As summer comes to an end and fall is just around the corner, so is cold and flu season. Now is a good time to implement some simple healthy habits and make sure you have what you need to take care of yourself when a sore throat or sniffles begin. While there is no way to stop every virus in its tracks, healthy habits can support normal immune function and help you stay healthier throughout the season.
If you have been experiencing frequent infections or feeling run down, it is worth considering some of the everyday factors that can affect immune health.
Factors That Can Affect Immune Health
- A diet high in highly processed foods
- A diet lacking important vitamins and minerals
- Poor overall nutrition
- Not eating enough fruits and vegetables
- Not getting enough healthy fats, such as those found in fish, chia, flax, and hemp seeds
- Excessive alcohol use or smoking/vaping
- Chronic stress
- Lack of sleep
A healthy immune system depends on many factors, including adequate nutrition, physical activity, sleep and overall health. According to research on nutrition and immune function, adequate nutrition and overall dietary quality play important roles in maintaining normal immune function.
Signs You May Be Getting Sick More Often
If you’re frequently experiencing:
- Frequent colds or other respiratory infections
- Sore throats
- Feeling very tired
- Headaches
- Aching muscles
- Other recurring or persistent symptoms
It’s worth discussing them with a healthcare professional, particularly if infections are unusually frequent, severe, or difficult to recover from.
Top Ten Immune-Support Tips
1. Eat plenty of fresh fruit and vegetables.
Good sources include carrots, beetroot, sweet potatoes, garlic, onions, sprouts, tomatoes and broccoli, as well as watermelon, strawberries, blueberries and raspberries.
Eating a variety of fruits and vegetables provides vitamins, minerals, fiber and other beneficial compounds that contribute to a healthy diet and normal immune function. Research examining the relationship between diet and immune function suggests that overall dietary patterns and adequate nutrient intake are more important than any individual “immune-boosting” food.
2. Ensure your diet includes good-quality protein.
Good sources include chicken, fish, eggs, quinoa and legumes. Protein provides amino acids that the body needs for many important functions, including maintaining immune cells and tissues.
Research into nutrition and infectious disease has found that adequate nutrition and protein are important for maintaining normal immune responses.
3. Eat healthy fats.
Good sources include oily fish such as salmon and trout, as well as nuts, seeds, avocado and extra-virgin olive oil. Chia, flax and hemp seeds are also good plant sources of healthy fats.
Rather than relying on a single type of fat or food, aim for a varied diet that includes a range of nutritious fat sources.
4. Consume whole grains.
Brown rice, steel-cut oats, buckwheat, quinoa and millet are nutritious choices that can contribute to a balanced diet.
Whole grains can provide fiber, vitamins, minerals and other nutrients as part of an overall healthy eating pattern.
5. Enjoy freshly made soups loaded with vegetables.
Soups can be an easy way to include a variety of vegetables and other nutritious ingredients in your diet. Garlic and onions can also add flavor and nutrients.
6. Choose whole fruits and vegetables regularly.
Fresh produce provides a variety of vitamins, minerals and other beneficial compounds. If you enjoy vegetable juice, it can be part of a healthy diet, but whole fruits and vegetables also provide fiber that is lost or reduced when produce is juiced.
7. Limit foods and drinks high in added sugar.
Rather than thinking of sugar as something that immediately “depresses” the immune system, it’s more accurate to focus on the overall quality of your diet. Diets high in added sugars can make it harder to maintain a balanced eating pattern and may contribute excess calories without providing many essential nutrients.
Research on dietary patterns and immune function suggests that overall diet quality is more meaningful than focusing on a single food or nutrient.
8. Reduce your intake of highly processed foods.
Choose nutrient-dense whole or minimally processed foods more often, including vegetables, fruits, whole grains, legumes, nuts, seeds, and lean sources of protein.
9. Limit excessive alcohol and avoid smoking.
Smoking can negatively affect the body’s ability to fight disease, while excessive alcohol consumption can also have harmful effects on health. Avoiding smoking and limiting alcohol are sensible parts of maintaining overall health and supporting immune function.
