would help reduce healthcare burdens through lowering the risk of developing multiple chronic diseases, including cancer, cardiovascular disease, and diabetes, and extending disease-free life expectancy.”

Can You Improve Your Healthspan?

Questioning ManI posed the question at the beginning of this article, “Can you improve your healthspan?” These two studies showed that you can improve both your life expectancy and your disease-free life expectancy. So, the answer to the original question appears to be, “Yes, you can improve your healthspan. You can create your personal “Fountain of Youth.”

However, as a nation we appear to be moving in the wrong direction. The percentage of US adults adhering to a healthy lifestyle has decreased from 15% in 1988-1992 to 8% in 2001-2006.

The clinical trials that these studies drew their data from were very well designed, so these are strong studies. However, like all scientific studies, they have some weaknesses, namely:

  • They looked at the association of a healthy lifestyle with life expectancy and disease-free life expectancy. Like all association studies, they cannot prove cause and effect.
  • The clinical trials they drew their data with included mostly Caucasian health professionals. The results may differ with different ethnic groups.
  • These studies did not look at the effect of a healthy lifestyle on the onset of Alzheimer’s disease and other forms of dementia. However, other studies have shown that people who were low risk for each of the 5 lifestyle factors (diet, exercise, body weight, smoking, and alcohol use) individually have a reduced risk of developing Alzheimer’s and/or dementia.

Finally, I know you have some questions, and I have answers.

Question: What about supplementation? Will it also improve my healthspan?

Answer: When the investigators analyzed the data, they found that those with the healthiest lifestyles were also more likely to be taking a multivitamin. So, they attempted to statistically eliminate any effect of supplement use on the outcomes. That means these studies cannot answer that question.

However, if you calculate your Alternate Healthy Eating Index below, you will see that most of us fall short of perfection. Supplementation can fill in the gaps.

Question: I cannot imagine myself reaching perfection in all 5 lifestyle categories? Should I even try to achieve low risk in one or two categories?

Answer: The good news is that there was a linear increase in both life expectancy and disease-free life expectancy as people went from low-risk in one category to low-risk in all 5 categories. I would encourage you to try and achieve low risk status in as many categories as possible, but very few of us, including me, achieve perfection in all 5 categories.

Question: I am past 50 already. Is it too late for me to improve my healthspan?

Answer: Diet and some of the other lifestyle behaviors were remarkably constant over 34 years in both the Nurse’s Health Study and the Health Professional’s Follow-Up Study. That means that the lifespan and healthspan benefits reported in these studies probably resulted from adhering to a healthy lifestyle for most of their adult years.

However, it is never too late to start improving your lifestyle. You may not achieve the full benefits described in these studies, but you still can add years and disease-free years to your life.

How To Calculate Your Alternative Healthy Eating Index

You can calculate your own Alternative Healthy Eating Index score by simply adding up the points you score for each food category below.

Vegetables

Count 2 points for each serving you eat per day (up to 5 servings).

One serving = 1 cup green leafy vegetables or ½ cup for all other vegetables.

Do not count white potatoes or processed vegetables like French fries or kale chips.

Fruits

Count 2½ points for each serving you eat per day (up to 4 servings).

One serving = 1 piece of fruit or ½ cup of berries.

          (do not count fruit juice or fruit incorporated into desserts or pastries). 

Whole Grains

Count 2 points for each serving you eat per day (up to 5 servings).

One serving = ½ cup whole-grain rice, bulgur and other whole grains, cereal, and pasta or 1 slice of bread.

(For processed foods like pasta and bread, the label must say 100% whole grain).

Sugary Drinks and Fruit Juice

Count 10 points if you drink 0 servings per week.

Count 5 points for 3-4 servings per week (½ serving per day).

Count 0 points for 7 or more servings per week (≥1 serving per day).

One serving = 8 oz. fruit juice, sugary soda, sweetened tea, coffee drink, energy drink, or sports drink.

Nuts, Seeds and Beans

Count 10 points if you eat 7 or more servings per week (≥1 serving per day).

Count 5 points for 3-4 servings per week (½ serving per day).

Count 0 points for 0 servings per week.

One serving = 1 oz. nuts or seeds, 1 Tbs. peanut butter, ½ cup beans, 3½ oz. tofu.

Red and Processed Meat

Count 10 points if you eat 0 servings per week.

Count 7 points for 3-4 servings per week (½ serving per day).

Count 3 points for 3 servings per week (1 serving per day).

Count 0 points for ≥1½ servings per day.

One serving = 1½ oz. processed meats (bacon, ham, sausage, hot dogs, deli meat)

          Or 4 oz. red meat (steak, hamburger, pork chops, lamb chops, etc.)

Seafood

Count 10 points if you eat 2 servings per week.

Count 5 points for 1 serving per week.

Count 0 points for 0 servings per week.

1 serving = 4 oz.

Now that you have your total, the scoring system is:

  • 41 or higher is excellent
  • 37-40 is good
  • 33-36 is average (remember that it is average to be sick in this country)
  • 28-32 is below average
  • Below 28 is poor

Finally, for the purposes of these two studies, a score of 37 or higher was considered low risk.

The Bottom Line

Two recent studies have developed a healthy lifestyle score based on diet, exercise, body weight, smoking, and alcohol use. When they compared the effect of lifestyle on both lifespan (life expectancy) and healthspan (disease-free life expectancy), they reported:

  • Women who had had a healthy lifestyle lived 14 years longer than women with an unhealthy lifestyle.
  • Men who had a healthy lifestyle lived 12 years longer than men with an unhealthy lifestyle.
  • Women who had a healthy lifestyle lived 11 years longer free of diabetes, heart disease, and cancer than women had an unhealthy lifestyle.
  • Men who had a healthy lifestyle lived 8 years longer free of diabetes, heart disease, and cancer than men who had an unhealthy lifestyle.
  • It is not necessary to achieve a perfect lifestyle. Lifespan and healthspan increased in a linear fashion for each low-risk lifestyle behavior (diet, exercise, body weight, smoking, and alcohol use) achieved.
  • These studies did not evaluate whether supplement use also affects healthspan.
    • However, if you calculate your diet with the Alternate Healthy Eating Index they use (see above), you will see that most of us fall short of perfection. Supplementation can fill in the gaps.

The authors concluded: “Our findings suggest that promotion of a healthy lifestyle would help reduce healthcare burdens through lowering the risk of developing multiple chronic diseases, including cancer, cardiovascular disease, and diabetes, and extending disease-free life expectancy.”

For more details, including how to calculate whether you are low risk in each of the 5 lifestyle categories, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Health Tips From The Professor