Category: Food and nutrients

We are all know about the benefits of fruits and vegetables and the importance of getting our 5 a day.

Focussing on fruits – they are a fantastic source of antioxidants, vitamins, minerals and fibre which need to be consumed as part of a well-balanced healthy diet.

It is important not to stress too much on the benefits of one fruit over another but bear in mind it is a good idea to eat a variety of different coloured fruits and vegetables in your diet. Ever heard the phrase “eat a rainbow?”  This means choosing a variety of different coloured whole foods throughout the day and week.

However, did you know that as many fruits ripen this can affect the nutritional composition?

Nutrition consultant, Debra Williams from Eat Well Now explains this in more detail.

Sugar content increases as fruits ripen

As fruits go through the ripening process there is an increase in the breakdown of starch which is converted into simple sugars such as sucrose, glucose and fructose.   These sugars are more easily and quickly absorbed into the bloodstream.  This is something to bear in mind if you are diabetic as you ideally want to consume carbohydrates that are more slowly absorbed and have a low glycaemic index. As an example, for diabetics it is best to have bananas that are more unripe (greener in colour) and avoid too many yellow bananas.

Another fact to note is more sugar means more calories so for people that are trying to lose weight this may be a concern. However, to counter that for some individuals eating under ripe fruit may be an advantage in that some fruits for example, green bananas contain more resistant starch. Resistant starch is not digested in the small intestine and can be helpful as a food source for our gut bacteria.

Antioxidants generally increase as fruits ripen

Why is this?  Fruits undergo important metabolic changes during ripening, including chlorophyll breakdown, anthocyanin or carotenoid pigment accumulation. However, this is not the case for all fruits and some antioxidant classes (phenolic compounds) can decrease as fruits ripen. There is a huge array of research published on the health benefits of antioxidants and them being protective against heart disease, cancer and other diseases. Blackberries are particularly high in antioxidants. Blackberries are a rich source of anthocyanins, powerful antioxidants that give them their deep purple colour. However, they are also high in vitamin C and potassium.

Vitamin C can increase or decrease during ripening

This really depends on the type of fruit. For example, in citrus fruits such as oranges and lemons the vitamin C is highest when the fruit is not as ripe.  Vitamin C (ascorbic acid) is highly unstable and has a short shelf life so when fruits are stored for too long the vitamin C can diminish over time. Vitamin C is a water-soluble vitamin and has various benefits such as boosting our immune system, maintaining healthy skin and aid in wound healing.

The  level of minerals in fruit does not change much as they ripen

The mineral content of fruit very rarely changes much during the ripening process so for example a green banana will contain a similar amount of potassium as a yellow banana.

What about buying frozen, canned or dried fruit?

It is also important to note that frozen, dried and tinned fruit can be equally as nutritious as fresh fruit as they are often processed immediately after harvesting so some nutrients are likely to be higher as the fruits will not have been left in storage for too long.

There are many factors that can affect the nutritional composition of fruit and these include use of fertilisers, soil composition, growing and storage conditions.

So when we next look at the fruit in our fruit bowls it is well worth thinking about the journey the fruit has taken from when it has been harvested and how over time the nutritional content can vary.  Overall though we all need to be eating more fruits and vegetables in our diets. With the cost-of-living crisis a concern for many of us it can be comforting to know that we do not always need to buy fresh fruit and we can consider buying tinned, frozen or dried fruit.

Carbohydrates are often viewed unfavourably when talking about a “healthy” diet. But in truth, these macronutrients are vital for several key functions in the body. They are a primary source of energy and act as a fuel for our brains.

However, not all carbohydrates were created equally; refined sugary carbohydrates like cakes, biscuits and sugary drinks, do not provide as many health benefits as starchy high fibre carbohydrates such as wholegrain cereals or pulses. These are nutrient dense, for example lentils are packed full of B vitamins, magnesium, zinc and potassium.

There are so many myths and conflicting information concerning carbohydrates. Some common misconceptions are listed and explained below:

Myth 1: “Carbohydrates are bad for you”

One of the primary functions of carbohydrates is to act as an energy store. Through digestion in your body, they are broken down to glucose, which travels in the blood to our cells. This provides us with energy to go about our daily life!

Dietary fibre (a type of carbohydrate) is fundamental to our gut health. Soluble and insoluble fibre both pass through the body undigested, promoting good digestive health and acting as a fuel for friendly gut bacteria. Soluble fibre also slows the rise of our blood glucose levels, so we feel more energised for longer.

Some research also suggests that combining tryptophan-rich foods with carbohydrates, can help tryptophan reach the brain and promote a good night’s sleep. Tryptophan is an amino acid found in small amounts in protein rich foods, and in higher amounts in yogurt, milk and bananas. You could for example combine banana and yogurt, or salmon and lentils.

Myth 2: “Carbohydrates are fattening”

When choosing carbohydrates, the type and quality is key. Refined carbohydrates, such as white flour, white pasta and pastries are a risk factor for heart conditions or developing diabetes. High sugar foods are generally calorie dense and of little nutritional value. When eaten in excess, there is potential for weight gain, but this is a consequence of overeating and not from these foods alone.

However unprocessed, unrefined carbohydrates will have greater positive benefits, providing other nutrients. These include oats which are fibre rich and high in protein, or brown rice, quinoa and lentils.

Myth 3: “Cutting out carbohydrates leads to weight loss”

Recent research highlights the role of low carbohydrate diets like the Atkins or Ketogenic diet, in promoting short-term weight loss. However, in the long-term these diets reduce overall nutrient and fibre intake and so can damage the gut microbiome, leading to reduced overall health. Reducing carbohydrate intake should be balanced with an overall healthier lifestyle, such as increasing the amount of unprocessed whole foods, and reducing sugar intake.

It is possible to take a “whole body” approach and acknowledge the benefit of certain carbohydrate over others, without labelling them as “good” or “bad”. This does not serve any purpose except encourage feelings of guilt. Moderation overall is best approach in relation to carbohydrates and the focus should lie upon the quality and type, to ensure optimal gut health and long-lasting energy.

Restricting carbohydrates may serve for short-term weight loss but does not tend to be a long-term sustainable approach. The government’s Eatwell Guide recommends that just over a third of your diet should stem from starchy carbohydrate foods, and another third from fruit, vegetables, and salad. It is hard therefore, to deny the importance of unrefined and unprocessed carbohydrates in a healthy balanced diet.

I hope that this article has solved some of the questions with regards the ongoing debate on carbohydrates.

Written by Lara Bracher (student) and edited by Debra Williams (RD)

References
1: Crispim CA; Zimberg IZ; dos Reis BG; Diniz RM; Tufik S; de Mello MT . (2011). Relationship between food intake and sleep pattern in healthy individuals. Journal of Clinical Sleep Medicine.
2: Jacka, F. (2019). Brain changer; How diet can save your mental health. Yellow Kite.