Does an apple a day really keep the doctor away? A nutritionist explains the science behind ‘functional’ foods.

How accurate is the adage "an apple a day keeps the doctor away"? Apples do not have a high vitamin A content and are not as good for your eyes as carrots. They don't have as much vitamin C as oranges do, which makes them less effective at preventing colds.

Apples do, however, contain a variety of bioactive compounds, which are natural molecules that are present in food in minute levels and have biological effects on the body. These substances are not categorised as vitamins or other nutrients. Apples are regarded as a "functional" food since they contain numerous bioactive compounds that are beneficial to health.

I have extensive experience instructing university courses on nutrition such vitamins, minerals, carbohydrates, proteins, and lipids. However, I recently created a course that is exclusively about functional meals. The course examines the numerous bioactive compounds found in food and how some of them may possibly have medicinal properties.

Defining functional foods

Superfoods and functional foods are not the same thing. Marketers use the term "superfood" to advertise foods like kale, spinach, and blueberries. Their "super" designation attracts customers and boosts revenue.

However, the term "superfood" often refers to a food that has higher nutritional value and is rich in nutrients that are good for the body. Because the omega-3 fats in salmon and tuna have been associated with heart health, they are regarded as superfoods.

Superfood commercials promise health benefits from consuming the food. The issue is that, unlike the requirements for functional foods, the majority of those claims are not supported by scientific evidence.

Functional foods contain a variety of bioactive compounds, each of which has a specific role in the body, in addition to the nutrients that our bodies require for growth and development. The bioactive ingredients might be added during manufacturing or found naturally in food.

As science advances, the list of bioactive ingredients in food extends constantly. The ingredients themselves are not new, but the evidence-based study demonstrating their health advantages is.

The most recognisable types of bioactive chemicals are carotenoids. The 850 distinct pigments that give red, orange, and yellow fruits and vegetables their colour are part of this family. Carotenoids generally serve as antioxidants, which means they support health by assisting in the prevention of cellular deterioration. Different carotenoids may each have a different way of working.

Because of its abundance in carrots, beta-carotene is the carotenoid that is most well-known. After being ingested, beta-carotene transforms into vitamin A in the body. Normal vision requires the nutrient vitamin A.

The yellow carotenoids present in maize and peppers are lutein and zeaxanthin. Both of these support vision, particularly in older persons.

Carotenoids found in food and other types of bioactive compounds may aid in the prevention of some malignancies and enhance heart health, according to research. It's crucial to highlight that while carotenoids in supplements have fewer health advantages, they are still linked to lower chances of various malignancies and cardiovascular disease.

The functional food movement's history

Although the proverb "apples and health" dates back to the 1800s, nutrition is still a relatively new field of study. The concept of functional foods and bioactive ingredients is even more recent.

Vitamin inadequacies were the focus of nutrition study from the early 1900s until the 1970s. To avoid nutrient deficiency illnesses like rickets, which is brought on by a protracted vitamin D shortage, or scurvy, which is brought on by a severe vitamin C deficit, the public was urged to consume more vitamin-fortified processed foods.

People often focused on particular nutrients as a result of this stress on eating to make up for dietary deficits, which can lead to overeating. Weight gain as a result of this and the greater accessibility of highly processed foods led to rising incidence of diabetes, high blood pressure, and heart disease.