the six keys to living longer

Although we now know that unhealthy lifestyle behaviors are associated with an increased risk of various chronic diseases and death, this was not always the case.

The first studies to measure this relationship in a standardized way focused on three parameters: monitoring of the Mediterranean diet, the number of years of smoking, and body mass index.

Later, throughout this century, experts have worked with multiple indices.

Searching for the ideal index

In May 2024, the group of Iranian scientist Elaheh Dehghani, from the Tehran University of Medical Sciences, selected five tools:

1. Healthy lifestyle questionnaire. It includes a balanced diet, respect for meal times, reducing tobacco and alcohol consumption, improving rest habits and increasing physical activity.

2. Adolescent Lifestyle Index. It is based on water consumption, physical activity, sun protection, social relationships, the search for clean air, eating habits, risk behaviors and leisure habits.

3. Vegetarian Lifestyle Index. Evaluate your consumption of the following dietary components: whole grains, legumes, soy, meat substitutes, vegetables, fruits, nuts and seeds, water, and reliable sources of vitamin B-12. It also takes into account physical activity.

4. Healthy lifestyle questionnaire for breast cancer survivors. It includes dietary habits, environment (for example, exposure to pollutants), physiology, responsible behavior with one’s own health, stress management, social relationships and spiritual growth.

5. Healthy Lifestyle Index. It takes into account five parameters: smoking, physical activity, diet, alcohol consumption and sleep duration.

Of all these instruments, the last one stands out for its wide applicability and for having been evaluated in multiple studies with diverse populations. It has proven useful in both research and clinical practice to evaluate and improve habits.

One of the first attempts to apply it dates back to 2001. That year, researchers Andrew Steptoe and Jane Wardle, from the Department of Epidemiology and Public Health at University College London, replaced the concept of “factor” with that of “behavior.”

Steptoe and Wardle thus determined eleven health behaviors for seven activities: regular exercise, alcohol consumption, inclusion of fat in the diet, fiber consumption, adding salt to food, wearing a seat belt and using sun protection.

These behaviors were used to evaluate the lifestyle of the participants, ranging from a value of 0 (no healthy behaviors) to 11 (all healthy behaviors).

Endorsed by the WHO

Last July, and based on the European Prospective Investigation into Cancer and Nutrition (EPIC), the World Health Organization (WHO) issued a document stating that the healthy lifestyle index It is capable of measuring the risk of type 2 diabetes, cardiovascular diseases, cancer and premature mortality.

The study affirms its usefulness both in its standard form, giving equal weight to each component of the lifestyle, and in its specific form. In the latter case, the relevance of each item is adjusted according to its relationship with a particular medical situation, such as diabetes, cardiovascular disease or cancer. In this way, the index is more personalized and can offer a more precise evaluation for each type of ailment.

The authors of the report compared different parameters, such as the risk ratio, a measure that compares the risk of a disease between two groups; Harrell’s C index, which assesses a model’s ability to correctly predict outcomes, and population attributable fractions, the proportion of cases of a disease that could be avoided if a specific risk factor were eliminated.

Attentive to the results

The results reflect that the high value of this index is associated with a lower risk of type 2 diabetes, cardiovascular diseases, cancer and premature mortality. The following parameters are evaluated:

• Smoking. There are three possibilities: the person evaluated has never smoked, is an ex-smoker or currently smokes.

• Alcohol intake. Daily amount consumed.

• Physical activity. Active, moderately active or inactive level.

• body mass index.

• Feeding. Score based on adherence to the Mediterranean diet.

• Sleep quality. Considered as an important factor to evaluate the relationship between lifestyle and health outcomes.

If, as the study indicates, the healthy lifestyle index is a valuable tool for evaluating the combined impact of multiple behaviors, it should be used in three strategies:

• Promotion of healthy habits: do not smoke, moderate alcohol consumption, follow a balanced diet, engage in regular physical activity and maintain an adequate body weight.

• Implementation of public health policies: The results can guide the formulation of more precise and specific recommendations to prevent chronic diseases.

• Personal evaluation: Any individual and health professionals can use the index as a tool to evaluate and improve lifestyle habits.

Because as William Shakespeare wrote:

“Our bodies are our gardens; our decisions, our gardeners.”

* José Miguel Soriano del Castillo is a professor of Nutrition and Bromatology at the Department of Preventive Medicine and Public Health, University of Valencia.

**This article was originally published on The Conversation.