Female actors over 50 are less likely to be nominated for an Academy Award than their male counterparts, according to research exploring the gender age gap in Hollywood.

Dr Judy Todd, who runs aesthetic medical practice The Synergy Clinic in Glasgow and London, looked at the stars nominated in the four main Oscar acting categories - Best Actress, Best Actor, Best Supporting Actress and Best Supporting Actor - over the last 10 years and examined the relationship between age and nominations.

This year there is a combined 21.5-year age difference between the male and female nominees, based on their combined average ages of 61.3 and 39.8, respectively.

The oldest male nominee is Sir Anthony Hopkins, 82, who is in the running for Best Supporting Actor for his role in Two Popes, while the youngest is 36-year-old Best Actor contender Adam Driver, who is nominated for marriage story.

For women, the youngest actor is Little Women's Florence Pugh, 24, and the oldest is Kathy Bates, 71, for Richard Jewell. Both are competing in Best Supporting Actress.

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Dr Judy Todd, of The Synergy Clinic, researched the gender age gap in Hollywood. This year there is a combined 21.5-year age difference between the male and female nominees, based on their combined average ages of 61.3 and 39.8, respectively. Sir Anthony Hopkins, 82, left, is the oldest acting nominee this year and Florence Pugh, 24, right, is the youngest

The Oscar gender age gap: This year's crop of nominees at a glance Al Pacino, 79, has been nominated in the best actor in a supporting role category, for his role in The Irishman ACTOR IN A LEADING ROLE Antonio Banderas, 59 Leonardo DiCaprio, 45 Adam Driver, 36 Joaquin Phoenix, 45 Jonathan Pryce, 72 ACTOR IN A SUPPORTING ROLE Tom Hanks, 63 Anthony Hopkins, 82 Al Pacino, 79, Joe Pesci, 76 Brad Pitt, 56 Average age of all male acting nominees: 61.3 Margot Robbie has been nominated in the best actress in a supporting role category for Bombshell ACTRESS IN A LEADING ROLE Cynthia Erivo, 33 Scarlett Johansson 35 Saoirse Ronan, 25 Charlize Theron, 44 Renée Zellweger, 50 ACTRESS IN A SUPPORTING ROLE Kathy Bates, 71 Laura Dern, 52 Scarlett Johansson, 35 Florence Pugh, 24 Margot Robbie, 29 Average age of all female acting nominees: 39.8 Advertisement

There are two other female acting nominees in their 20s (Saoirse Ronan, 25, and Margot Robbie, 29) and a further two in their 30s: Cynthia Erivo, 33, Scarlett Johansson 35, who is nominated in both categories. The next youngest men after Driver are Joaquin Phoenix and Leonardo DiCaprio, who are both 45.

Dr Todd found that female actors over 50 are less than half as likely to be nominated as male actors of the same age.

She also found that the gender age gap - the number of years' difference between the average ages of the male and female nominees - has grown by 35 per cent in the last decade.

There are three female nominees in their 20s, including Saoirse Ronan, 25, left, who is in the Best Actress race. Right, Best Actor nominee Jonathan Pryce, 72

Dr Todd's research shows this year's disparity is far from unique. Over the last decade, just 27 per cent of women nominated in the two acting categories have been over 50, compared to 47 per cent of men.

The figure for women drops to 23 per cent if Meryl Streep, now 70, who received six nominations in the 2010s, is removed from the calculations.

The gap is even more pronounced for the over-60s. Only 19 per cent of female actors nominated in the last 10 years were aged 60 or older, compared to 29.1 per cent of men.

Dr Judy Todd (pictured) runs the Synergy Clinic in Glasgow and London which specialises in aesthetic treatments

Once again, this figure changes dramatically if Meryl Streep is removed, dropping to 14.4 per cent.

Dr Judy Todd said: 'Our gender age gap research has exposed a glass ceiling of opportunity for female actresses after the age of 50. It's hard to see any other reason for this other than they don't look as attractive and youthful as they used to.

'The gender age gap has grown significantly in the past 10 years and something needs to be done to prevent what is a clear case of discrimination.'

She added it is not just a problem affecting women in Hollywood.

Dr Judy added: 'The gender age gap is not just a problem in the film industry. There is growing discrimination for mature women in the UK to get jobs and promotions after they hit 50.

'Many of my female clients in their mid to late 40s tell me that job opportunities for women become seriously reduced after 50, which is one of the main reasons why they are having aesthetic rejuvenation treatments.'