Benefits Of Raisins For Weight Loss

What are raisins?

It is almost impossible to have a christmas pudding or mince pies without tasting these delicious little ingredients, seen commonly in the baking aisles in our markets. There are three different varieties of dried grapes found in markets namely raisins, sultanas and currants. Though the type of grapes used and manufacturing process are different, their nutritional profiles are similar.¹ Raisins are the largest of the three and are made from several varieties of vine-grown grapes. They are usually made from sun-drying them naturally for about three weeks whereas sultanas are made dried artificially in a few hours and coated with preservative to retain the colour.¹

Health benefits of raisins

These dense, sweet treats are packed with a high amount of nutrients. They are an excellent source of iron which is important for formation of red blood cells. Raisins are very good sources of vitamins,potassium, magnesium, boron and several phytonutrients.² The phytonutrients are plant chemicals and have lots of health benefits. The phytonutrients present in raisins are said to have significant protective effects on heart health. 

Raisins have a high content of dietary fibre. A serving of 1 oz of raisins provides 3.0 g of dietary fibre per 90 calories making them highly rated for fibre-content.³  Intake of dietary fibre has been found to be beneficial in life-style related diseases namely, diabetes, heart disease and high blood cholesterol.⁵ Data from several studies illustrate that dietary fibre intake is protective from coronary heart disease.⁵ This type of heart problem is related to clogging of the coronary arteries which supply the heart with oxygen and can eventually lead to a heart attack.

Studies on the health benefits of dried fruits like raisins have found that high levels of consumption have significant reductions in blood pressure compared to low levels.⁶

Raisins reduce the risk of developing diabetes due to their antioxidant properties, effect on gut health and hormone secretion and on the immune system.³ They have been found to reduce sugar absorption in the gut following food intake thus reducing blood sugar levels. In 1974, Kiehm et al., studied the effects of high fibre diets in diabetic patients. They found that insulin dose requirement reduced by 38% on an average after being on a high fibre diet for a month. In addition, their serum cholesterol was found to be lowered by 27% and triglycerides (another type of fat in blood) by 3%.¹³

Raisins have been found to be excellent sources of polyphenols and flavonoids which act as antioxidants in the body. On comparing a wide array of fruits and vegetables, raisins were high on the list for their antioxidant profile.⁴

Consuming raisins has also been associated with good oral hygiene owing to the  properties, poor adherence to teeth and help maintain oral pH.⁹ Rivero-Cruz et al in 2008 studied the antimicrobial properties of two compounds extracted from raisins on oral bacteria linked to caries and gum disease. They found that the harmful bacteria were inhibited by these compounds.⁹   

Several clinical and laboratory studies have established the benefits of dried fruits like raisins against progression of some cancers. These studies demonstrated a remarkable reduction in relative risk of pre-cancerous gut polyps, developing prostate cancer or death from pancreatic cancer associated with 3-5 servings of dried fruit per week.¹¹ These observations were similar or stronger than the association with raw fruits. Research has shown that the consumption of raisins is especially important to prevent cancers of the gastrointestinal system.¹¹

Benefits of raisins for weight loss

Because of their high-fibre content, raisins have been found not only to promote weight loss but also helps sustain it.⁵ Several reasons have been proposed for mechanisms for weight-loss by high-fibre containing foods like raisins,like, they take longer to eat and they bring on the satisfaction sooner. Also, since they leave the stomach later than other foods, they make us feel full longer. This also lowers the level of insulin in the blood, which in turn lowers our hunger levels. These effects are especially more beneficial in obese diabetic individuals to promote better blood sugar control and in non-diabetic persons for weight-loss.⁵ 

Anderson and Woodend (2003) researched the effect of raisin snacks on the appetite of children in comparison with chips and cookies. During the observation period of 8 hours, they found that the children had decreased appetite and less food intake.⁷ Extensive research has been made on the ways in which raisins can bring about weight loss. One of the mechanisms is by affecting the secretion of gut hormones which in turn bring about a feeling of fullness and reduced appetite.⁸  

Glucagon-like peptide-1 (GLP-1) and gastrointestinal polypeptide are two gut hormones, also known as incretins, which stimulate the secretion of insulin. One study found lower levels of incretin hormones following raisin consumption compared to glucose intake.¹⁰ Lower levels of incretins have a cascading effect on insulin, appetite, fat metabolism and weight loss.

Nutritional facts

The sweet taste of raisins is attributed to their sugar content which is about 60%. Glucose and fructose are the predominant sugars in raisins and are misconceived to be unhealthy. During the process of dehydrating grapes, some of the grape sugars get converted into fructan, a type of fibre. Due to its high fibre nature and prebiotic content, they confer a lot of health benefit.⁹

Studies were performed to study the beneficial effects of raisins in gut health. These study show that raisin intake has potential to promote colonisation and proliferation of beneficial gut bacteria like lactobacilli and bifidobacteria.⁹

Some people make raisin water by adding a few raisins to hot water and letting them soak overnight. It is recommended to drink it the first thing in the morning. They claim that it has some of the nutrients in raisins like iron and antioxidants, in addition to being flavourful. While the benefits of raisin water is yet to be studied, it is healthier to consume raisins instead.

In a study by Fulgoni et al, it was found that raisin consumers had a lower risk of metabolic syndrome by 54%.¹²  Metabolic syndrome is diagnosed based on a set of physical and chemical parameters which precede the onset of life-style diseases. Additionally, those who ate raisins were found to use added sugars and other sources of sugars less frequently.¹²

Side effects and other concerns

Even though there are a lot of benefits in consuming raisins, we need to be aware of some concerning facts as well. 

During the wet seasons, raisins can be exposed to humid conditions during the drying process and get exposed to a fungus called aspergillus. This fungus secretes a toxic substance called ‘ochratoxin A’ which has a lot of harmful effects on our body. However, both short-term and long-term effects of this toxin exposure have been minimal and outweighs the benefits.

During the manufacturing process of the ‘golden raisins’ or sultanas, they get coated with a chemical called sulphur dioxide in order to retain the colour. Some people may be intolerant to this chemical and need to exercise caution while eating them.

Eating about 80-90 grams (half a cup) of raisins is beneficial to overall health.⁹ However, as with any snack it's prudent to avoid eating too much. These sweet delicacies are packed with sugar and calories. People trying to lose weight and diabetic patients need to eat them in moderation. Consuming raisins without taking enough water can cause indigestion in some people.

Some nutritionists advise soaking raisins in water overnight and consuming them increases health benefits including antioxidant activity.

Summary

Overall, we have seen that raisins are an excellent addition to our daily diets. They have plenty of nutrients and health benefits to the overall functioning of the body. When consumed in moderate amounts they greatly aid in weight loss by controlling hunger. They improve the 

outcome in many lifestyle diseases like diabetes. The benefits of these baking additives far out-weigh any concerns about them.