My 12-year-old son is prone to attack by biting insects. How can he protect himself?

Does he eat a lot of sugar? This attracts mosquitoes and other biters. Give him lots of garlic because the smell, excreted through the skin, deters insects. B vitamins, especially B1, does the same. Otherwise, Barefoot Botanicals offers a natural repellant called Zap, which is safe even for three-month-old babies (0870 2202273).

As a man in my 40s, I am aware of changes that can occur in the prostate. To combat any potential problems, I take a cranberry supplement. However, for about two months I have noticed a dull ache in the bladder area. Is this a reaction to the cranberry or changes in the prostate?

Cranberry is excellent for recurrent urinary tract infections . Although I haven't heard of it causing bladder ache, you could stop taking it and see if the ache disappears. The most common prostate complaint is benign prostatic hyperplasia, or BPH, which affects half of all 50-year-old men. This doesn't cause pain but increased urinary frequency and reduced speed of flow. Ask your GP to check because prostatitis, or inflammation of the prostate, does cause tenderness and needs medical treatment. There are natural ways to encourage prostate health: extract of the fruit of the saw palmetto tree has been shown in clinical studies significantly to decrease the symptoms of BPH. A concentrated extract, as used in the studies, can be found in the supplement Prostex by Nature's Best - £19.90 for 180 capsules (take two a day), 01892 552117 or NaturesBestOnline.com.

· Emma Mitchell is a natural health therapist. Before following Emma's recommendations, you should consult your GP about any medical problems or special health conditions.

Send your questions to Wellbeing, Guardian Weekend, 119 Farringdon Road, London EC1R 3ER. Email: ask.emma@theguardian.com.