10. Prioritize sleep, physical activity and stress management.
Getting enough sleep and staying physically active are important parts of maintaining overall health. A systematic review examining exercise and immune-cell function found evidence that exercise can influence several aspects of immune function, although the effects vary depending on the type and intensity of exercise.
Good sleep and effective stress management are also important components of a healthy lifestyle.
What About Supplements?
A balanced diet should be the primary source of most of the nutrients your body needs. Some people may benefit from supplements, particularly if they have a documented deficiency or another reason that makes supplementation appropriate.
However, more is not necessarily better. Taking high doses of vitamins and minerals can cause side effects and, in some cases, interact with medications.
Vitamin C
Getting enough vitamin C through a varied diet is important; good sources include citrus fruits, berries, peppers, broccoli, and other vegetables. According to a Cochrane review of 29 trials involving more than 11,000 people, regular vitamin C supplementation was associated with a modest reduction in the duration of colds.
Diet is important for vitamin C, but supplementation can help you meet your nutritional needs. However, more isn’t necessarily better, and very high doses may cause digestive upset.
Vitamin D
Vitamin D plays an important role in normal immune function, but taking additional vitamin D is not guaranteed to prevent respiratory infections.
The research has produced mixed results. A 2025 systematic review and meta-analysis of randomized trials found no statistically significant overall reduction in acute respiratory infections among people taking vitamin D supplements.
People who are deficient in vitamin D may have different needs, so supplementation is best discussed with a healthcare professional.
Zinc
Zinc is another nutrient that plays an important role in normal immune function. Some research suggests that zinc supplementation may modestly shorten the duration of a common cold when used soon after symptoms begin, although the evidence varies depending on the formulation and dose.
According to a systematic review of randomized trials, zinc supplementation may reduce the duration of a common cold by around two days in some circumstances, although the evidence was not uniform across all formulations.
High doses of zinc can cause side effects and can interfere with the absorption of other minerals, so high-dose supplementation should not be taken routinely without professional guidance.
Selenium
Selenium is an essential mineral that contributes to normal immune function. Good food sources include seafood, meat, eggs, grains, and Brazil nuts.
Because Brazil nuts can contain particularly high amounts of selenium, you don’t need to eat large quantities to obtain the mineral. Excessive selenium intake over time can cause adverse effects, so supplementation should be based on individual needs rather than assuming that more is better.
Read More: This Everyday Plant May Support Blood Sugar, Blood Pressure, and Immune Health
Don’t Forget Proven Ways to Prevent Illness
Healthy eating, adequate sleep, physical activity, and other lifestyle habits can support your overall health, but they don’t replace proven ways to prevent serious respiratory infections.
Other measures, such as washing your hands, covering coughs and sneezes, and avoiding close contact with sick people, can also help reduce the spread of respiratory illnesses.
If you do become sick, rest, fluids, and appropriate symptom management can help you recover. Seek medical advice if symptoms are severe, persistent, or concerning, or if you are at increased risk of complications.
About Dr. Cobi
Dr. Cobi Slater is a Doctor of Natural Medicine and Functional Medicine Practitioner with more than 20 years of clinical experience and over 10,000 patients helped. With a PhD in Natural Health Sciences specializing in endocrine dysfunction, her work focuses on helping women uncover the root causes behind hormone imbalance, perimenopause, fatigue, metabolic changes and digestive concerns. She is a Registered Nutritionist, Clinical Herbalist and the author of five bestselling books, known for making complex health information practical, understandable and empowering.
You can learn more about Dr. Cobi and her approach to health and wellness on her website.
Disclaimers: This information is not intended to be a substitute for professional medical advice, diagnosis or treatment and is for information only. Always seek the advice of your physician or another qualified health provider with any questions about your medical condition and/or current medication. Do not disregard professional medical advice or delay seeking advice or treatment because of something you have read here.
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